Maurer, C.*; Bar, J.*; Kusmierczyk-Michulec, J.*; Crawford, A.*; Eslinger, P. W.*; Seibert, P.*; Orr, B.*; Philipp, A.*; Ross, O.*; Generoso, S.*; et al.
Journal of Environmental Radioactivity, 192, p.667 - 686, 2018/12
It is very important to understand the impact for CTBT stations caused by radioxenon emitted from medical isotope production facilities for detection of underground nuclear tests. Predictions of the impact on six CTBT radionuclide stations in the Southern Hemisphere of radioxenon emitted from the medical isotope production facility in Australia were carried out by participants from ten nations using ATM (Atmospheric Transport Modeling) based on the emission data of radioxenon from this facility, as part of study on impact of radioxenon emitted from medical isotope production facilities on CTBT radionuclide stations.
Enerugi Rebyu, (10), p.38 - 41, 2018/09
Suzuki, Mitsutoshi; Demachi, Kazuyuki*
Journal of Nuclear Science and Technology, 55(5), p.559 - 567, 2018/05
Facility design of nuclear power plant for a sabotage protection is investigated and an effect of the design change for damage control on reduction of sabotage risk is shown using the vital area identification methodology. The loss of offsite power leading to the station blackout is assumed to be a typical example for further evaluation. In this study, the vulnerability of target set is defined as the multiplication of the accessibility, the distribution of target and the degree of adversary's interference. The built-in measures for damage control are of vital importance in case of the existence of adversary's interference until neutralization. It is confirmed that not only the physical protection system but also the facility design play an important role in the effective and efficient sabotage protection. It is very important to introduce a security by design approach in an initial stage of the NPP construction while considering the interface between safety and security.
Tazaki, Makiko; Suda, Kazunori; Shimizu, Ryo; Tamai, Hiroshi; Kitade, Yuta
Nihon Kaku Busshitsu Kanri Gakkai Dai-38-Kai Nenji Taikai Rombunshu (Internet), 9 Pages, 2018/04
Kikuchi, Masahiro*; Suzuki, Mitsutoshi
Wiley StatsRef; Statistics Reference Online (Internet), 7 Pages, 2018/03
A near-real-time accountancy (NRTA) as a timely statistical test method for nuclear material inventory verification in international safeguards has a unique feature and development history, and it has been maintained and updated in large nuclear facilities in Japan. A recent discussion on approaches of measurement uncertainty may have impacted on the decision criteria of NRTA because its development origin dates back to the 1970's and derived from the conventional random and systematic error model. In this article, we will show the overview associated with this issue.
Ho, D. M. L.*; Nelwamondo, A. N.*; Okubo, Ayako; Ramebck, H.*; Song, K.*; Han, S.-H.*; Hancke, J. J.*; Holmgren, S.*; Jonsson. S.*; Kataoka, Osamu; et al.
Journal of Radioanalytical and Nuclear Chemistry, 315(2), p.353 - 363, 2018/02
The Fourth Collaborative Material Exercise (CMX-4) of the Nuclear Forensics International Technical Working Group (ITWG) registered the largest participation for this exercise in nuclear forensics, with seven of the 17 laboratories participating for the first time. In this paper, participants from five of the first-time laboratories shared their individual experience in this exercise, from preparation to analysis of samples. The exercise proved to be highly useful for testing procedures, repurposing established methods, exercising skills, and improving the understanding of nuclear forensic signatures and their interpretation trough the post-exercise review meeting.
Kristo, M. J.*; Williams, R.*; Gaffney, A. M.*; Kayzar-Boggs, T. M.*; Schorzman, K. C.*; Lagerkvist, P.*; Vesterlund, A.*; Ramebck, H.*; Nelwamondo, A. N.*; Kotze, D.*; et al.
Journal of Radioanalytical and Nuclear Chemistry, 315(2), p.425 - 434, 2018/02
In a recent international exercise, 10 international nuclear forensics laboratories successfully performed radiochronometry on three low enriched uranium oxide samples, providing 12 analytical results using three different parent-daughter pairs serving as independent chronometers. The vast majority of the results were consistent with one another and consistent with the known processing history of the materials. In general, for these particular samples, mass spectrometry gave more accurate and more precise analytical results than decay counting measurements. In addition, the concordance of the U-Pa and U-Th chronometers confirmed the validity of the age dating assumptions, increasing confidence in the resulting conclusions.
Risk Assessment, p.133 - 151, 2018/02
A integrated risk assessment could be developed to promote synergism between safety, security, and safeguards (3S). One of the synergies of the integrated 3S risk assessment is a 3S by Design approach for new nuclear facilities. In safety, the classical probabilistic risk assessment (PRA) has been developed to estimate the frequency of severe accident using the basic event frequency. Because of recent concern about nuclear security, a vital area identification method based on the ETs/FTs has been explored to protect vital areas of nuclear power plants against sabotage. The different difficulty in applying risk assessment to safeguards is determining the initiation of diversion of nuclear material and misuse, because the diversion of nuclear material and misuse of technology are induced by the motivation of states and intentional acts of facility operation. In this chapter, a balance among 3S risk would be explored to pursue an optimal and a cost-effective management.
