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Journal Articles

Demonstration result of sample assay system equipped alternative He-3 detectors

Tanigawa, Masafumi; Mukai, Yasunobu; Tobita, Hiroshi; Kurata, Noritaka*; Kobayashi, Nozomi*; Takase, Misao*; Makino, Risa; Ozu, Akira; Nakamura, Hironobu; Kurita, Tsutomu; et al.

56th Annual Meeting of the Institute of Nuclear Materials Management (INMM 2015), Vol.1, p.693 - 701, 2016/00

no abstracts in English

Journal Articles

Numerical evaluation of the light transport properties of alternative He-3 neutron detectors using ceramic scintillators

Ozu, Akira; Takase, Misao*; Haruyama, Mitsuo; Kurata, Noritaka*; Kobayashi, Nozomi*; Kureta, Masatoshi; Nakamura, Tatsuya; To, Kentaro; Sakasai, Kaoru; Suzuki, Hiroyuki; et al.

Nuclear Instruments and Methods in Physics Research A, 798, p.62 - 69, 2015/10

 Times Cited Count:2 Percentile:74.39(Instruments & Instrumentation)

The light transport properties of scintillator light inside alternative He-3 neutron detector modules using scintillator sheets have been investigated by a ray-tracing simulation code. The detector module consists of a light-reflecting tube, a thin rectangular ceramic scintillator sheet laminated on a glass plate, and two photo-multiplier tubes (PMTs) mounted at both ends of the detector tube. The light induced on the surface of the scintillator sheet via nuclear interaction between the scintillator and neutrons are detected by the two PMTs. The light output of various detector modules in which the scintillator sheets are installed with several different arrangements were examined and evaluated in comparison with experimental results. The results derived from the simulation reveal that the light transport property is strongly dependent on the arrangement of the scintillator sheet inside the tube and the shape of the tube.

Journal Articles

Analytical study on uranium measurement in uranium waste drums by the fast neutron direct interrogation method

Komeda, Masao; Ozu, Akira; Haruyama, Mitsuo; Takase, Misao*; Kureta, Masatoshi; Nakatsuka, Yoshiaki; Zaima, Naoki; Nakashima, Shinichi; Otsuka, Yoshimasa

Proceedings of INMM 55th Annual Meeting (Internet), 9 Pages, 2014/07

We have researched and developed the FNDI method for a long time through experiments in NUCEF in JAEA Tokai. Referred from the pilot machine, we designed a demonstrator, called as JAWAS-N, for applying to non-destructive assay tools for uranium waste drums in JAEA Ningyo. In this paper, we present the modeling and the simulations concerning JAWAS-N's characteristics, and discuss for practical use compared analytical results with obtained some experimental data.

Journal Articles

Neutron-sensitive ZnS/$$^{10}$$B$$_{2}$$O$$_{3}$$ ceramic scintillator detector as an alternative to a $$^{3}$$He-gas-based detector for a plutonium canister assay system

Nakamura, Tatsuya; Ozu, Akira; To, Kentaro; Sakasai, Kaoru; Suzuki, Hiroyuki; Honda, Katsunori; Birumachi, Atsushi; Ebine, Masumi; Yamagishi, Hideshi*; Takase, Misao; et al.

Nuclear Instruments and Methods in Physics Research A, 763, p.340 - 346, 2014/05

 Times Cited Count:2 Percentile:76.73(Instruments & Instrumentation)

A neutron-sensitive ZnS/$$^{10}$$B$$_{2}$$O$$_{3}$$ ceramic scintillator detector was developed as an alternative to a $$^{3}$$He-gas-based detector for use in a plutonium canister assay system. The detector has a modular structure, with a flat ZnS/$$^{10}$$B$$_{2}$$O$$_{3}$$ceramic scintillator strip that is installed diagonally inside a light-reflecting aluminium case with a square cross section. The prototype detectors, which have a neutron-sensitive area of 30 mm $$times$$ 250 mm, exhibited a sensitivity of 21.7-23.4 $$pm$$ 0.1 cps$$/$$nv for thermal neutrons, a $$^{137}$$Cs $$gamma$$-ray sensitivity of 1.1-1.9 $$pm $$0.2 $$times$$ 10$$^{-7}$$ and a count variation of less than 6% over the detector length. A trial experiment revealed a temperature coefficient of less than -0.24$$pm$$ 0.05% / $$^{circ}$$C over the temperature range of 20-50$$^{circ}$$C.

