Light-weight radioisotope heater unit (LWRHU) impact tests

Journal Article · Wed Jan 14 23:00:00 EST 1998 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.54756· OSTI ID:21179666

Reimus, M A. H.; Rinehart, G H; Herrera, A; Lopez, B; Lynch, C; Moniz, P ^[1]

---

1. Nuclear Materials Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

The light-weight radioisotope heater unit (LWRHU) is a {sup 238}PuO{sub 2}-fueled heat source designed to provide one thermal watt in each of various locations on a spacecraft. Los Alamos National Laboratory designed, fabricated, and safety tested the LWRHU. The heat source consists of a hot-pressed {sup 238}PuO{sub 2} fuel pellet, a Pt-30Rh vented capsule, a pyrolytic graphite insulator, and a fineweave-pierced fabric graphite aeroshell assembly. To compare the performance of the LWRHUs fabricated for the Cassini mission with the performance of those fabricated for the Galileo mission, and to determine a failure threshold, two types of impact tests were conducted. A post-reentry impact test was performed on one of 180 flight-quality units produced for the Cassini mission and a series of sequential impact tests using simulant-fueled LWRHU capsules were conducted respectively. The results showed that deformation and fuel containment of the impacted Cassini LWRHU was similar to that of a previously tested Galileo LWRHU. Both units sustained minimal deformation of the aeroshell and fueled capsule; the fuel was entirely contained by the platinum capsule. Sequential impacting, in both end-on and side-on orientations, resulted in increased damage with each subsequent impact. Sequential impacting of the LWRHU appears to result in slightly greater damage than a single impact at the final impact velocity of 50 m/s.

• OSTI ID: 21179666
• 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

30 DIRECT ENERGY CONVERSION
CAPSULES
COMPARATIVE EVALUATIONS
DAMAGE
FAILURES
FUEL PELLETS
GRAPHITE
IMPACT TESTS
JUPITER PLANET
LANL
NESDPS Office of Nuclear Energy Space and Defense Power Systems
PERFORMANCE
PLATINUM
PLUTONIUM 238
PLUTONIUM COMPOUNDS
RADIOISOTOPE HEAT SOURCES
SAFETY
SPACE FLIGHT
THERMOELECTRIC CONVERSION
THERMOELECTRIC GENERATORS