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Journal Articles

Sample thickness effect on nuclear material quantification with NRTA for particle like debris of melted fuel

Tsuchiya, Harufumi; Harada, Hideo; Koizumi, Mitsuo; Kitatani, Fumito; Takamine, Jun; Kureta, Masatoshi; Iimura, Hideki; Becker, B.*; Kopecky, S.*; Kauwenberghs, K.*; et al.

Proceedings of INMM 54th Annual Meeting (CD-ROM), 6 Pages, 2013/07

Journal Articles

Recent progress in research and development on the neutron resonance densitometry for particle-like debris of melted fuel

Harada, Hideo; Kitatani, Fumito; Koizumi, Mitsuo; Tsuchiya, Harufumi; Takamine, Jun; Kureta, Masatoshi; Iimura, Hideki; Seya, Michio; Becker, B.*; Kopecky, S.*; et al.

Proceedings of INMM 54th Annual Meeting (CD-ROM), 10 Pages, 2013/07

In this contribution, progress made in the development of NRD for the characterization of nuclear materials mixed with highly radioactive nuclides is presented, together with the basic concept and principles. The use of a special $$gamma$$-ray spectrometer for NRCA and an evaluation of the achievable accuracy are discussed. The discussion is based on results of Monte Carlo simulations combined experimental data from measurements carried out at GELINA. In addition, a prototype compact NRD system, which will be installed at the JAEA Tokai-site, has been designed and is presented. Other results, such as the impact of the particle size and nuclear data, are presented in other contributions to this symposium.

Journal Articles

Contribution of the JRC to the development of neutron resonance densitometry to characterize melted fuel from severe accidents

Schillebeeckx, P.*; Becker, B.*; Emiliani, F.*; Kopecky, S.*; Kauwenberghs, K.*; Moens, A.*; Mondelaers, W.*; Sibbens, G.*; Harada, Hideo; Kitatani, Fumito; et al.

Proceedings of INMM 54th Annual Meeting (CD-ROM), 7 Pages, 2013/07

Journal Articles

New attempt to assess interruption probability with sensor-signal variations

Terao, Norichika; Suzuki, Mitsutoshi

Proceedings of INMM 54th Annual Meeting (CD-ROM), 10 Pages, 2013/07

As a new trial on probabilistic risk assessment in nuclear security field, system effectiveness of physical protection is evaluated in terms of interruption probability considering variation of detection and communication performance. Although the Estimate of Adversary Sequence Interruption (EASI) developed by Sandia National Laboratory has been used worldwide, actual and realistic effect due to fluctuation of signals from sensors and monitoring cameras is not taken into account. Probability distribution of detection and communication variables is introduced into the EASI method to calculate the overall performance of interruption, and system effectiveness is investigated by using a hypothetical model of nuclear facility. Distribution of interruption probability is numerically calculated through detection and communication probabilities with a Monte Carlo method using the normal random number.

Journal Articles

Feasibility study on passive neutron technique applied to fuel debris measurement at Fukushima Daiichi Nuclear Power Plants

Nagatani, Taketeru; Nakajima, Shinji; Asano, Takashi

Proceedings of INMM 54th Annual Meeting (CD-ROM), 8 Pages, 2013/07

Fukushima Daiichi Nuclear Power Plants (1F) were struck by the earthquake and tsunami on March 11, 2011 and meltdown of the reactor cores of Units 1-3 occurred. Japan decided decommissioning of them. For decommissioning of 1F, Japan plans to recover fuel debris safely and to account nuclear material in it adequately. Survey of applicable technologies for nuclear material quantification of fuel debris, currently, is being conducted by Japan Atomic Energy Agency (JAEA) and United States Department of Energy (DOE) under the collaborative agreement. This survey will identify technologies with the most promising capability to meet IAEA safeguards needs. As one of candidate technologies of plutonium quantification in fuel debris, we, Plutonium Fuel Development Center of JAEA, consider the application of the passive neutron technique which is wildly applied to the field of material accountancy and safeguards in plutonium handing facilities. Fuel debris contains minor actinides and fission products which are intense neutron and $$gamma$$ ray emitter due to burn-up of fuel in the reactor. It also contains neutron absorber such as gadolinium included in fuel to moderate burn-up and boron added after accident to avoid re-criticality. These materials make it difficult to quantify plutonium by the current passive neutron technique. Therefore, R&D activities regarding selective counting for neutron derived from plutonium, reduction of $$gamma$$ ray influence and estimation of neutron absorber influence are required in order to overcome above difficulties. This paper provides a concept for application of passive neutron technique to fuel debris measurement.

