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EA-0915; Environmental Assessment and (FONSI) Waste Tank Safety Program Hanford Site, Richland, Washington

TABLE OF CONTENTS

 ENVIRONMENTAL ASSESSMENT and (FONSI) WASTE TANK SAFETY PROGRAM HANFORD SITE, RICHLAND, WASHINGTON 
 Executive Summary
 Glossary
 1.0  Purpose and Need for Agency Action
 2.0  Background              
2.2  Information Pertaining to Ferrocyanides                      
2.3  Information Pertaining to Floating Organic Solvent Layer     
2.4  Information Pertaining to Nuclear Criticality                
2.5  Information Pertaining to Noxious and Toxic Gas Releases
 3.0  Alternatives Including the Proposed Actions
3.1  Proposed Actions                                           
3.1.1  Unreviewed Safety Question-Flammable Gas Tanks (Hydrogen
Tanks)                                                          
3.1.2  Unreviewed Safety Question-Ferrocyanide Tanks         
3.1.3  Unreviewed Safety Question-Floating Organic Solvent 
       Layer in Tank 241-C-103                               
3.1.4  Unreviewed Safety Question-Nuclear Criticality        
3.1.5  Toxic Vapors                                          
3.1.6  Infrastructure Upgrades                               
3.1.7  Interim Stabilization of Single-Shell Tanks           
3.1.8  High-Heat Generation                                   
3.2  Alternative(s) to the Proposed Actions                   
3.2.1  No-Action Alternative                                  
3.2.2  Strategies Involving Non- or Minimal-Intrusive
       Operations                                             
3.2.3  Other Alternatives                                    
 4.0  Affected Environment
 5.0  Environmental Impacts
5.1  Proposed Actions:  Impacts from Routine Operations       
5.2  Proposed Actions:  Impacts from Accidents                
5.2.1  Unreviewed Safety Question-Flammable Gas Tanks         
5.2.2  Unreviewed Safety Question-Ferrocyanide Tanks          
5.2.3  Unreviewed Safety Question-Floating Organic Solvent Layer
       Tank                                                  
5.2.4  Toxic Vapors                                          
5.2.5  Infrastructure Upgrades                               
5.2.6  Interim Stabilization of Single-Shell Tanks           
5.2.7  Maximum Reasonably Foreseeable Accident               
5.3  Alternative Actions                                     
5.3.1  Alternative Actions                                   
5.3.2  Non- and Minimal-Intrusive Alternatives               
5.4  Proposed Actions:  Cumulative Impacts 
 6.0  Permits and Regulatory Requirements 
7.0 Agencies Consulted
8.0 References
Figures
Appendix A Projected Tank Farm Safety Activities, Hanford Site, Richland, Washington Projected Tank Farm Activities Hanford Site, Richland, Washington
Appendix B Accident Scenario Consequence Conclusions from Finding of No Significance Impact Determinations
Finding of No Significant Impact Waste Tank Safety Program at the Hanford Site

List of Tables

1.  Environmental Assessments Surrounding Hydrogen Generation, Organics,
    and Ferrocyanides                                                  
2.  Unreviewed Safety Question-Specific Underground Storage Tanks      

List of Figures

1.  Single-Shell and Double-Shell Tank Configurations                  
2.  Hanford Site                                                       
					 ENVIRONMENTAL ASSESSMENT
                     WASTE TANK SAFETY PROGRAM
                   HANFORD SITE, RICHLAND, WASHINGTON
                        U.S. DEPARTMENT OF ENERGY
                                 FEBRUARY 1994
                           

Executive Summary

     The U.S. Department of Energy (DOE) needs to take action in the near-
term, to accelerate resolution of waste tank safety issues at the Hanford Site
near the City of Richland, Washington, and reduce the risks associated with
operations and management of the waste tanks.
     The DOE has conducted nuclear waste management operations at the
Hanford Site for nearly 50 years.  Operations have included storage of high-
level nuclear waste in 177 underground storage tanks (UST), both in single-
shell tank (SST) and double-shell tank configurations.  Many of the tanks, and
the equipment needed to operate them, are deteriorated.  Sixty-seven SSTs are
presumed to have leaked a total of approximately 3,800,000 liters (1 million
gallons) of radioactive waste to the soil.
     Safety issues associated with the waste have been identified, and include
(1) flammable gas generation and episodic release; (2) ferrocyanide-containing
wastes; (3) a floating organic solvent layer in Tank 241-C-103; (4) nuclear
criticality; (5) toxic vapors; (6) infrastructure upgrades; and (7) interim
stabilization of SSTs.  Initial actions have been taken in all of these areas;
however, much work remains before a full understanding of the tank waste
behavior is achieved.  The DOE needs to accelerate the resolution of tank
safety concerns to reduce the risk of an unanticipated radioactive or chemical
release to the environment, while continuing to manage the wastes safely.
     Further, knowledge of the UST tank contents is incomplete, and based
primarily on historical operating records which provide limited sampling
information to confirm the waste inventory.  The Hanford Federal Facility
Agreement and Consent Order includes characterization commitments entered into
by the DOE, the State of Washington Department of Ecology and the
U.S. Environmental Protection Agency.  As a result of these existing
conditions and regulatory requirements, a more aggressive and focused approach
is needed by the DOE in order to accelerate the resolution of the tank farm
safety and operational issues.
     Flammable gases are the most serious safety issue at the Hanford Site
because substantial concentrations and volumes are periodically released from
the tank waste.  Mitigation efforts, including vapor monitoring and mixer-pump
testing, are ongoing.  In addition, workers also have been periodically
exposed to potentially toxic vapors from the tanks.  The DOE believes toxic
vapor risks are greatest near Tank 241-C-103, but other tanks are potential
toxic vapor sources.  Further, some tanks contain chemicals (particularly
ferrocyanide and organics) which, under certain limited conditions and high
temperatures, could explode.  Additional investigations need to be completed
to more fully characterize these wastes in order to resolve the safety issues,
and support the safe and effective storage of the waste.
     The existing SSTs do not meet criteria for double containment.  The
pumpable liquid has been removed from many of the tanks, but approximately 19
million liters (5 million gallons) remain to be pumped from 43 tanks.  The SST
monitoring equipment and waste transfer systems also require upgrades to
enhance leak detection and mitigation efforts.
     Further, the tank farm infrastructure requires upgrading and physical
modification.  Physical or hardware upgrade needs include modernization of
facilities, improvements in plant instrumentation and data collection systems,
and modifications to ventilation systems.  In addition, long-term upgrade
needs exist, and include new waste transfer lines, replacement of tanks, and
other major projects.  These long-term upgrades, however, are not part of the
scope of this Environmental Assessment (EA), but will be addressed in future,
separate National Environmental Policy Act of 1969 reviews.
     It is expected that the actions proposed within the scope of this EA
would provide data that would be useful in limiting the risk associated with
the long-term actions.  In addition, data generated would be useful in
providing support for the safe interim storage of the waste until final
disposition.
     The proposed actions would include general and specific waste tank
characterization and mitigation activities, and facility modifications, at the
Hanford Site.  This would allow the DOE to address tank safety concerns, while
continuing to manage the waste safely.  These activities would include
installation, operation, maintenance, and removal of in-tank and external
monitoring devices; modifications to ventilation systems; minor upgrades to
the infrastructure of the tank farms; removal of pumpable liquids from SSTs;
and sampling (by way of various modes) for waste characterization.  The
proposed actions would further the understanding of both routine operations
and postulated accident scenarios associated with Hanford Site tank farm
issues.
     Alternatives have been considered in this analysis.  Along with the
No-Action Alternative, the DOE considered strategies involving less intrusive
techniques for resolution of tank safety issues.  For example, waste
characterization using solely non-intrusive methods (such as computer modeling
based on historical process knowledge and laboratory simulants) was
considered.  Also, a strategy involving limited intrusive activities (e.g.,
monitoring without characterization) was considered.  These alternatives were
not considered viable because the DOE believes intrusive operations (including
monitoring, sampling, and minor modifications) are necessary to resolve the
tank safety issues, and could be conducted without compromising worker and
public safety.  
     The potential for significant individual and cumulative environmental
impacts due to the conduct of the proposed action has been analyzed.  No
substantial increase in Hanford Site operational environmental impacts would
be expected from the proposed actions.  Rather, the proposed actions would
contribute to an overall decrease in the potential risks associated with
routine Hanford Site tank farms operations by resolving tank safety issues,
and by increasing the understanding of waste characteristics.
     The potential environmental impacts from postulated accident scenarios
also were evaluated, and indicated that the risks associated with the proposed
action would be small, and not substantially different than previously
analyzed for similar actions.  Indeed, the proposed actions would mitigate the
potential for inadvertent releases of radioactive and hazardous materials from
USTs.

Glossary

CY                   Calendar Year
DOE                  U.S. Department of Energy
DOH                  State of Washington Department of Health
DOT                  U.S. Department of Transportation
DST                  double-shell tank
EA                   Environmental Assessment
Ecology              State of Washington Department of Ecology
EDE                  Effective Dose Equivalent
EPA                  U.S. Environmental Protection Agency
FONSI                Finding of No Significant Impact
GAO                  General Accounting Office
HDW-EIS              Final Environmental Impact Statement:  Disposal of
                     Hanford Defense High-Level, Transuranic and Tank Wastes,
                     Hanford Site, Richland, Washington
HLW                  High-Level Waste
LCF                  latent cancer fatality
LFL                  lower flammability limit
LOW                  liquid observation well
MEI                  maximally exposed individual
NEPA                 National Environmental Policy Act of 1969
NPH                  normal paraffin hydrocarbon
PUREX                Plutonium-Uranium Extraction
RCRA                 Resource Conservation and Recovery Act of 1976
rem                  roentgen equivalent man
SOP                  Standard Operating Procedure
SST                  single-shell tank
TBP                  tributylphosphate
TCT                  thermocouple tree
TMAC                 Tank Monitor and Control System
Tri-Party Agreement  Hanford Federal Facility Agreement and Consent Order
USQ                  Unreviewed Safety Question
UST                  underground storage tank
          

1.0 Purpose and Need for Agency Action

     The U.S. Department of Energy (DOE) needs to take action in the near-term
to accelerate resolution of waste tank safety issues at the Hanford Site near
the City of Richland, Washington, and reduce the risks associated with
operations and management of the waste tanks.
     The DOE has conducted nuclear waste management operations at the
Hanford Site for nearly 50 years.  Operations have included storage of High-
Level Nuclear Waste (HLW) in 177 underground storage tanks (UST), both in
single-shell tank (SST) and double-shell tank (DST) configurations (Figure 1). 
Many of the tanks, and the equipment needed to operate them, are deteriorated. 
Sixty-seven SSTs are presumed to have leaked a total of approximately
3,800,000 liters (1 million gallons) of radioactive waste to the soil. 
Further, knowledge of the tank contents is incomplete, and is based primarily
on historical operating records with limited sampling information to confirm
the waste inventory.  The Hanford Federal Facility Agreement and Consent Order
(Tri-Party Agreement [Ecology et al. 1992]) includes characterization
commitments entered into by the DOE, the State of Washington Department of
Ecology (Ecology) and the U.S. Environmental Protection Agency (EPA). 
Further, on November 5, 1990, the U.S. Congress enacted Public Law 101-510,
Section 3137, Safety Measures for Waste Tanks at Hanford Nuclear Reservation,
which addresses safety issues concerning the handling of HLW contained in
Hanford Site USTs, and directs the Secretary of Energy to take several steps
to ensure safe management of tank waste.  As a result of these existing
conditions and regulatory requirements, a more aggressive and focused strategy
is needed by the DOE in order to accelerate the resolution of the tank farm
safety and operational issues.
     Safety issues associated with the waste have been identified (DOE 1992a),
and include (1) flammable gas generation and episodic release; (2)
ferrocyanide-containing wastes; (3) a floating organic solvent layer in
Tank 241-C-103; (4) nuclear criticality; (5) toxic vapors; (6) infrastructure
upgrades; and (7) interim stabilization of SSTs.  Initial actions have been
taken to address each of these safety issues; however, much work remains to
achieve a full understanding of the tank waste.  The DOE needs to accelerate
the resolution of tank safety concerns to reduce the risk of an unanticipated
radioactive or chemical release to the environment, while continuing to manage
the wastes safely.
     Flammable gases are the most serious safety issue at the Hanford Site
because substantial concentrations and volumes are periodically released from
the tank waste posing an ignition risk.  The consequences of an ignition
potentially would be catastrophic.  Mitigation efforts, including vapor
monitoring and mixer-pump testing, are ongoing.  
     Workers have periodically been exposed to potentially toxic vapors coming
from the tanks.  The DOE believes toxic vapor risks are greatest near Tank
241-C-103, but other tanks also are potential toxic vapor sources.
     Some tanks contain potentially unstable compounds such as ferrocyanide
and organics, which under certain conditions, and high temperatures, could
explode.  Additional investigations need to be completed to more fully
understand and characterize these wastes.  The ongoing characterization
program is vital to the resolution of safety issues, and support of safe and
effective treatment and disposal of the tank waste.
     Further, the tank farm infrastructure requires upgrade and physical
modification.  Physical or hardware upgrade needs include modernization of
facilities, improvements in plant instrumentation and data collection systems,
and modifications to ventilation systems.  In addition, long-term upgrade
needs exist, and include new waste transfer lines, replacement of tanks, and
other major projects.  These long-term upgrades, however, are not part of the
scope of this Environmental Assessment (EA), but will be addressed in future,
separate National Environmental Policy Act of 1969 reviews.
     The existing SSTs do not meet criteria for double containment.  The
pumpable liquid has been removed from many of the tanks, but approximately 19
million liters (5 million gallons) remain to be pumped from 43 tanks.  Tank
monitoring equipment and waste transfer systems require upgrades to enhance
the DOE's ability to detect leaks and take mitigative measures.
                           

