EA-1112; Environmental Assessment and FONSI Sludge and Solid Residue Stabilization at The

The Department of Energy (DOE) desires to continue to reduce worker exposure to radiation at the Plutonium Finishing Plant (PFP), located on the Hanford Site, Richland, Washington. This exposure is reduced incrementally as sludges and residues remaining in process areas are removed, stabilized and moved to vault storage.

The DOE also desires to accelerate stabilization of plutonium-bearing materials stored in existing vaults at the PFP in accordance with WHC-EP-0853, the Hanford Site Integrated Stabilization Management Plan (SISMP), in response to Defense Nuclear Facility Safety Board (DNFSB) Recommendation 94-1.

Information previously generated in approved document DOE/EA-0978 (Sludge EA), AEnvironmental Assessment: Sludge Stabilization at the Plutonium Finishing Plant,@ is incorporated by reference into this Environmental Assessment (EA)> The proposed action in this EA is an extension of the action analyzed in the Sludge EA.

This EA evaluates the proposed action to install and operate up to nine (9) additional laboratory-size muffle furnaces within three to five glovebox enclosures located in the Plutonium Finishing Plant (PFP), Hanford Site, Richland, Washington, while continuing operation of the two muffle furnaces now operating in accordance with the Sludge EA. In addition, the proposed action would allow stabilization of additional chemically reactive sludges and solid residues beyond those allowed via the Sludge EA.

Alternatives to the proposed action considered in this EA include No Action, Disposal, Processing, Offsite Treatment and Storage, and Slow Stabilization. The Disposal Alternative would dispose of the proposed sludges and residues in a retrievable waste form awaiting a final decision regarding the ultimate disposition of plutonium-bearing materials. The Processing Alternative would operate the Plutonium Reclamation Facility (PRF) and a portion of the Remote Mechanical C (RMC) Line to solidify and partially stabilize sludges and residues, using muffle furnaces to complete the stabilization. J The Offsite Treatment and Storage Alternative would involve transport of the sludges and residues to an offsite location for stabilization and subsequent storage. The Slow Stabilization Alternative consists of operating the two existing muffle furnace to eventually stabilize the proposed amount of sludges and residues.

Environmental Impact Statement (EIS) DOE-EIS/0244 is in preparation to analyze the proposed stabilization of the PFP and plutonium bearing materials located at the PFP. The Notice of Intent was published in October 1994, and the Record of Decision (ROD) is anticipated in June 1996. The proposed action to add more furnaces and continue stabilization of sludges and process residues would be an interim action pending completion of the PFP Stabilization EIS analysis and its associated ROD.

The design of the proposed additional muffle furnaces would be very similar to the existing furnaces described in the Sludge EA. The total of up to eleven muffle furnaces would be used to stabilize 1400 to 1600 batches of chemically reactive sludges and some residues that contain an approximate total of 184 kilograms (405 pounds) of plutonium in a total bulk weight of approximately 1130 kg (2485 pounds). The heating sequence would be similar to that used for the existing two furnaces. The uncertainty in the number of batches is due to the varying plutonium content of sludges to be collected from process areas, an assumed recycle rate and other factors. The resulting stable powder, an impure plutonium oxide, would be stored in the PFP vaults. There is sufficient capacity in PFP vaults to accept this material.

The sludges and some residues to be stabilized will be cleaned from the interiors or process equipment during ongoing and near-term clean out actions. Other solid residues to be stabilized are currently in vault storage at PFP. Stabilization of these sludges and residues is consistent with ACriteria for Interim Safe Storage of Plutonium Bearing Solid Materials@, which were issued in October 1995 as an addendum to the DNFSB Recommendation 94-1 Implementation Plan (DOE 1995b).

Under normal operating conditions, the total of 11 furnaces could generate up to a maximum of 5.5 times the amounts of gaseous butene, nitrogen oxides, carbon dioxide and water that are currently being generated by the two operating furnaces. These amounts are very small. The resulting maximum onsite and offsite concentrations from continuous emission of these chemicals out the plant stack would increase only slightly from the factor given in the Sludge EA for the applicable health standards. Radionuclide emissions would show a similar increase, but would remain small.

Approximately 0.05 cubic meters (2.5 cubic feet) of solid waste, per day, could be generated from disposal of storage containers and normal operational waste from activities such as material handling, removal of packaging and lab analyses.

Recent operation of two muffle furnaces along with associated activities has resulted in cumulative dose of just under 10 person-rem for 200 batches. This number can be used as a maximum for cumulative dose calculations, as PFP operators have found several methods of dose reduction which were put into effect well into the 1995 operation. At the expected maximum number of batches (approximately 1600), the maximum cumulative dose would be 80 person-rem for the duration of the stabilization action. This would result in an estimated health effect of approximately 0,032 LCF for the directly exposed workers. No fatal cancers are expected to be attributable to this exposure. No physical impact would result outside the plant from the postulated bounding accident.

The bounding accident postulated for this operation was determined to be a flammable gas (butene) deflagration [the same as the original assessment] inside the glovebox, which breaches the glovebox, and disperses 126 grams (0.28 pounds) of plutonium into the room. The probability for this accident is estimated to be less than 0.00001 occurrences per year. This postulated accident could result in 0.048 grams (0.001 pounds) of plutonium released from the plant stack which would have a health effect of 0.0015 LCF (3.75 person-rem) to the 140 exposed onsite population and 0.011 LCF (22 person-rem) to the 114,734 exposed offsite population. No offsite or onsite population fatal cancers are expected to be attributable to this exposure.

1.0 Purpose and Need for Agency Action

The Department of Energy (DOE) desires to continue to reduce worker exposure to radiation at the Plutonium Finishing Plant (PFP), located on the Hanford Site, Richland, Washington (see Figures 1 and 2). This exposure is reduced incrementally as sludges and residues remaining in process areas are removed, stabilized and moved to vault storage.

The DOE also desires to accelerate stabilization of plutonium-bearing materials stored in existing vaults at the PFP in accordance with the Implementation Plan (DOE 1995b) in response to Defense Nuclear Facility Safety Board (DNFSB) Recommendation 94-1 (Conway).

1.1 Background

Information previously discussed in DOE/EA-0978 (Sludge EA), AEnvironmental Assessment: Sludge Stabilization at the Plutonium Finishing Plant,@ is incorporated by reference into this Environmental Assessment (EA). The proposed action in this EA is an extension of the action analyzed in the Sludge EA (DOE 1994a).

Environmental Impact Statement (EIS) DOE-EIS/0244 is in preparation to analyze the proposed stabilization of the PFP and plutonium bearing materials located in the PFP. The Notice of Intent was published in October 9114, and the Record of Decision (ROD) is anticipated in June 1996. The proposed action to add more furnaces an continue stabilization of sludges and process residues would be an interim action pending completion of the PFP Stabilization EIS analysis and its associated ROD.

