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Japan's plutonium puzzle

Nuclear Monitor Issue: 
Jim Green ‒ Nuclear Monitor editor

We reported in Nuclear Monitor in October that Japan has abandoned plans to restart the ill-fated Monju fast reactor.1 That decision calls into question the rationale for Japan's ongoing development of reprocessing (in particular the partially-built Rokkasho plant). In the absence of a fast-reactor rationale, the only use for plutonium separated at Rokkasho would be incorporation into mixed uranium‒plutonium MOX fuel (or, of course, incorporation into nuclear weapons). MOX fuel makes no sense since uranium is plentiful and cheaper than MOX fuel.

Hideyuki Ban, Co-Director of the Tokyo-based Citizens Nuclear Information Center, takes up this story in the latest edition of Nuke Info Tokyo:2

"On September 21, 2016, the Ministerial Committee on Nuclear Power, which consists of the Chief Cabinet Secretary, Minister of Economy, Trade and Industry and other relevant cabinet members, adopted a policy entitled "Procedure for Future Fast Reactor Development." This policy included a drastic review of Monju, including its decommissioning, but the continued promotion of the nuclear fuel cycle. Based on the adoption of this policy, the Fast Reactor Development Committee has been established under the initiative of the Minister of Economy, Trade and Industry. The new policy states that the committee is scheduled to reach a conclusion on future development before the end of 2016.

"However, the decision to decommission Monju will not be overturned by the committee. This is because "The committee will not discuss whether Monju should be continued or discontinued" (Toshio Kodama, President of the Japan Atomic Energy Agency). Thus the committee has been set up and will conduct deliberations on the premise that Monju will be decommissioned.

"The specific actions the Ministerial Committee on Nuclear Power plans to promote for the nuclear fuel cycle are to restart the experimental reactor Jōyō and to cooperate with fast reactor development in France. The fast reactor Jōyō was first started in 1977, and was operated as a non-breeding reactor after its breeding function was evaluated. Its operation has been suspended since an accident occurred in 2008. It is currently under investigation for compatibility with the new regulatory standards.

"France plans to build a demonstration fast reactor named ASTRID (Advanced Sodium Technological Reactor for Industrial Demonstration). The cooperation between Japan and France began in 2014. ... The ASTRID project is still at the basic design stage and it has not yet been decided whether construction will go ahead or not. Koji Okamoto (Professor, Nuclear Professional School, University of Tokyo) who has been a strong advocate of nuclear energy in Japan, clearly states in an article contributed to Energy Review, a Japanese industrial monthly, that the ASTRID project is close to coming off the tracks.

"The new Japanese governmental policy states that one purpose of the ASTRID development is to lower the toxicity of radioactive wastes. However, a study (called the OMEGA Project) to reduce the toxicity of radioactive wastes has been ongoing for more than 30 years in Japan, resulting in no practical achievements. Presenting a new aim does not necessarily mean that practical achievements have become more obtainable.

"The construction cost of ASTRID is estimated to be 570 billion yen, of which Japan has been asked to provide 290 billion yen, according to a media report. However, the construction cost is considered likely to increase, and if Japan continues to cooperate, it is certain that the cost shouldered by Japan will increase each time construction budgets are reviewed.

"Even if cooperation with the French project results in some achievements, Japan has no way of taking advantage of them. After the Fukushima Dai-ichi NPS accident, the demonstration reactor project that would follow Monju has been shelved, and has, in fact, been returned to the drawing board, with even the site for construction as yet undetermined. Under such circumstances, it is unimaginable for an area of this country to accept the construction of a fast reactor, which is far more dangerous than a light-water reactor. If a fast reactor cannot be built, the achievements of the cooperation with France cannot be used. Japan's nuclear fuel cycle policy will, it seems, fade away in the not-too-distant future."

Commitment to reprocessing

Yet while the prospects for the development of fast reactor technology in Japan are bleak, there is no sign of any weakening of the commitment to complete and operate the Rokkasho reprocessing plant. Japan's Ministry of Economy, Trade and Industry (METI) established the Nuclear Reprocessing Organization (NRO) on 3 October 2016 to pursue reprocessing under the Spent Nuclear Fuel Reprocessing Implementation Act, which was approved on 11 May 2016. The NRO's operations are entrusted to Japan Nuclear Fuel Ltd., funded by obligatory contributions from each electric power utility.3

Perhaps this financial burden imposed on the power utilities will help to slowly unravel the so-far rock-solid commitment to reprocessing.

