Analysis of in-situ electrical conductivity data from the HFIR TRIST-ER1 experiment
- Oak Ridge National Lab., TN (United States)
- Tohoku Univ. (Japan); and others
The current vs. applied voltage data generated from the HFIR TRIST-ER1 experiment have been analyzed to determine the electrical conductivity of the 15 aluminum oxide specimens and the MgO-insulated electrical cables as a function of irradiation dose. With the exception of the 0.05%Cr-doped sapphire (ruby) specimen, the electrical conductivity of the alumina specimens remained at the expected radiation induced conductivity (RIC) level of <10{sup -6} S/m during full-power reactor irradiation (10-16 kGy/s) at 450-500{degrees}C up to a maximum dose of {approximately}3 dpa. The ruby specimen showed a rapid initial increase in conductivity to {approximately}2 x 10{sup -4} S/m after {approximately}0.1 dpa, followed by a gradual decrease to <1 x 10{sup -6} S/m after 2 dpa. Nonohmic electrical behavior was observed in all of the specimens, and was attributed to preferential attraction of ionized electrons in the capsule gas to the unshielded low-side bare electrical leads emanating from the subcapsules. The electrical conductivity was determined from the slope of the specimen current vs. voltage curve at negative voltages, where the gas ionization effect was minimized. Dielectric breakdown tests performed on unirradiated mineral-insulated coaxial cables identical to those used in the high voltage coaxial cables during the 3-month irradiation is attributable to thermal dielectric breakdown in the glass seals at the end of the cables, as opposed to a radiation-induced electrical degradation (RIED) effect.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- OSTI ID:
- 543215
- Report Number(s):
- DOE/ER-0313/22; ON: DE97008797; TRN: 97:020255
- Resource Relation:
- Other Information: PBD: Aug 1997; Related Information: Is Part Of Fusion materials semiannual progress report for period ending June 30, 1997; PB: 358 p.
- Country of Publication:
- United States
- Language:
- English
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