This proposed action is being addressed prior to the ROD in order to continue reduction of worker exposure. This action will provide stabilization of less than five (5) percent of the quantity of plutonium at the PFP. All methods of stabilization under consideration for the EIS action will result in similar final materials (impure plutonium oxide) as those resulting from operation of muffle furnaces. For these reasons, this proposed action would not limit the choice of reasonable alternatives for the EIS.

On February 28, 1995, DOE expressed a desire to accelerate clean out and stabilization of plutonium-bearing materials located in process areas of the PFP in response to DNFSB 94-1. In addition, DNFSB 94-1 recommends that plutonium-bearing materials currently stored in PFP secure vaults be evaluated against current requirements, ACriteria for Interim Safe Storage of Plutonium Bearing Solid Materials@, which were issued in October 1995 as an addendum to the DNFSB Recommendation 94-1 Implementation Plan (DOE 1995c). Containers of materials not meeting the criteria will be opened and stabilized, then repackaged before returning to storage. Stabilization of the materials include din the scope of the Sludge EA is nearly complete. Continued acceleration of thermal stabilization to meet the end date recommendation in DNFSB 94-1.

Figure 1. Location of the Hanford Site

Figure 2. Location of the Plutonium Finishing Plant (This figure is not to scale.)

2.0 Description of the Proposed Action

The proposed action would install and operate up to nine (9) additional laboratory-size muffle furnaces in the PFP, and continue to operate two existing muffle furnaces for thermal stabilization of reactive sludges and residues containing approximately 184 kilograms (405 pounds) of plutonium along with the other chemicals in mixtures of varying moisture content with a total estimated bulk weight of 1130 kilograms (2485 pounds). Once stabilized, the resulting impure estimated bulk weight of 1130 kilograms (2485 pounds). Once stabilized, the resulting impure plutonium oxide would be packaged and stored in existing secure vaults at the PFP.

The proposed action would be completed within two years. The total quantity of plutonium in the sludges and residues is less than five (5) percent of the total quantity of plutonium at the PFP.

The additional muffle furnaces would be installed in three to five glovebox enclosures. A combination of existing and replacement gloveboxes would be used, all located within existing radiation zone spaces within the PFP.

2.1 Sludge and Residue Stabilization

The DOE proposes to stabilize certain plutonium-bearing sludges and other process residues in similar fashion as previously discussed in the Sludge EA. The materials would be heated to drive off volatile components and convert the plutonium to solid, stable plutonium oxide (PuO₂). Other chemicals not driven off as vapors remain as stable impurities in the resulting solid. J The impure plutonium oxide would be packaged and stored in existing secure vaults at the PFP.

2.1.1 Residues in Vault Storage

The bulk of the residues to be stabilized in the interim action described in this EA is currently in vault storage at the PFP. These residues fall into two categories: a) reduction residues or sand, slag and crucible (SS&C), which consists of crucible pieces, cushioning sand and the slag which was formed during the reduction of PU fluoride powder into metal and b) partially stabilized ash, from Hanford and other DOE incinerators run in earlier decades to minimize waste volumes from plutonium production.

The residues in vault storage were stabilized in the past to meet previous criteria, and contain far less volatile or reactive components than sludges. Stabilization of these sludges and residues will be required to meet technical criteria (DOE 1995c) for material form, moisture content and safety aspects of the packaging system.

2.1.2 Sludges and Residues in Process Areas

The sludges and some residues to be stabilized remain in process equipment and enclosures, to be removed during routine clean out actions addressed in other NEPA analyses (see reference in Section 8). Most of these materials were generated during the last Plutonium Reclamation Facility (PRF) campaign in 1987, the final Remote Mechanical C Line (RMC) metal production campaign in 1989, and the 1993 PRF training run. A small portion of the sludges remain in Remote Mechanical A (RMA) Line equipment from historical operations.

These sludges are in the form of Aholdup@. Holdup is defined as material that has accumulated or been retained in PFP Facility gloveboxes, hoods, process equipment, piping, exhaust and ventilation systems, and the canyon as a result of years of operation at the facility. The holdup is on equipment and facility surfaces in PRF, on the canyon floor and in access gloveboxes; in RMS gloveboxes; in RMA gloveboxes; and in ductwork association with these process areas. As this material is not yet in containers, the bulk weight and total number of containers the sludges will occupy are uncertain= current estimated re 185 kg and 545 containers.

The locations and amounts of materials proposed for stabilization in accordance with this EAS are shown in Table 1 below.

Table 1.Estimated Additional PFP Sludges and Residues to be Stabilized via Muffle Furnace

Sources of Sludges and Residues	Condition	# Items	Bulk Wt (kg)	Pu Wt (kg)
Glovebox / Canyon Sludges	holdup	500	155	54
Ductwork Sludges	holdup	45	30	10
Reduction Residues (SS&C)	in storage	266	275	43
Ash	in storage	499	670	77
TOTALS		1310	1130	184

2.2 Process Description

The equipment for each muffle furnace system and the process to be used for stabilization of the additional sludges and residues would be similar to the process now in use (as discussed in detail in the Sludge EA, Section 2.2). The muffle furnaces consist of heating elements surrounding a cavity approximately one cubic foot in size, with filtered exhaust gases piped to the plant exhaust ventilation system. A cover gas, carbon dioxide, is used with those residues which contain volatile materials. The maximum batch size would be calculated based on characterization so that not batch would contain more than 10 grams of volatile organics. The maximum batch would be less than 1000 grams bulk weight, placed in Aboats@ with sufficient freeboard to minimize spillage. The typical furnace operating cycle would heat the materials up to a maximum temperature of about 1000^oC (1800^oF), hold at that temperature for a few hours and cool down slowly, consistent with current stabilization operations. The heating and handling cycle for each batch would typically take ten to fourteen hours to complete, with variations based on material type.

Analysis of this action assumes a maximum of twenty-two batches per day. Selection criteria for suitable residues to be stabilized would remain the same, i.e., each batch of sludges or residues must contain less than ten (10) grams of volatile organics to minimize flammable gas generation. Transport, unpack aging, size reduction and repackaging for storage activities would also be very similar to current sludge stabilization activities.

2.3 Facility Description

An overall description of the PFP facility is contained in the Sludge EA, Section 2.3.1. A detailed description of the existing muffle furnace installation in Room 230-A is contained in the Sludge EA, Sections 2.3.2 and 2.3.3.

Probable locations within Building 234-5Z for the proposed installation of additional muffle furnaces are described below. All locations which may be chosen, as well as adjoining rooms and corridors, are serviced by the PFP ventilation system. The ventilation system is described in the Sludge EA, Section 2.3.1. For locations of both existing and proposed stabilization processing areas, see Figure 3 below.