Kijima, Yuichi; Yamamoto, Yoichi; Oda, Tetsuzo
JAEA-Technology 2017-028, 33 Pages, 2018/01
The International Noble Gas Experiment related to monitoring network for radioactive noble gas (xenon) has been carried out all over the world, as part of the International Monitoring System (IMS) of CTBT. Thirty IMS radionuclide stations including the Takasaki station in Japan are monitoring radioxenon. The past measurement results show that several stations often detect radioxenon and the major emission source of these radioxenon is medical radioisotope production facilities. And nuclear power plants and medical institutions used radioxenon for nuclear medicine diagnosis, and so on are also considered as the possible sources of radioxenon, and it is therefore important to understand the background behavior of radioxenon originated from above facilities for enhancement of monitoring capability for nuclear tests. The international joint measurement was conducted in 2012 by the Preparatory Commission for the CTBT Organization, US Pacific Northwest National Laboratory, Japan Chemical Analysis Center and JAEA at the Ohminato site of JAEA Aomori Research and Development Center in Mutsu city, Aomori, as part of investigation on radioxenon background in East Asia region. In 2014, the additional measurement was carried out at the same place for further investigation. A high sensitive Transportable Xenon Laboratory developed by PNNL was used for this measurement. This paper describes the outline and the results of the joint measurement conducted in 2012 and 2014.
Tamai, Hiroshi; Tazaki, Makiko; Suda, Kazunori
Nippon Genshiryoku Gakkai-Shi, 60(1), p.25 - 29, 2018/01
IAEA Low Enriched Uranium Bank, which is one of international management initiatives of nuclear materials operated by IAEA, will be realized soon. During increasing concern on proliferation risk of sensitive nuclear technologies as well as in this century the potential acquisition by terrorists, the IAEA bank will offer the fuel assurance aiming at decreasing incentive for acquiring those sensitive technologies. Throughout the argument on the criteria for the fuel supply, the bank site and its requirement have been established and will be in operation next year. The background, significance, and development of this initiative are described.
Sekine, Megumi; Tomikawa, Hirofumi
Energy Procedia, 131, p.274 - 278, 2017/12
The IAEA has proposed in its long-term R&D plan, development of real-time measurement technology for monitoring and verifying nuclear material movement continuously. At a PULEX reprocessing facility, HNO solution with dissolved spent fuel, such as FPs and nuclear materials, flows in pipes and stores in tanks. In order to detect and deter nuclear material being stolen from the process, measuring the 10.8 MeV rays emitted by N(n,)N reaction activated by spontaneous neutrons might be useful for continuous monitoring of liquid flow. In general, since high dose rays emitted from FPs are dominant below 3 MeV, it is expected that the 10.8 MeV peak would not be affected by the FP peaks. As the first step, some kinds of detectors and measurement configuration were analyzed through MCNP based on 10.8 MeV rays activated by neutrons from a Cf source.
Tamai, Hiroshi; Okubo, Ayako; Kimura, Yoshiki; Shinohara, Nobuo; Tazaki, Makiko; Shimizu, Ryo; Suda, Kazunori; Tomikawa, Hirofumi
Proceedings of INMM 58th Annual Meeting (Internet), 6 Pages, 2017/07
Nuclear forensics is a technical measure to analyse and collate samples of illegally used nuclear materials, etc., to clarify their origins, routes, etc. and contribute to criminal identifications. Close collaboration with police and judicial organizations is essential. The national response framework is being built up with international cooperation. Discussions on promoting technical capability and regional cooperation are presented.
Matsuki, Takuya; Yamanaka, Atsushi; Sekine, Megumi; Suzuki, Satoshi*; Yasuda, Takeshi; Tsutagi, Koichi; Tomikawa, Hirofumi; Nakamura, Hironobu; LaFleur, A. M.*; Browne, M. C.*
Proceedings of INMM 58th Annual Meeting (Internet), 8 Pages, 2017/07
The Tokai Reprocessing Plant (TRP) has been developing a new detector from 2015 to 2017 for purpose to monitor Pu amount in High Active Liquid Waste (HALW) containing FP. It can make a contribution to an advanced approach to effectively and efficiently conduct safeguards for reprocessing facilities because it becomes available to monitor and verify nuclear material movement continuously by a new detector, which has proposed by IAEA. For the second step of this project, we conducted dose rate measurement on the guide rail installing in the cell storing the HALW tank and comparison between measured dose rate distribution and calculation result by MCNP simulation in order to investigate the dose rate distribution which is needed for shielding design of a new detector that is used for radiation (neutron/ spectrum) measurement in the cell and inquest on the monitoring position of the detector for Pu monitoring. In this paper, we report the result of the dose rate measurement in the cell, improvement of the simulation model which is cleared by comparison between measurement result and calculation result and our future plan.
