MOX Average Power 30 GWd/MT PIE: Final Report; Vol.1 Rev.0

Technical Report · Thu Nov 01 04:00:00 EST 2001

DOI:https://doi.org/10.2172/1409171· OSTI ID:1409171

Morris, R. N. ^[1]; Baldwin, C. A. ^[1]; Hodge, S. A. ^[1]; Packan, N. H. ^[1]

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1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

This report summarizes the results of the post irradiation examination of the 30 GWd/MT MOX average power test capsules (numbers 3 and 10). The purpose of this examination was to document and monitor the progress of the MOX average power irradiation. Both capsules were examined, opened, and the fuel pin removed. Capsule 3 contained Fuel Pin 6 and Capsule 10 contained Fuel Pin 13. Both fuel pins were easily removed from the capsules and were found to be in excellent condition. Visual and dimensional inspections revealed no problems. Measurement of the fission gas release fraction (1.5 to 2.3%) and fuel pellet stack gamma scan measurements indicate that the fuel is behaving satisfactorily. Metallo graphic mounts were prepared from both fuel pins and fuel behavior was examined with no indications of excessive swelling or fuel restructuring. As was found in previous PIEs, the size range of plutonium-rich agglomerates is rather large, up to approximately 600 microns in size. Careful observation of the metallographic mounts indicates that the fuel swelling is as predicted. There is evidence of irradiation-induced clad expansion (creep) along with some minor pelletclad mechanical interaction due to hourglassing. The fuel grain size was observed to be larger in the hotter center of the pellet than at the cooler edge. The TIGR-treated fuel appeared to exhibit relatively larger grain growth than the untreated fuel. The gallium content of the clad was in the sub ppm range indicating no significant migration of gallium from the fuel to the clad. Overall, both capsules underwent the irradiation with no detrimental effects and gallium migration/effects have not proved to be an issue.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1409171
• Report Number(s): ORNL/MD/LTR--212
• Country of Publication: United States
• Language: English

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