2.3.1 Installation Locations for New Muffle Furnaces

Two existing gloveboxes proposed for muffle furnace installation are located in Room 235-B: Gloveboxes HA-21I and HA-20MB, which do not currently contain any processing equipment. These gloveboxes could contain up to six furnaces. For the rest of the proposed furnace installations, new gloveboxes would be needed. The PFP has acquired, via the Hanford excess equipment program, several unused clean gloveboxes formerly located at the Fuels and Materials Examination Facility (FMEF). These gloveboxes could be installed in Room 235-B to contain the rest of the proposed nine muffle furnaces.

Room 235-B is one of a series of rooms within the PFP radiation zone located in an interior concrete shell which housed the former RMA Line plutonium metal processing area. Much of the RMA Line equipment has been removed from this room. Room 235-B is 7.9 meters (26 feet) north to south, 6.7 meters (22 feet) east to west and has a 4.9 meter (16-foot) ceiling height. The north and south walls of the room are of concrete, 20-centimeters (8-inches) thick, which extend upwards to enclose that portion of the building=s duct level which serves the RMA Line. The east and west walls are made of steel wall panels. J Routine access to Room 235-B is via a double door leading from Corridor 6 via an anteroom, or from Room 235-A on the east. The amount of room space available may dictate that an older, deactivated (i.e., empty and clean) glovebox be removed in order to install one or more of the new gloveboxes. Planning for removal of certain inactive gloveboxes has been ongoing for some time; required documentation is in place for the removal of Glovebox 235B-1 in Room 235-B. See Figure 3 for probable locations of replacement gloveboxes within Room 235-B.

2.3.2 Glovebox Descriptions

Each glovebox will be capable of containing up to three of the new muffle furnaces and associated equipment. A remote control panel for these furnaces would be located in Room 230-A or Room 235-B at a distance from the gloveboxes for shielding purposes. The co-location of several furnaces in one room would result in minimizing the number of control panels installed, worker time (and hence worker radiological dose) and permit enhanced efficiency of the stabilization operation compared to operations involving the original two muffle furnaces located in Room 230-A.

The construction of the former FMEF gloveboxes is similar to PFP gloveboxes, with a stainless steel frame and large windows for good visibility while working.

Figure 3. Existing and Proposed Thermal Stabilization Process Areas in the PFP

3.0 Alternatives to the Proposed Action

Each alternative to the proposed action is similar to the alternatives described in the Sludge EA, Section 3. Differences will be highlighted in the discussion below.

3.1 No-Action Alternative

The No-Action Alternative would recommend continued monitoring and storage of the sludges and residues while waiting for approval and implementation of the PFP Stabilization EIS. The sludges would remain in process areas. Workers would continue to receive radiation doses during required glovebox operations such as safeguard inventories, routine housekeeping, and preventative maintenance. The No-Action Alternative would not continue stabilization of additional plutonium-bearing sludges and residues following the completion of the current sludge stabilization effort described in the Sludge EA.

Long term worker dose rates would not be reduced under this alternative, and acceleration of stabilization activities as recommended by DFSB 94-1 would not be achieved.

The No Action Alternative does not meet the Purpose and Need of this EA.

3.2 Disposal Alternative

The Disposal Alternative would dispose of sludges and residues in a retrievable waste form awaiting a final decision regarding the ultimate disposition of plutonium-bearing materials. Although disposal of some residue items is allowable under current rules, disposal of this class and total amount of material is not allowable according to DOE Order 5633.3B, Control and Accountability of Nuclear Materials (DOE 1994d). However, if allowable, the most likely disposal process for these solid sludges would be to cement the solids in a form that meets Waste Isolation Pilot Plant (WIPP) disposal criteria.

The discussion of the Disposal Alternative in the Sludge EA is relevant to this EA. The bulk weight of the sludges and residues considered in this EA is approximately ten times the total weight of materials stabilized under the Sludge EA. Quantities of waste would be about ten times that discussed in the Sludge EA.

The Disposal Alternative does not meet the stated Purpose and Need of this EA.

3.3 Processing Alternative

Operation of the PRF and a portion of the RMC Line could be used to partially stabilize sludges and residues. As the RMC calciner is not designed to operate at required temperatures (1000^oC), additional thermal stabilization would still be required using muffle furnaces or another piece of equipment to achieve the required temperature. This alternative is more expensive than using only muffle furnaces. The Processing Alternative is similar to historical defense production processes at PFP, would purify the residues, and could expose the operating staff to substantially higher doses of radiation than stabilization using muffle furnaces.

Permission to operate substantial portions of the PFP would be required to implement the Processing Alternative. Monitoring and storage of the sludges and residues would continue while waiting for approval to operate the PRF and RMC. The holdup would remain in process areas. Workers would continue to receive radiation doses during required glovebox operations such as safeguard inventories, routine housekeeping, and preventative maintenance.

In addition, obtaining permission to operate portions of the PFP would not fulfill the DOE desire to accelerate stabilization of residues in accordance with DNFSB Recommendation 94-1.

The Processing Alternative can meet only part of the stated Purpose and Need of this EA.

3.4 Offsite Treatment and Storage Alternative

The Offsite Treatment and Storage Alternative would involve transport of sludges or other residues to an offsite facility for treatment and storage. However, existing regulations prohibit offsite transport of unstabilized fissile materials. Also, the transportation of this material on public roads would require packaging not yet developed to meet transportation requirements (49 CFR 173.416 and 173.417). Accordingly, this alternative has been dismissed from further consideration.

3.5 Slow Stabilization Alternative

The Slow Stabilization Alternative consists of operating the two existing muffle furnaces to stabilize the proposed sludges and residues. This alternative would result in the eventual stabilization of the entire proposed amount of sludges and residues.

Stabilization of the planned amount of sludges and residues under this alternative would take up to six times as long to complete as the proposed action, and would not take advantage of co-location of multiple furnaces to reduce worker radiological dose. Procurement, installation or stabilization activities involving additional muffle furnaces would not be permitted under this alternative; that is, not until after determination and issuance of the PFP Stabilization EIS ROD.

Although the long term worker dose rate at the PFP would be decreased by this alternative, acceleration of stabilization activities as recommended by DNFSB 94-1 would not be achieved. Therefore, the Slow Stabilization Alternative can meet only part of the stated Purpose and Need of this EA.

4.0 Affected Environment

Section 4.0 of the Sludge EA provides a description of the environment on the Hanford Site and the area surrounding the PFP complex, and is incorporated by reference.

In summary, the PFP is location within a secured area in the 200 West Area of the Hanford Site in south central Washington. The nearest population center, Richland, adjoins the southernmost portion of the Hanford Site and is about 40 kilometers (25 miles) from the PFP.

5.0 Environmental Impacts

Discussion of environmental impacts in Section 5.0 of the Sludge EA is applicable to this EA, and is supplemented below.

