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Ono, Ayato; Takayanagi, Tomohiro; Ueno, Tomoaki*; Horino, Koki*; Yamamoto, Kazami; Kinsho, Michikazu
JAEA-Technology 2020-023, 40 Pages, 2021/02
JAEA-Technology-2020-023.pdf:2.98MB
The 3 GeV rapid cycling synchrotron of Japan Proton Accelerator Research Complex (J-PARC) uses a large number of electromagnet power supplies in order to generate a high-intensity beam of 1 MW. These devices have been specially developed to meet the required specifications of the proton beams. Ten years have passed since the 3 GeV synchrotron had started operation, and we need to replace and update of the components due to failures caused by the aging deterioration. Since the J-PARC is used by many users, it is quite important to recover as soon as possible when a trouble occurs. However, we often spend lots of time to investigate the status and cause of the problem, then it results in the delay of recovery work. One of the major reasons is due to the differences in the manufacturers of sensors and monitors. Therefore, we have to create a manual for each power supply and prepare some exclusive tools. However, troubles rarely occur in the same state and situation, so we have to rely on the experience and knowledge. Even for power supplies with different purposes and specifications, some components, such as sensors, can be shared in many cases. In addition, if the concept of the interlock system, for monitoring the status of the power supply and detecting malfunctions, is shared between the different power supplies, the method and response for failure investigation can be standardized. By using a device with good maintainability, the accelerator operation will be more stable and reliable. In this report, we introduce the necessity of sharing the design concept and common parts. We also explain the basic design model for safety and reliability, using an example of manufacturing an electromagnet power supply for the 3 GeV synchrotron.
Yamaguchi, Yoshihito; Mano, Akihiro; Katsuyama, Jinya; Masaki, Koichi*; Miyamoto, Yuhei*; Li, Y.
JAEA-Data/Code 2020-021, 176 Pages, 2021/02
JAEA-Data-Code-2020-021.pdf:5.26MB
In Japan Atomic Energy Agency, as a part of researches on the structural integrity assessment and seismic safety assessment of aged components in nuclear power plants, a probabilistic fracture mechanics (PFM) analysis code PASCAL-SP (PFM Analysis of Structural Components in Aging LWR - Stress Corrosion Cracking at Welded Joints of Piping) has been developed to evaluate failure probability of piping. The initial version was released in 2010, and after that, the evaluation targets have been expanded and analysis functions have been improved based on the state-of-the art technology. Now, it is released as Ver. 2.0. In the latest version, primary water stress corrosion cracking in the environment of Pressurized Water Reactor, nickel based alloy stress corrosion cracking in the environment of Boiling Water Reactor, and thermal embrittlement can be taken into account as target age-related degradation. Also, many analysis functions have been improved such as incorporations of the latest stress intensity factor solutions and uncertainty evaluation model of weld residual stress. Moreover, seismic fragility evaluation function has been developed by introducing evaluation methods including crack growth analysis model considering excessive cyclic loading due to large earthquake. Furthermore, confidence level evaluation function has been incorporated by considering the epistemic and aleatory uncertainties related to influence parameters in the probabilistic evaluation. This report provides the user's manual and analysis methodology of PASCAL-SP Ver. 2.0.
Tanaka, Masaaki; Nakada, Kotaro*; Kudo, Yoshiro*
Nihon Kikai Gakkai-Shi, 123(1222), p.26 - 29, 2020/09
In the nuclear engineering, simulations are used in radiation, thermal hydraulic, chemical reaction, and structural fields, and the integrated fields thereof, to be applied to the design, construction and operation of nuclear facilities. This article describes brief history of discussion in the AESJ to the publication and introductory explanation of the procedures in the five major elements described in the "Guideline for Credibility Assessment of Nuclear Simulations (AESJ-SC-A008: 2015)". And also, a practical experience of the V&V activity according to the fundamental concept indicated in the Guideline is introduced.
Osawa, Hideaki; Otomo, Shoji*; Hirose, Yukio*; Onuma, Susumu*
Ningen Kankyogaku Kenkyu, 17(1), p.59 - 64, 2019/06
This study examined the determinants of public acceptance of siting a repository for High-level radioactive waste (HLW), focusing on procedural fairness and trust. To examine the presumption, the study implemented a hypothetical scenario experiment that manipulated two factors: an opportunity of voice as an antecedent of procedural fairness and similarity value to the authority as a component of trust. Results indicated that affective reaction, procedural fairness, and trust determined public acceptance. A process analysis indicated that the effect of procedural fairness was strengthened when the trust on similarity was negative.
