平成17年度研究炉加速器管理部年報; JRR-3, JRR-4, NSRR及びタンデム加速器の運転、利用及び技術開発

Annual report of Department of Research Reactors and Tandem Accelerator, JFY2005; Operation, utilization and technical development of JRR-3, JRR-4, NSRR and Tandem Accelerator

研究炉加速器管理部

Department of Research Reactor and Tandem Accelerator

本報告書はJRR-3, JRR-4及びNSRRの研究炉並びにタンデム加速器の運転管理,利用,技術開発について報告するものである。平成17年度の運転管理,利用,技術開発等における主な成果としては次のとおりである。(1)JRR-3では7サイクルで156日間の、JRR-4では37サイクルで145日の施設共用運転を行い、シリコン照射等の照射件数633件,放射化分析等のキャプセル総数2,922個,中性子ビーム実験利用では延べ利用日数5,511件・日の利用に供した。(2)JRR-3の冷中性子ビーム強度10倍化計画については、液体水素が喪失した場合の高性能減速材容器の応力解析を実施し、その健全性を確認した。(3)JRR-4を用いるBNCTに関する照射技術の開発では、さまざまな部位へ適用を可能にするための技術開発の一環として、頭頸部ガンへの照射を可能にする延長コリメータを実用化した。(4)NSRRは、高燃焼度の軽水炉燃料を対象とした4回の反応度事故模擬実験を計画どおり実施した。(5)タンデム加速器は182日の運転を行い、計画したすべての実験項目を遂行し、機構内外の重イオンを用いた研究開発に貢献した。

The Department of Research Reactors and Tandem Accelerator is responsible for the operation, utilization and technical development of JRR-3(Japan Research Reactor-3), JRR-4(Japan research Reactor-4) and NSRR(Nuclear Safety Research Reactor) as well as Tandem Accelerator. The following services and technical developments were achieved in Japanese Fiscal Year (JFY) 2006: JRR-3 was operated for 156 days in 7 cycles and JRR-4 for 145 days in 37 cycles. They provided neutrons for research and development of internal and external users. (1) JRR-3 and JRR-4 were utilized through deliberate coordination as follows, (a) Neutron irradiations of 633 such as neutron transmutation doping of silicon, (b) Capsule irradiations of 2922 such as neutron activation analyses, (c) Neutron beam experiments of 5511 (cases*workdays). (2) According for the plan increasing cold neutron beam strength 10 times, Integrity of moderator vessel at liquid-hydrogen-evaporation events was confirmed by the stress analyses. Also, it was confirmed by optical tests that glass type carbon plates promising as radiation-resistant neutron guides possesses the same performance of glass plates, and irradiation tests of glass type carbon plates was prepared. (3) In Born Neutron Capture Therapy using JRR-4, an extended collimator that enable clinical trials for head-and-neck cancer were put into practical use. (4) In NSRR, pulse operations of 4 were carried out as planed, to experiment the high burn-up fuel of LWR. The capsule loading facility Type B was completed for to high- plutonium-content and high-burn-up MOX fuel. (5) Tandem accelerator was operated for 182 days to carry out all the scheduled experiments with heavy ions for internal and external users. The multi-charge ion injector in the high voltage terminal was moved to the other side in the terminal so that the beam stability was improved.