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Taguchi, Shigeo; Taguchi, Katsuya; Makino, Risa; Yamanaka, Atsushi; Suzuki, Kazuyuki; Takano, Masato; Koshino, Katsuhiko; Ishida, Michihiko; Nakano, Takafumi; Yamaguchi, Toshiya
Nihon Hozen Gakkai Dai-17-Kai Gakujutsu Koenkai Yoshishu, p.499 - 502, 2021/07
In 2018, Tokai Reprocessing Plan (TRP) shifted to the decommissioning stage. In order to proceed with steady decommissioning work, TRP effort to enhance project management function. This paper describes the establishment and role of the Decommissioning Project Management Office, effectiveness of applying the project management tool and its utilization concept, and the method of materialize the equipment dismantling plan.
Nagaoka, Shinichi; Ishida, Michihiko; Kanamori, Sadamu; Hayashi, Shinichiro
Proceedings of International Conference on Toward and Over the Fukushima Daiichi Accident (GLOBAL 2011) (CD-ROM), 5 Pages, 2011/12
The feasibility of applying PSA to nuclear fuel cycle facilities such as reprocessing plants has been also studied. We conducted a simplified risk assessment of each of the selected individual accident events and compared the assessment results for four accident categories (fire, explosion, criticality, and other accident events in which large amounts of radioactive materials are released).
Ishida, Michihiko; Hayashi, Yoshiaki*; Ueda, Yoshinori*; Yoshida, Kazuo
Nihon Genshiryoku Gakkai Wabun Rombunshi, 9(1), p.71 - 81, 2010/03
A special committee of "Research on the analysis methods for accident consequence of nuclear fuel cycle facilities (NFCF)" was organized by the Atomic Energy Society of Japan (AESJ) under the entrustment of Japan Atomic Energy Agency (JAEA) for a research on the state-of-the-art of consequence analysis method for Probabilistic Safety Assessment (PSA) of NFCF such as fuel reprocessing and fuel fabrication facilities. The objectives of this research is to obtain the basic useful information related for establishing the quantitative performance requirement and for risk-informed regulation through qualifying issues needed to be resolved for applying PSA to NFCF. In this technical report, it was summarized that the research result about basic experimental data related to the consequence of the radiolytically generated hydrogen gas explosion postulated in the radioactive solution reserve tank caused by the loss of dilution air supply.
Kobayashi, Yasushi; Yamada, Tsutomu; Naito, Morimasa; Yui, Mikazu; Nakayama, Masashi; Sato, Haruo; Nishida, Takahiro*; Hironaga, Michihiko*; Yamamoto, Takeshi*; Sugiyama, Daisuke*; et al.
JAEA-Research 2009-013, 70 Pages, 2009/06
JAEA-Research-2009-013.pdf:8.85MB
Cementitious materials will be used to ensure construction and operational safety and work efficiency in a deep geological repository. The low alkaline cement has been developed to reduce uncertainties due to hyper alkaline for the long-term safety performance of the repository system. Functions of cementitious material required in each phase of repository construction, operation and closure were summarized in a separate report entitled "Application Study on Low Alkaline Cementitious Materials for Deep Geological Repository of High Level Radioactive Wastes (Phase I) "In this report, properties of low alkaline cement/concrete which have been developed both at home and abroad, and recipes of the low alkaline concrete taken account of application to the repository component have been investigated. Fresh and hardened properties of the low alkaline cement are equivalent to the OPC and the low alkaline cement has an advantage over OPC in terms of leaching resistance. The HFSC developed by JAEA, which belongs to a pozzolanic type low alkaline cement will be able to apply to the shotcrete and the lining concrete by choosing an adequate recipe. Clarification of influences of the chemical composition of groundwater on leachate properties of the hydrates, examination of pH measurement of cement leachate, evaluation of corrosion behavior of rebar embedded in the HFSC concrete are raised as open questions for future activities.
Kobayashi, Yasushi; Yamada, Tsutomu; Naito, Morimasa; Yui, Mikazu; Nakayama, Masashi; Sato, Haruo; Nishida, Takahiro*; Hironaga, Michihiko*; Yamamoto, Takeshi*; Sugiyama, Daisuke*; et al.
JAEA-Research 2008-112, 43 Pages, 2009/03
JAEA-Research-2008-112.pdf:4.58MB
In deep geological repository, use of cementitious material for rock support, lining, and grouting is essential for construction and operation and possibly raises in groundwater pH due to leachate from the cements. Since this hyperalkaline condition may lead to degradation of barriers, there is concern that it gives significant impact on long-term safety performance of the repository system. Because of these backgrounds, developments of low alkaline cement have been conducted both at home and abroad. JAEA is now planning to conduct an in-situ test for shotcreting using low alkaline cement at the Horonobe URL. On the other hand, CRIEPI has studied and developed cementitious materials for disposal of radioactive wastes. This joint research report summarizes requirements and expected performance of cementitious materials in repository taking account of surrounding conditions in each stage of the repository program so as to reflect them to further development of the low alkaline cement.