Takei, Hayanori; Furukawa, Kazuro*; Yano, Yoshiharu*; Ogawa, Yujiro*
Journal of Nuclear Science and Technology, 55(9), p.996 - 1008, 2018/09
Times Cited Count：2 Percentile：20.93(Nuclear Science & Technology)Experiences with existing high-power proton accelerators indicate that frequent beam trips are inevitable. One of the reasons for such frequent beam trips is the accidental interruption to protect accelerators against fatal failures. Generally, the failure frequency for the general machinery can be evaluated based on a reliability database for its components. On the other hand, the beam-trip frequency for the accidental interruption was not evaluated based on the reliability database because it has not yet been established. A principal reason for the lack of this reliability database is the inconsistency of data collection and analysis methods among laboratories. For example, there are at least three methods to estimate Mean Time Between accidental Interruptions (MTBI) for klystron systems. In the present study, the MTBI of the klystron systems of an electron/positron injector linac at the High Energy Accelerator Research Organization (KEK) was evaluated based on the reliability engineering method, in order to build the reliability database using the unified data collection and analysis method. As the result, the mean values of the MTBI by the traditional three methods were evaluated as 30.9, 32.0, and 50.4 hours. On the other hand, that by the reliability engineering method was evaluated as 57.3 hours, i.e., more than 1.14 times of the traditional results. Although these results are obviously different from traditional results, it appears that the present estimation based on the reliability engineering method is suitable for the MTBI of accelerator components as typified by the klystron system.
Katsuyama, Jinya; Masaki, Koichi; Miyamoto, Yuhei*; Li, Y.
JAEA-Data/Code 2017-015, 229 Pages, 2018/03
JAEA-Data-Code-2017-015.pdf:5.8MBJAEA-Data-Code-2017-015(errata).pdf:0.15MB
As a part of the structural integrity research for aging light water reactor components, a probabilistic fracture mechanics (PFM) analysis code PASCAL has been developed in JAEA. The PASCAL code can evaluate the conditional failure probabilities and failure frequencies for core region in reactor pressure vessels under the pressurized thermal shock events. In this study, we improved many functions such as the stress intensity factor solutions, the fracture toughness models, or confidence level evaluation function by considering epistemic and aleatory uncertainties related to influence parameters in the structural integrity assessment. We also developed the analysis module PASCAL-Manager which calculates the failure frequency for the entire core region taking into consideration the failure probabilities obtained from PACAL-RV. Based on these improvements, the new analysis code is upgraded to PASCAL Ver.4. This report provides the user's manual and theoretical background of PASCAL Ver.4.
Nakada, Kotaro*; Kudo, Yoshiro*; Koshizuka, Seiichi*; Tanaka, Masaaki
Nihon Genshiryoku Gakkai-Shi ATOMO
, 60(3), p.173 - 177, 2018/03
The Atomic Energy Society of Japan (AESJ) published "Guideline for Credibility Assessment of Nuclear Simulations 2015" in June, 2016 which specifies the concepts on methodology for the prediction with uncertainty quantification and the quality management based on the concept of verification and validation (V&V) of modeling and simulation. In this report, the outlines of activities in AESJ for publication of the guideline and the expectation for effective implementation of the guideline are described including that of the lectures with major respondents of the questionnaires.
Okajima, Satoshi
Nihon Kikai Gakkai 2017-Nendo Nenji Taikai Koen Rombunshu (DVD-ROM), 3 Pages, 2017/09
Fitness-For-Service (FFS) assessment for the component with metal-loss is desired to reflect the effect of usual maintenance. Introduction of evaluation method based on reliability is one of the effective measures to achieve this. High Pressure Institute of Japan published HPIS Z 109TR:2016 "Metal loss assessment for pressure equipment based on reliability", which provides methods and technical backgrounds of metal loss assessment for pressure equipment based on reliability. This technical report provides evaluation method for simply evaluating reliability of the pressure equipment with metal loss based on the partial safety factor method. We present outline of the evaluation method based on the partial safety factor method.
Tanaka, Masaaki
Nihon Genshiryoku Gakkai Keisan Kagaku Gijutsu Bukai Nyusu Reta (Internet), (27), p.9 - 15, 2017/03
In this report, the outline of the contents in the lecture course for "Guideline for Credibility Assessment of Nuclear Simulations 2015" published in June, 2016 from the Atomic Energy Society of Japan (AESJ) and the result of the lectures held in Tokyo and Osaka are introduced with the results of the questionnaires from the audience.
