Characterization of Pu-238 Heat Source Granule Containment

Conference · Wed Feb 11 00:00:00 EST 2015

OSTI ID:1170259

Richardson, Paul Dean II ^[1]; Sanchez, Joey Leo ^[1]; Wall, Angelique Dinorah ^[1]; Chavarria, Rene ^[1]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

The Milliwatt Radioisotopic Themoelectric Generator (RTG) provides power for permissive-action links. Essentially these are nuclear batteries that convert thermal energy to electrical energy using a doped silicon-germanium thermopile. The thermal energy is provided by a heat source made of ²³⁸Pu, in the form of ²³⁸PuO₂ granules. The granules are contained by 3 layers of encapsulation. A thin T-111 liner surrounds the ²³⁸PuO₂ granules and protects the second layer (strength member) from exposure to the fuel granules. An outer layer of Hastalloy-C protects the T-111 from oxygen embrittlement. The T-111 strength member is considered the critical component in this ²³⁸PuO₂ containment system. Any compromise in the strength member seen during destructive testing required by the RTG surveillance program is characterized. The T-111 strength member is characterized through Scanning Electron Microscopy (SEM), and Metallography. SEM is used in the Secondary Electron mode to reveal possible grain boundary deformation and/or cracking in the region of the strength member weld. Deformation and cracking uncovered by SEM are further characterized by Metallography. Metallography sections are mounted and polished, observed using optical microscopy, then documented in the form of microphotographs. SEM mat further be used to examine polished Metallography mounts to characterize elements using the SEM mode of Energy Dispersive X-ray spectroscopy (EDS).

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• DOE Contract Number: AC52-06NA25396
• OSTI ID: 1170259
• Report Number(s): LA-UR-15-20994; TRN: US1600051
• Resource Relation: Conference: Nuclear and Emerging Technologies for Space 2015, Albuquerque, NM (United States), 24 Feb 2015
• Country of Publication: United States
• Language: English

Related Subjects

07 ISOTOPE AND RADIATION SOURCES
SCANNING ELECTRON MICROSCOPY
PLUTONIUM 238
GRAIN BOUNDARIES
METALLOGRAPHY
GERMANIUM
LAYERS
SILICON
DOPED MATERIALS
OPTICAL MICROSCOPY
X-RAY SPECTROSCOPY
DEFORMATION
THERMOCOUPLES
ENCAPSULATION
RADIOISOTOPE BATTERIES
PLUTONIUM OXIDES
MILLIWATT POWER RANGE
THERMOELECTRIC GENERATORS
NESDPS Office of Nuclear Energy Space and Defense Power Systems