Water Solubility of Plutonium and Uranium Compounds and Residues at TA-55

Technical Report · Mon Jun 13 00:00:00 EDT 2016

DOI:https://doi.org/10.2172/1257103· OSTI ID:1257103

Reilly, Sean Douglas ^[1]; Smith, Paul Herrick ^[1]; Jarvinen, Gordon D. ^[1]; Prochnow, David Adrian ^[1]; Schulte, Louis D. ^[1]; DeBurgomaster, Paul Christopher ^[1]; Fife, Keith William ^[1]; Rubin, Jim ^[1]; Worl, Laura Ann ^[1]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States

Understanding the water solubility of plutonium and uranium compounds and residues at TA-55 is necessary to provide a technical basis for appropriate criticality safety, safety basis and accountability controls. Individual compound solubility was determined using published solubility data and solution thermodynamic modeling. Residue solubility was estimated using a combination of published technical reports and process knowledge of constituent compounds. The scope of materials considered includes all compounds and residues at TA-55 as of March 2016 that contain Pu-239 or U-235 where any single item in the facility has more than 500 g of nuclear material. This analysis indicates that the following materials are not appreciably soluble in water: plutonium dioxide (IDC=C21), plutonium phosphate (IDC=C66), plutonium tetrafluoride (IDC=C80), plutonium filter residue (IDC=R26), plutonium hydroxide precipitate (IDC=R41), plutonium DOR salt (IDC=R42), plutonium incinerator ash (IDC=R47), uranium carbide (IDC=C13), uranium dioxide (IDC=C21), U₃O₈ (IDC=C88), and uranium filter residue (IDC=R26). This analysis also indicates that the following materials are soluble in water: plutonium chloride (IDC=C19) and uranium nitrate (IDC=C52). Equilibrium calculations suggest that PuOCl is water soluble under certain conditions, but some plutonium processing reports indicate that it is insoluble when present in electrorefining residues (R65). Plutonium molten salt extraction residues (IDC=R83) contain significant quantities of PuCl₃, and are expected to be soluble in water. The solubility of the following plutonium residues is indeterminate due to conflicting reports, insufficient process knowledge or process-dependent composition: calcium salt (IDC=R09), electrorefining salt (IDC=R65), salt (IDC=R71), silica (IDC=R73) and sweepings/screenings (IDC=R78). Solution thermodynamic modeling also indicates that fire suppression water buffered with a commercially-available phosphate buffer would significantly reduce the solubility of PuCl₃ by the precipitation of PuPO₄.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC52-06NA25396
• OSTI ID: 1257103
• Report Number(s): LA-UR-16-24113; TRN: US1601490
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
URANIUM OXIDES U3O8
URANIUM DIOXIDE
ASHES
PLUTONIUM PHOSPHATES
URANIUM CARBIDES
URANIUM NITRATES
MOLTEN SALTS
PLUTONIUM CHLORIDES
WATER
SOLUTIONS
SOLUBILITY
PLUTONIUM 239
PLUTONIUM DIOXIDE
URANIUM 235
CALCIUM COMPOUNDS
SILICA
MATHEMATICAL MODELS
EXTRACTION
FILTERS
EQUILIBRIUM
PLUTONIUM FLUORIDES
PLUTONIUM HYDROXIDES
RESIDUES
PLUTONIUM COMPOUNDS
OXYCHLORIDES
plutonium uranium compound residue water solubility