5.1 Air Emissions

Maximum routine gaseous emissions to the environment which would result from the proposed action are discussed below.

5.1.1 Radionuclide Air Emissions

DOE Order 5400.5, radiation protection of the public and the environment, establishes radiation exposure limits to individual members of the general public from all exposure pathways to 100 millirem (mrem) per year. Subpart H of 40 CFR limits the public to radiation exposure due to emissions to the ambient air from DOE activities to 10 mrem per year. The offgas from the proposed action would contribute up to 5.5 times the emissions as the existing stabilization operation (from 2 existing furnaces operating simultaneously to a maximum of eleven furnaces operating simultaneously), adding a maximum of about 0.01 percent to the total plant exhaust flow. The sources of in-process radionuclides and hence the health effects, from historical plant emissions were much greater than emissions which would result from this proposed residue stabilization action. Latent cancer fatalities (LCF) to members of the public due to historical plant emissions, found in the Sludge EA, Section 5.1.1, are estimated at an average of 0.00005 LCF for the population within 80 kilometers (50 miles) of the PFP. It is extremely unlikley that a LCF would occur specifically due to stabilization operations.

5.1.2 Chemical Air Emissions

Should a total of eleven (11) furnaces be installed and operated simultaneously, the gaseous chemical emissions discharged from the main PFP ventilation stack due to residue stabilization operations each day would total a maximum of up to 5.5 times greater than the operation analyzed in the Sludge EA.

The maximum anticipated emissions for a batch of sludge remain the same; about 9 grams (0.02 pounds) of butene from decomposition of organic materials and about 90 grams (0.2 pounds) of nitrogen oxides (NOx) from decomposition of nitric acid and metal nitrates. The only other emissions would be less than 230 grams (0.5 pounds) each of carbon dioxide and water. The reduction residues would have maximum anticipated emissions of 50 grams (0.11 pounds) of iodine and about 10 grams of hydrogen fluoride (0.02 pounds), based on the flowsheet for RMC reduction batches. Most residues would emit far less of these components.

Modeling of the onsite and offsite chemical concentrations for these batch emissions (except water) was updated to assume a continuous operation running at a maximum of twenty-two batches per day.

These concentrations are shown in Tables 2 and 3 below, along with comparison to any applicable Threshold Limit Values - both the Time Weighted Average (TLV-TWA) (NIOSH 1990) and the Short Term Exposure Limit (TLV-STEL) (ACGIH 1991), or Acceptable Source Impact Levels (ASILs) (WAC 173-460, 1991). TLV-TWA is a measure of the chemical concentration level to which a worker can safely be exposed 8 hours per day, 40 hours per week. The TVL-STEL measures the safe exposure level to a worker for a fifteen minute period. Both of these limits are applicable to onsite concentration., The ASIL is a measure of safe exposure level to the public, and is therefore applicable to offsite concentrations. The predicted chemical concentration levels range from a factor of 10,000 to 1,000,000,000 below the applicable TLV-TWA, TLV-STEL or ASIL values.

5.2 Worker Radiation Exposure

The proposed action would result in an exposure reduction of about 6 to 10 person-rem per year for the PFP operators. Avoidance of exposure to residues in ductwork contributes about 6 person-rem per year while reduced surveillance of PRF and RMC areas, allowable due to removal of holdup from those areas to below certain limits, would be fractionally reduced by 2 to 4 person-rem once the residues are stored in secure vaults. However, the proposed action would result in radiation exposure to the workers when they perform operations involving close proximity to the sludges and residues.

Recent experience with sludge stabilization operations resulted in a cumulative measured dose of just under 10 person rem for the stabilization of over 200 batches of sludge over a time period of five months. Twelve operators are directly involved with stabilization operations within Room 230-A. Routine area dose rates at the glovebox face and at the remove control panel were approximately 12 millirem per hour and 2.4 millirem per hour, respectively. This value is conservative for cumulative dose calculations, as PFP operators have found several methods of dose reduction which were put into effect during the course of these recent operations.

At the expected maximum number of batches (approximately 1600), the cumulative dose would be 80 person-rem for the 2-year duration of the stabilization action. This would result in an estimated health effect of approximately 0.032 LCF for the directly exposed workers.

Workers are subject to routine radiation exposure from many of the operations within the plant. The radiation exposure resulting from the proposed action would be cumulative with exposures received from other operations. Radiation exposures during normal conditions are limited by DOE and the Environmental Protection Agency. Several controlling documents apply to radiation exposure limits: final rule AOccupational radiation Protection (DOE 10 CFR Part 835), and the DOE Radiological Control Manual (DOE/EHG-0256T, revision 1) establish a radiation exposure limit of 5 Rem per year for radiological workers. There are adequate operations staff at PFP to perform the proposed action and other reasonably foreseen plant activities within this administrative control level.

Table 2. Chemical Concentrations at the Maximum Onsite Receptor Locations Based on 99.5 Percent Meteorology and Comparison to TLV-TWA and TLV-STEL Limits

Chemical	Concentration (8 hr)(mg/m³)	TLV-TWA (mg/m³)	Concentration (15 min) (mg/m³)	TVL-STEL (mg/m³⁾
NOx	0.0000341	5.6	0.000088	9.4
Butene	0.00000341	NA	0.0000088	NA
Carbon Dioxide	0.000088	9000	0.00022	54000
Iodine	0.0000191		0.00048	5400
Hydrogen Fluoride	0.0000038		0.0000095

Table 3.Chemical Concentrations at the Maximum Offsite Receptor Locations Based on Annual Average Meteorology and Comparison to ASIL Values

Chemical	Concentration (24 hr)(mg/m³⁾	ASIL (mg/m³⁾
NOx	0.00000275	NA
Butene	0.000000275	NA
Carbon Dioxide	0.00000715	NA
Iodine	0.0000015	NA
Hydrogen Fluoride	0.0000005	NA

5.3 Solid Waste

The residue stabilization process would generate a small amount of radioactive solid waste. This would result from disposal of the containers in which the sludges and residues would be brought to the stabilization glovebox. There would also be waste from material handling activities, sample analysis work, and other miscellaneous activities. Solid waste generation would be minimized in accordance with the current PFP waste minimization program. The volume of solid radioactive and mixed waste is estimated to be 0.05 cubic meter (2.5 cubic foot) per day at the expected processing rate. Approximately 21.5 cubic meters (750 cubic feet) of waste would be stored or disposed at the Hanford Central Waste Complex.

5.4 Accidental Potential

5.4.1 Accident Scenario

The bounding accident postulated for this operation is encompassed by the scenario postulated for the Sludge EA (Ramble 1994), which was extremely conservative. A similar accident analysis performed for dissolution operations in Glovebox MT-5 found that flammable concentrations are not physically possible (Shapley 1994). Both scenarios were based on the presence of tributyl phosphate (TBP) from PRF operations within sludge, which would form butene and waster as it decomposes while heated.

