Kimura, Takashi; Tazaki, Makiko; Shimizu, Ryo; Tamai, Hiroshi; Nakatani, Takayoshi; Suda, Kazunori
Nihon Kaku Busshitsu Kanri Gakkai Dai-40-Kai Nenji Taikai Puroshidhingusu, p.85 - 88, 2019/11
This is the summary of research result of methods for denuclearization and IAEA verification after the denuclearization in South Africa. South Africa had developed and possessed nuclear weapons, and dismantled them including the related facilities and equipment etc. by itself secretly in the past. The method for the denuclearization and the verification is unique in the world. This report could give us the lessons to investigate how to denuclearize and to verify them.
Tazaki, Makiko; Kimura, Takashi; Shimizu, Ryo; Tamai, Hiroshi; Nakatani, Takayoshi; Suda, Kazunori
Nihon Kaku Busshitsu Kanri Gakkai Dai-40-Kai Nenji Taikai Puroshidhingusu, p.81 - 84, 2019/11
South Africa had developed, manufactured, and possessed nuclear weapons, but later dismantled them all together with related facilities and equipment. After joining Treaty on the Non-Proliferation of Nuclear Weapons as a non-nuclear weapon state and concluding a Comprehensive Safeguards Agreement with the Atomic Energy Agency (IAEA), it started peaceful use of nuclear energy. In that sense, South Africa's denuclearization is one of good examples of past denuclearization in the world, although the South Africa's specific policy of apartheid had been deeply connected with its nuclear weapons development and denuclearization. Analysing South Africa's motivations for nuclear weapons development, incentives for denuclearization, and characteristics of its denuclearization could serve as a good reference for not only preventing nuclear weapons development but also considering their denuclearization in current and future states.
Tanaka, Masaaki; Kudo, Yoshiro*; Nakada, Kotaro*; Koshizuka, Seiichi*
Proceedings of 18th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-18) (USB Flash Drive), p.1473 - 1484, 2019/08
Verification and validation (V&V) including uncertainty quantification on modeling and simulation activities has been very much focused on. Due to increase of requirement for standardization of the procedures on the V&V and prediction process to enhance the simulation credibility, "Guideline for Credibility Assessment of Nuclear Simulations (AESJ-SC-A008: 2015)" was published on July 2016 from the AESJ through ten-year discussion. The paper describes brief history of discussion in the AESJ to the publication and introductory explanation of the procedures in the five major elements and one scheme described in the Guideline. And also, a practical experience of the V&V activity according to the fundamental concept indicated in the Guideline is introduced.
Proceedings of 12th International Topical Meeting on Nuclear Reactor Thermal-Hydraulics, Operation and Safety (NUTHOS-12) (USB Flash Drive), 14 Pages, 2018/10
A numerical simulation code MUGTHES has been developed to estimate high cycle thermal fatigue in SFRs. In development of numerical simulation code, verification, validation, and uncertainty quantification (VVUQ) are indispensable. In this study, numerical simulation at impinging jet condition in the WATLON experiment which was the water experiment of a T-junction piping system was performed for the fundamental validation. Based on the previous studies, the simplified least square version GCI method and the area validation metrics were employed as reference methods to quantify uncertainty and to measure the degree of difference between the numerical and the experimental results, respectively. Through the examinations, the potential applicability of the MUGTHES to the thermal striping phenomena was indicated and requirements of modification in the simulation was suggested in accordance with the uncertainty values.
Kaku Deta Nyusu (Internet), (117), p.23 - 29, 2017/06
Validation of the nuclear data library using the criticality experiments and nuclear reactor experiments, i.e., integral experiments, is one of the most important process. The analyses of the integral experiments become the more important along with the accuracy improvement of the library. This validation procedure is mainly carried out by the specialists of the reactor physics because it is complicated for the nuclear data evaluators. Furthermore, it takes a long time and much effort even if the specialists carry it out. To realize the efficient nuclear data validation cycle for the next version of JENDL, the automatic nuclear data validation system VACANCE (Validation Environment for Comprehensive and Automatic Neutronics Calculation Execution) is developed. In this presentation, the outline and functions of VACANCE are demonstrated in detail and examples of the new nuclear data evaluation and subsequent integral experiment analyses will be shown.
