APPENDIX A OPERATIONAL WASTE VOLUME PROJECTION FOR HANFORD DOUBLE-SHELL TANK FARMS
TABLE OF CONTENTS
OPERATIONAL WASTE VOLUME PROJECTION FOR HANFORD DOUBLE-SHELL TANK FARMS
A.1 BACKGROUND A-1
A.2 OPERATIONAL WASTE VOLUME PROJECTION ASSUMPTIONS AND CHANGES A-3
APPENDIX A REFERENCES A-7
LIST OF TABLES
A-1 Double-Shell Tanks Space Need Projections in Millions of Gallons A-2
APPENDIX A OPERATIONAL WASTE VOLUME PROJECTION FOR HANFORD DOUBLE-SHELL TANK FARMS
Although the SIS-EIS considers only interim actions that can be accomplished through the year 2000, this OWVP for Hanford's DST waste presents a basis for evaluating future DST space needs through the end of fiscal year (FY) 2005. Section A.1 summarizes the projected range of tank space and the need to build additional DSTs based on recent analysis by the TWRS program. The assumptions and changes which have affected the OWVP, are discussed in Multi-Function Waste Tank Facility, Phase Out Basis (WHC 1995), and are summarized in Section A.2. The most recent information shows that wastes in the TWRS current baseline can be managed within the existing waste tank capacity through FY 2003. Additional DST tank storage capacity is not needed until FY 2004 or later. Table A-1 provides a summary of the DST space need projections through FY 2005.
A.1 BACKGROUND
The OWVP system is a complex simulation which was developed to assist in managing the tank space and identifying needs for new tanks. The OWVP system simulates the evaporator operation, the 28 DSTs and the associated transfer systems. It considers the effects of chemistry, mass, volume, and operational logistics to evaluate various operational scenarios. This projection is based upon the best estimates of waste generation and composition provided by the waste generators. WHC periodically issues an OWVP report based on best available data. The last WHC Operational Waste Volume Projection Report, Revision 20 was issued in September 1994 (WHC 1994). Since its issue, studies have been conducted to assess alternative scenarios for operating Hanford Tank Farms without constructing new tanks at least through 2004. A special OWVP report was prepared in June 1995 to support phase out of the Multi-Function Waste Tank Facility (MWTF) project (WHC 1995).
Double-Shell Tanks Space Need Projections
in Millions of Gallons
FISCAL YEAR
Waste Type and Needs
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
(A) Concentrated Waste 14.8 15.2 16.1 17.5 18.3 17.9 18.0 18.1 18.1 18.2 18.7 17.1
(B) Supernate Liquid 9.1 5.8 4.8 5.0 4.9 5.0 4.8 4.8 4.8 4.8 4.8 6.5
(C) 200W Receiver Tanka 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2
(D) 241-AW-102 and 241-AW-106b 2.3 2.3 2.3 2.3 2.3 2.3 2.3 2.3 2.3 2.3 2.3 2.3
Evaporator Support
(E) Spare Space 2.3 2.3 2.3 2.3 2.3 2.3 2.3 2.3 2.3 2.3 2.3 2.3
(F) Impact of Evaporator 0.0 0.2 0.3 0.6 0.8 1.0 1.1 1.1 1.1 1.1 1.1 1.1
Limits (Specific Gravity of
1.35 versus 1.5)
(G) Segregated Space 1.5 2.4 1.9 1.1 1.1 0.7 0.7 0.7 0.7 0.7 0.7 0.7
(H) Passive Mitigationc 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
241-SY-101
(A+B+H) Total Space Needed for 23.90 21.00 20.90 22.50 23.20 22.90 22.80 22.90 22.90 23.00 23.50 23.60
Waste Storage
(C+D+E+F+G) Total Space Needed 7.30 8.40 8.00 7.50 7.70 7.50 7.60 7.60 7.60 7.60 7.60 7.60
for Operational Needs and
Specific Use
31.20 CAPACITY29.40EDd28.90 30.00 30.90 30.40 30.40 30.50 30.50 30.60 31.10 .31.20
Source: WHC 1995
aStaging space needed to receive and transfer 200 West Area waste streams (Tank 102-SY is the current 200 West Area
receiver tank).
bStaging space needed to support evaporation of waste by 242-A Evaporator.
cAlternate decision for passive mitigation of Tank 101-SY by a 1:1 dilution ratio would add 8.3 million L (2.2 million
gal) of needed space.
d28 DSTs provide 118,410,000 L (31,280,000 gal) of capacity.
Several management actions have been initiated since the Draft EIS was issued in
August 1994, to ensure that the projected waste volume would not exceed the
available waste storage capacity in the DSTs. These actions include the
following.
. Improved tank space use.
. Reduced waste volume generation by the Hanford Site facilities.
. Decreased waste volume reduction factors for the 242-A Evaporator
operations.
. Modified management practices to concentrate waste to the specific gravity
operating limit of 1.35 in all future evaporator campaigns. This limit
was selected by WHC based on empirical data.
. Revised waste segregation requirements as described in Section A.2. TRU
solids and complexed waste will be segregated per DOE Order 5820.2A.