The original scenario in the Sludge EA was determined to be a flammable gas (butene) deflagration, caused by instantaneous decomposition of TBP, which breaches the glovebox and disperses 126 grams (0.28 pounds) of plutonium into the room. To assure worst-case analysis, several simultaneous errors and equipment failures were presumed along with the assumption that the entire batch weight was plutonium oxide of respirable particle size. That scenario bounds potential scenarios for this EA, as plutonium makes up no more than about one-third of the material, and in most cases much less. The probability for this accident is estimated to be less than 0.00001 occurrences per year.

Similar to current stabilization operations, operating specification for the stabilization activity would limit the organic content of feed materials to a maximum of 10 grams per batch. Carbon dioxide cover gas would be fed to the furnace during the processing of batches containing organic material. The cover gas acts as a diluting gas to reduce the oxygen concentration such that the lower flammability limit (LFL) of butene is not reached in the furnace offgas. The LFL is defined as the minimum concentration of vapor in air at which propagation of a flame will occur on contact with a source of ignition.

5.4.2 Source Team

The discussion in the Sludge EA, Section 5.4.3, is relevant to this EA. All airborne plutonium (126 grams or 0.28 pounds) is conservatively assumed to be expelled into the processing room. (Realistically, some of the airborne plutonium would be drawn into the glovebox ventilation system which provides an additional stage of filtration.) All processing rooms are serviced by the E-3 ventilation system that provides on stage of HEPA filtration prior to discharge out the 291-Z-1 stack. The resulting release to the environment through the filtered ventilation from a butene deflagration in a stabilization glovebox would be 0.048 grams (0.0001 pounds) of plutonium.

Using an alternate assumption which was used for the Glovebox MT-5 safety analysis (Shapley 1994), the ignition of 12.6 grams (0.03 pounds) of butene in a stabilization glovebox would disperse 35 grams of plutonium into the processing room, and hence an even lower release to the environment.

5.4.3 Accident Consequences

Based on the release of 0.048 grams (0.0001 pounds) of plutonium out the PFP stack, the maximally exposed onsite individual would receive an effective dose equivalent (EDE) of 0.015 rem and the maximally exposed individual at the site boundary would be exposed to an EDE of 0.0016 rem. The population exposure and related health effect are shown in Table 4. Based on the estimated LCFs it is very unlikely that there would be any cancer fatalities from exposure resulting from the postulated accident.

An estimate of the consequences to the six to nine workers present in room 235-B is based on several assumptions. The room is presumed to be the same size as Room 230-A for ease of comparison. The plutonium is expelled throughout the room immediately, and the workers inhale some of the plutonium before they exit the room. (In the event of airborne contamination, the workers are trained not to breathe before exiting the room.)

There would be no physical impact outside of the plant. The accident would likely result in equipment damage and physical injury to workers in the room and contamination spread to adjacent areas within the building, but the secure, reinforced room would limit physical impact.

Table 4. Health Effects from Accident Scenario

	Sector	Exposed Population	Committed Effective Dose Equivalent	Health Effects
Worst Case Onsite Population	WNW	140	3.58 person-rem	0.0015 LCF
Worst Case Offsite Population	SE	114,734	21.5 person-rem	0.011 LCF

5.5 Socioeconomic Impacts

The discussion in the Sludge EA is applicable to this EA without change, and is incorporated by reference. There is no increase in the current level of facility staff anticipated for this work. Therefore, there will be no anticipated socioeconomic impacts.

5.6 Cumulative Impacts

A cumulative impact is defined as Athe impact on the environment which results from the incremental impact of the action when added to other past, present, and reasonably foreseeable future actions regardless of what agency (federal or non-federal) or person undertakes such other actions. Cumulative impacts can result from individually minor, but collectively significant actions taking place over a period of time (40 CFR 1508.7).@

This section examines the cumulative environmental effects of the proposed action along with impacts from past, present, and anticipated future activities at the Hanford Site. The past, present, and anticipated future activities associated with this environmental assessment are included within, and are thereby bounded by, the Plutonium Finishing Plant Draft Environmental Impact Statement (DOE-EIS/0244) [DOE, 1995A]. The EIS analyses, as provided in Section 6.0 of reference DOE, 1995a, will indicate that for the TOTAL scope of the PFP Stabilization the following potential cumulative impacts could be anticipated. A comparison of these impacts to the EA is then included below.

The EIS provides the basis for the small impacts that when added to other Hanford Site actions the resultant impacts do not cause nay incremental or collective impact. Since the actions of this EA are included within the analyses of the EIS, these associated incremental and collective impacts will be even less.

5.6.1 Human Health Impacts

The 1993 air emissions from the Hanford Site facilities resulted in a potential dose to a maximally exposed individual of 0.03 mrem (PNL, 1994). The average dose from Hanford operations to the local population of 380,000 within the 80 km radius was 0.001 mrem in 1993.

There is no indication that routine PFP stabilization and removal activities would add to the overall dose or cumulative impact to the offsite population or non-involved worker. Operating experience during the past year for thermal stabilization activities have indicated no change in the facility baseline airborne emissions.

Routine operations for the EIS work are conservatively predicted to result in 140 person rem exposure to the population living within 80 km (50 miles) of the PFP facility. This would result in no predicted LCF to the offsite population. As noted in the EA, the routine operations for this work are predicted to result in maximum of 0.1 person rem to the population and a resultant 0.0005 LCF over the two year span of the work.

Radiation exposure to the directly involved in-facility worker for the total stabilization period is anticipated to be 930 person rem resulting in 0.37 LCF. The anticipated worker exposure for this EA work is 80 person rem resulting in 0.032 LCF.

5.6.2 Waste Generation

The anticipated TRU and Mixed TRU waste generation for the PFP facility over the next 30 years at Hanford is approximately 3000 cubic meters. That associated with the Sludge and Solid Residue EA is estimated to be 21.5 cubic meters, which is included in the 9\30 year projections.

5.7 Environmental Justice

The scope of this action is relatively minor. Existing staff at the PFP facility would be used to implement the proposed action. No income or population group would experience disproportionately high health or environmental effects under any of the alternatives.

6.0 Permits and Regulatory Requirements

Discussion of regulatory requirements in the Sludge EA is applicable to the proposed action, with the addition of the discussion below:

6.1 Air Quality

Air emissions from the PFP would comply with the National Emissions standards for Hazardous Air Pollutants regulations administered by the U.S. Environmental Protection Agency (EPA), the Radioactive Airborne Emissions Program regulations administered by the State of Washington Department of Health (DOH), and the nonradioactive air emissions regulations administered by the State of Washington Department of Ecology (Ecology).

