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) Nihon 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 BC 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.

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

https://doi.org/10.1007/978-4-431-55111-9_2

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.

Present status of J-PARC linac

Oguri, Hidetomo; Hasegawa, Kazuo; Ito, Takashi; Chishiro, Etsuji; Hirano, Koichiro; Morishita, Takatoshi; Shinozaki, Shinichi; Ao, Hiroyuki; Okoshi, Kiyonori; Kondo, Yasuhiro; et al.

Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.389 - 393, 2014/10

http://www.pasj.jp/web_publish/pasj2014/proceedings/PDF/FSP0/FSP021.pdf

no abstracts in English

Developments of a LaBr 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

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

https://doi.org/10.1016/j.nds.2014.04.118

GEANT4 simulation study of a -ray detector for neutron resonance densitometry

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

JAEA-Conf 2013-002, p.119 - 124, 2013/10

https://doi.org/10.11484/jaea-conf-2013-002

We have proposed a system to quantify nuclear materials in melted fuels in the reactors of the Fukushima Daiichi Nuclear Power Plant. The system utilizes non destructive techniques combining neutron resonance transmission analysis (NRTA) and neutron resonance capture analysis (NRCA). This is because the melted fuels are though to involve not only nuclear materials but also impurities such as Hydrogen, Boron, Zirconium, and Iron. Using the combined system, we would be able to identify those non-nuclear materials by NRCA and accurately measure nuclear materials by NRTA. A -ray detector for NRCA consists of a cylindrical LaBr scintillation counter and a well-type LaBr one. The well-type counter is served as a back-catcher detector and individual signals recorded in the two counters are summed to aim at reducing the Compton edge originating from Cs that generate intense background for the NRCA measurement. According to GEANT4 simulation, It can be seen that the Compton edge is suppressed by the well-type counter. For example, thanks to the well-type counter, a count at an energy of B-derived -rays (478 keV) is reduced by 0.15. In this presentation, we show performance of the -ray detector using GEANT4 simulation. In addition, comparing results based on evaluated cross sections of ENDF-VII.0 with those based on JENDL-4.0, we discuss differences in performance expected for the -ray detector.

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.

Kaku Busshitsu Kanri Gakkai (INMM) Nihon Shibu Dai-34-Kai Nenji Taikai Rombunshu (Internet), 6 Pages, 2013/10

Neutron resonance densitometry (NRD) has been proposed to quantify nuclear materials in particle-like debris of melted fuel formed in severe accidents of nuclear reactors such as Fukushima Daiichi Nuclear Power Plants. NRD is a method combining NRTA (neutron resonance transmission analysis) and NRCA (neutron resonance capture analysis). It relies on neutron TOF (time of flight) technique using a pulsed white neutron source. The use of a special -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 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.

Conceptual design of multipurpose compact research reactor; Annual report FY2011

Watahiki, Shunsuke; Hanakawa, Hiroki; Imaizumi, Tomomi; Nagata, Hiroshi; Ide, Hiroshi; Komukai, Bunsaku; Kimura, Nobuaki; Miyauchi, Masaru; Ito, Masayasu; Nishikata, Kaori; et al.

JAEA-Technology 2013-021, 43 Pages, 2013/07

JAEA-Technology-2013-021.pdf:5.12MB

The number of research reactors in the world is decreasing because of their aging. On the other hand, the necessity of research reactor, which is used for human resources development, progress of the science and technology, industrial use and safety research is increasing for the countries which are planning to introduce the nuclear power plants. From above background, the Neutron Irradiation and Testing Reactor Center began to discuss a basic concept of Multipurpose Compact Research Reactor (MCRR) for education and training, etc., on 2010 to 2012. This activity is also expected to contribute to design tool improvement and human resource development in the center. In 2011, design study of reactor core, irradiation facilities with high versatility and practicality, and hot laboratory equipment for the production of Mo-99 was carried out. As the result of design study of reactor core, subcriticality and operation time of the reactor in consideration of an irradiation capsule, and about the transient response of the reactor to the reactivity disturbance during automatic control operation, it was possible to do automatic operation of MCRR, was confirmed. As the result of design study of irradiation facilities, it was confirmed that the implementation of an efficient mass production radioisotope Mo-99 can be expected. As the result of design study with hot laboratory facilities, Mo-99 production, RI export devised considered cell and facilities for exporting the specimens quickly was designed.

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 -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.

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 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.