A.2 OPERATIONAL WASTE VOLUME PROJECTION ASSUMPTIONS AND CHANGES
The following major planning assumptions and management practice changes
impacting OWVP at the tank farms are discussed in this section.
. Combination of Partially Full Separate Neutralized Cladding Acid Waste
(NCAW) and Neutralized Cladding Removal Waste (NCRW) Tanks - In-tank
washing of the NCAW solids from Tanks 101-AZ 132,000 L (35,000 gal) of
solids and 102-AZ 360,000 L (95,000 gal) of solids would be combined into
Tank 102-AZ. The NCAW supernatant and washes were assumed to be
concentrated and combined into Tank 101-AY. The in-tank washing of the
solids should be complete by FY 1999.
The following wastes would all be consolidated into Tank 103-AW during FY
1999:
- PFP TRU solids and residual liquids in Tank 102-SY 541,000 L
(143,000 gal)
- NCRW solids from Tank 103-AW 1.84 million L (487,000 gal)
- NCRW solids from Tank 105-AW 1.14 million L (300,000 gal).
. Mitigation of Watchlist Tanks - Active mitigation of Watchlist Tank 101-SY
by mixer pump would be continued at least through FY 2006. It is assumed
that passive mitigation by dilution of other Watchlist flammable gas DSTs
would not be necessary. If a decision is made for passive mitigation of
the Tank 101-SY by 1:1 dilution ratio, approximately 8.3 million L (2.2
million gal) of additional DST space or two new DSTs would be needed.
. Spare Space - Operational space in Tanks 102-AW and 106-AW would be used
to provide 2.7 million L (720,000 gal) of the required 7.6 million L (2
million gal) of spare space starting in FY 1999.
. Use of Tank 102-SY for Pumping Complexed SWL - Current SWL pumping
practices require that a DST be available for receiving the liquid wastes
pumped out of SSTs. Two of the tanks in the 200 West Area (Tanks 101-SY
and 103-SY) are on the flammable gas Watchlist and cannot receive waste
additions. Therefore, all SWL pumped in the 200 West Area will be routed
through Tank 102-SY.
Tank 102-SY contains a sludge layer of Pu-bearing solids. Pumping non-
complexed SWL to Tank 102-SY with the Pu-bearing solids in the bottom
should not present a problem. However, complexed wastes and TRU solids
have been segregated, both to minimize the expense of disposal and to
comply with DOE Order 5820.2A, "Radioactive Waste Management." The OWVP
assumes that solids in Tank 102-SY would be retrieved to allow pumping of
the complexed SWL from January 1999 through FY 2000 (WHC 1994). The
preferred alternative in this EIS includes retrieval of Tank SY-102
solids.
. A cross-site transfer capability is assumed to be functional and available
for this projection. The ECSTS is operable for the transfer of dilute
waste starting in 1995 with the RCSTS becoming operational with the
ability to transfer slurries in 1998.
. Contingency Space - A total of 8.3-million L (2.2-million gal) of spare
space consisting of one aging and one non-aging waste tank is reserved in
case of a leak and emergencies per requirements of DOE Order 5820.2A. In
the past, an additional one tank contingency space has been set aside to
account for inaccuracies in the projections.
A management decision was made to eliminate the requirement for the
additional contingency space set aside in addition to the required spare
space. Therefore the special OWVP assumes no additional contingency
space.
. SWL Volumes - The revised estimates for the SWL to be pumped from SSTs
during 1995 through 2000 is assumed to be 23.5-million L (6.2-million
gal). This amount was previously estimated at 13.6-million L (3.6-million
gal). Approximately 42 percent of this waste is assumed to be complexed
resulting in 9.8-million L (2.6-million gal) of complexed SWL which was
previously estimated at 1.89-million L (500,000 gal). The revised waste
volume reduction factors, from SWL to Double-Shell Slurry Feed, were 55
percent for non-complexed SWL and 10 percent for complexed SWL.
. Facility Generation Rate - Reassessment of the waste volume generation by
various facilities contributing wastes to the tank farms has resulted in
lower projections of the total facility generation rate.
. Privatization - TWRS Program privatization concepts are not included in
this EIS. Privatization is currently believed to have no negative impact.
. TWRS Actions - The DST space needs for the TWRS actions such as retrieval,
pretreatment, immobilization, and lag storage is not included in this
projection. The TWRS EIS will evaluate these needs.
. Watchlist Tank Inventories - It is assumed that the Watchlist tanks
inventories remain constant from 1995 through 2005.
. Headspace Above Pu-Bearing Solids - These projections assume headspace
above Pu-bearing solids would be used to store Dilute Non-Complexed waste.
. All DSTs Remain Sound - The special OWVP assumes that all existing DSTs
remain intact for at least another 10 years.
APPENDIX A REFERENCES
WHC, 1995, Multi-Function Waste Tank Facility, Phase Out Basis, Awadalla N.G., WHC-SD-W236A-ER-021, Revision 2, June 1995. WHC, 1994, "Operational Waste Volume Projection", WHC-SD-WM-ER-029, Rev. 20, September 1994.
|
NEWSLETTER
|
| Join the GlobalSecurity.org mailing list |
|
|
|