Journal Articles

Evaluation of light transport property in alternative He-3 neutron detectors using ceramic scintillators by a ray-tracing simulation

Ozu, Akira; Takase, Misao*; Kurata, Noritaka*; Kobayashi, Nozomi*; Tobita, Hiroshi; Haruyama, Mitsuo; Kureta, Masatoshi; Nakamura, Tatsuya; Suzuki, Hiroyuki; To, Kentaro; et al.

Proceedings of 2014 IEEE Nuclear Science Symposium and Medical Imaging Conference; 21st International Symposium on Room-Temperature Semiconductor X-ray and $$gamma$$-ray detectors (NSS/MIC 2014), 5 Pages, 2014/00

In Japan Atomic Energy Agency, the helium-3 alternative neutron detector using ceramic scintillators for nuclear safeguards is under development with the support of the government. The alternative detector module consists of four components: an aluminum regular square tube, a light reflecting foil put on the inner surface of the square tube, a rectangular scintillator sheet sintered on a glass plate, and two PMTs provided at both ends of the tube. The scintillator sheet is fit on the diagonal inside the square tube. The light transport property of scintillator lights inside the tube influences on the fundamental performance of the alternative detector. Therefore, the properties of the lights emitted on the surface of the scintillator sheet and scintillation lights passing through the glass plate to the PMTs in several arrangements of the scintillator in the tubes were investigated with a ray-tracing simulation. The results are described in comparison with the experimental results.

Journal Articles

Development of an alternative plutonium canister assay system (APCA) using He-3 alternative neutron detector

Ozu, Akira; Kureta, Masatoshi; Haruyama, Mitsuo; Takase, Misao; Kurata, Noritaka; Kobayashi, Nozomi; Soyama, Kazuhiko; Nakamura, Tatsuya; Sakasai, Kaoru; To, Kentaro; et al.

Kaku Busshitsu Kanri Gakkai (INMM) Nippon Shibu Dai-34-Kai Nenji Taikai Rombunshu (Internet), 9 Pages, 2013/10

no abstracts in English

Journal Articles

Practical study for uranium measurement in uranium bearing wastes with the fast neutron direct interrogation method

Komeda, Masao; Ozu, Akira; Zaima, Naoki; Nakatsuka, Yoshiaki; Nakashima, Shinichi; Takase, Misao; Haruyama, Mitsuo; Kureta, Masatoshi

Kaku Busshitsu Kanri Gakkai (INMM) Nippon Shibu Dai-34-Kai Nenji Taikai Rombunshu (Internet), 9 Pages, 2013/10

no abstracts in English

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

Optical guide property of alternative He-3 neutron detectors using solid scintillators for nuclear safeguards

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

Proceedings of 2013 IEEE Nuclear Science Symposium and Medical Imaging Conference Record (NSS/MIC), 4 Pages, 2013/00

Alternative He-3 neutron detectors using inorganic solid (ZnS:Ag/10B$$_{2}$$O$$_{3}$$) scintillators for nuclear safeguards have been developed in Japan Atomic Energy Agency (JAEA). The detector module is made mainly of three components: an aluminum regular square tube (32 mm $$times$$ 32 mm $$times$$ 300 mm), a rectangular scintillator sheet (39 mm $$times$$ 250 mm) and two PMTs. The scintillator sheet is fit on the diagonal inside the square tube, while the two PMTs are installed at both ends of the tube. At present, the detection efficiency of around 50% of that of the He-3 gas detector has been already achieved. The $$gamma$$ ray sensitivity of $$<$$ 5$$times$$10$$^{-7}$$ is also obtained. The fundamental performance of the alternative detector is strongly dependent on the optical guide property of scintillation lights inside of the tube. The transport properties of the scintillation lights detected with the PMTs was evaluated by a ray-tracing simulation. The results are discussed in comparison with the experimental results.

