Progress Report on Disassembly and Post-Irradiation Experiments for UCSB ATR-2 Experiment

Nanstad, Randy K¹  Odette, G. R.²  Robertson, Janet Pawel¹  Yamamoto, T² 

[1] Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States);Univ. of California, Santa Barbara, CA (United States)

关键词: post-irradiation examination;    reactor;    flux;    fluence;    reactor pressure vessel;    microhardness;    fracture toughness;    hot cell;   

DOI  :  10.2172/1223085
RP-ID  :  ORNL/TM--2015/561
PID  :  OSTI ID: 1223085
Others  :  Other: RC0304000
Others  :  NERC006

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来源: SciTech Connect

【 摘 要 】

The reactor pressure vessel (RPV) in a light-water reactor (LWR) represents the first line of defense against a release of radiation in case of an accident. Thus, regulations that govern the operation of commercial nuclear power plants require conservative margins of fracture toughness, both during normal operation and under accident scenarios. In the unirradiated condition, the RPV has sufficient fracture toughness such that failure is implausible under any postulated condition, including pressurized thermal shock (PTS) in pressurized water reactors (PWR). In the irradiated condition, however, the fracture toughness of the RPV may be severely degraded, with the degree of toughness loss dependent on the radiation sensitivity of the materials. As stated in previous progress reports, the available embrittlement predictive models, e.g. [1], and our present understanding of radiation damage are not fully quantitative, and do not treat all potentially significant variables and issues, particularly considering extension of operation to 80y.