2.0 Background

     Hanford Site HLW management operations were addressed in the Final
Environmental Statement:  Waste Management Operations, Hanford Reservation,
Richland, Washington (ERDA 1975).  Routine operations and a range of
postulated accidents based on facility design and operation were analyzed. 
Specifically included for HLW tanks farms were accident scenarios associated
with leaks, gaseous releases, dome failures, transfer line failures, and
events due to natural forces.  In the Final Environmental Impact Statement,
Supplement to ERDA-1538, December 1975, Waste Management Operations, Hanford
Site, Richland, Washington, Double-Shell Tanks for Defense High-Level
Radioactive Waste Storage, (DOE 1980), accident consequences for DST
operations were evaluated (including accumulation of hydrogen, organic fire,
explosion of nitrate compounds, and failure of vessel ventilation exhaust
filters).
     The DOE further addressed the risks associated with HLW management
operations in the 1987 Environmental Impact Statement (EIS), Final
Environmental Impact Statement:  Disposal of Hanford Defense High-Level,
Transuranic and Tank Wastes (DOE 1987).  The 1987 EIS concluded that the
maximum reasonably foreseeable accident associated with the HLW tanks at the
Hanford Site would be an explosion in a ferrocyanide-containing tank.  Since
completing the 1987 EIS, additional questions relevant to HLW tank risks have
arisen, which are now reflected in the safety issues described above.  For
example, the DOE and the general public have a heightened awareness of the
generation and episodic release of flammable gases in Tank 241-SY-101 and
other HLW tanks, of uncertainties regarding the potential consequences of an
explosion in a ferrocyanide-containing tank, and of potential worker hazards
associated with toxic vapor releases.  To address these issues, the DOE has
taken several specific initial actions to gather information needed to
understand and to reduce HLW tank farm risks.  In view of the uncertainties
associated with the risks at the HLW tank farms, including the potential for
catastrophic consequences, the DOE has conducted appropriate safety and
environmental reviews, including EAs, for each specific action to ensure that
the DOE has evaluated and addressed the risks of the actions themselves.
     In ten EAs, delineated in Table 1, the DOE analyzed specific initial
actions proposed to address Unreviewed Safety Questions (USQ).  The topic of
USQs is addressed in DOE Order 5480.21, Unreviewed Safety Questions (DOE
1991a).   The specific areas of concern associated with the USQs are
(1) flammable gas generation and episodic release; (2) ferrocyanide-containing
wastes; (3) floating organic solvent layer in Tank 241-C-103; and (4) nuclear
criticality.  Specific USQ tanks are listed in Table 2.  It is noted that as
characterization and testing continue, additions and/or deletions to the list
of specific USQ USTs may occur, resulting in changes to mitigative priorities
on a tank-by-tank basis.
                                   Table 1.
          Environmental Assessments Surrounding Hydrogen Generation, 
                         Organics, and Ferrocyanides. 
Environmental Assessment:  Collecting Crust Samples from Level Detectors in
Tank 101-SY at the Hanford Site, DOE/EA 0479, U.S. Department of Energy,
Richland, Washington (DOE 1990).
Environmental Assessment:  Characterization of Tank 241-SY-101, Hanford Site,
Richland, Washington, DOE/EA-0511, U.S. Department of Energy,
Richland, Washington (DOE 1991b).
Environmental Assessment:  Upgrading of the Ventilation system at the 241-SY
Tank Farm, Hanford Site, Richland, Washington, DOE/EA-0581, U.S. Department of
Energy, Richland, Washington (DOE 1991c).
Environmental Assessment:  Vapor Space Sampling of Ferrocyanide Tanks,
DOE/EA-0533, U.S. Department of Energy, Washington, D.C. (DOE 1991d).
Environmental Assessment:  Vapor Space Sampling of Ferrocyanide Tanks, Hanford
Site, Richland, Washington, DOE/EA-0533, U.S. Department of Energy, Richland,
Washington (DOE 1991e).
Environmental Assessment for Tank 241-SY-101 Equipment Installation and
Operation to Enhance Tank Safety, DOE/EA-0802, U.S. Department of Energy,
Washington, D.C. (DOE 1992b).
Environmental Assessment for Proposed Pump Mixing Operations to Mitigate
Episodic Gas Releases in Tank 241-SY-101, DOE/EA-0803,
U.S. Department of Energy, Washington, D.C. (DOE 1992c)
Environmental Assessment:  Intrusive Sampling and Testing of Ferrocyanide
Tanks, Hanford Site, Richland, Washington, DOE/EA-0596,
U.S. Department of Energy, Washington, D.C. (DOE 1992d).
Environmental Assessment:  Thermocouple Tree System Installation and Operation
in Non-Leaking Ferrocyanide Tanks, DOE/EA-0809, U.S. Department of Energy,
Richland, Washington (DOE 1992e)
Environmental Assessment:  Tank 241-C-103 Organic Vapor and Liquids
Characterization and Supporting Activities, Hanford Site, Richland,
Washington, DOE/EA-0881, U.S. Department of Energy, Richland, Washington (DOE
1993).
                                   Table 2.
        *Unreviewed Safety Question-Specific Underground Storage Tanks.
                               (September 1993)
Single-Shell Tanks                      Single-Shell Tanks 
Tank Number          Category           Tank Number                Category 
101-A                Hydrogen           101-TY                     Ferrocyanide 
101-AX               Hydrogen           103-TY                     Ferrocyanide 
103-AX               Hydrogen           104-TY                     Ferrocyanide 
102-BX               Ferrocyanide       103-U                      Hydrogen 
101-BY               Ferrocyanide       105-U                      Hydrogen 
103-BY               Ferrocyanide       107-U                      Hydrogen 
104-BY               Ferrocyanide       108-U                      Hydrogen 
105-BY               Ferrocyanide       109-U                      Hydrogen 
106-BY               Ferrocyanide       Total: 40 SSTs 
107-BY               Ferrocyanide                                   
108-BY               Ferrocyanide       Double-Shell Tanks 
110-BY               Ferrocyanide       103-AN                     Hydrogen 
111-BY               Ferrocyanide       104-AN                     Hydrogen 
112-BY               Ferrocyanide       105-AN                     Hydrogen 
103-C                Floating Organic   101-AW                     Hydrogen 
                     Solvent Layer      101-SY                     Hydrogen 
108-C                Ferrocyanide       103-SY                     Hydrogen 
109-C                Ferrocyanide       Total: 6 DSTs 
111-C                Ferrocyanide                                   
112-C                Ferrocyanide       * All 177 USTs at the 
                                          Hanford Site fall under 
                                          the criticality category 
                                          for USQs. 
102-S                Hydrogen                                       
111-S                Hydrogen                                       
112-S                Hydrogen                                       
101-SX               Hydrogen                                       
102-SX               Hydrogen                                       
103-SX               Hydrogen                                       
104-SX               Hydrogen                                       
105-SX               Hydrogen                                       
106-SX               Hydrogen                                       
109-SX               Hydrogen                                       
                     Potential. 
                     Other Tanks Vent Through It. 
107-T                Ferrocyanide                                   
110-T                Hydrogen                                       
118-TX               Ferrocyanide        
     Based on the information presented in the EAs listed in Table 1, the DOE
issued Findings Of No Significant Impact (FONSI) for the respective actions. 
Subsequently, work has been conducted under the descriptions and restrictions
provided by the EAs and FONSIs.  In all cases, the DOE's experience in taking
these actions indicates that the environmental and safety documentation was
extremely conservative, and that the DOE could resolve the safety issues with
minimal adverse environmental impacts.  Sections 2.1 to 2.4 provide
information pertaining to USQs.  Section 2.5 provides a summary of information
pertaining to noxious and toxic vapors. 

2.1 Information Pertaining to Flammable Gas Generation

     There are USTs on the Hanford Site in which the waste expands due to
generation of gases (hydrogen, nitrous oxide, nitrogen, and ammonia).  These
USTs experience episodic releases of gases including hydrogen, and nitrous
oxide.  These gases can be flammable.  Activities such as instrument
insertion, maintenance and operation, sampling, and equipment removal in Tank
241-SY-101 (considered the most hazardous tank in this category) have been
conducted safely under the analyses contained in several EAs (DOE 1990,
DOE 1991b, DOE 1991c, DOE 1992b, and DOE 1992c).  Such activities have been
carried out with minimal adverse environmental impacts (e.g., no additional
emissions above those normally experienced during routine tank farm
operations), and no unanticipated events associated specifically with safety
issues have occurred.
     Ongoing analyses have evaluated the behavior of other tanks in the
flammable gas generation category (i.e., Tanks 241-SY-103, 241-AN-103, 241-AN-
104, and 241-AN-105).  Compared to Tank 241-SY-101, these tanks retain gases
in a similar fashion; however, at only about 10 percent of the rate for Tank
241-SY-101.  Historical data pertaining to surface level changes supports the
premise that these four tanks, and the remainder of the USTs in the flammable
gas generation category, would not release enough gas to reach the lower
flammability limit (LFL).  
     The DOE installed a test mixer pump in Tank 241-SY-101 in July 1993.  The
mixer-pump test results in Tank 241-SY-101 are encouraging in regard to
mitigation of flammable gas generation and episodic release safety issues.  To
date, it appears that virtually all gases generated since pump installation
have been vented safely from the tank as a result of pump tests.  A series of
full-scale tests are planned through May 1994.  The DOE proposes to pursue
closure of the Tank 241-SY-101 flammable gas USQ by early 1995.

2.2 Information Pertaining to Ferrocyanides

     Ferrocyanide was added to radioactive waste in the 1950s to precipitate
cesium-137 as part of the volume reduction program.  A relatively high-heat
producer, cesium-137 joined strontium-90 and transuranic elements in the
sludge.  Following precipitation, the supernate liquid was discharged to the
ground, consistent with waste management practices at the time.  Subsequently,
postulated accident scenarios were developed in which an explosive release of
tank waste might result during mechanical retrieval, due to the presence of
sodium, nitrate, and ferrocyanide precipitates in a tank (DOE 1987), or due to
excessive heat from radionuclide content (DOE 1992a).
     The eighth quarterly report on the progress of activities addressing
safety issues associated with ferrocyanide-containing tanks (WHC 1993a)
indicates that USQ Tanks 241-C-112 and 241-C-109 lack the required components
to initiate a detonation.  Specifically, data show that there is a lack of
fuel, inadequate heat source, and too much moisture in the waste to allow an
event to occur.  The DOE's Safety Initiatives (Wagoner 1993) include closure
of the ferrocyanide USQ by January 1994.
     Similar to Tank 241-SY-101, risks associated specifically with
ferrocyanide-containing tanks, such as instrument insertion and operation,
sampling, and equipment removal have been found to be small (DOE 1991d, DOE
1991e, DOE 1992d, and DOE 1992e).  As with Tank 241-SY-101, conduct of
operations related to ferrocyanide-containing tanks has proceeded with minimal
adverse environmental impacts (e.g., no additional emissions above those
normally experienced during routine tank farm operations).

2.3 Information Pertaining to Floating Organic Solvent Layer

     Tank 241-C-103 contains a floating organic solvent layer, which poses a
safety concern due to potential ignition of the organic vapors.  Additionally,
the DOE has occasionally detected noxious vapors at or in the vicinity of the
tank.  Recent information, developed from an estimate of the tank contents
derived from historical records, suggests that the vapor space contents may
not be flammable.  A tank intrusive sampling program has proceeded safely (DOE
1993).  Results indicate that the headspace is convectively mixed and nearly
saturated with water vapor, supporting the nonflammability projection.  The
DOE's ongoing Safety Initiative (Wagoner 1993) involving Tank 241-C-103
includes completion of sampling and safety evaluations for the liquid organic
by March 1994, and the proposed removal of the floating organic solvent layer
from the tank by March 1995.

2.4 Information Pertaining to Nuclear Criticality

     A USQ regarding the potential for nuclear criticality in Hanford Site's
HLW tanks resulted from the discovery that although the Final Safety Analysis
Reports for the tank farms stated that a criticality was not credible, the
analysis to support that statement had not been performed adequately.  The
declaration of the USQ stopped all waste transfers in the tank farms (both
generator-to-tank and tank-to-tank) and any other activity which might affect
nuclear reactivity.  Exceptions allowing waste transfers have been made,
following criticality analyses, which supported a Justification for Continued
Operations.  This has allowed limited transfers under strict controls.
     As a result of this USQ, analyses have been undertaken to establish that
the tanks, in their current state, are subcritical.  The results of the
analysis of approximately 1,000 samples of tank waste have been used to
establish that the tanks are subcritical by a substantial margin.  The
parameters of interest were plutonium concentration and the ratios of uranium
to plutonium, iron to plutonium, manganese to plutonium, and the ratios of
several other waste constituents, all of which act as neutron absorbers.  In
every instance the ratios did not exceed established subcritical parameters. 
This has supported the conclusion that the tanks are subcritical.  Future
waste transfers will be controlled to maintain a safe margin of
subcriticality.
     The DOE's Safety Initiatives (Wagoner 1993) include closure of the
criticality USQ by March 1994.  Closure of this USQ will be accomplished by an
amendment to the Authorization Basis which would provide the analysis
demonstrating that the tanks are subcritical by a substantial margin.  No
specific physical activities are planned.

2.5 Information Pertaining to Noxious and Toxic Gas Releases

     Vapors that pose health hazards (e.g., ammonia) may be present in waste
tank vapor spaces and, ultimately, the work spaces.  Such vapors have been
found in Tank 241-C-103.  Nineteen vapor exposure events occurred at the
Hanford Site between July 1987 and May 1993.  All of the vapor exposures
involved first-aid medical consultation, and some resulted in lost time to
workers.  Ten of these vapor exposure events were associated with the 241-C
Tank Farm (many involving Tank 241-C-103).  A program plan has been developed
which focuses on Tank 241-C-103 as a pilot program; the appropriate elements
of the plan methodology may then be applied to other waste tank vapor issues.
     Current data from Tank 241-C-103 monitoring and analyses indicate that no
substantial release of toxic vapors should occur as a result of ongoing
storage and characterization activities (DOE 1993).  Appropriate procedures
and administrative controls (e.g., self-contained breathing apparatus is
presently standard equipment for operators) are in place to mitigate potential
worker, health, and safety impacts from noxious and toxic vapors.  Minimal
releases of ammonia, tributylphosphate (TBP), normal paraffin hydrocarbons
(NPH), hydrogen cyanide, hydrazine, or oxides of nitrogen have resulted from
ongoing characterization activities, with no known adverse health effects to
workers.
   

