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Title: Ir/PuO/sub 2/ compatibility: transfer of impurities from plutonium dioxide to iridium metal during high temperature aging

Conference ·
OSTI ID:5048057

Plutonium oxide fuel pellets for powering radioisotopic thermoelectric generators for NASA space vehicles are encapsulated in iridium which has been grain-boundary-stabilized with thorium and aluminum. After aging for 6 months at 1310/sup 0/C under vacuum, enhanced grain growth is observed in the near-surface grains of the iridium next to the PuO/sub 2/. Examination of the grain boundaries by AES and SIMS shows a depletion of thorium and aluminum. Iron, chromium, and nickel from the fuel were found to diffuse into the iridium along the grain boundaries. Enhanced grain growth appears to result from thorium depletion in the grain boundaries of the near-surface grains next to the fuel. However, in one instance grain growth was slowed by the formation of thorium oxide by oxygen diffusing up the grain boundaries.

Research Organization:
Du Pont de Nemours (E.I.) and Co., Aiken, SC (USA). Savannah River Lab.; Oak Ridge National Lab., TN (USA); Los Alamos National Lab., NM (USA)
DOE Contract Number:
AC09-76SR00001
OSTI ID:
5048057
Report Number(s):
DP-MS-83-85; CONF-840218-4; ON: DE84008301; TRN: 84-008440
Resource Relation:
Conference: 113. annual meeting of the American Institute of Mining, Metallurgical and Petroleum Engineers, Los Angeles, CA, USA, 26 Feb 1984; Other Information: Portions are illegible in microfiche products
Country of Publication:
United States
Language:
English