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Hamamoto, Shimpei; Shimizu, Atsushi; Inoi, Hiroyuki; Tochio, Daisuke; Homma, Fumitaka; Sawahata, Hiroaki; Sekita, Kenji; Watanabe, Shuji; Furusawa, Takayuki; Iigaki, Kazuhiko; et al.
Nuclear Engineering and Design, 388, p.111642_1 - 111642_11, 2022/03
Times Cited Count：2 Percentile：50.96(Nuclear Science & Technology)Following the Fukushima Daiichi Nuclear Power Plant accident in 2011, the Japan Atomic Energy Agency adapted High-Temperature engineering Test Reactor (HTTR) to meet the new regulatory requirements that began in December 2013. The safety and seismic classifications of the existing structures, systems, and components were discussed to reflect insights regarding High Temperature Gas-cooled Reactors (HTGRs) that were acquired through various HTTR safety tests. Structures, systems, and components that are subject to protection have been defined, and countermeasures to manage internal and external hazards that affect safety functions have been strengthened. Additionally, measures are in place to control accidents that may cause large amounts of radioactive material to be released, as a beyond design based accident. The Nuclear Regulatory Commission rigorously and appropriately reviewed this approach for compliance with the new regulatory requirements. After nine amendments, the application to modify the HTTR's installation license that was submitted in November 2014 was approved in June 2020. This response shows that facilities can reasonably be designed to meet the enhanced regulatory requirements, if they reflect the characteristics of HTGRs. We believe that we have established a reference for future development of HTGR.
Hashidate, Ryuta; Kato, Shoichi; Onizawa, Takashi; Wakai, Takashi; Kasahara, Naoto*
Proceedings of ASME 2021 Pressure Vessels and Piping Conference (PVP 2021) (Internet), 9 Pages, 2021/07
It is very essential to clarify the structure failure mechanisms under excessive seismic loads. However, structural tests using actual structural materials are very difficult and expensive. Therefore, we have proposed the structure test approach using lead alloys in order to simulate the structure failure mechanisms under the excessive seismic loads. In this study, we conducted material tests using lead alloy and verified the effectiveness of the simulated material tests. Moreover, we formulated inelastic constitutive equations (best fit fatigue curve equation and cyclic stress range - strain range relationship equation) of lead alloy based on the results of a series of material tests. Nonlinear numerical analyses, e.g. finite element analyses, can be performed using the proposed equations. A series of simulation material test technique enables structural tests and analyses using lead alloy to simulate the structure failure phenomena under excessive seismic loads.
Wada, Shigeru; Kawamura, Sho; Suzuki, Makoto; Kimura, Kazuya; Nagadomi, Hideki
no journal, ,
In 1990, JRR-3 was modified for upgrade and resumed its operation as a high performance and multi-purpose research reactor with thermal power of 20MW. Since modified, JRR-3 has been utilized for neutron beam experiments, neutron activation analysis, production of radioisotopes, neutron transmutation doping of silicon, fuel and material irradiation, etc. The maximum thermal power of JRR-3 is 20MW. JRR-3 is a light water moderated and cooled, pool type research reactor using low-enriched silicide fuel. JRR-3 had been confirmed conformation to new regulations on research and test reactor facilities which came into force on 18th December 2013. The application has been submitted to NRA on 26th September 2014. Finally, installment license of JRR-3 was permitted November in 2018. Restart the JRR-3 is planted in the few years.
Kimura, Kazuya; Araki, Masaaki; Nagadomi, Hideki; Wada, Shigeru
no journal, ,
no abstracts in English
Hamamoto, Shimpei; Shimazaki, Yosuke; Nagasumi, Satoru; Tochio, Daisuke; Iigaki, Kazuhiko; Ishitsuka, Etsuo
no journal, ,
Regarding the countermeasures against accidents that may release a large amount of radioactive materials, which is one of the items of conformity review on the New Regulatory Requirements for HTTR (High temperature engineering test reactor), this presentation describes the concept of accident selection, the evaluation method and results of the reactor behavior at the time of the selected accident and the countermeasures to be taken at that time.
Shimazaki, Yosuke; Hamamoto, Shimpei; Nagasumi, Satoru; Tochio, Daisuke; Iigaki, Kazuhiko; Ishitsuka, Etsuo
no journal, ,
no abstracts in English