Suzuki, Kazuhiko*; Ishida, Michihiko
JNC TY8400 2005-008, 54 Pages, 2005/08
JNC-TY8400-2005-008.pdf:2.88MB
Risk management is major concern to Nuclear Fuel Cycle Facilities to improve plant and process reliability and ensure their safety. This is because we are required to predict potential risks before any accident or disaster occurs. The advancement of safety design and safety systems technologies showed large amount of useful safety-related knowledge that can be of great importance to plant operation to reduce operation risks and ensure safety. This research proposes safety knowledge modeling framework on the basis of ontology technologies to systematically construct plant knowledge model, which includes plant structure, operation, and the associated behaviors. In such plant knowledge model safety related information is defined and linked to the different elements of plant knowledge model. Ontology editor is employed to define the basic concepts and their inter-relations, which are used to capture and construct plant safety knowledge. In order to provide detailed safety knowledgebase, HAZOP results are analyzed and structured so that safety-related knowledge are identified and structured within the plant knowledgebase. The target safety knowledgebase includes: failures, deviations, causes, consequences, and fault propagation as mapped to plant knowledge. The proposed ontology-based safety framework is applied on case study nuclear plant to structure failures, causes, consequences, and fault propagation, which are used to support plant operation.
Takafumi, Nakano,; Ishida, Michihiko; Kazuyuki, Morimoto,; Inano, Masatoshi; Nojiri, Ichiro
JNC TN8410 2003-017, 190 Pages, 2004/03
JNC-TN8410-2003-017.pdf:6.61MB
Probabilistic Safety Assessment (PSA) methodology has been applied to evaluate the relative importance of safety functions that prevent the progress of event causing to postulate accidents.
Ishida, Michihiko; ; Kazuyuki, Morimoto,; Nojiri, Ichiro
Probabilistic Safety Assessment and Management, p.543 - 548, 2004/00
Probabilistic Safety Assessment (PSA) methodology has been applied on the Tokai Reprocessing Plant (TRP) to evaluate relative importance of safety functions that prevent the progress of events causing to postulated accidents. The relative importance of safety functions was evaluated by using two major importance measures, Fussell-Vesely and Risk Achievement Worth both generally used in PSA of nuclear power plants. Through these evaluations, some useful insights into the safety of the TRP have been obtained. The results of the relative importance measures would be utilized to qualify component/equipment as important safety function.
Ozawa, Masaki; Ishida, Michihiko; Sano, Yuichi
Russian Radiochemistry, 2003, 45(3), 0 Pages, 2003/00
None
Ishida, Michihiko; Nojiri, Ichiro; ;
Kaku Nenryo Saikuru Anzensei Kokusai Wakushoppu, 0 Pages, 2002/00
None
Ishida, Michihiko; Sudo, Toshiyuki; Omori, Eiichi; Nojiri, Ichiro
Vol.1 No.040, 1(40), 0 Pages, 2001/00
None
; Ishida, Michihiko; Sano, Yuichi
pp.82-85, p.82 - 85, 2001/00
None
Nagaoka, Shinichi; Taguchi, Katsuya; Ishida, Michihiko; Kanamori, Sadamu
no journal, ,
no abstracts in English
Ishida, Michihiko; Inano, Masatoshi; Suzuki, Kazuhiko*
no journal, ,
no abstracts in English
Ishida, Michihiko
no journal, ,
Current Status of the probabilistic safety assessment of the Tokai Reprocessing Plant is outlined. This material will be presented at the workshop of the risk information application of the nuclear fuel cycle facilities.
Ishida, Michihiko; Suto, Toshiyuki; Inano, Masatoshi; Aoshima, Atsushi; Muramatsu, Ken; Ueda, Yoshinori*
no journal, ,
A study to evaluate component failure rates for a reprocessing plant has started at the Japan Atomic Energy Agency (JAEA). The study is sponsored by the Japan Nuclear Energy Safety Organization (JNES) as a contract research. The Tokai Reprocessing plant(TRP) has been operating over 30 years since 1977. Maintenance records of plant components have been accumulated and compiled in the Tokai Reprocessing Plant Maintenance Support System (TORMASS). Since the TORMASS was thought to be an effective source to pick up component failure information, the evaluation work of component failure rates started at 2005 based on the maintenance records in the TORMASS. By the end of 2006, failure rates for 17 types of 392 components had been evaluated. This result is expected to contribute to building up generic database for reprocessing plant component failure rates in order to promote the utilization of the risk information for reprocessing plants in Japan.
Ishida, Michihiko; Inano, Masatoshi; Aoshima, Atsushi; Suto, Toshiyuki; Muramatsu, Ken; Ueda, Yoshinori*
no journal, ,
Component failure rates are one of the most important inputs for PSA. Although there are many component failure rates databases for NPPs, there are few for a reprocessing plant. Therefore, in order to perform reliable PSA of a reprocessing plant, it is important to establish the failure rate database based on the actual plant maintenance data. The Tokai Reprocessing Plant (TRP) has been operating over 30 years since 1977. Maintenance records of plant components have been accumulated and compiled in the Tokai Reprocessing Plant Maintenance Support System (TORMASS). A basic study has started in the JAEA from 2005 by using the TORMASS data to contribute the development of reliable component failure rates. The outlines of the component failure estimation are summarized.
Tamaki, Hitoshi; Yoshida, Kazuo; Ishida, Michihiko; Muramatsu, Ken; Ueda, Yoshinori*
no journal, ,
no abstracts in English
Ueda, Yoshinori*; Ishida, Michihiko; Tamaki, Hitoshi; Muramatsu, Ken
no journal, ,
no abstracts in English
Ishida, Michihiko; Suto, Toshiyuki; Inano, Masatoshi; Aoshima, Atsushi
no journal, ,
In the Tokai Reprocessing Plant (TRP), process safety has been evaluated since the fire and explosion incident of the bituminization facility in 1997. In this report, both deterministic and probabilistic safety assessment approaches of the TRP are summarized.