Under EPA definitions, the PFP complex is viewed as a single stationary source of emissions. The proposed action would not affect the established baseline of emissions from the PFP complex. Therefore, under this definition, notification of modification would not be required to be submitted to EPA.

The U.S. Department of Energy, Richland Operations Office (RL) has established with DOH a routine technical assistance meeting to review, discuss, and approve projects. The meetings provide opportunity to relay information as a streamlined Notice of Construction to DOH and receive approval to proceed. Representatives of RL and DOH sign the meeting minutes from the routine technical assistance meetings to formalize commitments and information exchanged during the meetings, and the DOH signature formalizes the NOC approvals obtained. On August 11, 1995, representatives of RL and the Westinghouse Hanford Company presented information to DOH regarding installation of additional muffle furnaces within the 234-5Z Building. The DOH approved installation of the muffle furnaces.

It is the policy of RL that a Notice of Construction for air toxics would not be required to be submitted to Ecology if the proposed action would be classified as a minor process change and it could be demonstrated that the emissions for Toxic Air Pollutants would be below small quantity emission rates as listed in WAC 173-460. The proposed action would be a minor process change. Based on recent data, calculations indicate the emission rates would be below the small quantity emissions rate.

6.2 Historic Preservation

The Washington State Historical Preservation Officer (SHPO) has concurred with a determination by RL that the RMA Line is eligible for listing in the National Historic Registry due to the pioneering technology, unique nature of the equipment used, and its role in the Cold Wear Era (SHPO 1995). Some RMA Line equipment would be removed during execution of the proposed action. The specific equipment to be removed is associated with syustems which no longer have historic integrity. The DOE has received concurrence from the SHPO that the proposed action will have no effect on the historic character of the RMA Line (see Appendix).

7.0 Agencies Consulted

Section 7.0 in the Sludge EA discusses consultation and coordination with tribes and stakeholders, including regulatory agencies and public interest groups. The proposed action was discussed with DOH at a routine technical assistance meeting on August 11, 1995. On August 11, 1995, representatives of RL and the Westinghouse Hanford Company presented information to DOH regarding installation of additional muffle furnaces within the 234-5Z Building. The DOH approved of installation of the muffle furnaces. Representatives of RL and DOH sign the meeting minutes from the routine technical assistance meetings formalizing the agreements made during the meetings.

SHPO has been consulted concerning the historical value of portions of the RMA line.

A draft of this document was sent to the U.S. Fish & Wildlife Service, the Yakama Indian Nation, Nex Perce Tribe, Confederated Tribes of the Umatilla Indian Reservation, the Wanapum People, the states of Washington and Oregon and other interested parties for pre-approval review. No comments were received.

8.0 References

49 CFR 173.416 and 173.417, AAuthorized Type B Packages,@ Code of Federal Regulations, as amended.

ACGIH, 1991, 1991-1992 Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices, American Conference of Governmental Industrial Hygienists Human Services, Cincinnati, Ohio.

Conway, J.T., DNFSB Recommendation 94-1, (Letter to H.R. O=Leary, U.S. Department of Energy, May 26, 1994), Defense Nuclear Facility Safety Board, Washington, D.C.

DOE, 1994a, AEnvironmental Assessment: Sludge Stabilization at the Plutonium Finishing Plant@, DOE/EA-0978, U.S. Department of Energy, Washington, D.C., October 1994.

DOE, 1994b, ACriteria for Safe Storage of Plutonium Metals and Oxides@ DOE-STD-3013-94, U.S. Department of Energy, Washington, D.C., December 1994.

DOE, 1994c, Hanford Site Radiation Control Manual, HSRCM-1, U.S. Department of Energy, Richland, Washington, October 1994.

DOE, 1995a, Plutonium Finishing Plant Stabilization Draft Environmental Impact Statement, DOE-EIS/0244, U.S. Department of Energy, Washington, D.C., November 1995.

DOE, 1995b, DNFSB Recommendation 94-1 Implementation Plan, (Letter to J.T. Conway, Defense Nuclear Facility Safety Board, February 28, 1995), U.S. Department of Energy, Washington, D.C.

DOE, 1995c, ACriteria for Safe Interim Storage of Plutonium Bearing Solid Materials@, addendum to DNFSB Recommendation 94-1 Implementation Plan, U.S. Department of Energy, Washington, D.C., October 1995.

National Environmental Policy Act of 1969 (NEPA), 42 USC 4321 et seq.

NIOSH, 1990, NIOSH Pocket Guide to Chemical Hazards, U.S. Department of Health and Human Services, Washington, D.C.

PNL, 1994, Hanford Site Environmental Report for Calendar Year 1993, PNL-9823, Pacific Northwest Laboratory, Richland, Washington.

Ramble, A.L., 1994, to L.H. Rodgers, AGlovebox HC-21C/MT-5 Comparison Letter Analysis Report,@ Internal Memorandum 8D143-094-014, dated June 28, 1994, Westinghouse Hanford Company, Richland, Washington.

Shapley, J.E., 1994, MT-5 Safety Assessment, WHC-SD-CP-SAR-012, Rev. 2, Westinghouse Hanford Company, Richland, Washington.

SHPO, ANear-Term Cleanout Activities in the Remote Mechanical A-line, Plutonium Finishing Plant@ (letter, Mary M. Thomson to John D. Wagoner, reference log # 082195-03-DOE, August 21, 1995.)

SISMP, DFNSB Recommendation 94-1 Hanford Site Integrated Stabilization Management Plan, WHC-EP-0853, Rev. 0, Westinghouse Hanford Company, Richland, Washington, August 1995.

WAC 173-460, 1991, AControls for New Sources of Toxic Air Pollutants,@ Washington Administrative Code, as amended.

Finding of No Significant Impact
For Sludge and Solid Residue Stabilization
At The Plutonium Finishing Plant
Hanford Site, Richland, Washington
U.S. Department of Energy Richland Operations Office
November 1995

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); Sludge and Solid Residue Stabilization, DOE/EA-1112, to assess the environmental impacts associated with: a) installing up to nine additional muffle furnaces, and b) stabilizing an additional 1130 kg of sludges and solid residues containing 184 kg of plutonium at the Plutonium Finishing Plant on the Hanford Site. Alternatives considered were the No Action alternative, disposal of the materials as waste, and stabilizing the material by historic purifying production type processing.

The action to install up to nine additional muffle furnaces and to stabilize the sludges and residues in the gloveboxes is an allowable interim action per 40 CFR 1506.1(a) pending completion of the broader Plutonium Finishing Plant Stabilization Environmental Impact Statement (EIS), DOE/EIS-0244.

The sludges are residues remaining from previous production processing operations at the PFP. These sludges and residues contain approximately 184 kilograms (405 pounds) of plutonium along with other chemicals in a slurry with high moisture content. The sludge and solid residue stabilization would continue the current stabilization effort conducted under DOE/EA-0978 and complete the associated work in about two years.

