Investigation on cause of outage of Wide Range Monitor (WRM) in High Temperature engineering Test Reactor (HTTR); Transport operation toward investigation for cause of outage

Shinohara, Masanori; Sawahata, Hiroaki; Kawamoto, Taiki; Motegi, Toshihiro; Saito, Kenji; Takada, Shoji; Yoshida, Naoaki; Isozaki, Ryosuke; Katsuyama, Kozo

JAEA-Technology 2012-025, 31 Pages, 2012/08

JAEA-Technology-2012-025.pdf:4.69MB

An event, in which one of WRMs were disabled to detect the neutron flux in the reactor core, occurred during the period of reactor shut down of HTTR in March, 2010. The actual life time of WRM was unexpectedly shorter than the past developed life time. Investigation of the cause of the outage of WRM toward the recovery of the life time up to the developed life is one of the issues to develop the technology basis of High Temperature Gas cooled Reactor (HTGR). Then, a post irradiation examination was planned to specify the damaged part causing the event in the WRM was also planned. For the investigation, the X-ray computed tomography scanner in Fuels Monitoring Facility (FMF). This report describes the preliminary investigation on the cause of outage of the WRM. The results of study for transportation method of the irradiated WRM from HTTR to FMF is also reported with the record to complete the transport operation.

Effective Maintenance Method Based on the Reasonable Inspection Technique for the Deteriorating Hot Laboratory Exhaust Stack

Isozaki, Ryosuke; Mizukoshi, Yasutaka; Katsuyama, Kozo; Kodaka, Hideo

no journal, , 

no abstracts in English

Development of risk assessment method to cope with an aging degradation for the facilities using nuclear material, 1; Risk assessment flow of equipments

Tamaoki, Yuichi; Isozaki, Ryosuke; Suzuki, Ryuta; Akada, Masataka; Sawahata, Satoshi; Yonezawa, Ryoma; Suzuki, Hisashi; Mizukoshi, Yasutaka; Sakamoto, Naoki

no journal, , 

The five post-irradiation examination facilities in the Oarai Research and Development Institute of the Japan Atomic Energy Agency have been operated for over 40 years in order to investigate the irradiation performance and physicochemical characteristics of nuclear fuels and materials for fast reactors. The equipments associated with these facilities have been managed to maintain secure from the problems that occurred in the process of aging. Therefore, we established a safety assessment method for aging facilities in 2002, and we have been conducting maintenance management of facilities since then. In this study, designing risk assessment flow is considered in order to solve the issues detected as a result of analysis based on the experience of the repairment during the periodic safety review monitoring.

Development of risk assessment method to cope with an aging degradation for the facilities using nuclear material, 1; Risk point evaluation of aging equipment

Isozaki, Ryosuke; Tamaoki, Yuichi; Suzuki, Ryuta; Akada, Masataka; Sawahata, Satoshi; Suzuki, Hisashi; Yonezawa, Ryoma; Fujishima, Tadatsune; Mizukoshi, Yasutaka; Sakamoto, Naoki

no journal, , 

no abstracts in English