Hiroshima Repoto 2017-Nen Ban; Kakugunshuku, Kakufukakusan, Kakusekyuriti Wo Meguru 2016-Nen No Doko, p.163 - 165, 2017/03
The series of Nuclear Security Summit, initiated by President Barack Obama, was held biennially, four times since 2010, and played an important role in promoting international efforts to enhance nuclear security. Despite Russia's refusal to participate in the fourth meeting, these summit-level meetings have gained both international and domestic attention, which have led to remarkable improvements in the field of nuclear security of each participating country. Therefore, there is an urgent need to take continuous measures to keep this momentum alive even after the final Nuclear Security Summit concluded in 2016. The challenges in strengthening nuclear security, prospects in the post-Nuclear Security Summit phase, as well as efforts and measures that Japan should pursue are investigated.
Tamai, Hiroshi; Okubo, Ayako; Kimura, Yoshiki; Kokaji, Lisa; Shinohara, Nobuo; Tomikawa, Hirofumi
Dai-37-Kai Kaku Busshitsu Kanri Gakkai Nippon Shibu Nenji Taikai Rombunshu (CD-ROM), 8 Pages, 2017/02
Nuclear Forensics capability has been developed under the international collaborations. For its effective function, technical development in analysis of seized nuclear materials as well as the institutional development in comprehensive response framework are required under individual national responsibility. In order to keep the "chain of custody" in the proper operation of sample collection at the event scene, radiological analysis at the laboratory, storage of the samples, and further inspection and trial, close cooperation and information sharing between relevant organisations are essential. IAEA issues the Implementing Guide to provide the model action plan and assists individual national development. International cooperation for the technical improvement and awareness cultivation is promoted. Examples in such national developments will be introduced and prospective technical/institutional prerequisite for nuclear forensics response framework will be studied.
Tazaki, Makiko; Iwamoto, Tomonori*; Suda, Kazunori; Shimizu, Ryo; Tamai, Hiroshi; Kokaji, Lisa
Dai-37-Kai Kaku Busshitsu Kanri Gakkai Nippon Shibu Nenji Taikai Rombunshu (CD-ROM), 9 Pages, 2017/02
As to states determination on physical protection measures of nuclear material and nuclear facilities against unauthorized removal of nuclear material, International Atomic Energy (IAEA) makes recommendation of states to follow a Table which sets out three different categories-based physical protection measures. Primary factors of such categories are isotope, quantity and radiation of nuclear material. On the other hand, in the US, attractiveness of nuclear material including physical form and degree of dilution of special nuclear material (SNM) are also primary determining factors of physical protection measures, in addition to IAEAs primary factors. Focusing on SMN within radioactive waste, authors carried out a study on optimization of physical protection measures for the radioactive waste, using the IAEA Implementing Guide and the US regulations as references.
Tanigawa, Masafumi; Mukai, Yasunobu; Nakamura, Hironobu; Kurita, Tsutomu; Henzlova, D.*; Menlove, H. O.*
Dai-37-Kai Kaku Busshitsu Kanri Gakkai Nippon Shibu Nenji Taikai Rombunshu (CD-ROM), 9 Pages, 2017/02
Tazaki, Makiko; Shimizu, Ryo; Suda, Kazunori
JAEA-Review 2016-019, 118 Pages, 2016/10
In November 2015, the new nuclear cooperation agreement between US and ROK entered into force. A top priority of their negotiation for revising their old agreement was whether or not the US grants its advanced consent to the ROK engagement in uranium enrichment and pyroprocessing of US-origin nuclear material. Under the new agreement, in principle, the ROK is able to conduct uranium enrichment and reprocessing at certain facilities prescribed in Annexes III and II to the Agreed Minute of the new agreement. However, as of the date of validation of the agreement, no facilities are prescribed in both Annexes. It means that the US does not grant its advanced consent to ROK such activities. The new agreement allows the US adherence of its nuclear nonproliferation policy, while it also allows ROK future possibility of engaging such activities. Such result can be analyzed that the new agreement was a product of reality-based and maximal compromise among the US and ROK.
Kawakubo, Yoko; Sekine, Megumi; Tomikawa, Hirofumi
JAEA-Review 2016-017, 57 Pages, 2016/10
Nuclear transparency is recognized as essential to provide additional assurance and enhance confidence building in the Asia-Pacific as this region has a broad spectrum of nuclear development underway and planned in the future. It is expected that elevated nuclear transparency should also supplement and reinforce International Atomic Energy Agency (IAEA) safeguards. With this recognition, Japan Atomic Energy Agency (JAEA) has committed various studies and activities for enhancing regional transparency mainly with U.S. Department of Energy (DOE) and its national laboratories. The efforts include transparency concept study, development of the remote monitoring system at the Experimental Fast Reactor JOYO, cooperation to Council for Security and Cooperation in Asia Pacific (CSCAP) to develop internet-based transparency tools, establishment of Information Sharing Framework (ISF), and the hosting of a series of workshops. Based on all the achievements of the past efforts, JAEA is now moving from "study phase" toward the "implementation phase" of information sharing for enhancing its nuclear transparency. The ISF website was opened in 2015 as a part of Asia Pacific Safeguards Network (APSN) website for JAEA to provide relevant information to APSN members. This report summarizes the past studies and activities performed in JAEA for almost 20 years to enhance regional nuclear transparency and discusses the future prospect.
Kokusai Seiji, (185), p.114 - 125, 2016/10