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Title: Characterization of Pu-238 Heat Source Granule Containment

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 SEMmore » mode of Energy Dispersive X-ray spectroscopy (EDS).« less
Authors:
 [1] ;  [1] ;  [1] ;  [1]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
OSTI Identifier:
1170259
Report Number(s):
LA-UR--15-20994
TRN: US1600051
DOE Contract Number:
AC52-06NA25396
Resource Type:
Conference
Resource Relation:
Conference: Nuclear and Emerging Technologies for Space 2015, Albuquerque, NM (United States), 24 Feb 2015
Research Org:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States
Language:
English
Subject:
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