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Rossi, F.; Lee, J.; 児玉 有; 弘中 浩太; 小泉 光生; 堀 順一*; 寺田 和司*; 佐野 忠史*
Proceedings of 65th Annual Meeting of the Institute of Nuclear Materials Management (Internet), 8 Pages, 2024/07
Various non-destructive assay techniques are being used to verify different nuclear material. However, one of the difficulties of current NDA is the measurement of highly radioactive materials. Since 2015, the JAEA has been working on the development of various active non-destructive assay techniques to address some of the current challenges in nuclear safeguards. Among the various technologies proposed, the Neutron Resonance Analysis system combines signatures from NRTA, NRCA and the newly proposed NRFNA. The combination of those techniques can provide accurate information on the small fissile content in a sample. Neutrons are generated by a pulsed neutron source and slowed down into the moderator. Neutrons are collimated using lead and borated polyethylene to reach the sample, where various neutron-induced reactions occur. n/g PSD plastic scintillators are used to measure the captured gamma rays and fission neutrons at sample location. GS20 is used to collect the transmitted neutrons downstream of the source-sample beamline. A first measurement campaign was performed using natural uranium sample. The possibility of using NRFNA to identify fissile materials within a sample was clearly demonstrated, but the detectors used were not sufficient to achieve a good n/g PSD. New PSD scintillators were introduced. A first measurement campaign was performed in 2023. The acquired data are currently being analyzed, but preliminary results show distinct fission resonance peaks of increasing intensity with varying thicknesses of the same natural uranium samples. Currently, an assembly of multiple scintillators is being investigated to provide a better signal. The new setup will be tested starting in early 2024. In this paper, we will describe in detail the NRA project development and the latest results from experimental campaign. This work is supported by MEXT under the subsidy for the "promotion for strengthening nuclear security and the like"
Kyffin, J.*; Dia, A.*; Nkosi, G.*; Nizhnik, V.*; 林 昭彦; 長谷 竹晃
Proceedings of 65th Annual Meeting of the Institute of Nuclear Materials Management (Internet), 8 Pages, 2024/07
In collaboration with the Japan Safeguards Office, the Nuclear Material Control Centre, and the JAEA, the IAEA Department of Safeguards is implementing a new neutron detector system for the verification of plutonium hold-up in process gloveboxes at MOX fuel fabrication facilities in Japan. The previous verification technique utilised the so-called Super Glove Box Assay System (SBAS), which, while capable of detecting partial defects, is a heavy and bulky detector system that requires both significant operator support for safe assembly and positioning, and long measurement times. The recent development of a detector system based on two Plutonium Neutron Coincidence Collar (PNCL) miniature neutron slabs provides the capability of detecting gross defects with semi-quantitative plutonium mass measurement, and is sufficient in respect to inspections for timeliness purposes. For regular use, the Mini-slab detector offers several advantages, including improved safety, reduced operator support requirements and shorter measurement times. The Mini-slab detector satisfies the required verification role with a quarter of the inspector-days compared to SBAS. Furthermore, it has the capability to measure in tighter spaces, with the need for such use expected to grow as parts of these facilities begin decommissioning.
Rodriguez, D.; 赤松 駿介*; Rossi, F.; 鈴木 敏*; 高橋 時音
Proceedings of 65th Annual Meeting of the Institute of Nuclear Materials Management (Internet), 9 Pages, 2024/07
Under the MEXT subsidy to promote nuclear security related activities, we will present the preliminary results from the new Fission Signature Assay Instrument that was fabricated and fully installed in November 2023. We will describe the instrument within the context of the JAEA-JRC collaboration development and the experimental activities planned with it in the larger context of finishing off Phase-III development.
Broughton, D.*; 鈴木 梨沙; 長谷 竹晃; 岡田 豊史; Henzlova, D.*; Longo, J.*; Mendez, J.*; Rael, C.*; Swinhoe, M. T.*
no journal, ,
プルトニウム燃料技術開発センターでは、プルトニウムを含有する核燃料物質の国内計量管理のために、非破壊測定装置(ENMC)を使用している。近年プルトニウム燃料技術開発センターでは、施設の廃止措置に伴い発生するスクラップ等の影響により、高いアルファ値を持つ核燃料物質が増加しており、非破壊測定が困難になっている。本発表では、プルトニウム燃料技術開発センターで実施したENMCによる核燃料物質測定試験の結果をもとに、様々な評価方法により非破壊測定の精度向上を検討した。