Development of a Waste Treatment Process to Deactivate Reactive Uranium Metal and Produce a Stable Waste Form

Conference · Thu Jan 17 00:00:00 EST 2002

OSTI ID:15002228

Gates-Anderson, D D; Laue, C A; Fitch, T E

This paper highlights the results of initial investigations conducted to support the development of an integrated treatment process to convert pyrophoric metallic uranium wastes to a non-pyrophoric waste that is acceptable for land disposal. Several dissolution systems were evaluated to determine their suitability to dissolve uranium metal and that yield a final waste form containing uranium specie(s) amenable to precipitation, stabilization, adsorption, or ion exchange. During initial studies, one gram aliquots of uranium metal or the uranium alloy U-2%Mo were treated with 5 to 60 mL of selected reagents. Treatment systems screened included acids, acid mixtures, and bases with and without addition of oxidants. Reagents used included hydrochloric, sulfuric, nitric, and phosphoric acids, sodium hypochlorite, sodium hydroxide and hydrogen peroxide. Complete dissolution of the uranium turnings was achieved with the H{sub 3}PO{sub 4}/HCI system at room temperature within minutes. The sodium hydroxide/hydrogen peroxide, and sodium hypochlorite systems achieved complete dissolution but required elevated temperatures and longer reaction times. A ranking system based on criteria, such as corrosiveness, temperature, dissolution time, off-gas type and amount, and liquid to solid ratio, was designed to determine the treatment systems that should be developed further for a full-scale process. The highest-ranking systems, nitric acid/sulfuric acid and hydrochloric acid/phosphoric acid, were given priority in our follow-on investigations.

• Research Organization: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 15002228
• Report Number(s): UCRL-JC-147189; TRN: US0400659
• Resource Relation: Conference: 28th Annual Waste Management Symposium, Tucson, AZ (US), 02/24/2002--02/28/2002; Other Information: PBD: 17 Jan 2002
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
36 MATERIALS SCIENCE
61 RADIATION PROTECTION AND DOSIMETRY
ADSORPTION
DISSOLUTION
HYDROGEN PEROXIDE
ION EXCHANGE
OXIDIZERS
PHOSPHORIC ACID
PRECIPITATION
SODIUM
SODIUM HYDROXIDES
STABILIZATION
URANIUM
URANIUM ALLOYS
WASTE FORMS
WASTE MANAGEMENT
WASTE PROCESSING