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Journal Articles

Demonstration of $$gamma$$-ray pipe-monitoring capabilities for real-time process monitoring safeguards applications in reprocessing facilities

Rodriguez, D.; Tanigawa, Masafumi; Nishimura, Kazuaki; Mukai, Yasunobu; Nakamura, Hironobu; Kurita, Tsutomu; Takamine, Jun; Suzuki, Satoshi*; Sekine, Megumi; Rossi, F.; et al.

Journal of Nuclear Science and Technology, 55(7), p.792 - 804, 2018/07

 Percentile:100(Nuclear Science & Technology)

Nuclear material in reprocessing facilities is safeguarded by random sample verification with additional continuous monitoring applied to solution masses and volume in important tanks to maintain continuity-of-knowledge of process operation. Measuring the unique $$gamma$$ rays of each solution as the material flows through pipes connecting all tanks and process apparatuses could potentially improve process monitoring by verifying the compositions in real time. We tested this $$gamma$$ ray pipe-monitoring method using plutonium-nitrate solution transferred between tanks at the PCDF-TRP. The $$gamma$$ rays were measured using a lanthanum-bromide detector with a list-mode data acquisition system to obtain both time and energy of $$gamma$$-ray. The analysis and results of this measurement demonstrate an ability to determine isotopic composition, process timing, flow rate, and volume of solution flowing through pipes, introducing a viable capability for process monitoring safeguards verification.

Journal Articles

Delayed $$gamma$$-ray spectroscopy combined with active neutron interrogation for nuclear security and safeguards

Koizumi, Mitsuo; Rossi, F.; Rodriguez, D.; Takamine, Jun; Seya, Michio; Bogucarska, T.*; Crochemore, J.-M.*; Varasano, G.*; Abbas, K.*; Pedersen, B.*; et al.

EPJ Web of Conferences (Internet), 146, p.09018_1 - 09018_4, 2017/09

 Percentile:100

Journal Articles

Influence of the neutron transport tube on neutron resonance densitometry

Kitatani, Fumito; Tsuchiya, Harufumi; Koizumi, Mitsuo; Takamine, Jun; Hori, Junichi*; Sano, Tadafumi*

EPJ Web of Conferences (Internet), 146, p.09032_1 - 09032_3, 2017/09

 Percentile:100

Journal Articles

Delayed gamma-ray spectroscopy, 1; Development and current status

Rodriguez, D.; Rossi, F.; Takamine, Jun; Koizumi, Mitsuo; Seya, Michio; Crochemore, J. M.*; Varasano, G.*; Bogucarska, T.*; Abbas, K.*; Pedersen, B.*

Proceedings of INMM 58th Annual Meeting (Internet), 6 Pages, 2017/07

The JAEA is collaborating with the EC-JRC to develop a NDA system combining four active techniques to improve safeguards verification. Delayed gamma-ray spectroscopy can determine nuclide ratios by correlating observed fission products' time-dependent, high-energy, $$gamma$$ rays to the sample's complex fission yield. To quantify fissile nuclides of significant interest, the fast neutrons from compact, transportable sources must be thermalized to where the fissile nuclides have large cross-sections while maintaining high fluxes to provide significant signals. Experiments are underway at some facilities to improve DGS, including the PUNITA system at JRC-Ispra. These neutron fluxes and measurement conditions are used to develop a Monte Carlo that will be used to analyze the DGS data by an inverse-MC method. The DGS program described here summarizes the 3-year development to optimize the moderator, perform experiments, and create the IMC in preparation for a demonstration of the technique.

Journal Articles

Delayed gamma-ray spectroscopy, 2; Experimental studies for determination of fissile materials ratios

Rossi, F.; Koizumi, Mitsuo; Rodriguez, D.; Takamine, Jun; Seya, Michio; Pedersen, B.*; Crochemore, J. M.*; Abbas, K.*; Bogucarska, T.*; Varasano, G.*

