Demonstration of -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

https://doi.org/10.1080/00223131.2018.1439412

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 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 ray pipe-monitoring method using plutonium-nitrate solution transferred between tanks at the PCDF-TRP. The rays were measured using a lanthanum-bromide detector with a list-mode data acquisition system to obtain both time and energy of -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.

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, 146, p.09032_1 - 09032_3, 2017/09

https://doi.org/10.1051/epjconf/201714609032

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.

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

http://publications.jrc.ec.europa.eu/repository/bitstream/JRC107151/esarda_symposium_proceedings-final.pdf

Development of active neutron NDA techniques for nonproliferation and nuclear security, 4; Experimental studies for analyzing nuclear materials by High-Energy Delayed Gamma-ray Spectroscopy (HE-DGS)

Koizumi, Mitsuo; Rossi, F.; Seya, Michio; Rodriguez, D.; Takamine, Jun; Kureta, Masatoshi

Proceedings of INMM 57th Annual Meeting (Internet), 6 Pages, 2016/07

Utilizing delayed 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 -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.

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) Nihon 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.

Development of NRD, 1; Developments of a LaBr 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) Nihon 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 -ray analysis (PGA)). NRCA/PGA is used to identify contaminant elements, which is difficult to be detected by NRTA. To observe rays emitted in neutron capture reaction, a spectrometer consisting of LaBr 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.

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

https://doi.org/10.1016/j.nima.2014.09.009

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.

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