3.0 Alternatives Including the Proposed Actions

3.1 Proposed Actions

     The proposed actions would include general and specific waste tank
characterization and mitigation activities, and facility modifications at the
Hanford Site.  The DOE proposes to implement the current program plan for
specific activities as shown in Appendix A.  This would allow the DOE to
address the tank safety concerns, while continuing to manage the waste safely
until the DOE implements final disposal of the tank wastes.  These activities
would include installation, operation, maintenance, and removal of in-tank and
external monitoring devices, modifications to ventilation systems, minor
upgrades to the infrastructure of the tank farms, as well as sampling (by way
of various modes) for waste characterization.  The proposed actions would
further the understanding of Hanford Site tank farm issues, as they relate to
both routine operation and postulated accident scenarios.  The proposed
actions emphasize the DOE's closure of the specific USQs, which were generated
due to concerns involving potential loss of tank integrity from ignition or
nuclear criticality, events that could release radioactive and hazardous
chemical contamination to the environment.  The DOE expects that the proposed
actions could be conducted in a safe and environmentally sound manner, while
achieving the goals of reducing tank farm risks, and supporting the ultimate
disposition of Hanford Site tank waste.
     Schedules and priorities would be reviewed and evaluated periodically
based on concurrent planning and coordination between the DOE, the operating
contractor, and appropriate regulatory authorities (including Ecology, EPA,
and the State of Washington Department of Health [DOH]).  This  would be
essential for the most efficient prioritization and use of resources and
minimization of waste, while providing optimum protection to the human health
and the environment and maintaining compliance with the Tri-Party Agreement
(Ecology et al. 1992).
     In every instance, the proposed actions would be governed by state-of-
the-art engineering and relevant DOE orders and guidelines.  Appropriate
materials of construction, calibrations, quality assurance, safety
documentation, and other necessary systems would be used.
     Also, before the proposed activities are conducted, the DOE would review
and/or prepare, as necessary, appropriate safety and environmental
documentation to ensure potential risks had been completely evaluated, and
adequately addressed in this EA.  Implementation of any of the activities
described in this EA would be carried out only after appropriate safety and
environmental evaluations indicated that the work could be accomplished with
minimal risk to workers, the public, and the environment.  The activities
would be conducted in conformance with contractor procedures and applicable
environmental regulations which have been approved by the DOE.  Each activity
also would be evaluated against the current authorization basis to ensure that
no new USQ would be involved.
     Many proposed tank farm activities (Appendix A) involve in-tank and
external monitoring and maintenance.  In-tank monitoring includes (but is not
limited to) the periodic installation, operation maintenance, and removal of
remote devices such as video cameras, infrared scanners, neutron or gamma
probes for moisture or liquid measurement, gas measuring probes, thermocouple
trees (TCT), liquid observation wells (LOW), and surface level detectors.  All
equipment would be designed and constructed to appropriate standards (DOE
1989), with accompanying certification, and consideration given to necessary
parameters (e.g., materials of construction, calibration, and detection
levels).
     The proposed actions also include waste characterization.  The proposed
activities would support the resolution of tank safety issues, improvement of
the general waste characterization program, and the regulatory requirements
set forth in the Tri-Party Agreement.
     In addition to the characterization and mitigation measures, the proposed
actions involve necessary capital improvements to the Hanford Site's 200 Area
tank farm infrastructure aimed at upgrading the original design capabilities
of the tank farms.  The improvements would provide upgraded systems in the
areas of ventilation, piping, electrical, instrumentation, and support
facilities.  These actions are consistent with the DOE policy of safe and
environmentally sound nuclear waste management.
     Many of these activities are considered routine in nature when not
associated with the specific USQ tanks (Table 2), and are presently conducted
in non-USQ tanks throughout the tank farms.  The proposed actions encompass
some activities evaluated in other NEPA reviews (ERDA 1975, DOE 1980, DOE
1987), and the EAs listed in Table 1.

3.1.1 Unreviewed Safety Question-Flammable Gas Tanks (Hydrogen Tanks)

     Table 1 includes a list of those specific tanks currently designated for
flammable gas (hydrogen) USQs.  The DOE addressed specific actions involving
hydrogen generation in Tank 241-SY-101 (DOE 1990, DOE 1991b, DOE 1991c, DOE
1991d, DOE 1992b, and DOE 1992c).  The DOE incorporates these previous EAs by
reference, and believes the risk of the proposed action is small, and no
greater than those projected in the aforementioned EAs.
     This belief is based on the fact that other flammable gas tanks present
the same safety concerns and hazards as addressed in the previous
documentation (e.g., vapor ignition, gas release, sample drops, and spills)
but on a reduced scale as compared to Tank 241-SY-101.  Historical data and
ongoing safety reviews indicate that the risks associated with other flammable
gas tanks would be less than those for Tank 241-SY-101.  For example, as
discussed in the "Planned Work Activities for Tank 241-SY-103," (Harmon 1993),
gas release events in flammable gas USQ Tank 241-SY-103 occur less frequently
than those in Tank 241-SY-101, and when they do occur, they are of a smaller
magnitude with no increase in tank pressure. 
3.1.1.1
  Installation, Operation, and Removal of In-Tank Monitoring Equipment. 
The proposed actions would involve the installation and operation of in-tank
monitoring equipment in USQ flammable gas tanks.  The present planning base,
shown in Appendix A, includes (but is not limited to) such items as
video cameras, gas probes, viscosity measuring devices, multi-functional
instrument trees, TCTs, and surface monitoring equipment.  Additionally, the
proposed actions would include the removal of these items for maintenance and
replacement, as well as the removal and disposal of existing equipment such as
sludge weights and air lances.
     Approved procedures and controls would be in place prior to initiation of
the proposed activities.  For example, prior to beginning the proposed
installation and removal of equipment, the vapor space would be sampled to
assure that no flammable gases greater than 25 percent of the LFL were present
(using a calibrated gas flammability meter).  A riser flange would be removed
and the appropriate sampling and testing system inserted.  Any item(s) removed
from the tank would be appropriately packaged and shipped to an onsite
facility(s) for treatment (if necessary), storage and/or disposal.  
     Minor alterations to existing tank configurations (e.g., installation of
riser inserts, modifications to pump pits) may be conducted to enhance
monitoring flexibility and capability and/or operational safety.  Structures
(such as small control room buildings or concrete pads) may be constructed to
support existing and expanded instrumentation controls and computerized data
acquisition systems.
     Additionally, storage and episodic release of flammable gas mixture
(hydrogen and oxides of nitrogen) mitigation evaluations are underway. 
Examples include mixer-pump testing, which is currently ongoing in Tank 241-
SY-101.  The proposed actions would, based on the results of that testing
(anticipated to be completed in Calendar Year [CY] 1994), include
installation, operation and maintenance of additional mixer pumps in other
flammable gas tanks.  The environmental impacts of a similar, specific
activity in Tank 241-SY-101 were analyzed, and determined to be insignificant
(DOE 1992c).  Other proposed mitigation testing includes thermal cycling
(i.e., intervals of in-tank heating and cooling), waste dilution studies, and
effects of sonic probes and vibratory oscillation of tank waste to alleviate
pressure buildup.  The proposed actions would include removal of mitigation
equipment for replacement or maintenance, or onsite disposal should such items
prove to be ineffective or unnecessary.
     The DOE expects that the risks associated with all proposed activities
pertaining to flammable gas tanks, either currently documented or those which
may be identified based on additional operational data, would be small and
less than the risks associated with installing a mixer-pump in Tank 241-SY-
101.  This is based on historical data and ongoing safety reviews which
indicate that although similar event initiators are present, risks associated
with other flammable gas tanks would be less than those for Tank 241-SY-101. 
Appropriate safety review would be completed to verify this expectation prior
to future activities.
3.1.1.2
  Waste Characterization.  The DOE proposes to further characterize the
waste in USQ flammable gas tanks by intrusive means, such as using auger and
core sampling, or similar methods.  The equipment systems also might include a
sludge weight system and a penetrometer testing system (DOE 1992d). 
Appropriate controls, provided by approved procedures, would be in place prior
to the proposed activities.  The general activities are summarized as follows.
       The vapor space would be sampled to assure that no flammable gases
greater than 25 percent of the LFLs were present (using a calibrated gas
flammability meter).  A riser flange would be removed, and the appropriate
sampling and testing system inserted.  Samples would be obtained, (typically
less than 1 liter [0.25 gallons] of sludge or 100 milliliters [0.025 gallons]
of liquid waste) and the system removed completely from the tank, using
essentially the reverse of the installation procedures.  The samples would be
inserted into compatible shipping casks (or other approved transportation
equipment) for transport to appropriate laboratory facilities for analyses. 
The contaminated sampling equipment would be appropriately packaged (e.g.,
placed in plastic bags and/or other appropriate additional containment for
decontamination and reuse or disposal), using standard packaging procedures.
     It is anticipated that most samples would be transported to laboratory
facilities onsite (e.g., the 222S Laboratory in the 200 West Area or the 325
Facility in the 300 Area).  Additionally, selected samples may be sent to
approved laboratories offsite.  In either case, Standard Operating Procedures
(SOP) and approved shipping containers (e.g., proper shielding, materials of
construction, applicable regulations [e.g., U.S. Department of
Transportation]) would be used, or reviewed and revised as appropriate.  It is
anticipated that the samples transported offsite would typically contain less
than less than 1 liter (0.25 gallons) of sludge or 100 milliliters
(0.025 gallons) of radioactive liquid waste.
     Sampling would be conducted using SOPs for sampling HLW waste tanks,
which reflect the potential presence of flammable or explosive material in the
tank or waste.  The proposed actions would be conducted using non-sparking
materials, electrical bonding, spark resistant tools, portable containment
enclosures (i.e., greenhouses), and plastic ground cover around the riser used
for sampling.  Prior to actual use of these systems, specific tank farm
operating procedures would be reviewed, and revised as necessary.
3.1.1.3
  Ventilation System Monitoring and Minor Modifications.  The proposed
actions would involve installation and operation of Tank Monitor and Control
Systems (TMAC), flow meters, thermocouples and humidity gauges on vent headers
of waste tanks, as well as inlet filter installations, and monitoring (e.g.,
gas analysis) cabinets and other equipment.  Minor modifications (e.g.,
sparkless fan installations, modular exhausters, piping connections, riser
reconfigurations, miscellaneous hardware additions) to existing systems also
may occur to enhance flow patterns, and discharge filtration efficiency. 
Appropriate safety documentation would be reviewed and/or prepared prior to
initiation of activities.  

3.1.2 Unreviewed Safety Question-Ferrocyanide Tanks

     Table 1 includes a list of those specific ferrocyanide-containing tanks
currently designated USQs.  Previously approved NEPA documentation (DOE 1991e,
DOE 1992d, and DOE 1992e) exists supporting data collection in certain
ferrocyanide-containing tanks.  Ferrocyanide was used in early chemical
processing operations for the removal of cesium from the waste.  Safety
concerns are associated with a postulated explosive release of tank waste
resulting during mechanical retrieval, due to the presence of sodium, nitrate,
and ferrocyanide precipitates in a tank (DOE 1987), or due to excessive heat
from radionuclide content (DOE 1992a).
3.1.2.1
  Installation, Operation, and Removal of In-Tank Monitoring Equipment. 
The proposed actions would involve the installation and operation of in-tank
monitoring equipment in USQ ferrocyanide tanks.  The present planning base
(Appendix A) includes (but is not limited to) such items as infrared scanning
equipment for surface anomalies and moisture measurement, LOWs, gamma or
neutron probes for moisture or liquid measurement, waste chemical sensors,
continuous gas measurement system, and additional TCTs.  Additionally, the
proposed actions would include the removal of these items for maintenance and
replacement, as well as the removal of old equipment such as sludge weights
and air lances.  Approved procedures would be in place prior to the proposed
activities, with the vapor space tested for flammable gases.  Removed items
would be appropriately packaged and shipped to an onsite facility(s) for
treatment (if necessary), storage and/or disposal.
3.1.2.2
  Waste Characterization.  As with the flammable gas tanks (Section
3.1.1.2), the DOE proposes to further characterize the waste in USQ
ferrocyanide-containing tanks.  Sludge samples would be obtained using
sampling methods similar to those discussed for flammable gas tanks.  The
general procedures discussed earlier for flammable gas tank sampling,
including appropriate safety reviews prior to initiation of activities,
(Section 3.1.1.2) also are applicable.
3.1.2.3
  Ventilation System Enhancements and Minor Modifications.  The
proposed actions would allow installation and operation of TMAC, flow meters,
thermocouples, and humidity gauges on vent headers of ferrocyanide-containing
waste tanks, as well as inlet filter installations, and monitoring (e.g., gas
analysis) cabinets and other equipment.  Minor modifications (e.g., piping
connections, minor riser reconfiguration, miscellaneous hardware additions) to
existing systems also would occur to enhance flow patterns and discharge
filtration efficiency, and deter uncontrolled temperature increases.

3.1.3 Unreviewed Safety Question-Floating Organic Solvent Layer in Tank 241-

C-103
     Tank 241-C-103 is one of the original approximately 2 million-liter
(530,000-gallon) tanks constructed from 1943 to 1944.  A USQ was declared for
this tank in September 1992, because the potential for ignition and combustion
of the floating organic solvent layer is not fully addressed by existing
safety documentation.  It is believed that the organic layer (estimated to be
less than 150,000 liters [less than 40,000 gallons]) consists of approximately
70 volume percent TBP and approximately 30 volume percent NPH, both of which
were used in the Plutonium-Uranium Extraction (PUREX) process.  The PUREX
process was designed for individual separations of uranium, plutonium,
neptunium and fission products via solvent extraction (DOE 1983).  The
material is present due to transfer of tank waste from Tank 241-C-102 during
CY 1975.
3.1.3.1
  Organic Characterization.  The proposed actions would continue the
vapor and liquid characterization of Tank 241-C-103 (DOE 1993).  Additional
data would verify the composition and volume of material, and assist in
determining the interim options and final disposition of the floating organic
solvent layer.
3.1.3.2
  Organic Removal.  The proposed actions would include removal of the
floating organic solvent layer to regulatory-compliant storage (e.g., Resource
Conservation and Recovery Act of 1976 [RCRA]) in the 200 East Area prior to
final disposition.  The transfer operations would be conducted using properly
engineered systems designed to minimize the risk to the workers and the
public.  These would include enclosed and shielded pumping and transfer
systems as well as designs which minimize the risk of solvent ignition.  Based
on past experience at the Hanford Site, no unique hazards to workers or the
general public would be expected from the removal and storage of this
material.  Large volumes of contaminated organics have been managed safely on
a routine basis during PUREX processing (ERDA 1975, DOE 1987).  It is
anticipated that standard technology (i.e., use of sparkless tools for the
installation of a floating suction pump), and subsequent transfer of the
organic solvent layer to existing non-HLW tankage (designed for safe storage
of radioactive materials) would be used, with no additional emissions or
exposure above those currently being experienced during base storage
operations.
     Initial sample analyses of the floating organic solvent layer indicate
that the low surface dose rates would allow the material to be pumped directly
to approved (e.g., U.S. Department of Transportation [DOT], RCRA) tanker truck
or other transportable vessels, located near Tank 241-C-103, prior to final
disposition.  However, should additional analyses indicate radiological
contamination above applicable threshold limits, consideration would be given
to pumping the material directly to the 244-CR vault for interim storage.  The
244-CR vault is located nearby in the 200 East Area, and transfer would be
conducted by way of the Tank 241-C-103 valve pit, using existing transfer
lines.
     Several options for final organic disposition are presently being
explored in an engineering study (anticipated to be completed by the end of
June 1994).  Potential alternatives would include routing the material through
PUREX for packaging (i.e., truck tankers or 55-gallon drums) and subsequent
shipment to an appropriate facility for use as fuel for diesel boilers
(adequacy of the material for fuel would depend upon radiolytic content and
ratio of TBP and NPH).  The shipment of the organic liquid would comply with
DOT packaging and shipping requirements.  Also, consideration is being given
to distillation of the material, with the radioactive residue (radioactive
mixed waste) stored onsite in RCRA-compliant units.  The nonradioactive
distillate would be transported offsite for incineration at a properly
permitted facility.  Additional NEPA review, as appropriate, would be
conducted prior to final disposition of the organic.