Journal Articles

Performance test results of the advanced verification for inventory sample system (AVIS)

Nakajima, Shinji; Nagatani, Taketeru; Asano, Takashi; Marlow, J. B.*; Swinhoe, M. T.*; Menlove, H. O.*; Rael, C. D.*; Kawasue, Akane*; Iso, Shoko*; Kumakura, Shinichi*; et al.

Proceedings of INMM 54th Annual Meeting (CD-ROM), 10 Pages, 2013/07

The advanced verification inventory system (AVIS) is a nondestructive assay (NDA) system developed by Los Alamos National Laboratory (LANL) to measure small samples of bulk plutonium and uranium mixed oxide (MOX) powder and pellets at the Japan Nuclear Fuel Limited (JNFL) mixed oxide fuel fabrication plant (J-MOX). In order to mitigate the workload on the Rokkasho On-Site Laboratory (OSL), it is intended that the AVIS measurement will be substituted for a part of the Destructive Assay (DA) for J-MOX. Based on the commission from Office for Nuclear Non-Proliferation and Safeguards (JSGO) of Ministry of Education, Culture, Sports, Science and Technology (MEXT) and Nuclear Material Control Center (NMCC), Japan Atomic Energy Agency (JAEA) has conducted the performance test of the AVIS in order to confirm the system performance before installation at the J-MOX site. The performance test consists of two phases. In the phase 1 test, detector parameters such as detector efficiency and die-away time were evaluated by using a californium-252 neutron source. These results agreed well with design value and were reported at the 53rd INMM annual meeting. JAEA conducted the phase 2 test by using MOX materials in order to evaluate the total measurement uncertainty (TMU). In the test, influence of sample density, plutonium concentration and organic additives in samples were also evaluated. Consequently, it is expected that AVIS can achieve the target TMU of 0.5% required in user requirement of IAEA by optimizing measurement condition and by using well-characterized standards. This paper provides a summary of the results of comprehensive performance test of AVIS.

Journal Articles

R&D status and future plan of nuclear forensics for analytical technology and national library at JAEA

Kimura, Yoshiki; Shinohara, Nobuo; Sato, Kaneaki; Toda, Nobufumi; Shinoda, Yoshiharu; Watahiki, Masaru; Kuno, Yusuke

Proceedings of INMM 54th Annual Meeting (CD-ROM), 7 Pages, 2013/07

Japan Atomic Energy Agency (JAEA) that possesses sufficient analytical capabilities to fulfil the mission of nuclear forensics technology development has started R&D project from JFY 2011. The R&D of the nuclear forensics technology at JAEA covers the development of analytical technology such as isotope and impurity measurements, morphology analysis, age determination technique, and proto-type of national nuclear forensics library. Each topic of the R&D has been promoted under the international cooperation with US-DOE. This paper will present the present status and brief results of the R&D project on nuclear forensics analytical technology and nuclear forensics library at JAEA. Some future plan of the R&D such as attribute identification of Japanese nuclear materials, data populating plan for existing nuclear materials data in JAEA fuel cycle facilities will be also introduced in the presentation.

Journal Articles

Study on sustainable regional nuclear fuel cycle framework from nuclear non-proliferation viewpoint, 4; A Specific proposal of Asian regional MNA framework

Kuno, Yusuke; Tazaki, Makiko; Akiba, Mitsunori*; Adachi, Takeo*; Takashima, Ryuta*; Tanaka, Satoru*

Proceedings of INMM 54th Annual Meeting (CD-ROM), 10 Pages, 2013/07

This paper presents a specific proposal of Asian regional MNA framework as the final result of our study. The target facilities include frontend and backend, especially, enrichment, reprocessing, MOX fabrication / storage and Spent Fuel storage facilities.