Proceedings of INMM 58th Annual Meeting (Internet), 7 Pages, 2017/07

In the field of nuclear safeguards, new and improved active-interrogation NDA technologies are needed for the independent verification of the fissile composition in HRNM. JAEA and the JRC are now collaborating to develop DGS to determine ratios of fissile nuclides present in the sample measuring the decay gamma rays from FP. Measurements of LRNM samples are underway using different facilities. To minimize the interference from the LLFP, it is important to use shielding and to consider those gamma rays above 3-MeV. Different compact neutron sources are available, but all of them need to be slowed down to the thermal energy region. We are optimizing moderator and reflector materials using MCNP. Optimization of the irradiation, transfer and measurement sequence is now underway. The experiments we are conducting using certified mono-elemental U/Pu samples allow us to associate observed DG to the proportional isotopic compositions. In this paper we will present the current status of the optimization process and the experimental campaign for the determination of the ratio of fissile materials of U and Pu in a sample.

Journal Articles

Delayed gamma-ray analysis for characterization of fissile nuclear materials

Koizumi, Mitsuo; Rossi, F.; Rodriguez, D.; Takamine, Jun; Seya, Michio; Bogucarska, T.*; Crochemore, J.-M.*; Varasano, G.*; Abbas, K.*; Pedersen, B.*; et al.

EUR-28795-EN (Internet), p.868 - 872, 2017/00

Journal Articles

Development of active neutron NDA techniques for nuclear nonproliferation and nuclear security, 7; Measurement of DG from MOX and Pu liquid samples for quantification and monitoring

Mukai, Yasunobu; Ogawa, Tsuyoshi; Nakamura, Hironobu; Kurita, Tsutomu; Sekine, Megumi; Rodriguez, D.; Takamine, Jun; Koizumi, Mitsuo; Seya, Michio

Proceedings of INMM 57th Annual Meeting (Internet), 7 Pages, 2016/07

The development of Delayed Gamma-ray Spectroscopy (DGS) for analyzing the composition ratio of fissile nuclides ($$^{239}$$Pu, $$^{241}$$Pu, $$^{235}$$U) focused on the Delayed Gamma-ray having energy over 3 MeV has been performed for the development of active neutron non-destructive assay techniques. In PCDF, measurement tests of Delayed Gamma-ray using Pu solution and MOX powder samples to prove the DGS technique is planned to be performed in following 4 stages. (1) Measurements for Delayed Gamma-ray originated from spontaneous fission nuclide (Passive), (2) Measurements for the Delayed Gamma-ray with fast neutron (Active), (3) DGSI (DGS combined with self-interrogation) measurements (Passive), (4) Measurements for the Delayed Gamma-ray with thermal neutron (Active) In this paper, the plan of measurement tests for nuclear material samples with use of DGS is presented.

Journal Articles

Utilizing delayed $$gamma$$ rays for fissionable material measurement in NDA

Rodriguez, D.; Takamine, Jun; Koizumi, Mitsuo; Seya, Michio

Proceedings of 37th ESARDA Annual Meeting (Internet), p.831 - 836, 2015/08

A non-destructive analysis system using a pulsed neutron source is under design by researchers of the JAEA, and JRC-ITU (Ispra) and JRC-IRMM. The system will utilize a combination of neutron resonance transmission analysis and differential die-away and both prompt and Delayed Gamma-ray (DG) Spectroscopy (DGS) techniques. This system will be applied toward safeguards applications by effectively determining Nuclear Material (NM) compositions within MOX fuel samples and NM samples with high neutron or $$gamma$$-ray emissions (including the melted fuel). Additionally, this system can be applied toward nuclear security by detecting the high-energy DGs that can more efficiently pass through shielding materials. This presentation will describe the initial status of the DG portion of this system and how it will be used in conjunction with the other techniques to provide both high accuracy and high precision of the composition of the NM of interest.

Journal Articles

Preliminary delayed $$gamma$$-ray spectroscopy for non-destructive analysis of fissionable material

Rodriguez, D.; Heyse, J.*; Koizumi, Mitsuo; Mondelaers, W.*; Pedersen, B.*; Schillebeeckx, P.*; Seya, Michio; Takamine, Jun

Proceedings of INMM 56th Annual Meeting (Internet), 8 Pages, 2015/07

There is a growing interest regarding how to effectively safeguard NM, specifically how to efficiently determine the composition of mixed materials. Currently researchers of the JAEA and JRC are discussing the development of a NDA system using a pulsed DT neutron source. The system will utilize a combination of DDA, NRTA, PGA, and DGS techniques. Of specific interest is applying this system toward determining the Pu/U composition of purified MOX fuel and non-purified NM. The DGS technique has the potential to establish fissionable material ratios to relatively high precision. These fission products generate time-dependent $$gamma$$-ray energy spectra that extend well above 3 MeV, a benefit when applied to the NM of interest that have high passive emissions. This presentation will describe initial studies regarding the precision that the DGS portion of this system can obtain and how it will be used in conjunction with the other techniques to analyze the composition of the NM of interest.