Tanaka, Masaaki
Nihon Genshiryoku Gakkai Keisan Kagaku Gijutsu Bukai Nyusu Reta (Internet), (24), p.16 - 28, 2015/09
In order to enhance the simulation credibility, it is necessary to establish the procedure on verification and validation including the estimation of the modeling uncertainty. Lessons learned from the Fukushima Daiichi NPP Accident have indicated that it was important to recognize the credibility of the simulation. By putting forward to standardize the procedure on verification and validation including the estimation of the modeling uncertainty, it is expected to establish the basis of the simulation technology to realize the world highest level of nuclear safety and continuous improvement. The recent activity in the Atomic Energy Society of Japan (AESJ) for the guideline establishment is introduced.
Inagaki, Yaohiro*; Mitsui, Seiichiro*; Makino, Hitoshi*; Ishiguro, Katsuhiko*; Kamei, Gento*; Kawamura, Kazuhiro*; Maeda, Toshikatsu; Ueno, Kenichi*; Bamba, Tsunetaka*; Yui, Mikazu*
Genshiryoku Bakkuendo Kenkyu, 10(1-2), p.69 - 84, 2004/03
no abstracts in English
Suzudo, Tomoaki; Nabeshima, Kunihiko; Takizawa, Hiroshi*
Nihon Genshiryoku Gakkai Wabun Rombunshi, 2(4), p.500 - 509, 2003/12
A new methodology to construct distributed computing systems specially targeting nuclear power plant monitoring systems is proposed. In this framework, a monitoring system is composed of multiple modules and a client that administrates them. Each module is designed as a TTY-based program, and therefore has a great flexibility when it is developed. The client holds virtual modules, each of which works as an interface to a module in the remote hosts. Because the virtual modules are defined as a class in the meaning of object-oriented programming, the whole system is easily structured. A prototype of neural-network-based monitoring system has been developed utilizing this methodology, and the expected advantages have been confirmed.
Yokobayashi, Masao; Oikawa, Tetsukuni; Muramatsu, Ken
Nihon Genshiryoku Gakkai Wabun Rombunshi, 1(1), p.95 - 105, 2002/03
no abstracts in English
Yoshikawa, Hideki; Ishikawa, Hirohisa;
JNC TN8200 2001-004, 160 Pages, 2001/06
JNC-TN8200-2001-004.pdf:129.13MB
None
Sakurai, Kiyoshi; Ueki, Kotaro*
Nihon Genshiryoku Gakkai-Shi, 43(4), p.351 - 352, 2001/04
no abstracts in English
Yokobayashi, Masao; Kondo, Masaaki*
JAERI-Tech 2001-007, 90 Pages, 2001/03
JAERI-Tech-2001-007.pdf:4.02MB
no abstracts in English
Kitamura, Akira; *
JNC TN8400 2001-009, 54 Pages, 2001/01
Spectroscopic measurements of neodymium(III) and samarium(III) were carried out by spectrophotometer and laser-induced photoacoustic spectroscopic (LPAS) system for the investigation of the detection limit of both systems. The absorption spectra and photoacoustic spectra of Nd
and Sm were obtained with varying the concentration of the ions from 2
10
to 210
mol
dm
. The absorption spectrum of Nd was also determined by a special spectrophotometer, of which the measurement cell was set in a glove box filled with inert nitrogen gas. For the comparison with these photoacoustic and absorption spectra, the absorption spectra of Nd and Sm were determined by an usual spectrophotometer with the light-path lengths of 1 cm and 10 cm. The detection limit of the photoacoustic measurement was reported much lower than that of absorbance measurement by several researchers. However, the present study was concluded that the detection limit of photoacoustic measurement with the present LPAS system was similar to that of absorbance measurement with the light-path length of 10 cm. The detection limits of neptunium(IV,V) were estimated and the possibility of the speciation of neptunium(IV) was discussed from the results of the present study.
JNC TN1400 2000-012, 250 Pages, 2000/11
JNC-TN1400-2000-012.pdf:10.18MB
no abstracts in English
; ; Shimizu, Kazuhiko; Miyahara, Kaname; ; Seo, Toshihiro; Fujita, Tomoo
JNC TN1410 2000-008, 100 Pages, 2000/10
JNC-TN1410-2000-008.pdf:4.23MB
no abstracts in English