Journal Articles

Study on sustainable regional nuclear fuel cycle framework from nuclear non-proliferation viewpoint, 5; Comprehensive evaluation of Asian regional MNA framework

Kuno, Yusuke; Tazaki, Makiko; Akiba, Mitsunori*; Adachi, Takeo*; Takashima, Ryuta*; Tanaka, Satoru*

Proceedings of INMM 54th Annual Meeting (CD-ROM), 10 Pages, 2013/07

This paper discusses the evaluation result for proposed Asian regional MNA framework.

Journal Articles

Proposal of direct alpha estimation technique by using ring ratio in the continuous neutron monitor (CNM)

Nakamura, Hironobu; LaFleur, A. M.*; Mukai, Yasunobu; Hayashi, Hiroyuki*; Menlove, H. O.*; Marlow, J. B.*; Kurita, Tsutomu

Proceedings of INMM 54th Annual Meeting (CD-ROM), 8 Pages, 2013/07

To improve safeguards and material accountancy of holdup measurements, a continuous neutron monitor (CNM) that continuously monitors the singles rate from holdup in glove boxes was designed and implemented at PCDF. In totals neutron counting, it is impossible to get Pu mass directly from the singles count rate without predetermination of alpha value and multiplication (M). In case of holdup deposits, since M can be seen as 1, the determination of the alpha value by direct measurement of the holdup is very important. In this research, we have developed a new approach called Direct Alpha Estimation technique. To establish the relation, the ring ratio of the FCAS which has dual ring He-3 tubes was applied. By using different alpha of samples, relation between alpha and ring ratio was studied. As a result, a good correlation between them was obtained. Thus, since the ring ratio can estimate alpha value, we would propose that this technique with dual ringed CNM be extended to not only Pu mass determination, but also to monitor the impurity contents or Pu isotopic composition change in holdup.

Journal Articles

Rehearsal and actual measurement of Fugen spent fuel assemblies by integrated PNAR and SINRD under the JAEA-USDOE collaboration program

Hayashi, Kenta; Nakamura, Takahisa; Takagi, Hisatsugu; Horie, Kaoru; Nakayama, Tamotsu; Hashimoto, Kazuhiko; Hayashi, Shoichi; Nakamura, Shinji; Takenaka, Shigeki; Ishizuka, Nobuo; et al.

Proceedings of INMM 54th Annual Meeting (CD-ROM), 10 Pages, 2013/07

JAEA and USDOE (Los Alamos National Laboratory (LANL)) have been collaborating on spent fuel measurements with a PNAR/SINRD NDA instrument at Fugen, in the course of the NGSI Spent Fuel Nondestructive Assay Project. In this collaboration, LANL's role has been to design and fabricate the detector (integrated PNAR and SINRD system), while JAEA's role has been to undertake the installation of the detector at the appropriate position in the spent fuel pool and to prepare for the actual measurements. In this paper we report the rehearsal of the measurement using a mock-up detector and a dummy fuel assembly in December 2012 and the plan of actual measurements in June 2013 (at the time of submission of this paper).

Journal Articles

Utilization of process monitoring data in the Tokai Reprocessing Plant for future nuclear security

Shimizu, Yasuyuki; Yamazaki, Katsuyuki; Kimura, Takashi; Endo, Yuji; Nakamura, Hironobu

Proceedings of INMM 54th Annual Meeting (CD-ROM), 7 Pages, 2013/07

Japanese regulation of reprocessing safety and security was revised in March 2012, and almost all requirements except for nuclear material accountancy and control described in the INFCIRC225/rev.5 are included into the regulation. We have many things to do to meet the requirements within 2 years pursuant to the regulation. Separately from the revised regulation, we think that utilizing the process monitoring data not only for the safety control but also for the nuclear material security would be useful in establishing more effective and efficient nuclear material security. Since we observe the process monitoring data to confirm the operational condition including unusual change for the safety purpose, it is though that the various alarm information through the process monitoring data help to detect the risk of sabotage and unauthorized removal. As future challenge, we would like to establish a possible method of utilizing the process monitoring data in combination with the physical protection to make it possible to give more effective and efficient nuclear material security.

