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

Journal Article · Thu Jan 15 04:00:00 EST 1998 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.54769· OSTI ID:21179674

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

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1. Los Alamos National Laboratory, P.O. Box 1663, MS-E502, Los Alamos, New Mexico 87545 (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.

• OSTI ID: 21179674
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 420; ISSN 0094-243X; ISSN APCPCS
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
CAPSULES
COMPARATIVE EVALUATIONS
CORRELATIONS
CRACKS
DATA ANALYSIS
ENGINEERING
FUEL PELLETS
GAMMA RADIOGRAPHY
IRIDIUM ALLOYS
NESDPS Office of Nuclear Energy Space and Defense Power Systems
PERFORMANCE
PLUTONIUM 238
PLUTONIUM OXIDES
RADIOISOTOPE HEAT SOURCES
SAFETY
SPACE FLIGHT
THERMOELECTRIC GENERATORS
TRANSDUCERS
ULTRASONIC TESTING
WELDED JOINTS