Corrosion of Commercial Spent Nuclear Fuel. 2. A Radiochemical Analyses of Metastudtite and Leachates

Journal Article · Tue Mar 01 04:00:00 EST 2005 · Radiochimica Acta

DOI:https://doi.org/10.1524/ract.93.3.169.61615· OSTI ID:15016738

McNamara, Bruce K; Hanson, Brady D; Buck, Edgar C; Soderquist, Chuck Z

Immersing commercial spent nuclear fuel (CSNF) in deionized water produced two corrosion products after a 2-year contact period. Suspensions of aggregates were observed to form at the air-water interface for each of five samples. These suspended aggregates were characterized by X-ray diffraction (XRD) to be metastudtite (UO{sub 4} {center_dot} 2H{sub 2}O), while the corrosion present on the surface of the fuel itself was determined to be studtite [(UO{sub 2})(O{sub 2})(H{sub 2}O){sub 2}](H{sub 2}O){sub 2}. The presence of unreacted UO{sub 2} matrix was below the limits of detection by XRD for the three samples examined. The result prompted a radiochemical analysis of the solids collected from the sample air-water interface. The analysis indicated that high concentrations of {sup 90}Sr, {sup 137}Cs, and {sup 99}Tc, relative to the fuel inventory, had concentrated at the air-water interface along with the aggregates of metastudtite. Concentrations of {sup 241}Am were at least two orders of magnitude lower than expected in these solids, and retention of {sup 237}Np and {sup 239}Pu into the corrosion product was observed. The combined radiochemical analyses of the air-water interface aggregates and leachate samples are a rare example of radionuclide partitioning to an alteration phase and may provide preliminary evidence for mechanisms that give rise to such noticeable departures from fuel-inventory values. The leachate radiochemical data are compared to existing data from hydration of the same CSNF.

• Research Organization: Pacific Northwest National Lab., Richland, WA (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 15016738
• Report Number(s): PNNL-SA-43013
• Journal Information: Radiochimica Acta, Journal Name: Radiochimica Acta Journal Issue: 3 Vol. 93; ISSN RAACAP; ISSN 0033-8230
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
CORROSION
CORROSION PRODUCTS
CSNF
STUDTITE
METASTUDTITE
DETECTION
HYDRATION
LEACHATES
NUCLEAR FUELS
RADIOCHEMICAL ANALYSIS
RADIOISOTOPES
RETENTION
SPENT FUELS
WATER
X-RAY DIFFRACTION