Advice on the Department of Energy's Cleanup Technology Roadmap Gaps and Bridges (2009) / Chapter Skim
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Appendix D: Hanford Reservation
Appendix D: Hanford Reservation
Pages 178-199
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From page 178... ...
B R ITIS H C O L U M B IA WA S H IN G TO N Se a t tle Sp o k a n e ID AH O H an fo rd S i te Sna ke Riv er Ric h la n d Ke n n e wic k P as c o N P o rt la n d 0 50 10 0 M i le s O R E GO N 0 50 100 1 50 K ilom e ters FIGURE D.1 The Hanford reservation is a 670 square mile site in southeastern Washington. Industrial-scale production of nuclear weapons materials began on the site in 1944.
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From page 179... ...
This appendix thus provides support for the findings and recommendations developed by the committee. HISTORY In March of 1943, 670 square miles in southeastern Washington State were chosen to be the site for the plutonium manufacturing operations of The agenda for this meeting is shown in Appendix B
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From page 180... ...
The first reactors built were called single-pass reactors because the cooling water ran only once through the core, where it became contaminated with radioactive activation and sometimes fission products, before being discharged to the Columbia River or soil. Water recirculation was included in the last of nine reactors built onsite; it came online in 1964 (Gephart 2003)
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From page 181... ...
Also, other processes have been used to recover radionuclides. Acidic waste streams were made caustic by adding concentrated sodium hydroxide, and sometimes the tanks were used as dumps for miscellaneous waste such as experimental fuel elements, ion exchange columns, and plastic bottles containing plutonium and uranium.
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From page 182... ...
In carrying out its tank cleanup mission, the ORP will be dealing with more than 50 million gallons of tank waste in 177 underground tanks. ORP is also responsible for construction of the Waste Treatment Plant (WTP)
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From page 183... ...
As described above, tank waste is highly heterogeneous among Hanford's 177 tanks, and it is also heterogeneous within any given tank. This is due to the variety of fuel reprocessing and plutonium recovery processes used at the site, especially in the early years of production, and the fact that the acidic reprocessing waste was neutralized and made alkaline for extended storage in Hanford's carbon steel waste tanks.
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From page 184... ...
Pretreatment The purpose of waste pretreatment is to process incoming tank waste in order to obtain two waste streams for vitrification either as HLW or as LAW. A quarter-scale pretreatment engineering "platform" is being installed to test and demonstrate pretreatment operations including integrated sludge washing, leaching, and waste concentration.
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From page 185... ...
on these and similar issues, including waste stream rheology in pipes and during mixing in tanks, sludge washing, hydrogen generation, process chemistry, and online instrumentation. In describing the pretreatment ion exchange operations, intended to remove cesium-137 and some other radionuclides from the LAW stream, Tamosaitis explained that there is need for better understanding and optimization of waste filtration and the Cs-removal ion exchange resin.
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From page 186... ...
The process development team includes: AREVA NC, Swenson Technologies, Savannah River National Laboratory, Georgia Institute of Technology, and CH2M HILL. Fractional crystallization uses evaporation and crystallization to separate radioactive isotopes from the nonradioactive sodium salts that make up a large fraction of Hanford tank waste.
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From page 187... ...
includes waste storage, retrieval, and tank closure within the waste processing program area. Information on these topics was presented during the committee's Richland meeting and the Hanford site visit.
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From page 188... ...
. Hanford's waste retrievals have met the tank cleaning requirements of the TPA, but continued improvements to make the retrievals faster and less expensive will be sought during the remaining decades of the tank cleaning work.
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From page 189... ...
. There are 761 buried waste sites in the River Corridor project (i.e., sites located along the Columbia River)
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From page 190... ...
The Groundwater Remediation Project is largely responsible for ensuring the plan is implemented. The goals of the program are to prevent contaminated groundwater from migrating to the Columbia River, avoid groundwater contamination in the future, and remediate existing contamination (Jewell 2008)
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From page 191... ...
Contaminants from the central plateau (200 Area) that may reach the river based on their half-lives, mobility, and inventory -- including uranium, Tc-99, and carbon tetrachloride.
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From page 192... ...
described the following challenges: • Develop cost-effective in situ remediation of carbon tetrachloride and hexavalent chromium in the vadose zone, • Develop cost-effective in situ remediation for radionuclides in the deep vadose zone, • Develop numerical models that include chemical reactions by contaminants and their transport in groundwater and the vadose zone, and • Develop improved, cost-effective methods for subsurface access to support characterization and remediation.
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From page 193... ...
. The 75-square-mile Central Plateau houses fuel reprocessing and waste management facilities, including the five very large "canyon" facilities used for reprocessing irradiated spent fuel from Hanford reactors.
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From page 194... ...
. Roadmap Area: Spent Fuel and Nuclear Materials SNF There are 2,100 metric tons of SNF, mostly N-reactor fuel, which is zirconium-clad uranium metal at Hanford.
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From page 195... ...
Cs-137 and Sr-90 Capsules In 1968 Hanford's B-Plant began separating cesium and strontium from tank waste in order to reduce radioactive decay heat in the waste tanks and allow less-radioactive reprocessed tank liquids to be discharged into the soil. A new facility was added in 1974 to encapsulate these radionuclides, as CsCl and SrF2, inside stainless steel cylinders.
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From page 196... ...
3. Radiochemical Processing Facility: • soil and groundwater biogeochemical fate and transport research; • waste and process chemistry, physical properties, mixing, transport, separations, and immobilization; • laboratory and bench-scale testing with bench tops, hoods, and hot cells; and • category-II nuclear facility for highly radioactive spent fuels, tank waste, contaminated soils and solutions, as well as spiked simulants.
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From page 197... ...
Presented to the Committee on Development and Implementation of a Cleanup Technology Roadmap. Hanford, Richland, WA, October 31.
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From page 198... ...
2003. Improving the Scientific Basis for Managing DOE's Excess Nuclear Materials and Spent Nuclear Fuel.
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From page 199... ...
Presented to the Committee on Development and Implementation of a Cleanup Technology Roadmap, Hanford, Richland, WA, October 31. Uziemblo, N
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