Review of research activities on partitioning and transmutation in Japan

日本における分離変換研究

辻本 和文 

Tsujimoto, Kazufumi

2014年に閣議決定されたエネルギー基本計画では、原子力発電は重要な基幹電源として位置付けているが、対策を将来へ先送りせず着実に進める取組として、「使用済燃料対策を抜本的に強化し、総合的に推進する。」こととしている。こうした取組の一環として、「将来の幅広い選択肢を確保するため、放射性廃棄物の減容化・有害度低減などの技術開発を進める。」とされている。原子力機構では、新たなエネルギー基本計画の策定を受けて、「放射性廃棄物の減容化・有害度低減技術」の選択肢の一つとして高速炉や加速器駆動炉(ADS)による分離変換技術に関する研究開発を強化している。本発表では、主に原子力機構を中心とした日本における分離変換技術の研究開発の現状や将来計画について報告する。

The Government of Japan periodically formulates the Basic Energy Plan in accordance with an article in the Basic Act on Energy Policy that entered into force in 2002. The latest version, called the Strategic Energy Plan, was issued in April, 2014. The largest change from the previous versions must be the accident of the Fukushima Daiichi Nuclear Power Plant. In spite of the accident, the Plan defines the nuclear power as an important base-load power source as a low carbon and quasi-domestic energy source, contributing to stability of energy supply-demand structure, on major premise of ensuring of its safety. The Plan puts emphasis on the importance of activities to resolve the challenge of how to manage and dispose of spent fuel, as well as the Fukushima restoration, safety operation of nuclear plants, and public acceptance. As for the P&T technology, the Government will promote technology development on volume reduction and mitigation of degree of harmfulness of radioactive waste. Specifically, development of technologies for decreasing the radiation dose remaining in radioactive waste over a long period of time and enhancing the safety of processing and disposal of radioactive waste, including nuclear transmutation technology using fast reactors and accelerators, will be promoted by utilizing global networks for cooperation. Based on this new Strategic Energy Plan, research and development (R&D) on P&T are being accelerated in Japan. The Japan Atomic Energy Agency (JAEA) has been continuously implementing R&D on P&T technology to reduce the burden of the backend of the nuclear fuel cycle. The R&D on P&T in JAEA are basing on two kinds of concepts: one is the homogeneous recycling of minor actinide (MA) in fast reactors and the other is the dedicated MA transmutation, so-called double-strata strategy, using an accelerator-driven system (ADS). In this work, recent R&D activities based on these policies are briefly shown.