Journal Articles

Development of NRD, 3; Study of a new moderator for compact 14-MeV pulsed neutron sources

Takamine, Jun; Koizumi, Mitsuo; Kureta, Masatoshi; Harada, Hideo; Kitatani, Fumito; Tsuchiya, Harufumi; Seya, Michio; Iimura, Hideki

Kaku Busshitsu Kanri Gakkai (INMM) Nippon Shibu Dai-35-Kai Nenji Taikai Rombunshu (Internet), 10 Pages, 2015/01

A prototype device of neutron resonance densitometry (NRD) with a D-T neutron generator was planned for basic studies of actual NRD devices. D-T neutron generators had features of simple handling and compact compared with photo neutron sources driven by electron beam accelerators. But those of D-T neutron are higher energy and lower intensity than those of photo neutron. We designed a new type moderator to compensate for the shortcomings. In the new type moderator, the D-T neutron generator is surrounded by Lead, and Polyethylene is arranged in the beam direction on the surface of Lead. As the result of analysis using Monte Carlo code MCNP5, it was found that the new moderator achieved about four times larger production of low energy neutrons than polyethylene moderator without distorting the energy resolution below at least 100 eV. The lead part in the new moderator are changed to other heavy metals, which is Uranium, and Tungsten. Analysis like the above were performed. We report these results.

Journal Articles

Development of NRD, 2; Investigation on systematic effects due to sample thickness for areal density derived from NRTA

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

Kaku Busshitsu Kanri Gakkai (INMM) Nippon Shibu Dai-35-Kai Nenji Taikai Rombunshu (Internet), 9 Pages, 2015/01

We are developing neutron resonance densitometry that combines neutron resonance transmission analysis (NRTA) and neutron resonance capture analysis. The aim is to establish a non-destructive technique that can quantify nuclear materials in particle-like debris of melted fuel resulting from severe nuclear accidents like the one at the Fukushima Daiichi Nuclear Power Plant. Systematic effects due to sample thickness and mixed sample for the areal density measurement by NRTA were investigated at a neutron time-of-facility GELINA, IRMM. The experiments were conducted utilizing natural Cu metal discs with different thickness and a B$$_{4}$$C disc. Areal densities were derived with a resonance shape analysis code REFIT. It was found that they were inconsistent with those calculated by mass and area, when using recommended resonance parameters. Hence, a neutron width of resonance parameters was newly evaluated with the NRTA data and we found that derived areal density agreed within 2% with the expected ones. We also discuss the impacts of mixed sample for the areal density derived from NRTA measurement.

Journal Articles

Development of NRD, 1; Developments of a LaBr$$_{3}$$ scintillation detector system for neutron resonance densitometry

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

Kaku Busshitsu Kanri Gakkai (INMM) Nippon Shibu Dai-35-Kai Nenji Taikai Rombunshu (Internet), 8 Pages, 2015/01

We have proposed neutron resonance densitometry (NRD) as a method to quantify special nuclear materials in particle-like debris of melted fuel. NRD is a combination of neutron resonance transmission analysis (NRTA), and neutron resonance capture analysis (NRCA) (and prompt $$gamma$$-ray analysis (PGA)). NRCA/PGA is used to identify contaminant elements, which is difficult to be detected by NRTA. To observe $$gamma$$ rays emitted in neutron capture reaction, a spectrometer consisting of LaBr$$_3$$ scintillation detectors has been constructed. A newly installed data acquisition system enables us to measure 500 k event/s for each 8-channel inputs. In this presentation, the research and development of NRD is introduced and the status of the development of the spectrometer system is given as well.