Keisan Kogaku Koenkai Rombunshu (CD-ROM), 22, 4 Pages, 2017/05
In the development of the simulation code and the numerical estimation for high cycle thermal fatigue on a structure caused by thermal striping phenomena in sodium cooled fast reactors, implementation of verification and validation (V&V) process is indispensable. A procedure named V2UP (Verification and Validation plus Uncertainty quantification and Prediction) has been made by referring to the existing guidelines regarding the V&V and the methodologies of the safety assessment. In this paper, a challenging installation of quality management procedures into the V2UP procedure is attempted based on the JSCES Standard for "A Model Procedure for Engineering Simulation".
Li, Y.; Hayashi, Shotaro*; Itabashi, Yu*; Nagai, Masaki*; Kanto, Yasuhiro*; Suzuki, Masahide*; Masaki, Koichi*
JAEA-Review 2017-005, 80 Pages, 2017/03
For the improvement of the structural integrity assessment methodology on reactor pressure vessels (RPVs), the probabilistic fracture mechanics (PFM) analysis code PASCAL has been developed and improved in JAEA based on latest knowledge. The PASCAL code evaluates the failure probabilities and frequencies of Japanese RPVs under transient events such as pressurized thermal shock considering neutron irradiation embrittlement. In order to confirm the reliability of the PASCAL as a domestic standard code and to promote the application of PFM on the domestic structural integrity assessments of RPVs, it is important to verify the probabilistic variables, functions and models incorporated in the PASCAL and summarize the verification processes and results as a document. On the basis of these backgrounds, we established a working group, composed of experts on this field besides the developers, on the verification of the PASCAL3 which is a PFM analysis module of PASCAL, and the source program of PASCAL3 was released to the members of working group. Through one year activities, the applicability of PASCAL in structural integrity assessments of domestic RPVs was confirmed with great confidence. This report summarizes the activities of the working group on the verification of PASCAL in FY2015.
Ichikawa, Shoichi; Chiba, Yusuke; Ono, Fumiyasu; Hatori, Masakazu; Kobayashi, Takanori; Uekura, Ryoichi; Hashiri, Nobuo*; Inuzuka, Taisuke*; Kitano, Hiroshi*; Abe, Hisashi*
JAEA-Research 2016-021, 32 Pages, 2017/02
In order to reduce the influence on a plant schedule of the MONJU by the maintenance of dew point hygrometers, The JAEA examined a capacitance type dew point hygrometer as an alternative dew point hygrometer for a lithium-chloride type dew point hygrometer which had been used at the CV-LRT in the MONJU. As a result of comparing a capacitance type dew point hygrometer with a lithium-chloride type dew point hygrometer at the CV-LRT (Atmosphere: nitrogen, Testing time: 24 hours), there weren't significant difference between a capacitance type dew point hygrometer and a lithium-chloride type dew point hygrometer. As a result of comparing a capacitance dew point hygrometer with a high-mirror-surface type dew point hygrometer for long term verification (Atmosphere: air, Testing time: 24 months), the JAEA confirmed that a capacitance type dew point hygrometer satisfied the instrument specification (2.04C) required by the JEAC4203-2008.
Tanaka, Masaaki; Ohno, Shuji; Ohshima, Hiroyuki
Proceedings of OECD/NEA & IAEA Workshop on Application of CFD/CMFD Codes to Nuclear Reactor Safety and Design and their Experimental Validation (CFD4NRS-5) (Internet), 14 Pages, 2014/09
A procedure called as V2UP (Verification and Validation plus Uncertainty quantification and Prediction) was made by referring to the existing guidelines on V&V and the methodologies of the safety assessment (CSAU, ISTIR, EMDAP). The V2UP consisted of five components as follows: (1) phenomena analysis with the Phenomena Identification and Ranking Table (PIRT) method, (2) implementation of the V&V, (3) design and rearrangement of experiments for the V&V, (4) uncertainty quantification in each problem and integration of uncertainties and (5) numerical prediction (estimation) for the target issue. Although the complete application of the procedure has not been performed at this moment, a flow chart of the V2UP procedure was described in this paper with recent results of the examinations.