Journal Articles

Development of a virtual reality system for training in nuclear security

Hanai, Tasuku; Yamaguchi, Yasuo

Proceedings of INMM 54th Annual Meeting (CD-ROM), 10 Pages, 2013/07

The Integrated Support Center for Nuclear Nonproliferation and Nuclear Security (ISCN), under the Japan Atomic Energy Agency (JAEA), has been doing activities, since its establishment, that contribute to the strengthening of nuclear nonproliferation and nuclear security. ISCN is providing training courses for the purpose of capacity-building assistance through human-resource development. ISCN has a Virtual Reality (VR) System specifically for training in nuclear security. The course is specifically for trainees who have had few experiences in nuclear security. Trainees can see the nuclear physical-protection (PP) system of a nuclear power station in virtual space and learn how it works. ISCN has also been preparing another training course that will be for operators in Central Alarm Stations (CAS). Trainees will be able to brush up their skills through simulation exercises against enforced entry.

Journal Articles

Design of an Alternative Plutonium Canister Assay system (APCA) using ceramic scintillator neutron detectors for the safeguards NDA

Kureta, Masatoshi; Ozu, Akira; Haruyama, Mitsuo; Takase, Misao; Kurata, Noritaka; Kobayashi, Nozomi; Soyama, Kazuhiko; Nakamura, Tatsuya; Nakamura, Hironobu; Seya, Michio

Proceedings of INMM 54th Annual Meeting (CD-ROM), 8 Pages, 2013/07

Against the background of the serious shortage of He-3 gas, the ceramic scintillator neutron detectors have been developed for a safeguards-specific alternative to He-3 for neutron detection with support of Japan government (MEXT). In this paper, the evaluation of optical guide property on ceramic scintillator detectors and design of the demonstrator named Alternative Plutonium Canister Assay system (APCA).

Journal Articles

A Summary of JAEA's R&D programs for advanced technologies for nuclear security and safeguards

Bolind, A.; Seya, Michio

Proceedings of INMM 54th Annual Meeting (CD-ROM), 9 Pages, 2013/07

This paper reports on the recent progress on research and development programs for advanced technologies for the measurement and detection of nuclear material for security and safeguards. One program is based on a neutron detector that uses a ZnS ceramic scintillator material instead of $$^{3}$$He gas. We will conduct benchmark experiments to compare the performance of NDA systems that use the new scintillator detectors against the existing NDA systems that use $$^{3}$$He detectors. Our Nuclear Resonance Fluorescence (NRF) program is developing an NDA technique using NRF for measurement of nuclear material isotopes. NRF NDA uses a high-intensity, mono-energetic $$gamma$$ ray beam, which is produced by a Laser Compton Scattering (LCS) system with an energy-recovery linac (ERL). We have conducted several important NRF experiments this past year. Our Neutron Resonance Densitometry (NRD) program is also being designed to measure the nuclear material in melted nuclear-fuel debris. Also, our collaboration with Los Alamos National Laboratory to test a PNAR+SINRD NDA detector on used nuclear fuel assemblies at Fugen has greatly progressed.

Journal Articles

A Summary of the use of the BIC set to characterize used nuclear fuel assemblies for the purpose of nondestructive assay

Bolind, A.

Proceedings of INMM 54th Annual Meeting (CD-ROM), 10 Pages, 2013/07

This paper summarizes a recent journal article that examines how the burnup, initial enrichment, and cooling time - collectively called the BIC set of variables - of a used nuclear fuel assembly are necessary and sufficient quantities to characterize it for the purposes of non-destructive assay (NDA). Though this fact has been generally recognized for many decades, this article re-examines it from a holistic standpoint. It collects, in one place, the effects that the BIC variables have on the physics properties of the fuel assemblies, rather than just their effects on the responses of specific detectors and instruments. This collection of information then sheds light on how different NDA techniques can and, in fact, must be integrated together to determine the isotopic content and residual reactivity of used nuclear fuel assemblies. Furthermore, the limitations of the applicability of the BIC set become apparent, so that corresponding limitations in the NDA techniques that rely on the BIC set are also highlighted.