3.1.4 Unreviewed Safety Question-Nuclear Criticality

     No physical activities associated with the proposed actions would be
directed towards closure of the criticality USQ (i.e., characterization work
or equipment modifications).  None of the proposed actions would be expected
to impact the nuclear reactivity of the tanks and therefore would not alter
their subcritical state.  Closure of the criticality USQ would be accomplished
by the DOE's completion of an amendment to the Authorization Basis, which must
provide the analyses to demonstrate that the tanks are subcritical by a
substantial margin.  The DOE anticipates closure of the criticality USQ by
March 1994.
     The conclusions stated apply to the tanks in their current configuration,
and do not include considerations that would be involved in future operations,
such as retrieval or pre-treatment, which would be evaluated under separate
NEPA review.  Each of these cases would require safety analysis from which
appropriate controls would be devised to assure that subcritical conditions
are maintained.

3.1.5 Toxic Vapors

     The proposed actions would include sampling and characterization of
vapors from suspect tanks using comparable vapor space sampling equipment, and
similar methods which were used for Tank 241-C-103 (DOE 1993).  The proposed
actions also would include ventilation system enhancements and minor
modifications to mitigate noxious and toxic vapor emissions.
3.1.5.1
  Vapor Space Characterization.  The proposed actions would involve the
installation and operation of appropriate in-tank monitoring equipment.  The
present planning base includes (but is not limited to) such items as
continuous gas measurement systems and gas tracer experiments.  The proposed
actions would include the removal of these systems (or portions thereof) for
maintenance and replacement, as well as the removal of old equipment such as
sludge weights and air lances.  
     Prior to entrance to the tank farms, personnel would monitor for the
presence of toxic vapors and follow the appropriate mitigation actions (e.g.,
protective clothing, self-contained breathing apparatus).  Approved procedures
would be in place prior to the proposed installation activities, with the
vapor space tested for flammable gases before entering tank containment. 
Removed items would be appropriately packaged and shipped to an onsite
facility(s) for treatment (if necessary), storage and/or disposal.  This
activity is being proposed on the basis of information obtained from prior
vapor space characterization work performed by the DOE, and would be a
continuation and extension of operations surrounding Tank 241-C-103
(DOE 1993).
3.1.5.2
  Ventilation System Enhancements and Minor Modifications.  The
proposed actions would include minor ventilation upgrades to toxic vapor
tanks, where warranted.  The activities may include such items as inlet filter
installations (to ensure filtered pathways under all conditions), monitoring
(e.g., gas analysis) cabinets, and other equipment.  Minor modifications
(e.g., piping connections, miscellaneous hardware additions) to existing
systems also may occur to enhance flow patterns and discharge filtration
efficiency, and deter uncontrolled vapor increases.

3.1.6 Infrastructure Upgrades

     A draft restoration and upgrades plan for the Hanford Site tank farms is
presently being developed, with activities projected for completion beyond the
year 2000.  The draft plan includes longer-term activities such as new HLW
transfer lines, and replacement tanks.  Such activities would be addressed
under separate, appropriate NEPA documentation when sufficient information
becomes available, and would provide an evaluation of individual and/or
cumulative environmental effects.  Based upon the draft plan, the proposed
actions have been developed to be consistent with the long-term requirements,
and would not limit or preclude future options.
     The proposed actions addressed in this EA would include modernization of
facilities, improvements in plant instrumentation and data collection systems,
and minor modifications to ventilation systems, as required.  For example,
activities would include items such as installation of permanent personnel
changeroom facilities (i.e., prefabricated structures to allow change into
protective clothing for personnel safety), alarm panel upgrades, and
replacement of compressed air systems.

3.1.7 Interim Stabilization of Single-Shell Tanks

     The 149 SSTs have been in service longer than the originally projected
design life, and do not meet current regulatory requirements such as double
containment.  Sixty-seven SSTs are presumed to have leaked a total of
approximately 3,800,000 liters (1 million gallons) of radioactive waste to the
soil.  The pumpable liquid has been removed from 106 tanks.  However, an
estimated 19 million liters (5 million gallons) of pumpable liquids still
remain in 43 of the SSTs.  This proposed action would remove the pumpable
liquid from the 43 SSTs to minimize the impact from potential future tank
leaks.  This type of activity has been conducted routinely in the past (DOE
1987).  Although the interim stabilization program is going forward, the
ability to continue to transfer this liquid waste to appropriate DST storage
has been impeded by general tank safety issues and deteriorated waste transfer
systems.
     Under the DOE's current waste management program, if ongoing monitoring
indicated that a specific SST had become an assumed leaker (i.e., questionable
integrity), that tank would be elevated on the priority list for appropriate
stabilization actions regardless of its operational status.  The DOE proposes
to continue this program.  For example, Tank 241-T-101 (a ferrocyanide-
containing USQ SST) was determined to be an assumed leaker, and was pumped in
accordance with approved procedures, to a DST in 1993.  These approved
procedures establish the safety evaluations necessary to assure safe transfer
of waste.
3.1.7.1
  Installation, Operation, and Removal of Leak Detection Equipment. 
The proposed actions would include upgrades to leak detection equipment
associated with SSTs, providing enhanced response to, and mitigation of,
inadvertent liquid waste releases to the environment.  Activities would
include (but not be limited to) electrical modifications, alarm panel
installation, LOW installation, upgraded level detectors and instrumentation,
and upgraded radiation detectors. 
3.1.7.2
  Removal of Pumpable Liquid from Single-Shell Tanks.  The proposed
actions would include continued tank-to-tank transfer of pumpable liquid from
SSTs to DSTs, as appropriate, prior to final disposition of the tank waste. 
Primary consideration would be given to the use of existing pumps, and in-tank
and underground transfer piping hardware.  
     Additional equipment (e.g., saltwell screens, submersible pumps, and/or
above-ground, shielded, interim transfer lines) would be installed, as
appropriate, based on case-by-case adequacy of existing hardware, as
determined by safety documentation.  The overground transfer system would
consist of a primary pipe located inside secondary containment.  The piping
would take the straightest possible route from one tank pit to another tank
pit.  The liquid radioactive tank waste would be routed through an inlet
nozzle located in the SST pump pit, and then through existing underground
process lines into a DST receiver.

3.1.8 High-Heat Generation

     The DOE's Safety Initiatives (Wagoner 1993) specifically address Tank
241-C-106.  The tank contains waste which generates sufficient heat to require
the addition of cooling water to ensure that temperature levels remain well
below boiling, maintaining protection of the tank structure from damage due to
overheating.  Since this tank is a SST, it has a higher likelihood of leaking
in the future.
3.1.8.1
  Installation, Operation, and Removal of In-Tank Monitoring Equipment. 
The proposed actions would involve the installation and operation of in-tank
monitoring equipment.  The present planning base includes (but is not limited
to) such items as infrared scanning equipment for surface anomalies and
moisture measurement, LOWs, neutron probes for moisture measurement, waste
chemical sensors, continuous gas measurement systems, and additional TCTs. 
Additionally, the proposed actions would include the removal of these items
for maintenance and replacement, as well as the removal of old equipment such
as sludge weights and air lances.  Approved procedures would be in place prior
to the proposed activities, with the vapor space tested for flammable gases. 
Removed items would be appropriately packaged and shipped to an onsite
facility(s) for treatment (if necessary), storage and/or disposal.
3.1.8.2
  Sluicing of Tank 241-C-106.  Tri-Party Agreement Milestone M-05-08
calls for the interim stabilization of Tank 241-C-106 in order to stop the
practice of adding cooling water to the tank.  Another milestone under the
Tri-Party Agreement (M-07-00) calls for the initiation of a demonstration of
one form of SST retrieval.  To address these needs, the DOE proposes to
install several sluicers and a submersible pump in Tank 241-C-106, install a
sluicer pump in a receiver tank (Tank 241-AY-102), and provide various
improvements to the two tank farms to facilitate the sluicing operations. 
These actions are mentioned here only for completeness, as a separate NEPA
review is being developed to address the aforementioned transfer operations
for continued storage prior to final disposition.

3.2 Alternative(s) to the Proposed Actions

3.2.1 No-Action Alternative

     Under the No-Action Alternative, tank farm operations would continue
under existing conditions.  That is, ongoing monitoring, maintenance,
characterization and stabilization activities with existing NEPA coverage
(ERDA 1975, DOE 1987), and the EAs listed in Table 1, would continue.  There
would be no additional installation, operation, or removal of in-tank
monitoring equipment; modifications to ventilation systems; sampling of vapors
and wastes; or stabilization activities as described for the proposed actions
(Sections 3.0 and 3.1).  This would impede resolution of the USQs in a timely
fashion.  The lack of information obtained from tank monitoring and waste
characterization, coupled with minimal facility modifications and upgrades,
could increase the risk of chemical and radiation exposure to workers, the
public, and the environment, in the event of a breach of tank containment. 
This alternative would be inconsistent with the DOE's commitment for closure
of the USQs, and the Congressional directive to the DOE to take the necessary
steps to ensure safe management of Hanford Site tank waste.

3.2.2 Strategies Involving Non- or Minimal-Intrusive Operations

     The DOE considered less intrusive strategies involving closure of the
USQs.  For example, waste characterization using solely non-intrusive methods
such as computer modeling based on historical process knowledge, and
laboratory simulants, was considered.  This approach, while having merit for
reduction of worker exposure and avoiding initiators that could result in a
severe accident, has limited utility because actual tank data are required to
validate theoretical projections.
     Similarly, minimizing the intrusive operations to monitoring activities,
for example, would not provide the necessary data to close the USQs.

3.2.3 Other Alternatives

     No other reasonable alternatives were identified for addressing the waste
tank safety issues.
     Final disposition of the floating organic solvent layer in Tank 241-C-103
would undergo additional NEPA review, as appropriate, when sufficient
information about the associated actions and their alternatives are available. 
Similarly, issues discussed earlier pertaining to major out-year tank farm
infrastructure upgrades in future years would be evaluated under separate NEPA
review, as warranted, based on the results of future engineering studies.
                     

4.0 Affected Environment

     The tank farms are located in the 200 Areas of the approximately 1,450
square kilometers (560 square mile) semiarid Hanford Site in the southeastern
portion of the State of Washington (Figure 2).  The 200 East Area is
approximately 10 kilometers (6 miles) west of the Columbia River, the nearest
natural watercourse.  The 200 West Area is approximately 5 kilometers (3
miles) further west.  The nearest population center is the City of Richland,
approximately 32 kilometers (20 miles) away to the south.
     The Hanford Site has a mild climate with 15 to 18 centimeters (6 to 7
inches) of annual precipitation, and infrequent periods of high winds of up to
128 kilometers (80 miles) per hour.  Tornados are extremely rare; no
destructive tornados have occurred in the region surrounding the Hanford
Site.  The probability of a tornado hitting any given waste management unit on
the Hanford Site is estimated at 10 chances in 1 million during any given
year.  The region is categorized as one of low to moderate seismicity.
     The 200 Areas are not located within a wetland or in a 100- or 500-year
floodplain.  No plants or animals on the federal list of "Endangered and
Threatened Wildlife and Plants," (50 CFR 17) are found in the immediate
vicinity of the tank farms addressed in this EA, nor would existing plant or
animal species found on the Hanford Site be affected by the activities
associated with resolving USQs.  The geology of the site, where the proposed
actions would take place, is typical of the 200 Areas.  The surface is
veneered with loess and sand dunes of varying thickness, although the tank
farms and the majority of the area between them is composed of a disturbed
gravel layer.  Under the surface layer, in ascending order, are basement rocks
of undetermined origin, the Columbia River Basalt Group with intercalated
sediments of the Ellensburg Formation, the Ringold Formation, the Plio-
Pleistocene unit, and the Hanford Formation.  The depth to groundwater for the
200 Areas is 75 meters (246 feet).  Groundwater flow direction is generally in
an easterly and southeasterly direction, toward the Columbia River.  The
proposed actions would not be expected to impact the climate, flora and fauna,
air quality, geology, hydrology and/or water quality, land use, or the
population (DOE 1987, DOE 1990, DOE 1991c, DOE 1993).  General information
regarding the Hanford Site may be found in the Hanford Site National
Environmental Policy Act (NEPA) Characterization report (Cushing 1992).
     The Hanford Site is known to be rich in cultural resources, and contains
many well-preserved archaeological sites dating back to both prehistoric and
historical periods.  Over 10,000 years of human activity have left extensive
archaeological deposits along the Columbia River shoreline and at well-watered
inland sites.  Archaeological deposits at the Hanford Site have been spared
some of the severe disturbances that have befallen unprotected sites in the
area.  However, the proposed activities would occur in the 200 Areas, several
miles from any natural water courses and are not expected to impact sensitive
archaeological resources.  Further, the 200 Areas have been previously
disturbed over the past 50 years.  No sensitive cultural resources in the area
of the tank farms have been identified, or are anticipated.  Additional
information regarding the cultural resources on the Hanford Site may be found
in the Hanford Cultural Resources Laboratory Annual Report for 1992
(PNL 1993a).
                    