Based on the analysis in the EA, 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 NEPA. Therefore, the preparation of an Environmental Impact Statement (EIS) is not required.

COPIES OF THE EA ARE AVAILABLE FROM:

J.E. Mecca, Director
Operation Transition Division
U.S. Department of Energy
Richland Operations Office
Post Office Box 550
Richland, Washington 99352
(509) 376-7471

FOR FURTHER INFORMATION CONTACT:

Carol M. Borgstrom, Director
Office of NEPA Oversight
U.S. Department of Energy
1000 Independence Avenue, S.W.
Washington, D.C. 20585
(202) 586-4600 or (800) 472-2756

PURPOSE AND NEED: DOE desires to continue to reduce worker exposure to radiation at the PFP, and to accelerate stabilization of plutonium-bearing materials stored in existing vaults at the PFP.

BACKGROUND: The PFP was built in 1949 to convert plutonium nitrate solutions into plutonium metal. This activity continued in various campaigns until production operations were halted in 1989. As a result of the conversion process, a number of scrap forms of material were generated, some of which could not be immediately recycles into the process. These were stored for future processing. The shielded and secure vaults in Building 2736-Z were designed to store these materials in sealed storage containers. Sealed storage requires removal of any gas forming compounds. Historically, such compounds have been stabilized by heating them in a small furnace to high temperatures. This drove off water and decomposed organic or other molecules to gaseous forms. The resulting residues were canned to seal out moisture and contain the plutonium.

To reduce the likelihood of a flammable gas deflagration and to mitigate any attendant consequences, two muffle furnaces with improved flammable gas control were installed din glovebox HC-21C in Room 230 A. This room, as well as adjoining rooms and corridors, is serviced by the facility ventilation system equipped with High-Efficiency Particulate Air (HEPA) filters. Should process safety features be compromised, these filters would remove, at a minimum, 99.95 percent of the plutonium entrained in the air.

PROPOSED ACTION: DOE is proposing to install up to nine additional muffle furnaces in three to five glovebox enclosures within Building 234-5Z and to stabilize approximately 1130 kilograms (2485 pounds) of chemically reactive plutonium-bearing sludges and solid residues contained within the process gloveboxes and the storage vaults at the PFP.

These sludges and solid residues remain from previous production processing operations at the PFP, and contain approximately 184 kilograms (405 pounds) of plutonium along with other chemicals in a slurry with high moisture content. The total quantity of plutonium in the sludges and solid residues is less than five percent of the total inventory of plutonium in all the reactive materials stored at the PFP.

The sludges and solid residues will be stabilized by heating them to about 1000^oC (1800^oF) and converting them to plutonium oxide (PuO₂). Chemicals not driven off by the heat would remain as stable impurities in the resulting solid. The solid will be stored in sealed containers in the vaults at PFP.

The nine additional muffle furnaces that may be installed use a design similar to those analyzed in the EA on Sludge Stabilization at the PFP, DOE/EA-0978. The muffle furnaces will be installed in gloveboxes HC-21I and HA-20MB located in Room 235-B of Building 234-5Z within the PFP.

The proposed action is an allowable interim action per 40 CFR 1506.1(a) pending completion of the broader Plutonium Finishing Plant Stabilization Environmental Impact Statement (EIS), DOE/EIS-0244, concerning the proposed cleanout and stabilization of the PFP.

ALTERNATIVES CONSIDERED:

No Action: The No-Action Alternative consists of not stabilizing the plutonium-bearing material at this time. The material would continue to be stored in the process gloveboxes. The workers would continue to receive radiation doses during required glovebox operations such as monitoring the condition of the containers, accounting of the material, routine housekeeping, and preventative maintenance. All the PFP workers would continue to receive approximately 4 person-rem per year from storage of the sludges and solid residues.

The No-Action Alternative would not meet the dual need of reducing worker exposure and of increasing glovebox storage space to support future cleanup activities.

Disposal Alternative: This alternative would be to dispose of the material as a retrievable waste form before a final decision has been made regarding the ultimate disposition of the material. This is not allowable under current DOE discard limits for disposal of fissile materials. However, if allowable, the most likely disposal process for these solid residues and sludge would be to cement the solids in a form that meets Waste Isolation Pilot Plant (WIPP) disposal criteria.

The process would involve diluting the materials, mixing them with a concrete type of material, and then pouring the mixture into 0.5-liter (1-pint) containers. J The containers would then be packaged into 208-liter (55-gallon) drums for storage.

The total volume of waste is relatively small, however, because of its high curie content, the 250 rums of waste would consume approximately 60 percent of the total waste storage space within the Central Waste Complex. Therefore, it is more likely that this waste would be stored at another facility, possibly the 224-T Transuranic Waste Storage and Assay Facility (TRUSAF), which does not have a curie limit and is operating in interim status under the Resource Conservation and Recovery Act (RCRA) of 1976 and Washington Administrative Code (WAC) 173-303.

This alternative has been dismissed from consideration because it is currently unallowable, and would consume a large amount of the existing storage space in either the 224-T TRUSAF or the Central Waste Complex.

Processing Alternative: Several processing alternatives could stabilize the sludges and solid residues and free up glovebox space. These include operating the PRF. Although some of these alternatives are viable, they are more expensive; are similar to defense production processing; in some instances would make the form of stabilized material more difficult to work with in the future; and would expose the operating staff to substantially higher doses of radiation., The sludges and solid residues would still need constant handling with the accompanying worker exposure while the process is developed and prepared. For these reasons the alternatives would not meet the immediate need of reducing worker exposure.

Offsite Treatment and Storage of Sludges and Solid Residues Alternative: This alternative would involve transporting the sludges to an offsite facility for treatment and disposal. However, existing regulations prohibit offsite transport of unstabilized fissile materials, and transportation of this material on public roads would require development of packaging to meet transportation requirements (49 CFR 173.416 and 173.471). Accordingly, this alternative has been dismissed from further consideration.

ENVIRONMENTAL IMPACTS:

Air Emissions

Radionuclide Air Emissions: Offgas would be exhausted from the furnaces using the plant process vacuum system. This offgas would contain small concentrations of suspended radiodnuclide particles, primarily plutonium oxide, from the stabilization process. The offgas pollution control system includes a sintered metal filter at the exit of the furnace to remove the large particles. The offgas would then enter the E-4 ventilation system which includes two stages of HEPA filtration. Each stage of HEPA filtration removes at least 99.95 percent of the remaining 0.3 micrometer or larger radionuclide particles passing through them. The offgas would contribute a very small percentage (approximately 0.05 percent) to the total plant exhaust flow.

The radionuclide emissions from stabilization of the sludge are expected to be extremely low and would not result in a detectable increase in total PFP emissions.