Journal Articles

Trial plan for advanced NDA system of uranium wastes; Introduction of active neutron method applied to NDA system

Zaima, Naoki; Nakashima, Shinichi; Nakatsuka, Yoshiaki; Kado, Kazumi; Haruyama, Mitsuo; Takase, Misao; Ozu, Akira; Kureta, Masatoshi

Kaku Busshitsu Kanri Gakkai (INMM) Nippon Shibu Dai-33-Kai Nenji Taikai Rombunshu (Internet), 8 Pages, 2012/10

We developed uranium mass assay systems for 200-litter wastes drums applied passive neutron measurements by NDA method and applied for the actual wastes drums stored in URCP. The neutron measurement methodology of $$^{234}$$U($$alpha$$,n) reaction using $$^{3}$$He proportional counters delivered superior performance, however also included some problems that the neutron penetration rates are depend upon matrices or density of wastes drums, so it was difficult to determine uranium mass against "unknown objects". For the purpose of solving problems active neutron measurements appears promising, we are now challenging to improve our equipments, which are composed of neutron generator, polyethylene moderators and $$^{3}$$He proportional counters. The uranium mass are determined by counting secondary neutrons generated from nuclear fissions. Our preliminary simulations suggest good performances with higher sensitivities and accuracies. It is extremely expected to contribute in the fields of safeguards works.

Journal Articles

Measurement system modification for advanced NDA system of uranium wastes; Performance evaluation of active neutron method applied to NDA system

Haruyama, Mitsuo; Takase, Misao; Ozu, Akira; Kureta, Masatoshi; Zaima, Naoki; Nakashima, Shinichi; Nakatsuka, Yoshiaki; Kado, Kazumi

Kaku Busshitsu Kanri Gakkai (INMM) Nippon Shibu Dai-33-Kai Nenji Taikai Rombunshu (Internet), 9 Pages, 2012/10

no abstracts in English

Journal Articles

Development plan of Pu NDA system using ZnS ceramic scintillator

Kureta, Masatoshi; Soyama, Kazuhiko; Seya, Michio; Ozu, Akira; Haruyama, Mitsuo; Takase, Misao; Sakasai, Kaoru; Nakamura, Tatsuya; To, Kentaro

Kaku Busshitsu Kanri Gakkai (INMM) Nippon Shibu Dai-33-Kai Nenji Taikai Rombunshu (Internet), 9 Pages, 2012/10

Alternative techniques to neutron detection by helium-3 for nuclear security and safeguards systems are necessary to be developed since helium-3 shortage is serious. With support of Japanese government (the Ministry of Education, Culture, Sports, Science and Technology), we have started an R&D project of Pu NDA system using ZnS ceramic scintillator. Here we present development plan, production of a new type of ZnS ceramic scintillator experimentally and basic design of a PCAS alternative Pu NDA system. We are planning the demonstration tests using the alternative NDA system comparing with the current PCAS in which the helium-3 counters are installed.

Journal Articles

Development plan of Pu NDA system using ZnS ceramic scintillator

Kureta, Masatoshi; Soyama, Kazuhiko; Seya, Michio; Ozu, Akira; Haruyama, Mitsuo; Takase, Misao; Sakasai, Kaoru; Nakamura, Tatsuya; To, Kentaro

Proceedings of INMM 53rd Annual Meeting (CD-ROM), 8 Pages, 2012/07

Alternative techniques to neutron detection by helium-3 for nuclear security and safeguards systems are necessary to be developed since helium-3 shortage is serious. With support of Japanese government (the Ministry of Education, Culture, Sports, Science and Technology), we have started an R&D project of Pu NDA system using ZnS ceramic scintillator. Here we present development plan, production of a new type of ZnS ceramic scintillator experimentally and basic design of a PCAS alternative Pu NDA system. We are planning the demonstration tests using the alternative NDA system comparing with the current PCAS in which the helium-3 counters are installed.

Journal Articles

Research and development of a high-sensitivity non-destructive assay of fissile nuclide by using fast neutron direct interrogation method

Takamine, Jun; Haruyama, Mitsuo; Takase, Misao; Yamaguchi, Satoshi

Proceedings of 16th Pacific Basin Nuclear Conference (PBNC-16) (CD-ROM), 6 Pages, 2008/10

When an object including a lot of hydrogen atoms such as the cemented waste is measured by using the conventional active neutron method, radial sensitivity distribution in the region of surface and center is different more than 100 times. Then we developed the method to detect a nuclear fission neutron induced by the neutron which slowed down in the matrix itself, and so performed a position sensitivity difference of 10%. Furthermore, we understood that the background neutron in nuclear fission neutron counting area is great decrease by using SUS-304 instead of graphite as a moderator of conventional detection system. And then, this new system enabled to measure clearance level activity included in cemented waste. Besides, we modified the optimum structure of the detector bank, which enabled to measure precisely even metal compaction waste (the density is 3$$sim$$4 g/cm$$^{3}$$). In this session, we introduce the process of the past research, applied examples, recent results of the research.