5.0 Environmental Impacts

     The following sections present information on those potential
environmental impacts that have been identified as a result of activities
being proposed for resolution of tank farm USQs and other safety issues. 
There are uncertainties and risks associated with even the most routine tank
farm operations.  Also, while gathering and analyzing information required to
mitigate and resolve issues surrounding conduct of operations (which are
constantly reviewed and evaluated), inherently additional uncertainties (and
associated risks) may arise.  However, the proposed installation, operation,
and removal of the monitoring and sampling equipment, and associated materials
discussed previously to address the DOE's Safety Initiatives (Wagoner 1993),
would not be expected to result in any additional radiological or hazardous
material releases to the environment.  All activities would comply with
current DOE orders, and state and federal regulations.  

5.1 Proposed Actions: Impacts from Routine Operations

     The potential for release of radioactive emissions during routine
activities in the tank farms exists.  However, the primary tank farm
ventilation systems (providing filtration of waste tank airborne effluents)
would be operational during those activities in order to maintain radioactive
emissions well below DOE guidelines (5 roentgen equivalent man [rem]
per year), in keeping with As Low As Reasonably Achievable principles. 
Additionally, appropriate procedures and administrative controls (e.g.,
personnel training and a Radiation Work Permit) would be in place prior to any
proposed activities.  Also, radiation and hazardous chemical levels at the
waste site, and worker exposure levels, would be monitored during the proposed
actions.
     There would be some radiological exposure for the workers involved in the
proposed activities.  However, the anticipated exposure would not result in a
change in the average annual exposure to radiation by Hanford Site tank farm
workers from ongoing tank farm activities.  Average occupational external
exposure to workers in the Hanford Site tank farms (as measured by individual
dosimetry records) is approximately 14 millirem per year per worker, which is
substantially less than the maximum allowable exposure of 5,000 millirem per
year.
     Assuming 200 tank farm workers are directly involved with the proposed
activities and exposed to radiation at the average annual dose rate of 14 mrem
per year, based on a dose-to-risk conversion factor of 4.0 x 10-4 (onsite)
latent cancer fatalities (LCF) per person-rem (56 FR 23363), 0.001 LCFs per
year would be expected to result from the proposed action.  It is most likely
that no cancer fatalities would be induced by the proposed action during its
maximum 8-year duration.
     Also, no public exposure to radiation above that currently experienced
from Hanford Site operations is anticipated as a result of these actions. 
That is, as reported in the Hanford Site Environmental Report 1992, (PNL
1993b), the potential dose to the hypothetical offsite MEIs during CY 1992
from Hanford Site operations was 0.02 millirem.  The potential dose to the
local population of 380,000 persons from 1992 operations was 0.8 person-rem. 
The 1992 average dose to the population was 0.002 millirem per person.  The
current DOE radiation limit for an individual member of the public is
100 millirem per year, and the national average dose from natural sources is
300 millirem per year.  No adverse health effects would be expected to result
from these low doses.
     It is anticipated that routine operations would not provide additional
exposure of toxic or noxious vapors to workers.  Based on experience with Tank
241-C-103 (DOE 1993), additional administrative controls have been put into
place (e.g., additional protective equipment, facility access limitation)
throughout the tank farms to reduce the potential for worker exposure.
     No environmental impacts from the routine transportation of waste samples
would be anticipated as a result of the proposed action because the quantities
transported would be small and would be appropriately packaged.  Most samples
would be transported to an appropriate laboratory facility onsite (e.g., 222S
Laboratory in the 200 West Area), with selected samples sent to approved
laboratories offsite.  Typically, a sample of approximately 100 milliliters
(0.28 gallons) would be obtained using SOPs.  The sample would be packaged
into an approved shipping container (e.g., proper shielding, materials of
construction), and transported under the prescribed shipping regulations
(e.g., DOT) in force at the time.      
     Small quantities of hazardous materials (e.g., solvents, cleaning agents)
which may be generated during the proposed actions would be managed and
disposed of in accordance with applicable federal and state regulations. 
Radioactive material, radioactively-contaminated equipment, and radioactive
mixed wastes would be appropriately packaged, stored, and disposed of at
existing facilities on the Hanford Site.  None of the materials would be
anticipated to be generated in substantial quantities when compared to the
annual amount routinely generated throughout the Hanford Site.  For example,
during CY 1992, 23,800 cubic meters (840,489 cubic feet) of low-level
nonindustrial waste was received for disposal and/or storage in the 200 Areas
(WHC 1993b).
     Noise levels would be comparable to existing conditions in the tank
farms.  The amount of equipment and materials to be used, such as steel and
other metals for piping and enclosures necessary for modifications, represent
a minor long-term commitment of nonrenewable resources.

5.2 Proposed Actions: Impacts from Accidents

     A wide range of postulated accidents associated with Hanford Site tank
farm operations have been previously analyzed in EISs (ERDA 1975, DOE 1983,
DOE 1987 [supported by PNL 1986]), and in several EAs (DOE 1991d, DOE 1992c,
and DOE 1993).  The EA accidents are summarized in Appendix B, and are briefly
discussed below in Sections 5.2.1, 5.2.2, and 5.2.3, with a complete reference
listing provided in Section 8.0.  
     The events included high consequence/low probability scenarios, as well
as low consequence/high probability scenarios.  The most serious postulated
event analyzed was a gas ignition and detonation.  Although the consequences
of such an event would be catastrophic, the probability of such an occurrence
is extremely low, and therefore the overall risk is small.
     The proposed activities are similar to those safely conducted in the past
and analyzed in existing EAs (Table 1).  The accident analyses associated with
these similar activities were described in the previous EAs (Table 1) and are
expected to bound the potential accidents that could occur from the proposed
activities evaluated in this EA because in any particular category of safety
issue, similar accident initiators and potential risks would be present.  
     Over the past 2 years (1991 to 1993), major intrusive activities
associated with Tank 241-SY-101 (e.g., core drilling, auger sampling,
mixer-pump installation and operation), along with relatively minor actions
(e.g., installation of video cameras, gas monitoring systems) have required
entering tank containment 15 to 20 times.  No unanticipated events directly
associated with those proposed actions have occurred.  Similar activities are
scheduled (Appendix A) to address the spectrum of tank safety issues.  The DOE
will constantly review appropriate procedures and related information to
mitigate the potential for future unanticipated events.

5.2.1 Unreviewed Safety Question-Flammable Gas Tanks

     Accident scenarios specifically addressing the hydrogen issue in Tank
241-SY-101 have been analyzed previously for the installation, operation, and
removal of in-tank monitoring equipment, minor modifications to ventilation
systems, and sampling of vapors and wastes (DOE 1990, DOE 1991b, DOE 1991c,
DOE 1991d, DOE 1992b, DOE 1992c).  Similar initiators and risks are present in
all tanks.  A summary of those accident analyses is presented in Appendix B. 
It would be anticipated that other flammable gas tanks would have similar
initiators and potential accidents (with attendant probabilities).  However,
due to lower gas generation and retention rates, the associated risks would be
lower.
     The non-detonation accident sequences previously analyzed (Table 1)
included potential material spills, equipment drops, unfiltered releases from
open risers, and a range of potential ignition scenarios that would not result
in a detonation (Section 5.2.7, Maximum Reasonably Foreseeable Accident). 
Similar hazards, initiators, and probabilities would be anticipated for other
flammable gas tanks associated with the proposed actions.  The estimated
offsite LCFs that could result from radiological releases associated with the
non-detonation accident scenarios vary with the accident sequence from 1.5 x
10-5 (for a spill during removal, with estimated annual probability of
occurrence of 5.0 x 10-3) to 3.4 x 10-2 (for a gas ignition, with estimated
annual probability of occurrence of 1.0 x 10-7).  These correspond to
population doses of 0.03 and 68 person-rem, respectively.  The corresponding
doses to individual tank farm workers would range from about 6 millirem
(spill) to about 13 rems for the ignition scenario (2.4 x 10-6 and 5.2 x 10-3
LCFs, respectively).
     No future onsite or offsite health effects from exposure to toxic gases
(including throat or eye irritation) during any postulated accident sequence
would be expected.  The maximum exposures to the species of greatest concern,
ammonia (estimated to be approximately 1.3 percent), would be only slightly
above the immediately dangerous to life and health level (i.e., 500 parts per
million) and the exposures would only be for several minutes (DOE 1992c). 
Other toxic gas species are well below acceptable limits.  Also, the
previously mentioned incidents (Section 2.5) have resulted in additional
administrative controls (e.g., protective clothing) to mitigate the potential
for future events throughout the tank farms.  

5.2.2 Unreviewed Safety Question-Ferrocyanide Tanks

     Accident scenarios specifically addressing the ferrocyanide issue have
been analyzed previously for the installation, operation, and removal of in-
tank monitoring equipment and sampling of vapors and wastes (DOE 1987, DOE
1991e, DOE 1992d, and DOE 1992e), and their associated FONSIs.  Similar
hazards and initiators are present in all tanks.  A summary of those accident
analyses is presented in Appendix B.  
     The potential accident scenarios evaluated included a vapor space fire,
salt cake combustion, and a sample container drop outside the tank.  As stated
in the Environmental Assessment:  Intrusive Sampling and Testing of
Ferrocyanide Tanks (DOE 1992d), the consequences of a spark-caused fire and/or
a salt cake combustion due to impact as a result of the proposed actions could
be catastrophic.  The probability that the proposed actions would result in a
spark or impact induced fire or combustion is extremely low (approximately 1.0
x 10-9 per year).  
     A toxic gas release scenario also was discussed (DOE 1992d).  As stated
in that EA, the low annual probability of such a release, the protection to
workers afforded by gas monitoring in the work environment, and appropriate
procedures and equipment for worker safety, resulted in the expectation that
risks associated with the postulated accident scenario would be low.

5.2.3 Unreviewed Safety Question-Floating Organic Solvent Layer Tank

     Postulated accident scenarios associated with vapor and liquid
characterization of the floating organic solvent layer in Tank 241-C-103 were
analyzed in the Environmental Assessment:  Tank 241-C-103 Organic Vapor and
Liquids Characterization and Supporting Activities, (DOE 1993) and its FONSI. 
This EA analyzed a range of reasonably foreseeable accidents, including a
noxious or toxic gas release, a dip-sample bottle break outside the tank,
radiation exposure from a gas sampling tube, a lightning strike that ignites
organic vapors in the tank, and a vapor space fire, and subsequent burn of the
liquid organic layer in the tank.  A summary of those accident analyses is
presented in Appendix B.  The accident with the highest probability of
occurrence is the dip-sample bottle break, which would increase worker
exposure to radiation, but would not be expected to result in any adverse
health effects.  Additionally, the postulated noxious or toxic gas release
would not result in any adverse health effects to workers or the public.
     The activities associated with the proposed transfer and storage of the
liquid organic layer would be not pose any unique risks or safety hazards. 
The potential consequences and risks of accidents for the proposed transfer
and storage would be no greater than those presented in Environmental
Assessment:  Tank 241-C-103 Organic Vapor and Liquids Characterization and
Supporting Activities (DOE 1993).  The probability of a severe accident would
be less than 1.0 x 10-6; the consequences could be catastrophic.

5.2.4 Toxic Vapors

     An analysis of potential accidental emissions (which include hydrogen,
oxides of nitrogen, and ammonia) indicated that the probability of a gas
release during operations associated with Tank 241-SY-101 would be 1.0 x 10-4 
(DOE 1992b).  The maximum reasonably foreseeable case of toxic emissions would
occur from Tank 241-C-103 (DOE 1993).  As shown in Appendix B, the
consequences were that the noxious or toxic gas release would not result in
life-threatening health effects to workers due to limiting personnel access,
the use of protective clothing, and supplied air in the vicinity of the
sampling, and would have no impact on the public.  Potential exposure to
workers by vapors from other USTs would be mitigated by extending the
administrative controls and procedures presently established for Tank 241-C-
103.

5.2.5 Infrastructure Upgrades

     As shown in Appendix B, the risks associated with past infrastructure
upgrade activities have been investigated (DOE 1991c, DOE 1992b, DOE 1992c and
DOE 1992e).  Included activities are ventilation and equipment upgrades, and
installation of instrument measuring and control systems.  Hazards and
accident scenarios have been identified, and the frequency and consequence of
anticipated accidents were examined.  The results indicate that both the
frequency and consequences of postulated accidents are low.  No hazards or
potential accident scenarios associated with the proposed actions could be
identified that would be substantially different than those previously
examined.

5.2.6 Interim Stabilization of Single-Shell Tanks

     The potential accidents associated with interim stabilization of SSTs
have been examined (WHC 1993c).  The most significant accidents include breaks
in waste transfer and pumping systems, and hydrogen accumulation and ignition
in interim receiver tanks.  The estimated offsite LCFs that could result from
radiological releases associated with these accidents are 7.0 x 10-8 (for
pumping system breaks) and 1.5 x 10-5 (for hydrogen ignition).  The onsite
LCFs, which could result from the same accident, were estimated to be 1.7 x
10-4 and 8.0 x 10-4, respectively.  The corresponding doses for the pumping
system break are 4.4. x 10-2 rem for the onsite worker and 1.4 x 10-4 rem for
the offsite MEI.  The doses for the hydrogen ignition accident are 2.0 rem for
the onsite worker and 3.0 x 10-2 rem for the offsite MEI.  The probabilities
for the pumping system break and hydrogen accumulation and ignition were
calculated to be 1.4 x 10-3 and between 1.0 x 10-2 and 1.0 x 10-4, respectively.

5.2.7 Maximum Reasonably Foreseeable Accident

     A postulated detonation event in Tank 241-SY-101 would be considered the
maximum reasonably foreseeable accident.  The impacts of this activity have
been evaluated (DOE 1992c).  As discussed in Appendix B, this event is
considered highly unlikely, based on the estimated probability of less than
1.0 x 10-6 per year (under current conditions).  The pressures from such a
detonation would exceed, by a factor of two or more, the pressures that have
been found to be structurally limiting in Tank 241-SY-101.  This means that a
detonation, should it occur, would be expected to cause tank failure.  The
consequences of a detonation event in Tank 241-SY-101 would be similar to the
ferrocyanide explosion evaluated in the Final Environmental Impact Statement: 
Disposal of Hanford Defense High-Level, Transuranic and Tank Wastes, Hanford
Site, Richland, Washington (HDW-EIS) (DOE 1987).  The ferrocyanide event would
result in a short-term radiation dose to the offsite MEI of 200 millirem, and
an offsite collective dose commitment of 7,000 person-rem.  Such an explosion
would be expected to result in 4 offsite LCFs, the contamination of a
substantial area of land, and large doses to workers.  Although a 1990 General
Accounting Office (GAO) study estimated that the consequences of this event
would be 10 to 100 times greater than those projected in the HDW-EIS
(GAO 1990), the GAO did not reach a conclusion regarding the probability of a
tank explosion, and an independent DOE review determined that the probability
of such an event is low (Duffy 1990).  The proposed actions would not
appreciably increase the probability of a gas detonation event.  Further, the
mitigation of hydrogen evolution by operation of a mixer-pump would reduce the
probability and risk of such an event.  Based on the extremely low probability
of occurrence, even if the severe consequences of the GAO report are assumed,
the risks of a tank detonation resulting from the proposed actions are small.

