Tank Waste Retrieval, Processing, and On-site Disposal at Three Department of Energy Sites Final Report (2006) / Chapter Skim
Currently Skimming:
II Background and Overview of the Current Situation
II Background and Overview of the Current Situation
Pages 13-33
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From page 13... ...
depending on tank type. Some risers are larger: The Savannah River Site has 51 underground tanks1 that The center riser of a Type IV tank is approximately 2.7 m are used for storing 138,000 m3 (36.4 million gallons)
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FIGURE II-1 Simplified flowsheet of DOE's waste management plan for its tank and bin wastes at the Hanford, Idaho, and Savannah River sites. The waste processing box corresponds to the Waste Treatment and Immobilization Plant and supplemental treatment plant for Hanford; the steam reforming plant for the Idaho sodium-bearing waste; and sludge washing, and the Salt Waste Processing Facility at the Savannah River Site.
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The saltcake is a solid material composed of more than 99 DOE reported to the committee (Hill, 2006) on three sam pling studies:7 a 2002 statistical comparison of slurried percent salts, such as sodium nitrate, that contains concentrations of soluble and insoluble radioactive constituents sludge samples from eight individual tanks versus characterlower by approximately a factor of 10 to 20 than what is in ization predictions for those tanks, a review of seven superthe sludge.
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SOURCE: DOE-SRS, 2005b. TABLE II-1 Inventory of Radioactive Waste by Type at the Savannah River Site.
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. dedicated waste tank where it is "washed" to remove soluble salt constituents that will interfere with the glass-forming process and to reduce the volume of material that is sent to Savannah River Site Waste Processing the DWPF for vitrification into logs of waste glass.
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The plutonium production waste (supernate and saltcake) at the Savannah River Site.
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20 TANK WASTES AT THREE DOE SITES: FINAL REPORT FIGURE II-6 Map of the Hanford Site indicating the areas related to plutonium production and storage of high-level radioactive waste. NOTE: Figure does not include every facility in the 200 Area.
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,12 disposed to the ground after some radioSavannah River Site: highly alkaline waste in supernatant, saltcake, and sludge phases. The sodium hydroxide and nuclide removal (28.5 percent)
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This method produced liquid and solid alkaline waste containing high concentrations of organic complexants that retain some radioactive elements in solution. These separations, which removed approximately 90 percent of the strontium and cesium from the waste processed, were performed in the B Plant and produced intensely radioactive halide salts (cesium chloride and strontium fluoride)
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From page 23... ...
component of this potential problem revealed that radiolysis Like the tanks at the Savannah River Site, many Hanford had diminished the concentrations of the relevant species tanks have a bottom layer of sludge containing strontium and that they were diluted enough by other components of the waste to prevent significant further reaction rates. Based on information provided by site personnel, the committee judges that the global inventory of chemicals and 13The preferred method to estimate inventory is sampling, supplemented by process knowledge.
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From page 24... ...
As mentioned above, Hanford tank waste consists of Unlike waste at Hanford and the Savannah River Site, highly alkaline sludge, saltcake, and supernate. Cesium and sodium hydroxide was not added to the liquid tank waste, strontium isotopes and their decay products comprise most thus reducing the volume of storage space needed.
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. The bins are nearly all of the liquid waste from reprocessing of spent fuel contained in concrete vaults called Calcined Solids Storage at the Idaho National Laboratory, had been calcined by May Facilities (also known as "bin sets")
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discusses calcine characterization in Idaho bins and farm is called sodium-bearing waste. DOE describes sodiumpoints out both the discrepancies among characterization bearing waste as "a liquid mixed radioactive waste produced information and the heterogeneity of calcine properties from the second and third cycles of spent nuclear fuel repropotentially existing in the bins.
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From page 27... ...
sampled for steam reforming15 processing needs. Idaho Tank Inventories Idaho Tank Waste Processing and Tank Closure The vast majority of Idaho tank waste is in a liquid form, Waste processing at the Idaho National Laboratory is difbut a small amount of insoluble solids can be found at the ferent from that at the other two sites: There are no plans to bottoms of the tanks.
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DOE's plans for and status of waste tially to other wastes at the Savannah River and Idaho sites retrieval, processing, and tank closure at Idaho are described to which Sect. 3116 does not apply.
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. Savannah River Site and the Idaho National Laboratory (but Using the provisions of DOE Manual 435.1, DOE pro not Hanford)
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The meaning of the unmodified term "practical" in DOE's plans for Savannah River Site tank waste disposiSection 3116 requires some interpretation, i.e., whether it is tion are subject to the approval of the South Carolina Departthe same as the "technically and economically practical" ment of Health and Environmental Control under the found in Manual 435.1-1 or something different (including Savannah River Site Federal Facility Agreement (SRS FFA, more, fewer, or other considerations)
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; conditions in common with each other than with the · Piping and valve boxes connecting tanks and between Savannah River Site. It can also be seen that in the man tank farms; made features, particularly the fuel reprocessing methods TABLE II-4 Differences in the Natural Features from Site to Site Savannah River Site Hanford Site Idaho National Laboratory Average seasonal low/high temperature C (F)
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From page 32... ...
Tank sizes, 103 gal 55-1,160 750-1,300 30-318 60-471 Construction periods 1943-1964 SSTs Type I: 1954-1965 1953-1966 1960s (or years when in service) 1968-1986 DSTs Type II: 1956-1960 Type III: 1971-1992 Type IV: 1959-1965 Construction material Carbon steel Carbon steel Stainless steel Stainless steel Tank maximum ages in years More than 75 More than 75 More than 60 More than 40 at closure Tank conditions 67 confirmed and assumed 11 leakers, 1 to soil No leakers No leakers leakers, estimated 1 million gallons to soil Tank depth relative to Well above water table Some tank bottoms in Well above water table Above surface water table water table Extent of obstruction in tanks Abandoned equipment, Severe obstructions due Little or no obstructions debris to vertical cooling coils (cooling coils on the in most tanks bottom and walls)
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From page 33... ...
Hanford has completed techniques that are more or less likely to work in that parwaste retrieval from only 4 of its 177 tanks, while the ticular tank's environment. Savannah River Site has retrieved the waste from 4 of its 51 tanks -- in each case a small percentage of the number of FINDINGS AND RECOMMENDATIONS tanks to be emptied.
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