Shinohara, Nobuo; Inoue, Yoji; Uchikoshi, Takako*; Oda, Tetsuzo*; Kumata, Masahiro; Kurosawa, Yoshiaki; Hirota, Naoki*; Hokida, Takanori; Nakahara, Yoshinori*; Yamamoto, Yoichi
Dai-25-Kai Kaku Busshitsu Kanri Gakkai Nippon Shibu Nenji Taikai Rombunshu, p.51 - 58, 2005/00
The Japan Atomic Energy Research Institute (JAERI) conducts researches and developments related to Comprehensive Nuclear-Test-Ban Treaty (CTBT) on the basis of Japan's pragmatic and progressive efforts toward peaceful use of atomic energy and non-proliferation with the goal of realizing a peaceful and safe world free from nuclear weapons. The Treaty aims for the establishment of a global verification regime comprising an International Monitoring System (IMS) and the JAERI has engaged in the following activities: construction and operation of the radionuclide monitoring stations at Okinawa (RN37) and Takasaki (RN38) and the certified radionuclide laboratory at Tokai (RL11) as specified in Annex 1 of CTBT Protocol, and preparation of the National Data Center at Tokai (JAERI NDC). Research activities of JAERI related to the CTBT verification regime are presented in the paper. The subjects of this presentation are (1) an overview of the CTBT verification regime, (2) construction and operation of RN37, RN38 and RL11, and (3) preparation of the JAERI NDC for radionuclide data.
Amano, Hikaru; Takahashi, Tomoyuki*; Uchida, Shigeo*; Matsuoka, Shungo*; Ikeda, Hiroshi*; Hayashi, Hiroko*; Kurosawa, Naohiro*
JAERI-Conf 2003-010, p.112 - 121, 2003/09
The functionality of MOGRA is being verified by applying it in the analyses of the migration rates of radioactive substances from the atmosphere to soils and plants and flow rates into the rivers. This has been achieved by also taking their mode classifications into consideration. In this report, a hypothetical combination of land usage was supposed to check the function of MOGRA. The land usage was consisted from cultivated lands, forests, uncultivated lands, urban area, river, and lake. Each land usage has its own inside model which is basic module. Also supposed was homogeneous contamination of the surface land from atmospheric deposition of Cs-137 (1.0 Bq/m). The system can analyze the dynamic changes of Cs-137 concentrations in each compartment, fluxes from one compartment to another compartment.
Munakata, Masahiro; Kimura, Hideo; Tanaka, Tadao; Mukai, Masayuki; Maeda, Toshikatsu; Ogawa, Hiromichi
Nippon Genshiryoku Gakkai Wabun Rombunshi, 2(3), p.361 - 367, 2003/09
no abstracts in English
Yamamoto, Yoichi; Hokida, Takanori; Hirota, Naoki*; Oda, Tetsuzo; Nakahara, Yoshinori; Kumata, Masahiro; Inoue, Yoji; Uchikoshi, Takako*; Shinohara, Nobuo; Usuda, Shigekazu
Dai-23-Kai Kaku Busshitsu Kanri Gakkai Nippon Shibu Nenji Taikai Rombunshu, p.53 - 60, 2002/12
The Japan Atomic Energy Research Institute (JAERI) has developed the National Data Center (NDC) for radionuclide as part of the international monitoring regime related to the Comprehensive Nuclear-Test-Ban Treaty (CTBT). JAERI NDC already started to input gamma-ray spectrum data obtained from several International Monitoring System (IMS) stations into a database. Data analysis reports made by the International Data Center (IDC) are also stored in the database. Some software tools are under development for the NDC's independent analysis such as investigation of existence of the radionuclides derived from nuclear explosion and presumptive analysis of source location of radionuclide release. The NDC system will also be able to post IMS data and analysis results to the authorized users on the Internet. This paper presents the role, current state of system development and future plan of JAERI NDC.
Oda, Tetsuzo; Kumata, Masahiro; Nakahara, Yoshinori; Yamamoto, Yoichi; Hokida, Takanori; Hirota, Naoki*; Uchikoshi, Takako*; Inoue, Yoji; Shinohara, Nobuo
Dai-23-Kai Kaku Busshitsu Kanri Gakkai Nippon Shibu Nenji Taikai Rombunshu, p.29 - 37, 2002/12
The Comprehensive nuclear Test-Ban Treaty(CTBT) bans all nuclear explosions and also calls for a verification regime, which consists of the International Monitoring System(IMS) and On-site Inspection. The primary objectives of the IMS are to deter nuclear explosions in all environments and, if such an explosion does occur, to detect, locate, and identify its source. The CTBT was opened for signature on September 24, 1996 and the Preparatory Commission(PrepCom) for the CTBT Organization was established to prepare for the verification regime in order to monitor compliance with the Treaty. The Preparatory Commission comprises two main organs: a plenary body of all the States Signatories as the highest policy-making organ, and the Provisional Technical Secretariat(PTS). The plenary body has three subsidiary bodies: Working Group A(administrative matters and legal issues), Working Group B(verification issues), and an Advisory Group. This paper presents an overview and mandate of the PrepCom, and status of verification regime, and discusses future activities.