Journal Articles

A Proposed method for integrating the PNAR, TN, and CIPN techniques for the non-destructive assay of used nuclear fuel assemblies

Bolind, A.

Proceedings of INMM 54th Annual Meeting (CD-ROM), 10 Pages, 2013/07

In the first phase of its Spent Fuel Nondestructive Assay project, the Next Generation Safeguards Initiative (NGSI) of the U.S. Department of Energy (DOE) examined 14 NDA techniques for measuring the Pu and/or fissile content of used nuclear fuel assemblies, including the 3 techniques of passive neutron albedo reactivity (PNAR), total neutron counting (TN), and californium-252 interrogation with prompt neutron detection (CIPN). These 3 techniques were not integrated with each other because they all rely on the same physics of the multiplication of neutrons by fissile material. The 3 techniques also have a common problem, though. None of them can independently determine the fissile content, without additional information from either the reactor operator or some other NDA technique regarding the burnup, initial enrichment, and/or cooling time of the fuel assembly. In a recent journal article, the author has proposed a new way to integrate these 3 techniques to overcome this problem. In this INMM paper, the author will summarize this new method and describe how it can be applied to safeguards practice.

Journal Articles

Development of basic NDA technologies for nuclear material accountancy of debris of melted fuel formed in severe accidents

Seya, Michio; Harada, Hideo; Kitatani, Fumito; Koizumi, Mitsuo; Tsuchiya, Harufumi; Iimura, Hideki; Kureta, Masatoshi; Takamine, Jun; Hajima, Ryoichi; Hayakawa, Takehito; et al.

Proceedings of INMM 54th Annual Meeting (CD-ROM), 9 Pages, 2013/07

The forming of MF in a severe accident of a nuclear reactor may change the category of the nuclear reactor from item facility to non-item facility. Taking this removal process into account, the damaged reactor could be categorized as a bulk-handling facility. The NM accountancy is essential for the safeguards of a bulk-handling facility. This paper presents a categorization of debris of MF (into cut or small rock-like debris and particle (or grain)-like debris) and a selection of possible NDA technologies which could be applied to the NM accountancy of MF debris. The paper introduces two NDA technologies for NM accountancy of debris: NRD for particle-like (or grain-like) debris, and NRF NDA using LCS $$gamma$$ rays for cut or small rock-like debris. The paper also describes about the development of basic parts of these two technologies and near future plan.

Journal Articles

Calculated distributions of Pu concentrations within spent fuel assemblies of Fugen reactor

Seya, Michio; Katano, Yoshiaki; Ebara, Noriyasu

Proceedings of INMM 54th Annual Meeting (CD-ROM), 10 Pages, 2013/07

For evaluation of the data measured data of Fugen spent fuel assemblies by the PNAR/SINRD detector, which was obtained in the JAEA and USDOE (LANL) collaboration, we need data on the Pu content distribution in the measured assemblies. For nuclear material accountancy, JAEA has data on the quantity of Pu in each spent fuel assembly that is based on burn-up calculations. However, this calculation is just for the total amount of Pu in an assembly. Therefore, we have done burn-up calculations for two MOX-B type assemblies with high burn-up and very low burn-up to obtain Pu content distributions along the vertical axis of an assembly and also distribution differences among inner, middle and outer fuel rods. The data of the Pu content distributions within an assembly will be useful for evaluating the measured data.

Journal Articles

Contribution of the JRC to the development of neutron resonance densitometry to characterize melted fuel from severe accidents

Schillebeeckx, P.*; Becker, B.*; Emiliani, F.*; Kopecky, S.*; Kauwenberghs, K.*; Moens, A.*; Mondelaers, W.*; Sibbens, G.*; Harada, Hideo; Kitatani, Fumito; et al.

Proceedings of INMM 54th Annual Meeting (CD-ROM), 7 Pages, 2013/07

22 (Records 1-20 displayed on this page)