5.3 Alternative Actions

5.3.1 No-Action Alternative

     The No-Action Alternative would have no greater environmental impacts
than those presently experienced at the Hanford Site (PNL 1993b).  However,
the lack of information and data could hamper the ability to resolve USQs and
other safety concerns in a timely manner.  This could result in increased
long-term risk to the workers, public and the environment.
     Activities conducted under this alternative would be expected to have
environmental impacts similar to those currently experienced at the Hanford
Site.  As discussed in the Hanford Site Environmental Report 1992, (PNL
1993b), liquid and gaseous effluents, which may contain radioactive and
hazardous constituents, are continually monitored at the Hanford Site.  The
specific constituents monitored are selected based on applicability
(e.g., constituents would be considered for tank farm operations).  The
potential dose to the hypothetical offsite MEI in 1992 from Hanford operations
was 0.02 millirem (PNL 1993b), the same as calculated for 1991.  The potential
dose to the local population of 380,000 persons from 1992 operations was 0.8
person rem, compared to 0.9 person rem reported for 1991.  The 1992 average
dose to the population was 0.002 millirem.  The offsite MEI potentially
received 0.02 percent of the DOE dose limit and 0.007 percent of the national
average background dose from natural sources.  The average individual
potentially received 0.002 percent of the standard and 0.007 percent of the
300 millirem per year received from typical natural sources.
     The highest dose rates measured in the 200 Areas would continue to be
near waste-handling facilities, such as tank farms.  The average dose rate
measured in 1992 at the perimeter of the tank farms by thermoluminescent
dosimeters was 130 millirem per year (representing 24 hours per day, 365 days
per year), which was 8 percent above the average dose rate of 120 millirem per
year measured in 1991 (PNL 1993b).
     Additionally, air samples were collected for volatile organic compounds
and polychlorinated biphenyls.  All measured air concentrations of these
organic compounds were well below applicable maximum allowable concentration
standards for air contaminants.  Further, chemical water quality constituents
measured in Columbia River water during 1992 were generally similar upstream
and downstream and in compliance with applicable standards (PNL 1993b).

5.3.2 Non- and Minimal-Intrusive Alternatives

     These alternatives would be expected to contribute less worker and
offsite exposure.  As in the No-Action Alternative, the lack of information
and data could hamper the ability to resolve USQs and other safety concerns in
a timely manner.  This could result in increased long-term risk to the worker,
public, and environment.

5.4 Proposed Actions: Cumulative Impacts

     While the increased number of intrusive actions proposed would slightly
increase accident risks in the short-term, the accident risks would remain
small.  The proposed actions actually would contribute to an overall decrease
in the potential risks associated with routine Hanford Site tank farms
operations.  Enhanced monitoring capability, improvements to ventilation
systems, knowledge of tank waste composition and characteristics, and
infrastructure upgrades would minimize the potential for unnecessary exposures
to workers and the public.  Thus, this would contribute to a near-term
reduction from the 1992 tank farm perimeter dose rate of 130 millirem per
year, and the average 1992 worker dose rate of 14 millirem.
     The proposed actions also would mitigate the potential for, and
consequences of, inadvertent releases of radioactive and hazardous materials
from USTs.  Mixer-pump installation and operation would reduce buildup of
flammable gas mixtures.  Removal of the floating organic solvent layer would
substantially reduce the source term, should a postulated ignition occur in
Tank 241-C-103.
         

6.0 Permits and Regulatory Requirements

     The SSTs and DSTs are being operated under interim status as treatment
and storage units under Washington Administrative Code (WAC 173-303).  An
amended dangerous waste closure and postclosure plan would be submitted to
Ecology for closure of the SSTs (Tri-Party Agreement Milestone M-9-02 [Ecology
et al. 1992]).
     Notification and approval from the appropriate regulatory authorities
would be required prior to installation of mixer pumps or sluicing pumps.  The
DOH notification and/or approval may be required due to the potential increase
in radionuclide air emissions.  Additionally, approvals also may be required
by EPA and Ecology.  All required approvals would be obtained prior to the
initiation of a particular activity.
                      

7.0 Agencies Consulted

     No outside agencies were consulted regarding the preparation of this EA.
                            

8.0 References

50 CFR 17, 1992, "Endangered and Threatened Wildlife and Plants," Code of
     Federal Regulations, as amended.
54 FR 12440, 1988, "Disposal of Hanford Defense High-Level, Transuranic and
     Tank Wastes, Hanford Site, Richland, Washington; Record of Decision,
     Federal Register, April 14.
56 FR 23360, 1991, ""Nuclear Regulatory Commission, Preamble to Standards for
     Protection Against Radiation," Federal Register, May 21.
Cushing, C. E., ed., 1992, Hanford Site National Environmental Policy Act
     (NEPA) Characterization, PNL-6415, Rev. 5, Pacific Northwest Laboratory,
     Richland, Washington.
DOE, 1980, Final Environmental Impact Statement, Supplement to ERDA-1538,
     December 1975, Waste Management Operations, Hanford Site, Richland,
     Washington, Double-Shell Tanks for Defense High-Level Radioactive Waste
     Storage, DOE/EIS-0063, U.S. Department of Energy, Washington, D.C.
DOE, 1983, Addendum to the EIS:  Operation of PUREX and Uranium Oxide Plant
     Facilities, Hanford Site, Richland, Washington, DOE/EIS-0089, U.S.
     Department of Energy, Washington, D.C.
DOE, 1987, Final Environmental Impact Statement:  Disposal of Hanford Defense
     High-Level, Transuranic and Tank Wastes, Hanford Site, Richland,
     Washington, 5 vols, DOE/EIS-0113, U.S. Department of Energy,
     Washington, D.C.
DOE, 1989, General Design Criteria, DOE Order 6430.1A, U.S. Department of
     Energy, Washington, D.C.
DOE, 1990, Environmental Assessment:  Collecting Crust Samples from Level
     Detectors in Tank 101-SY at the Hanford Site, DOE/EA-0479, U.S.
     Department of Energy, Richland, Washington.
DOE, 1991a, Unreviewed Safety Questions, DOE Order 5480.21, U.S. Department of
     Energy, Washington, D.C. 
DOE, 1991b, Environmental Assessment:  Characterization of Tank 241-SY-101,
     Hanford Site, Richland, Washington, DOE/EA-0511, U.S. Department of
     Energy, Richland, Washington.
DOE, 1991c, Environmental Assessment:  Upgrading of the Ventilation system at
     the 241-SY Tank Farm, Hanford Site, Richland, Washington, DOE/EA-0581,
     U.S. Department of Energy, Richland, Washington.
DOE, 1991d, Environmental Assessment:  Preparation for Crust Sampling of
     Tank 241-SY-101, Hanford Site, Richland, Washington, DOE/EA-0495,
     U.S. Department of Energy, Richland, Washington.
DOE, 1991e, Environmental Assessment:  Vapor Space Sampling of Ferrocyanide
     Tanks, Hanford Site, Richland, Washington, DOE/EA-0533, U.S. Department
     of Energy, Richland, Washington.
DOE, 1992a, U.S. Department of Energy High-Level Waste Storage Tank Safety
     Issues Report, Rev. 4, DOE High-Level Waste Tank Working Group, November
     30, U.S. Department of Energy, Washington, D.C.
DOE, 1992b, Environmental Assessment for Tank 241-SY-101 Equipment
     Installation and Operation to Enhance Tank Safety, DOE/EA-0802,
     U.S. Department of Energy, Washington, D.C.
DOE, 1992c, Environmental Assessment for Proposed Pump Mixing Operations to
     Mitigate Episodic Gas Releases in Tank 241-SY-101, DOE/EA-0803,
     U.S. Department of Energy, Washington, D.C.
DOE, 1992d, Environmental Assessment:  Intrusive Sampling and Testing of
     Ferrocyanide Tanks, Hanford Site, Richland, Washington, DOE/EA-0596,
     U.S. Department of Energy, Washington, D.C.
DOE, 1992e, Environmental Assessment:  Thermocouple Tree System Installation
     and Operation in Non-Leaking Ferrocyanide Tanks, DOE/EA-0809, U.S.
     Department of Energy, Richland, Washington.
DOE, 1993, Environmental Assessment:  Tank 241-C-103 Organic Vapor and Liquids
     Characterization and Supporting Activities, Hanford Site, Richland,
     Washington, DOE/EA-0881, U.S. Department of Energy, Richland, Washington.
Duffy, L. P., 1990, "Ferrocyanide Studies," (Memorandum to J. D. Wagoner,
     October 3), U.S. Department of Energy, Washington, D.C.
Ecology, EPA, and DOE, 1992, Hanford Federal Facility Agreement and Consent
     Order, 2 vols., as amended, Washington State Department of Ecology,
     U.S. Environmental Protection Agency, and U.S. Department of Energy,
     Olympia, Washington.
ERDA, 1975, Final Environmental Statement:  Waste Management Operations,
     Hanford Reservation, Richland, Washington, 2 vol.,  ERDA-1538, U.S.
     Energy Research and Development Administration, Washington, D.C.
GAO, 1990, Consequences of Explosion of Hanford's Single-Shell Tanks are
     Understated, GAO/RCED-91-34, U.S. General Accounting Office, Washington,
     D.C.
Harmon, H. D., 1993, "Planned Work Activities for Tank 241-SY-103,"
     (Memorandum to J. H. Anttonen, Letter 9304164B R1, October 5),
     Westinghouse Hanford Company, Richland, Washington.
NCHS, 1988, Vital Statistics of the United States 1985, Volume II - Mortality,
     National Center for Health Statistics, U.S. Department of Health and
     Human Services, Hyatsville, Maryland.
PNL, 1986, Potential Radiological Impacts of Upper-Bound Operational Accidents
     During Proposed Disposal Alternatives for Hanford Defense Waste, PNL-
     5356, Pacific Northwest Laboratory, Richland, Washington.
PNL, 1993a, Hanford Cultural Resources Laboratory Annual Report 1992, PNL-
     8676, Pacific Northwest Laboratory, Richland, Washington.
PNL, 1993b, Hanford Site Environmental Report 1992, PNL-8682, Pacific
     Northwest Laboratory, Richland, Washington.
Public Law 101-510, "Safety Measures for Waste Tanks at Hanford Nuclear
     Reservation," Section 3137 of National Defense Authorization Act for
     Fiscal Year 1991, 42 U.S.C. 7274, et seq., November 5, 1990.
WAC 173-303, 1990, "Dangerous Waste Regulations," Washington Administrative
     Code, as amended.
Wagoner, J. D., 1993, "Secretary of Energy's Safety Initiatives," (Memorandum
     to T. P. Grumbly, Letter TWS:DJS 93-TWS-043, November 1), Westinghouse
     Hanford Company, Richland, Washington.
WHC, 1993a, Quarterly Report on Defense Nuclear Facilities Safety Board
     Recommendation 90-7 for the Period Ending March 31, 1993, WHC-EP 04748,
     Westinghouse Hanford Company, Richland, Washington
WHC, 1993b, Summary of Radioactive Solid Waste Received in the 200 Areas
     During Calendar Year 1992, WHC-EP-0125-5, Westinghouse Hanford Company,
     Richland, Washington.
WHC, 1993c, Safety Assessment for Interim Stabilization of Ferrocyanide Tanks,
     WHC-SD-WM-SAD-018, Rev. 2, Westinghouse Hanford Company,
     Richland, Washington.
                                    Figures
  Figure (Page F-1  Figure 1.  Single-Shell and Double-Shell Tank Configurations.) 
Figure (Page F-2 Figure 2. Hanford Site.)

Appendix A

                    Projected Tank Farm Safety Activities,
                      Hanford Site, Richland, Washington
                        Projected Tank Farm Activities
                      Hanford Site, Richland, Washington
                                                          Fiscal Year/Number of Tanks 
                 Activities
                                           1994   1995   1996   1997   1998   1999   2000   2001 
             Flammable Gas Tanks                                                             
 1. Install mixer pumps                              1      2      1      1             1    
 2. Install standard hydrogen monitors        14     9                                       
 3. Install ammonia monitors                  3      3                                       
 4. Take auger samples                        2                                              
 5. Install surface-level devices             3      3                                       
 6. Remove specific gravity probe             1                                              
 7. Install video cameras                     3      2      1                                
 8. Install Multi-Function Instrument         2      2      1                                
    Trees
 9. Install ventilation upgrades              3      7                                       
10. Deploy retained gas sampler                      2      2      2                         
11. Install void fraction meter               1                                              
12. Install multi-port riser                  1                                              
              Ferrocyanide Tank                                                              
 1. Vapor sample for thermocouple             15                                             
    installation
 2. Install thermocouple trees                9      3                                       
 3. Neutron probe support                     1                                              
 4. Install moisture monitoring upgrades             6     12                                
 5. Perform infrared scanning                                             18          
                     Projected Tank Farm Safety Activities
                      Hanford Site, Richland, Washington
                                                              Fiscal Year/Number of Tanks 
                   Activities
                                               1994   1995   1996   1997   1998   1999   2000   2001 
                 Organic Tanks                                                                   
 1. Dip sample Tank 241-C-103                     1                                              
 2. Vapor sample for thermocouple                 6      3                                       
    installation
 3. Install thermocouple trees                    4      5                                       
 4. Remove liquid organic layer                          1                                       
 5. Take auger sample                                    1                                       
    High-Heat Tank                                                                  
 1. Install video camera                                 1                                          
    Toxic Vapors                                                                   
 1. Flammability sampling for Tank 241-C-103      1                                              
 2. Nitrile sampling                              1                                              
 3. Vapor sampling                                17    19                                       
 4. Install vapor treatment system                       1                                       
    Nuclear Criticality                                                               
 1. Install nuclear criticality monitoring                                    1      2           
    equipment
                Hydroxide Control                                                                
 1. Install pH probe in Tank 241-AN-107           1                                              
 2. Install video camera in Tank 241-AN-107       1                                              
 3. Install caustic injection and mixer pump      1                                       
                    Projected Tank Farm Safety Activities,
                      Hanford Site, Richland, Washington
                                                          Fiscal Year/Number of Tanks 
                 Activities
                                               1994   1995   1996   1997   1998   1999   2000   2001 
 1. Push-mode core samples                      6      15     36                                 
 2. Rotary core samples                         6      32     28                                 
 3. Auger samples                               12     8      6                                  
 4. Grab samples                                20     30     30                          

