K Basin sludge dissolution engineering study

Technical Report · Fri Aug 28 04:00:00 EDT 1998

DOI:https://doi.org/10.2172/10148540· OSTI ID:10148540

Westra, A. G. ^[1]

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1. Fluor Daniel Hanford Inc., Richland, WA (United States)

The purpose of this engineering study is to investigate the available technology related to dissolution of the K Basin sludge in nitric acid. The conclusion of this study along with laboratory and hot cell tests with actual sludge samples will provide the basis for beginning conceptual design of the sludge dissolver. The K Basin sludge contains uranium oxides, fragments of metallic U, and some U hydride as well as ferric oxyhydroxide, aluminum oxides and hydroxides, windblown sand that infiltrated the basin enclosure, ion exchange resin, and miscellaneous materials. The decision has been made to dispose of this sludge separate from the fuel elements stored in the basins. The sludge will be conditioned so that it meets Tank Waste Remediation System waste acceptance criteria and can be sent to one of the underground storage tanks. Sludge conditioning will be done by dissolving the fuel constituents in nitric acid, separating the insoluble material, adding neutron absorbers for criticality safety, and then reacting the solution with caustic to co-precipitate the uranium and plutonium. There will be five distinct feed streams to the sludge conditioning process two from the K East (KE) Basin and three from the K West (KW) Basin. The composition of the floor and pit sludges which contain more iron oxides and sand than uranium is much different than the canister sludges which are composed of mostly uranium oxides. The sludge conditioning equipment will be designed to process all of the sludge streams, but some of the operating parameters will be adjusted as necessary to handle the different sludge stream compositions. The volume of chemical additions and the amount of undissolved solids will be much different for floor and pit sludge than for canister sludge. Dissolution of uranium metal and uranium dioxide has been studied quite thoroughly and much information is available. Both uranium metal and uranium dioxide have been dissolved on a large scale in nuclear fuel reprocessing plants in Europe, Japan, and the USA. Ash and sludge containing uranium compounds also have been dissolved in reprocessing or plutonium scrap recovery plants, but only a limited amount of information is available on how the ferric oxyhydroxide, aluminum compounds and silicates in the sand will behave during nitric acid dissolution. Laboratory work with simulants and hot cell work with actual K Basin sludge is in progress to obtain data in these areas.

• Research Organization: Fluor Daniel Hanford Inc., Richland, WA (United States)
• Sponsoring Organization: USDOE Office of Environmental Restoration and Waste Management; USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP)
• DOE Contract Number: AC06-96RL13200
• OSTI ID: 10148540
• Report Number(s): HNF--3096; ON: DE99050974; BR: EW7040000
• Country of Publication: United States
• Language: English

Related Subjects

050900
052001
054000
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
DISSOLUTION
FUEL STORAGE POOLS
HEALTH AND SAFETY
K Basin Sludge
NITRIC ACID
Nitric Acid
Nuclear Criticality Safety Program (NCSP)
RADIOACTIVE WASTE PROCESSING
REMEDIAL ACTION
SLUDGES
SPENT FUEL STORAGE
TRANSPORT, HANDLING, AND STORAGE
WASTE PROCESSING