Abandoning Rokkasho would mean giving up on the sunk costs ‒ the estimated total cost is ¥2.2 trillion (US$18.6 bn; €17.8 bn) and much of that has already been spent ‒ but continuing with Rokkasho means wasting billions more dollars.

If Rokkasho is abandoned, MOX fuel will sooner or later be abandoned. That said, if for some unfathomable reason Tokyo was determined to pursue the use of MOX fuel, existing plutonium stockpiles could be used to produce MOX fuel far into the future ‒ all the more so since it's unlikely that any more than a handful of reactors will be MOX-fuelled in the foreseeable future (of the 26 reactors either approved and under review for restart by the Nuclear Regulation Authority, only five use MOX fuel).

If fast reactors and reprocessing are abandoned, spent nuclear fuel will be managed as waste ‒ it will be destined for deep underground disposal.

International conference

Given the fluid nature of Japan's policies on fast-reactor R&D ‒ and the potential to unravel the government's illogical commitments to reprocessing and MOX ‒ the Citizens Nuclear Information Center (CNIC) and the US-based Union of Concerned Scientists are jointly organizing an international conference on 23-24 February next year at the United Nations University, Tokyo.4

The conference will focus on Japan's plutonium policy and the US-Japan 123 Agreement, which provides the basis for Japan's reprocessing program. The present Agreement came into effect in 1988 and is valid for 30 years. Thus it is due to expire in 2018. The Agreement is subject to automatic renewal unless either party notifies that it would like to negotiate changes. While it is likely that the Agreement will be automatically renewed in 2018, CNIC is planning to use this opportunity to draw attention to the serious problems with Japan's nuclear fuel cycle policy and the growing plutonium stockpile.

Issues to be considered at the conference include the international repercussions ‒ how do countries in the region react to Japan's massive stockpile of plutonium? How do they see the planned Rokkasho Reprocessing Plant, which will produce a further eight tons of plutonium per year? What is the real stance of the US on Japan's plutonium policy?

Organizers plan to include speakers from South Korea, China and Taiwan as well as several US experts. Japanese experts and government officials, both bureaucrats and members of parliament, will be invited to speak, as will speakers from local communities in Aomori Prefecture, host of the Rokkasho Reprocessing Plant.

Vitrified high-level nuclear waste shipments

One of the problematic aspects of Japan's nuclear fuel cycle policies has been the many shipments of spent fuel, MOX, separated plutonium and high-level nuclear waste between Europe (France and the UK) and Japan. These shipments are slowly coming to an end.

The Pacific Grebe, laden with 132 canisters of vitrified high-level waste (HLW) being returned from the UK, arrived on October 20 at Japan Nuclear Fuel, Ltd.'s High-Level Radioactive Waste Storage Center in Rokkasho-mura.5

From 1969-90 there were more than 160 shipments of spent fuel from Japan to Europe.6 The first shipment of vitrified HLW from France to Japan took place in 1995 and the final shipment was in 2007 ‒ in total, 1,310 HLW canisters were transported. Shipment of vitrified HLW from the UK to Japan commenced early in 2010 and will require about 11 shipments over 8‒10 years to move about 900 canisters. To date, 520 canisters have been sent to Japan from the UK.


1. 5 Oct 2016, 'The slow death of fast reactors', Nuclear Monitor #831,

2. Hideyuki Ban, 5 Dec 2016, 'Planned Monju Decommissioning ‒ The Changed Future of Japan's Nuclear Fuel Cycle', Nuke Info Tokyo No. 175 (Nov/Dec 2016),

3. CNIC, 5 Dec 2016, 'Nuclear Reprocessing Organization Inaugurated',

4. CNIC, 5 Dec 2016, 'International Conference on US-Japan Nuclear Cooperation Agreement and Japan's Plutonium Policy 2017',

5. CNIC, 5 Dec 2016, 'Vitrified HLW Returning from UK Arrives in Japan',

6. World Nuclear Association, Nov 2016, 'Japanese Waste and MOX Shipments From Europe',