Appendix B

                   Accident Scenario Consequence Conclusions
                                     from
               Finding of No Significance Impact Determinations
                Accident Scenario Consequence Conclusions from
               Finding of No Significance Impact Determinations
Environmental Assessment:  Collecting Crust Samples from Level Detectors in
Tank 101-SY at the Hanford Site, DOE/EA-0479, U.S. Department of Energy,
Richland, Washington (DOE 1990).
      Based on the analyses provided in the Safety Evaluation, the U.S.
Department of Energy has concluded that the likelihood of an accident would be
low based on past experience.  The offsite whole body doses due to a
postulated bounding accident would be less than 3 roentgen equivalent man
(rem).  Exposure to operators equipped with the required respiratory
protection would result in doses less than 5 rem.  Therefore the accident risk
posed by the proposed actions is small.  In addition, operating conditions
would be imposed, which would further lessen the doses from, or likelihood of,
an accident.
Environmental Assessment:  Characterization of Tank 241-SY-101, Hanford Site,
Richland, Washington, DOE/EA-0511, U.S. Department of Energy,
Richland, Washington (DOE 1991b).
      Dose consequences were calculated for a variety of reasonably
foreseeable accident scenarios.  Based on tests conducted using simulated tank
contents, auger sampling of the crust would result in temperatures well below
that necessary to cause a secondary crust reaction.  The analysis concludes
that a crust reaction would not occur in this scenario.  For the remaining
scenarios, the consequence analysis assumes that only minor crust reaction
would occur.  In a postulated scenario involving ignition of dome space gas in
Tank 241-SY-101, while obtaining a sample, the maximum dose to workers
involved with the proposed action was 11 rem Effective Dose Equivalent (EDE),
and the maximum doses elsewhere onsite and offsite EDE were 0.75 rem and
1.2 x 10-3 rem, respectively.  The consequences of other postulated accidents
are bounded by this scenario.
Environmental Assessment:  Upgrading of the Ventilation system at the 241-SY
Tank Farm, Hanford Site, Richland, Washington, DOE/EA-0581, U.S. Department of
Energy, Richland, Washington (DOE 1991c).
      The most significant hazard is the potential for a gas release from Tank
241-SY-101 during the installation process that could contain up to 1.3
percent (volume) ammonia in the immediate vicinity of the tank, (i.e., in gas
that might potentially be released through a tank riser, such as 7B, into the
work area above the dome, while the portable exhauster is being replaced by
the filtered air inlet).  This concentration, if inhaled, could result in a
"high mortality rate" per the National Research Council Subcommittee on
Ammonia.  The number of workers in the work area would be minimized in
accordance with As Low As Reasonably Achievable.
Environmental Assessment:  Vapor Space Sampling of Ferrocyanide Tanks,
DOE/EA-0533, U.S. Department of Energy, Washington, D.C. (DOE 1991d).
      A review of the proposed actions was provided in a Safety Assessment
(SA) to determine if a spark or static buildup, crust disturbance, or
contamination spread could occur.  Evaluations included determining the
potential for loss of ventilation, a gas release event occurring during
sampling, a spark being introduced during the insertion of the gas monitoring
probes, a heated probe surface due to friction, unintended drop of the
samplers, sampling causing a gas release event, and others.  Consequences for
each of these hazards were discussed and it was concluded that the likelihood
of any of these occurrences range from 1.0 x 10-2 to 1.0 x 10-6.  The onsite
and offsite whole body doses due to a postulated severe accident were less
than 1 millirem.  The operator doses are no more than 45 millirem (assuming no
respiratory protection.  Therefore the risk posed by this operation is
considered to be very small).
Environmental Assessment:  Vapor Space Sampling of Ferrocyanide Tanks, Hanford
Site, Richland, Washington, DOE/EA-0533, U.S. Department of Energy, Richland,
Washington (DOE 1991e).
      Four potential accident scenarios that could occur during conduct of the
proposed action and could result in a release of radioactive material were
considered.  These scenarios include (1) a vapor space fire; (2) saltcake
combustion; (3) ferrocyanide reaction; and (4) contamination of the sampling
assembly.  The probabilities for these events to occur and result in
radioactive releases as a result of the proposed action were calculated, to be
less than 1.0 x 10-7, 1.0 x 10-8, 1.0 x 10-8, and 1.0 x 10-6, respectively.  The
potential consequences of a vapor space fire, saltcake combustion, and
ferrocyanide reaction could be catastrophic.  These consequences, however,
would be the same or less than those of a ferrocyanide explosion (Section
5.2.7, Maximum Reasonably Foreseeable Accident).
      It is possible for a gas release event to occur during a "window,"
although it is estimated that approximately one-half of the tank gas inventory
is vented during the major release event that precedes the relatively
quiescent "window" period.  Thus, the gas release volume is expected to be
much smaller if it occurs during a window, with a corresponding reduction in
radiological release and ammonia concentration.  The value of 1.3 percent
ammonia is stated as a maximum tank dome concentration in the unlikely event
of a gas release during window operations, and is derived from tank
ventilation-dilution of a computed maximum of 4 percent ammonia that might
emanate from the tank surface in a major release.
      As discussed in the SA for this operation, all operating personnel in
the vicinity of the tank farm would be equipped with respirators and other
safety equipment.  Offsite consequences were not specifically calculated
because they would be substantially less than onsite consequences (i.e.,
greater than 100 meters (328 feet) from the tank farm) which were found to be
minimal.
      The other hazard is the potential for spark generation in the riser due
to installation activities (caused by removal of the riser cap or installation
of the temporary covers) that could ignite hydrogen during a tank venting
occurrence.  The probability of a spark igniting hydrogen in a riser is
1.0 x 10-7 per year.  If this event should occur, the operator EDE would be
less than 45 millirem, and doses to maximally exposed individuals (MEI), both
onsite and offsite, would be less than 1 millirem.  It should be understood
that this scenario only postulates a local accumulation of hydrogen in the
riser itself as the high point in the tank dome.  The bulk of the vapor space
is below the flammability limit as shown by the online hydrogen monitor in the
ventilation exhaust line (i.e., the riser would not be opened unless this were
the case).  In addition, upon removal of the riser cap, hydrogen would be
purged from the riser by in-flowing air due to the negative pressure normally
maintained in the dome space.  The riser cover would be bonded to the tank to
prevent static charges.  Only spark-resistant tools would be used except for
the initial loosening (not removing) of the bolts and the final tightening of
the bolts.
      A second potential for spark generation occurring as a result of working
on a riser would be the dropping of a tool into the tank.  Based on extremely
conservative set of assumptions regarding impact energy concentration and
local accumulation of flammable gas, two release scenarios were evaluated. 
The worker dose consequences from these dropped object scenarios were 45
millirem and 5 millirem, respectively.  The corresponding onsite and offsite
MEI doses were both estimated at less than 1 millirem.
      If, during installation, the riser for the inlet filter or the exhaust
header was left open too long while flow also was entering the tank through
the inlet flow paths in the pump pit, the tank pressure may reach atmospheric
pressure.  This also was possible if the backup exhaust fan fails while the
exhaust header work is being performed.  The worker dose would be less than 5
millirem, and the onsite and offsite MEI dose would be less than 1 millirem.
Environmental Assessment for Tank 241-SY-101 Equipment Installation and
Operation to Enhance Tank Safety, DOE/EA-0802, U.S. Department of Energy,
Washington, D.C. (DOE 1992b).
      The Environmental Assessment (EA) analyzed a variety of reasonably
foreseeable accidents that could occur as a result of the proposed action. 
The major concerns are related to potential worker exposure to radioactivity
or toxic gases, and to the potential for spark generation resulting in
ignition of flammable gas and subsequent release of radioactivity.
      The risks associated with worker exposure to toxic gases, such as
ammonia, are very small because the probability of toxic gas release during a
window is small (annualized probability of 1.0 x 10-4), and because
immediately dangerous concentrations of toxic gases would not occur.  Workers
near the tank would be wearing protective respiratory equipment that would
further minimize the risk.
      The consequences of dropping equipment outside the tank also were
considered in the EA.  The onsite MEI would receive an EDE of 2.2 rems; other
workers onsite would receive a maximum dose of 1.5 x 10-2 rem; and the maximum
dose to an individual offsite would be 2.3 x 10-5 rem.  No adverse health
effects would be expected to result from this accident.  The annualized
probability that such an equipment drop would occur is estimated as
1.0 x 10-4.
      The risks associated with an accident resulting in a gas ignition and
burn during the proposed action with the ventilation system operable also were
analyzed, and would be small.  The annualized probability that this event
would occur is estimated as 3.6 x 10-6.  The doses from such an accident would
be an EDE of 3.9 rem to a worker in the 241-SY Tank Farm and 0.0013 rem to the
offsite MEI.  No latent cancer fatalities (LCF) would be expected to result. 
Ammonia gas releases would be minimal.  The risks associated with accident
sequences involving a gas ignition and burn during  a period when the
ventilation system is inoperable were considered in the EA, and would be
extremely low because the estimated probability of occurrence is on the order
of 1.0 x 10-10 and the resulting doses would be similar to those estimated for
a burn with the ventilation system operable (Section 5.2.7, Maximum Reasonably
Foreseeable Accident).
Environmental Assessment for Proposed Pump Mixing Operations to Mitigate
Episodic Gas Releases in Tank 241-SY-101, DOE/EA-0803,
U.S. Department of Energy, Washington, D.C. (DOE 1992c)
      A wide range of reasonably foreseeable accidents that would not result
in a gas detonation were considered and analyzed in the EA and SA.  The
consequences of a gas detonation were considered in the EA but not quantified
in the SA, and would be significantly greater than the consequences for the
other scenarios considered in the EA and SA.  A gas detonation would be the
maximum reasonably foreseeable accident (Section 5.2.7, Maximum Reasonably
Foreseeable Accident).
      The non-detonation accident sequences analyzed included potential
material spills, equipment drops, unfiltered releases from open risers, and a
range of potential ignition scenarios that would not result in a detonation. 
Based on a conversion factor of 5.0 x 10-4 LCF per person-rem, the estimated
offsite LCF that could result from radiological releases associated with the
non-detonation accident scenarios vary with the accident sequence from 1.5 x
10-5 (for a spill during removal, with estimated annual probability of
occurrence of 5.0 x 10-3) to 3.4 x 10-2 (for a gas ignition, with estimated
annual probability of occurrence of 1.0 x 10-7), corresponding to population
doses of 0.03 and 68 person-rem, respectively.  The corresponding exposures to
individual tank farm workers would range from about 6 millirem for the spill-
during-removal scenario (largest probability of occurrence) to about 12.5 rems
for the ignition scenario.  The respective probabilities of inducing a LCF
associated with these individual exposures are 3 x 10-6 and 6 x 10-3.
      As indicated, the accident sequence with highest probability of
occurrence would be a small accidental spill of radioactive liquids during
equipment removal and flushing activities.  However, because of the non-
volatile form of the radionuclides, such a spill would not constitute an
airborne hazard to workers outside the immediate area of the spill.  Workers
in the immediate area would be protected with anti-contamination clothing and
breathing filters, and would immediately cleanup any spill using established
tank farm practices.
      No onsite or offsite health effects are expected to result from exposure
to toxic  gases during any of these accident sequences because the maximum
exposures to the species of greatest concern, ammonia, would be only slightly
above the health threatening level (i.e., 500 parts per million) and the
exposures would be short (several minutes).
      The maximum reasonably foreseeable accident sequence is the highly
unlikely gas detonation event with an estimated probability of occurrence of
less than 1.0 x 10-6 per year under current conditions.  The gas detonation
accident sequence discussed below could occur independently of the proposed
action.  The proposed action has the potential to slightly increase the
likelihood that the gas detonation accident sequence would occur because the
pump could generate a larger gas release than would be expected for the no
action alternative.  Although the DOE cannot quantify the probability of a
larger gas release, the probability of a detonation of such a release would
remain highly unlikely.  The relative probability of a detonation, between the
proposed action and the no action alternative, depends on the likelihood of
the pump test succeeding in limiting the hydrogen concentration in the tank
dome space to below the lower flammability limit (LFL) during the pump test. 
DOE conceived and designed the proposed pump mixing test with the expectation
that it would be successful in limiting flammable gas concentrations, but this
likelihood cannot be quantified in absolute terms at this time.  Failure of
the pump to limit hydrogen concentrations to below the LFL would not
necessarily result in an increased probability of a detonation.
      The EA indicates that the pressures resulting from a detonation could
exceed, by a factor of two or more, the pressures that have been found to be
structurally limiting in Tank 241-SY-101.  This means that a detonation,
should it occur, could be expected to cause tank failure and result in
consequences more severe than those discussed above for the non-detonation
scenarios.
      The Final Environmental Impact Statement:  Disposal of Hanford Defense
High-Level, Transuranic and Tank Wastes, Hanford Site, Richland, Washington
(HDW-EIS) projected that the maximum reasonably foreseeable accident
associated with the High-Level Waste (HLW) management operations would be an
explosion of a ferrocyanide-containing waste tank.  The risks associated with
an explosive detonation of flammable gas in Tank 241-SY-101 are similar to
those estimated for the maximum reasonably foreseeable accident in the HDW-EIS
in that there is a very low likelihood of occurrence, and, although there is
uncertainty regarding the consequences, the consequences would be
catastrophic.
      The HDW-EIS projected that a HLW tank explosion would result in a short-
term radiation dose to the maximally exposed member of the public of 200
millirem, and an offsite collective dose commitment of 7,000 person-rem.  Such
an explosion would be expected to result in 4 offsite LCFs, the contamination
of a substantial area of land, and significant doses to workers.
      However, a 1990 General Accounting Office (GAO) study estimated that the
consequences of this event could be 10 to 100 times greater than those
projected in the HDW-EIS.  Although the GAO study did not reach a conclusion
regarding the probability of a tank explosion, an independent DOE expert
review panel judged the probability of such an explosion to be low.
Environmental Assessment:  Intrusive Sampling and Testing of Ferrocyanide
Tanks, Hanford Site, Richland, Washington, DOE/EA-0596,
U.S. Department of Energy, Washington, D.C. (DOE 1992d).
      Four potential accident scenarios associated with the conduct of the
proposed actions were considered.  These scenarios, along with the annual
probability of occurrence associated with each postulated accident are:  (1)
spark-caused fire (1.0 x 10-9); (2) salt cake combustion due to impact
(1.0 x 10-9); (3) toxic gas release (1.0 x 10-5); and (4) sample container drop
outside tank (1.0 x 10-4).  The consequences of a spark-caused fire and/or a
salt cake combustion due to impact as a result of the proposed action could be
potentially catastrophic.  However, similar consequences (and conclusions)
regarding these consequences were reached in this Environmental Assessment,
and are addressed in Section 5.2.7.  
      In the scenario involving the drop of the sample container outside of
the tank, the SA calculated a probability of 1.0 x 10-4 of spilling the sample
contents.  In estimating the consequences of such an accident, it was
calculated that the worker operating the core drill truck (onsite MEI) would
receive an annual EDE of 0.29 rem and an organ dose equivalent annual
occupational limit of 50 rem.  Other personnel in the tank farm area would be
expected to receive much smaller doses due to dispersion, evacuation, and the
fact that not all of the release would be respirable.  Here again, no adverse
public health consequences are expected to result from this accident, because
the expected doses to offsite individuals would be very small. 
Environmental Assessment:  Thermocouple Tree System Installation and Operation
in Non-Leaking Ferrocyanide Tanks, DOE/EA-0809, U.S. Department of Energy,
Richland, Washington (DOE 1992e)
      The EA considered a range of reasonably foreseeable accident scenarios
associated with the proposed action that could result in a release of
radioactive material or toxic gases.  The accident scenarios and annualized
probabilities of occurrence are summarized as (1) transitory gas release of
2.2 x 10-9; (2) tree drop and tank penetration  of less than 1.0 x 10-6; and
(3) organic carbon combustion of less than 1.0 x 10-6.
      In the transitory gas release scenario, a seismic event is postulated to
occur during installation of the thermocouple trees (TCT), releasing
significant quantities of flammable gas trapped in the sludge.  The maximum
reasonably foreseeable seismic event is assumed to cause a TCT to swing into a
riser and cause a spark, initiating a vapor space fire.  The estimated
annualized probability of this accident occurring during installation of the
TCTs is 2.2 x 10-9.  Weaker seismic events would not result in tank releases. 
The consequences of a transitory gas release and vapor space fire would be no
greater than a ferrocyanide explosion (Section 5.2.7, Maximum Reasonably
Foreseeable Accident).
      In the TCT drop and tank penetration scenario, a TCT is postulated to
drop during installation, punching a hole in the tank bottom.  All drainable
liquid in the tank is assumed to discharge to the soil column beneath the
tank.  The annualized probability that this would occur is estimated to be
less than 1.0 x 10-6.  This probability is based on implementing the control
features specified in the SA.  The maximum reasonably foreseeable radioactive
release would occur if Tank 241-C-112 were punctured, resulting in a potential
release of 3,500 curies, which is contained in 1.2 x 105 liters (32,000
gallons) of tank liquid.  The EA concludes that the radioactive material would
be retained within the first 30.5 meters (100 feet) of soil beneath the tank,
and would remain at least 61 meters (200 feet) above the groundwater level.  A
leak in Tank 241-C-112 would not result in radiological exposures to onsite
personnel or offsite individuals.  Such a release would add to the volume of
soil that would require future cleanup.  Based on these consequences and the
very low probability of occurrence, the risks associated with this potential
accident are low.
      The scenario involving organic carbon combustion is concerned with only
one ferrocyanide tank, Tank 241-TX-118.  This tank has a predominance of
nitrate and nitrite saltcake, and relatively high organic carbon and plutonium
contents.  In this scenario, the TCT installation triggers a self-combustion
of organic carbon and nitrate or nitrites.  The EA notes that, assuming that
the organic carbon constituents are evenly distributed, the calculated organic
carbon concentration in Tank 241-TX 118 is below the concentration limit
believed to be required for self-combustion.  The EA estimates that the annual
probability of occurrence of this accident scenario is less than 1.0 x 10-6,
and concludes that the consequences of organic carbon combustion would be
similar to those projected in the Final Environmental Impact Statement: 
Disposal of Hanford Defense High-Level, Transuranic and Tank Wastes (Section