Journal Articles

Research for determination of elemental ratio between Uranium and Plutonium by Non-destructive method

Takamine, Jun; Haruyama, Mitsuo; Takase, Misao

Nippon Hozen Gakkai Dai-5-Kai Gakujutsu Koenkai Yoshishu, p.481 - 484, 2008/07

We have not yet known the nondestructive detection method to determine each quantity of the object which Uranium and Plutonium is mixed in, such a waste generated from nuclear fuel cycle facility, and so radioactive intensity of Pu-239 is 10,000 times as much as U-235. Therefore, on radioactive assessment, it is important to precisely quantify each mass. Then we paid attention to the component of delayed and prompt neutron obtained by 14 MeV neutron direct interrogation method and so developed the new method to determine mass ratio between Uranium and Plutonium from those correlations.

Journal Articles

Improvement of detection limit in 14 MeV neutron direct interrogation method by decreasing background

Haruyama, Mitsuo; Takase, Misao; Tobita, Hiroshi

Journal of Nuclear Science and Technology, 45(5), p.432 - 440, 2008/05

 Times Cited Count:10 Percentile:38.9(Nuclear Science & Technology)

For improvement of detection limit in the 14 MeV-neutrons direct interrogation method, the simulation calculation by the continuous energy Monte Carlo transportation code (MVP) was carried out. From the results, it was made clear that the background neutrons appearing in the nuclear-fission neutrons counting-area can be greatly decreased by adopting a stainless steel SUS-304 (an iron-base alloy) reflector in place of a graphite moderator in the conventional detection system. The background level of this modified detecting system becomes 1/10,000 of that with the conventional system and method. Namely, the background counting of 5,000 occurred in the graphite detecting system with the conventional method can be decreased down to 0.5 by adoption of the stainless steel detecting system. The detection limit for the cementation waste that is contaminated with the natural uranium is 0.000122 Bq/g with the stainless steel detecting system in a time of 10 minutes.

Journal Articles

Clearance inspection technology of uranium waste by fast neutron direct interrogation method

Haruyama, Mitsuo; Takase, Misao; Takamine, Jun

Dekomisshoningu Giho, (37), p.17 - 24, 2008/03

In recently year, clearance level of the uranium waste is concretized, and then the inspection technology with low cost and high precision is required. Therefore, We performed applicability evaluation for the uranium waste of Fast neutron direct interrogation method and developed a suitable measurement system for the waste. As a result, it was confirmed that the measurement to be lower than clearance level greatly was possible by using the optimized measurement system. In this report, we introduce applicability evaluation to the uranium waste of this technique and a principle and the refinement of the device.

Journal Articles

The Application for the inspection technique of concealed nuclear materials by plasma fusion neutron source

Haruyama, Mitsuo; Takamine, Jun; Takase, Misao; Yamaguchi, Satoshi

Nippon Hozen Gakkai Dai-1-Kai "Kensa, Hyoka, Hozen Ni Kansuru Renkei Koenkai", p.122 - 125, 2008/01

When a radioactive waste package fixed by a material such as the cement is measured by using conventional active neutron method, the problems related to quantification accuracy comes from fact that radial sensitivity distribution in the region of surface and center is different more than 100 times. In order to resolve the problem, we developed the method to detect a nuclear fission neutron induced by the neutron which slowed down in the matrix itself. By using this new method, we performed a position sensitivity difference of 10%. Recently, the inspection method to prevent the smuggling of the fissile material at the water's edge is demanded around the world. Presently, we progress the research and development to apply this new method to the inspection. In this research, we confirmed its availability through computer simulation.

Journal Articles

High-sensitive detection by direct interrogation of 14 MeV Acc neutrons, 2; Uranium-contained cloth matrix in a waste dram

Haruyama, Mitsuo; Tobita, Hiroshi; Takase, Misao*; Mori, Takamasa

Nippon Genshiryoku Gakkai Wabun Rombunshi, 6(1), p.65 - 72, 2007/03

no abstracts in English

Journal Articles

High-sensitive detection by direct interrogation of 14 MeV Acc neutrons, 1; Uranium-contained metal matrix in a waste dram

Haruyama, Mitsuo; Takase, Misao*; Tobita, Hiroshi; Mori, Takamasa

Nippon Genshiryoku Gakkai Wabun Rombunshi, 3(2), p.185 - 192, 2004/06

no abstracts in English

50 (Records 1-20 displayed on this page)