Evaluating techniques and phenomena of Stress Corrosion Cracking (SCC) in Light Water Reactors (LWRs); SCC evaluating techniques for predicting core internal and pipe aging of LWRs, technical data collection (Contract research)

Yamamoto, Masahiro; Kato, Chiaki; Sato, Tomonori; Nakano, Junichi; Ugachi, Hirokazu; Tsukada, Takashi; Kaji, Yoshiyuki; Tsujikawa, Shigeo*; Hattori, Shigeo*; Yoshii, Tsuguyasu*; et al.

JAEA-Review 2012-007, 404 Pages, 2012/03

JAEA-Review-2012-007.pdf:36.72MB

There are many LWRs which have been operated for more than 20 years in Japan and it is expected that technique corresponding to aging plants are necessary established for safety operation in LWRs. A lot of troubles related to SCC are reported and many investigations are concerned with SCC mechanism and technical evaluation. In this paper, those research data were collected as possible widely and reviewed systematically. Current circumstances concerned with SCC in LWRs were reviewed specifically as follows: SCC incidents, SCC evaluation methods for crack initiation and propagation, the investigations concerned with SCC mechanism and monitoring technique for corrosive environment. Influences with reactor types (BWR, PWR), materials (stainless steels, Ni alloys) and SCC evaluating methods (laboratories and actual plants) were summarized as graphs and tables easy to understand in common/difference points concerned with SCC. From these arranged results, future themes were considered and remarked SCC phenomenon was summarized in actual plants. As for SCC evaluations under the accelerate conditions in the laboratory test, it was suggested that a computational prediction and modeling including statistical technique and microscopic analysis in crack initiation were important. Furthermore it was suggested that monitoring techniques predicting SCC initiation and grasping plant circumstance in operation and feasibility in actual plants were important.

High-pressure activities in the new pulsed neutron source J-PARC

Hattori, Takanori; Arima, Hiroshi; Sano, Asami; Abe, Jun; Honda, Mitsunori; Fukazawa, Hiroshi; Utsumi, Wataru; Okuchi, Takuo*; Ono, Yoshiki*; Sasaki, Shigeo*; et al.

no journal, , 

The high-pressure neutron experiments above 10 GPa are limited so far due to the small neutron flux, which is insufficient for tiny high-pressure sample. Recent construction of the intense pulsed neutron source around the world has changed the situation. Inspired by the new Japanese pulsed neutron source JSNS at J-PARC, we started the high-P neutron experiments at the already operated beamlines (TAKUMI, NOVA) and the construction of the new beamline dedicated for high-pressure use (PLANET). This talk introduces these activities.

Systematization of assessment techniques of stress corrosion cracking for in-vessel components and piping in BWRs and PWRs

Kato, Chiaki; Yamamoto, Masahiro; Tsujikawa, Shigeo*; Hattori, Shigeo*; Yoshii, Tsuguyasu*; Kudo, Takeo*; Nemoto, Rikio*; Akashi, Masatsune*

no journal, , 

There are many LWRs which have been operated for more than 20 years in Japan and it is expected that technique corresponding to aging plants are necessary established for safety operation in LWRs. A lot of troubles related to SCC are reported and many investigations are concerned with SCC mechanism and technical evaluation. In this paper, those research data were collected as possible widely and reviewed systematically. Current circumstances concerned with SCC in LWRs were reviewed specifically as follows: SCC incidents, SCC evaluation methods for crack initiation and propagation, the investigations concerned with SCC mechanism and monitoring technique for corrosive environment. Influences with reactor types (BWR, PWR), materials (stainless steels, Ni alloys) and SCC evaluating methods (laboratories and actual plants) were summarized as graphs and tables easy to understand in common/difference points concerned with SCC. From these arranged results, future themes were considered and remarked SCC phenomenon was summarized in actual plants.