Journal Articles

Recent progress in research and development in neutron resonance densitometry (NRD) for quantification of nuclear materials in particle-like debris

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

Nuclear Back-end and Transmutation Technology for Waste Disposal, p.13 - 20, 2015/00

Neutron Resonance Densitometry (NRD) has been proposed for quantification of nuclear materials in melted fuel. NRD is a combined TOF technique of Neutron Resonance Transmission Analysis (NRTA) and Neutron Resonance Capture Analysis (NRCA) or Prompt Gamma ray Analysis (PGA). To establish the method, development of detectors is in progress. Experiments were carried out at a TOF facility, GELINA, under the collaboration with EC-JRC-IRMM. The progress of the project is reported.

Journal Articles

Impact of systematic effects on results of neutron resonance transmission analysis

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

Nuclear Instruments and Methods in Physics Research A, 767, p.364 - 371, 2014/12

 Times Cited Count:6 Percentile:36.56(Instruments & Instrumentation)

The impact of systematic effects on the areal density derived from a neutron resonance transmission analysis (NRTA) is investigated by measurements at the time-of-flight facility GELINA. The experiments were carried out at a 25 m station using metallic natural Cu discs with different thicknesses. To derive the areal density from a fit to the experimental transmission, the resonance shape analysis code REFIT was used. Large bias effects were observed using recommended resonance parameters. Therefore, neutron resonance parameters, in particular resonance energies and neutron widths, were derived from the transmission data obtained with a 0.25 mm thick Cu metallic sample. These parameters were used to study the impact of the resonance strength and sample thickness, on the accuracy of the areal density derived by NRTA.

Journal Articles

Uncertainty assessment of neutron resonance transmission analysis using the linear absorption model

Kitatani, Fumito; Harada, Hideo; Takamine, Jun; Kureta, Masatoshi; Seya, Michio

Journal of Nuclear Science and Technology, 51(9), p.1107 - 1113, 2014/09

 Times Cited Count:3 Percentile:61.51(Nuclear Science & Technology)

Journal Articles

Thickness and mixed sample effects on areal density measurement with NRTA for particle like debris of melted fuel

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

Proceedings of INMM 55th Annual Meeting (Internet), 6 Pages, 2014/07

Journal Articles

Developments of a LaBr$$_3$$ scintillation detector system for neutron resonance densitometry (NRD)

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

Proceedings of INMM 55th Annual Meeting (Internet), 7 Pages, 2014/07

Journal Articles

Development of neutron resonance densitometry

Harada, Hideo; Schillebeeckx, P.*; Tsuchiya, Harufumi; Kitatani, Fumito; Koizumi, Mitsuo; Takamine, Jun; Kureta, Masatoshi; Iimura, Hideki; Kimura, Atsushi; Seya, Michio; et al.

Proceedings of INMM 55th Annual Meeting (Internet), 8 Pages, 2014/07

Journal Articles

Analysis of Pu isotopes in melted fuel by neutron resonance transmission; Examination by linear absorption model

Kitatani, Fumito; Harada, Hideo; Takamine, Jun; Kureta, Masatoshi; Seya, Michio

Nuclear Data Sheets, 118, p.505 - 509, 2014/04

 Times Cited Count:1 Percentile:85.28(Physics, Nuclear)

Feasibility study of neutron resonance transmission analysis (NRTA) has been started to quantify nuclear materials in particle-like debris of melted fuel formed in severe accidents of nuclear reactor such as Fukushima Daiichi Nuclear Power Plants. The achievable measurement accuracy was examined by NRTA using a linear absorption model for the sample in which substances other than nuclear fuel materials, such as boron, were contained. In this study, boron and iron were considered to be contained in spent nuclear fuel as impurities. The neutron flight path is 5 m, that is the length between the neutron source and a neutron detector. Neutron absorption spectra were calculated using the total neutron absorption cross-section by JENDL-4.0. The absorption spectra together with their errors were evaluated. The achievable accuracy of Pu isotopic density was deduced as a function of neutron intensity and impurity density. This research was supported by JSGO/MEXT.

Journal Articles

Neutron resonance densitometry for particle-like debris of melted fuel

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

Nuclear Data Sheets, 118, p.502 - 504, 2014/04

 Times Cited Count:3 Percentile:63.98(Physics, Nuclear)

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