Historically, the total PFP emissions have not varied substantially during different operations including previous furnace stabilization operations. The total PFP emissions result from continuous ventilation of all process areas and gloveboxes within the PFP. Therefore, it is assumed that the health effects from historical total plant emissions will be greater than that resulting from just the sludge stabilization process, and this data was used as a bounding case to evaluate the health effects for the proposed action.

Chemical Air Emissions: Operation of the stabilization process would also generate gaseous chemical emissions which would be discharged from the main ventilation stack. These emissions for a typical batch being stabilized would consist of about 9 grams (0.32 ounces) of butene from decomposition of organic materials and about 90 grams (3.2 ounces) of NOx from decomposition of nitric acid and metal nitrates. The only other emissions would be less than 230 grams (8.1 ounces) each of carbon dioxide and water. Onsite and offsite concentrations for these emissions (except water) were modeled assuming continuous operation with up to a maximum of twenty-two batches per day.

Worker Radiation Exposure

The proposed action would result in a reduction of approximately 6 to 10 person-rem year for PFP operators. However, the proposed action would result in radiation exposure to the workers when they perform operations involving close proximity to the sludges. It is estimated that the process will require up to twelve operators to be directly involved with the stabilization operation. Routine area dose rates at the glovebox face and at the remote control panel have been approximately 12 millirem per hour and 2.4 millirem per hour, respectively. This value overestimates the dose to workers, as PFP operators have implemented several additional methods of dose reduction during the course of the recent operations.

Workers are subject to routine radiation exposure from many of the operations within the plant. The radiation exposure resulting from the proposed action would be cumulative with exposures received from other operations. Radiation exposures during normal conditions are limited by DOE and the Environmental Protection Agency. DOE regulations on Occupational Radiation Protection (10CF CFR 835), and the DOE Radiological Control Manual (DOE/EHG-0256T, revision 1) establish a radiation exposure limit of 5 Rem per year for radiological workers. There are adequate operations staff at PFP to perform the proposed action and other reasonably foreseen plant activities within this administrative control level.

Solid Waste

The sludge stabilization process would generate a small amount of radioactive solid waste. The waste would come from sealouts, sample analysis work, andother miscellaneous activities. The volume of wast eis estimated to be 0.05 cubic meter (2.5 cubic foot) per day at the expected processing rate. The approximate amount fo waste is expected to be 21.5 cubic meters (750 cubic feet) and would be stored or disposed of at the Handford Central Waste Complex.

Potential Accidents

Two potential accidents were analyzed for oepration of the sludge and solid residue stabilizationprocess: a majora fire in a gtlovebox and a flammable gas deflagration., Both accidents have a probability of occurrence of 1 x 10^-5 or less. The estimated probability for either accident leading to a release of radioactive materials is the same, and the consequences from the flammable gas accident would be slightly higher; therefore, this was evaluated as the bounding accident.

Flammable gas (i.e. butene) would be generated during sludge stabilization operations due to the presence of TBP in certain feedstocks. Tributyl phosphate decomposes slowly at temperatures just above 110^oC (230 ^oF) and the decomposition rate incrases as the boiling point is approached (268^oC [514^oF]). The major gaseous products from the thermal decomposition of TBP are butene and water.

The Operations Specifications Document for sludge stabilization would limit the TBP content of feed materials to a maximum of 10 grams (0.02 pounds) for a batch. A cover gas, CO₂ or inert gas, would be fed to the furnace during the processing of batches containing organic material. The cover gas acts as a diluting gas to reduce the oxygen concentration such that the lower flammability limit (LFL) of butene is not reached in the furnace offgas. The LFL is defined as the mimimum concentration of vapor in air at which propagation of a flame will occur on contact with a source of ignition.

For this analysis, it is assumed that 20 grams (0.04 pounds) of TBP are present in the batch. This value is conservatively chosen to account for an error in charging the boat or an error in determining the concentration of TBP present. It is further assumed that the covergas is absent, that the funace offgas is blocked, and that the controller fails in such a manner that all of butent potentially available is evolved instantaneously.

The amount of butene generated given 20 grams (0.04 pounds) of TBP present in the batch is 12.6 grams (0.03) pounds). The butene generated is conservatively assumed to form a flammable mixture in the glovebox and ignite. The resultant deflagration is conservatively assumed to breach the glovebox releaing material into the surrounding room.

Socioeconomic Impacts

The activities described will be performed by the existing PFP workforce. Therefore, no socioeconomic impacts are expected.

Environmental Justice

Executive Order 12898, Federal Actions to Address Environmental Justice in Minority Populations and Low-Income Populations, requires that federal agencies identify and address, as appropriate, disproportionately high and adverse human health or environmental effects of their programs and activities on minority and low-income populations. The environmental effects analyzed in this EA are expected to be minimal. No adverse health effects are expected to occur in any offiste community. No socioeconomic impacts are expected. Therefore, no disporportionate impacts on any subgroups of the public including minority and low-income populations are expected.

Cumulative Impacts

Ongoing or planned activities occurring on the Hanford Site are numerous. The predominant activities that are either ongoing or planned within the foreseeable future involve environmental restoration and waste management activities.

Cumulative Impacts - Air In calendar year 1991, the release of plutonium-239/240 to the atmosphere from the 200 Areas was very small, approximately 0.00044 curies. The atmospheric emissions from plutonium-239/240 in 1995 are expected to be equal to or less than the emissions that were rlleased in 1991.

Offgases resulting from the proposed action would contaim small concentrations of suspended radionuclide particles, primarily plutonium oxide. Additioanl radionuclide emissions to the atmosphere due to the proposed action would be extremely small, and would not be expected to result in any measurable increase in radiological emissions at the Hanford Site.

Cumulative Impacts - Solid Waste: The proposed action would generate apparoximately 0.05 cubic meters (2.5 cubic feet) of radioactive solid waste per day, which would be stored or disposed of in the Hanfoard Cnetral Waste Compelx. This waste would represent a very small incremental incureas ein the total maount of waste that is stored or disposed of on a daily basis at the Hanford Site, and can be accommodated within existing waste storage and disposal capacity. Storage and disposal of this waste would comply with applicable regulations.

DETERMINATION:

Based on the analysis in the EA, the proposed addition of up to nine additional muffle furnaces and the proposed sludge and solid residue stabilization, does not constitute a major federal actionsignificantly affecting the uality of the human environment within the meaning of the NEPA. Therefore, an EIS for the proposed action is not required.

Issued at Richland, Washington, this 21st day of November, 1995.

/s/ John D. Wagoner
Manager
Richland Operations Office

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Weapons of Mass Destruction (WMD)

EA-1112; Environmental Assessment and FONSI Sludge and Solid Residue Stabilization at The Plutonium Finishing Plant Hanford Site, Richland, Washington U.S. Department of Energy

Appendix

List of Figures

List of Tables