5.2.7 for Maximum Reasonably Foreseeable Accident).

Environmental Assessment:  Tank 241-C-103 Organic Vapor and Liquids
Characterization and Supporting Activities, Hanford Site, Richland,
Washington, DOE/EA-0881, U.S. Department of Energy, Richland, Washington (DOE
1993).
      The EA analyzed a range of reasonably foreseeable accidents, including a
noxious or toxic gas release, a dip-sample bottle break outside the tank,
radiation exposure from a gas sampling tube, a lightning strike that ignites
organic vapors in the tank, and a vapor space fire and subsequent burn of the
liquid organic layer in the tank.  The accident with the highest probability
of occurrence (approximately 1.0 x 10-5) is the dip-sample bottle break, which
would increase worker exposure to radiation, but would not be expected to
result in any adverse health effects.
      The noxious or toxic gas release (probability 1.0 x 10-6) and radiation
exposure from gas sampling (probability 2.5 x 10-6) would not result in any
adverse health effects to workers due to the use of protective clothing and
supplied air in the vicinity of the sampling, and would have no impact on the
public.
      The remaining two accident scenarios involving ignition of flammable
materials in the tank each have an estimated probability of 1.0 x 10-6
(Section 5.2.7, Maximum Reasonably Foreseeable Accident). 
                       Finding of No Significant Impact
                 Waste Tank Safety Program at the Hanford Site
AGENCY:     U.S. Department of Energy
ACTION:     Finding of No Significant Impact
SUMMARY:    The U.S. Department of Energy (DOE) has prepared an Environmental
Assessment (EA), DOE/EA-0915, to assess potential environmental impacts of a
proposed action involving activities needed to resolve high-level radioactive
waste tank safety issues at the Hanford Site.  These activities would include
the installation, operation, maintenance, and removal of in-tank and external
monitoring devices and mitigation equipment; minor modification to ventilation
systems and other portions of the tank farm infrastructure; waste
stabilization; sampling for waste characterization; and removal of organic
waste form one high-level waste tank for storage in a no-high-level waste
tank.
Based on the evaluation in the EA, the DOE has determined that the proposed
action is not a major Federal action significantly affecting the quality of
the human environment within the meaning of the National Environmental Policy
Act (NEPA) of 1969, 42 U.S.C. 4321, et seq. Therefore, the preparation of an
environmental impact statement is not required.
Addresses and Further Information:
Single copies of the EA and further information about the proposed project are
available from:
      Mr. R. E. Gerton, Director
      Tank Waste Storage Division
      U.S. Department of Energy
      P.O. Box 550
      Richland, Washington 99352
      Phone:  (509) 376-9106
For further information regarding the DOE NEPA process, contact:
      Carol M. Borgstrom, Director
      Office of NEPA Oversight (EH-25)
      U.S. Department of Energy
      1000 Independence Avenue, S.W.
      Washington, D.C. 20585
      Phone:  (202)586-4600  or leave a message at (800)472-2756
Background: DOE has conducted radioactive waste management operations at the
Hanford Site for nearly 50 years.  Operations have included storage of high-
level radioactive waste in 177 underground storage tanks in both single-shell
tanks and double-shell tanks.  Many of the tanks and the equipment needed to
operate them are deteriorated.  Sixty-seven of the single-shell tanks are
presumed to have leaked.  Knowledge of the tank contents is incomplete and is
based primarily on historical operating records and limited sampling
information.
Safety issues associated with the waste include:  (1) flammable gas generation
and episodic release; (2) potentially explosive ferrocyanide-containing
wastes; (3) a potentially flammable or explosive floating organic solvent
layer in Tank 241-C-103; (4) nuclear criticality; (5) toxic vapors; (6) the
need for infrastructure upgrades; and (7) the need to pump liquids from
single-shell tanks that are assumed to be leaking (interim stabilization).
DOE needs to take action to accelerate resolution of waste tank safety issues
at the Hanford Site to reduce the risks associated with operations and
management of the waste tanks, to respond to Congressional concerns about the
safety of Hanford tank operations as reflected in Public Law 101-510, to meet
Resource Conservation and Recovery Act (RCRA) analytical data requirements,
and to meet characterization commitments contained in the Hanford Federal
Facility Agreement and Consent Order, more commonly known as the Tri-Party
Agreement.
Proposed Action:  The proposed action would include general and specific waste
tank characterization and mitigation activities, and minor facility
modifications, at the Hanford Site.  These activities would include the
installation, operation, maintenance, and removal of in-tank and external
monitoring devices and mitigation equipment (including thermocouples, multi-
function instrument trees, liquid observation wells, various types of probes,
surface level detectors, video cameras, infrared scanners, sludge weights, air
lances, and various types of equipment designed to mitigate the buildup of
flammable gases in waste tanks); sampling for waste characterization; minor
modifications to ventilation systems and other portions of the tank farm
infrastructure; interim stabilization of single-shell tanks suspected of
leaking by pumping liquids to secure double-shell tanks;  and removal of the
layer of organic waste from Tank 241-C-103 to a tanker truck or a non-high-
level waste tank for storage.  Before the proposed activities are conducted,
DOE would review or prepare appropriate safety and environmental documentation
to ensure that the activities can be conducted safely and the potential risks
were evaluated in the EA.
Alternatives considered:  A no-action alternative was considered that would
consist of continuing ongoing tank farm operations.  Under that alternative
DOE would not gather the information needed to resolve waste tank safety
issues at Hanford.
DOE also considered alternative strategies involving less intrusive techniques
for resolution of tank safety issues.  For example, DOE considered
characterization using solely non-intrusive methods such as calculations based
on historical process knowledge, and laboratory simulants.  DOE also
considered minimizing intrusive operations (e.g., monitoring without intrusive
characterization activities).  These alternative strategies were not
considered viable, because new in-tank data are required to validate the
theoretical projections that would be derived from the information produced by
the non-intrusive alternatives.  No other reasonable methods of addressing
DOE's tank safety issues were identified.
Environmental impacts:  Routine conduct of the proposed activities would not
result in any increase in tank emissions.  Before beginning the proposed
activities, appropriate procedures and administrative controls would be in
place to maintain radiation exposure to workers and other onsite personnel
within requirements of DOE Orders and as low as reasonably achievable. 
Radiation and hazardous chemical levels at the sample riser and exposure of
the workers would be monitored.  Gas sampling of each tank's vapor space would
be conducted, as appropriate, to assure that no flammable gases greater than
20 percent of the lower flammability limit (LFL) are present.  Gas samples
would be obtained from a riser test port, which is isolated from the
environment by a high-efficiency particulate air filter.  If flammable gas
levels above 20 percent of the LFL are detected, the proposed activities would
no be performed in the tank unless additional evaluations show that flammable
gas concentrations are at safe levels.  Additional safety controls (such as
electrical grounding, spark resistant tools, vapor space purging, and the use
of protective clothing and/or supplied air) also would be utilized when
appropriate.
During routine conduct of the proposed activities, potential radiological
doses to  members of the public and workers performing the work would be
extremely small, and are not expected to result in any health effects.  The
risks to workers from chemical exposures, burns and other common industrial
hazards are expected to be low , and would be minimized by training and the
use of appropriate personal protective equipment.
Small quantities of low-concentration hazardous wastes, such as solvents and
cleaning agents, would be generated as a result of the proposed action.  Such
wastes would be managed at existing Hanford Site facilities in accordance with
all applicable requirements.
Cumulative impacts:  The proposed tank farm operation would not have a
substantial cumulative effect on day-to-day operations on the Hanford Site
with respect to worker exposure.  The incremental impact of handling the
increased amount of radioactive an non-radioactive materials would be very
small.  When added to the impacts from day-to-day operations on the Hanford
Site and surrounding community, the total impact also would remain very small. 
The proposed activities are expected to slightly increase the potential risk
of tank accidents in the short-term, but resolution of tank safety issues
would minimize the potential for tank accidents in the long-term.
Impacts from potential accidents:   The EA considered a range of reasonably
foreseeable accident scenarios associated with the proposed action that could
result in a release of radioactive material or toxic gases.  These include a
range of low probability, high consequence events and relatively higher
probability, lower consequence events.  Events with a relatively higher
probability include a pumping system break (probability of 1.4 chances in
1,000 per year) or a hydrogen ignition during interim stabilization operations
(probability of between 1 chance in 100 to 1 chance in 10,000 per year), a
spill during removal of a sample (probability of 5 chances in 100,000 per
year), and a release of toxic vapors (probability of 1 chance in 10,000 per
year).  None of these more probable events would be expected to have any
adverse health impacts on either workers or members of the public.
More severe accidents such as ignition of flammable gas within a tank
(probability of 1 chance in 10,000,000 year) and the maximum reasonably
foreseeable accident, detonation of Tank 241-SY-101 (probability of less than
1 chance in 1,000,000 per year) were also analyzed.  The consequences of the
maximum reasonably foreseeable accident would be no greater than those
projected for a ferrocyanide tank explosion in the 1987 Environmental Impact
Statement, Disposal of Hanford Defense High-Level, Transuranic and Tank
Wastes, (DOE/EIS-0013).  The 1987 EIS projected that such an explosion would
result in a short-term radiation dose of 200 millirems to the maximally
exposed member of the public, and an offsite collective dose of 7,000 person-
rem.  Such an explosion would be expected to result in 4 offsite latent cancer
fatalities, the contamination of a substantial area of land, and large doses
to workers.  A 1990 General Accounting Office study estimated that the
consequences of the ferrocyanide tank explosion could be 10 to 1000 times
greater than those projected in the 1987 EIS.  The GAO study did not reach a
conclusion regarding the probability of a tank explosion.  Even if the severe
consequences of a ferrocyanide tank explosion projected by the GAO are
assumed, in view of the extremely low probability of occurrence for the most
severe accidents that the proposed action could cause , the risks posed to the
environment and human health by this potential accident are small.
Determination:    Based on the analysis in the EA, and after considering the
preapproval review comments of the State of Washington, the Confederated
Tribes of the Umatilla Indian Reservation, and the Yakama Indian Nation, I
conclude that the proposed activities to address the DOE's safety initiatives
do not constitute a major Federal action significantly affecting the quality
of the human environment within the meaning of NEPA.  Therefore, an EIS for
the proposed action is not required.
Issued at Washington, D.C., this 25th day of February, 1994.
                  signature --  ??
                       for      Tara O'Toole, M.D., M.P.H.
                                Assistant Secretary
                                Environment, Safety and Health



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