Kumata, Masahiro; Oda, Tetsuzo; Miyamoto, Yutaka; Uchikoshi, Takako*; Nakahara, Yoshinori; Yamamoto, Yoichi; Hokida, Takanori; Hirota, Naoki*; Inoue, Yoji; Shinohara, Nobuo
Dai-23-Kai Kaku Busshitsu Kanri Gakkai Nippon Shibu Nenji Taikai Rombunshu, p.39 - 44, 2002/12
The International Monitoring System (IMS) will be established across the world to verify compliance with the Comprehensive Test Ban Treaty (CTBT). The IMS will be capable of detecting and identifying nuclear explosions of detonated within the atmosphere, underwater and underground. 321 monitoring stations will be set around the world as a monitoring network of the IMS. The four technologies of seismology, hydroacoustic, infrasound, and radionuclide will be used for monitoring purposes. In order to build the radionuclide monitoring network, 80 radionuclide stations were chosen. Particles in the atmosphere are collected on a filter at each station to measure radioactivity by a HP-Ge detector. Further, 40 out of these 80 stations will be equipped with an automatic radioactive noble gas sampler/analyzer. The JAERI is establishing infrastructure to host radionuclide air monitoring equipment for two raionuclide stations in Japan. This paper presents the current status of the establishment and promising performance of the stations in Japan.
Shinohara, Nobuo; Yamamoto, Yoichi; Inoue, Yoji; Kumata, Masahiro; Oda, Tetsuzo; Uchikoshi, Takako*; Hokida, Takanori; Hirota, Naoki*; Nakahara, Yoshinori; Usuda, Shigekazu
Dai-23-Kai Kaku Busshitsu Kanri Gakkai Nippon Shibu Nenji Taikai Rombunshu, p.45 - 52, 2002/12
no abstracts in English
Takase, Kazuyuki; Ose, Yasuo*; Suzuki, Takayuki*; Kunugi, Tomoaki*
Nippon Kikai Gakkai Kanto Shibu Yamanashi Koenkai (2001) Koen Rombunshu, p.197 - 198, 2001/00
no abstracts in English
Ohno, Shuji; Matsuki, Takuo*
JNC-TN9400 2000-106, 132 Pages, 2000/12
Sodium fire analyses were performed on 7 kinds of sodium leak tests using a computer code ASSCOPS which has been developed to evaluate thermal consequences of sodium leak accident in an FBR plant. By the comparison between the calculated and the test results of gas pressure, gas temperature, sodium catch pan temperature, wall temperature, and of oxygen concentration, it was confirmed that the ASSCOPS code and the parameters used in the analysis give valid or conservative results on thermal consequences of sodium leak and fire.
Takata, Takashi; Yamaguchi, Akira
JNC-TN9400 2000-065, 152 Pages, 2000/06
ln the liquid metal fast reactor (LMFR) using liquid sodium as a coolant, it is important to evaluate the effect of the sodium combustion on the structure, etc. Most of the previous analytical works are based on a zone model, in which the principal variables are treated as volume-average quantities. Therefore spatial distribution of gas and structure temperatures, chemical species concentration are neglected. Therefore, a multi-dimensional sodium combustion analysis code AQUA-SF (Advanced simulation using Quadratic Upstream differencing Algorithm - Sodium Fire version) has been developed for the purpose of analyzing the sodium combustion phenomenon considering the multi-dimensional effect. This code is based on a multi-dimensional thermal hydraulics code AQUA that employs SIMPLEST-ANL method. Sodium combustion models are coupled with AQUA; one is a liquid droplet model for spray combustion, and the other is a flame sheet model for pool combustion. A gas radiation model is added for radiation heat transfer. Some other models necessary for the sodium combustion analysis, such as a chemical species transfer, a compressibility, are also added. ln AQUA-SF code, bounded QUICK method in space scheme and bounded three-point implicit method in time scheme are implemented. Verification analyses of sodium combustion tests shown in the following have been carried out. (1)pool combustion test (RUN-D1) (2)spray combustion test (RUN-E1) (3)sodium leakage combustion test (Sodium Fire Test-II) (4)smaII-scale leakage combustion test (RUN,F7-1) ln each verification analysis, good agreements are obtained and the validity of AQUA-SF code is confirmed.
*; *; *
JNC-TY8400 2000-006, 52 Pages, 2000/03