Nondestructive inspection of General Purpose Heat Source (GPHS) fueled clad girth welds

Journal Article · Wed Dec 31 23:00:00 EST 1997 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.54769· OSTI ID:664645

Reimus, M A; George, T G; Lynch, C; Padilla, M; Moniz, P; Guerrero, A ^[1]; Moyer, M W ^[2]; Placr, A ^[3]

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1. Los Alamos National Laboratory, P.O. Box 1663, MS-E502, Los Alamos, New Mexico 87545 (United States)
2. Oak Ridge Y-12 Plant, Building 9203, MS-8084, Oak Ridge, Tennessee 37831 (United States)
3. Westinghouse Savannah River Company, Building 305-A, Aiken, South Carolina 29808 (United States)

The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements. The GPHS is fabricated using an iridium-alloy to contain the {sup 238}PuO{sub 2} fuel pellet. GPHS capsules will be utilized in the upcoming Cassini mission to explore Saturn and its moons. The physical integrity of the girth weld is important to mission safety and performance. Because past experience had revealed a potential for initiation of small cracks in the girth weld overlap zone, a nondestructive inspection of each capsule weld is required. An ultrasonic method was used to inspect the welds of capsules fabricated for the Galileo mission. The instrument, transducer, and method used were state of the art at the time (early 1980s). The ultrasonic instrumentation and methods used to inspect the Cassini GPHSs was significantly upgraded from those used for the Galileo mission. GPHSs that had ultrasonic reflectors in excess of the reject specification level were subsequently inspected with radiography to provide additional engineering data used to accept/reject the heat source. This paper describes the Galileo-era ultrasonic instrumentation and methods and the subsequent upgrades made to support testing of Cassini GPHSs. Also discussed is the data obtained from radiographic examination and correlation to ultrasonic examination results. {copyright} {ital 1998 American Institute of Physics.}

• OSTI ID: 664645
• Report Number(s): CONF-980103--
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 420; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

07 ISOTOPE AND RADIATION SOURCES
30 DIRECT ENERGY CONVERSION
COMPARATIVE EVALUATIONS
CORRELATIONS
DATA ANALYSIS
FUEL PELLETS
IRIDIUM ALLOYS
IRIDIUM BASE ALLOYS
MICRORADIOGRAPHY
NESDPS Office of Nuclear Energy Space and Defense Power Systems
PLUTONIUM
PLUTONIUM 238
RADIOISOTOPE HEAT SOURCES
THERMOELECTRIC GENERATORS
ULTRASONIC TESTING
WELDED JOINTS
WELDING