Neww Diplomacy Initiative
Ini ive

NOVEMBER
R 2018018

ND Policy Brief

NOVEMBER
R 2018018

Vol.

The Transition of Japan’s Plutonium Policy:Feasible Options for Reducing Plutonium
Taichi Kuboki, J.D.
Researcher, Energy Project TeamNew Diplomacy Initiative

Japan has adopted a nuclear fuel cycle policy since it began using nuclear power. The policy wasoriginally created with consideration for the fast breeder reactor fuel cycle; however, as the developmentof fast breeder reactors failed, the pluthermal cycle gained importance. The pluthermal cycle is aneconomically irrational policy, however, and following the Fukushima Daiichi nuclear disaster, the safetyof nuclear power generation has been widely questioned. As a result, plans to restart reactors have been
delayed, and as of the end of 2017, Japan’s plutonium stockpile has reached 46.9 tons. Now is the time for
the Japanese government to consider feasible options to reduce the country’s excess plutonium.

Nuclear power policies in the early days
Japan has adopted a nuclear fuel cycle policy since it began using nuclear power. A full reprocessing
policy has been continuously applied, where all spent nuclear fuel from nuclear power generation isprocessed in a reprocessing plant to extract plutonium. Initially, the nuclear fuel cycle was focused on acycle using fast breeder reactors. Nuclear fuel cycles using fast breeder reactors (fast breed reactor fuelcycle) produce power using plutonium, while generating more plutonium than originally consumed. The
extracted plutonium can then be reused to generate power, producing energy in an endless cycle. All aroundthe world, the development of nuclear power began with the aim of developing a fast breeder reactor cycle.
For Japan, a country with scarce natural resources, this dreamlike plan generated high expectations.

Fast breeder reactor fuel cycle（1）Failure of the fast breeder reactor cycle
From the 1980s to the 1990s, it turned out that there were more uranium reserves that could be used fornuclear fuel than expected, and breeding plutonium was no longer an urgent matter. Furthermore, in theND Policy
icy Brief
ief

3Neww Diplomacy Initiative
Ini ive

NOVEMBER
R 2018018

ND Policy Brief

1990s, due to many technical and economic challenges, major countries around the world including theUnited States, France, and Germany withdrew plans to implement fast breeder reactors.
Japan maintained its position, but the road toward implementing a fast breeder reactor fuel cycle waslong. In 1994, approximately 9 years after the main construction work began (1985), the Monju reactor
achieved criticality at last. The following year, in 1995, a fire caused by a leakage of sodium forced
operations to come to a halt. Afterwards, in December 2016, it was decided that the reactor, which had
seen minimal operation, would be decommissioned. The Monju Nuclear Power Plant was in operation for
only 250 days out of its 22-year life expectancy, but on 11 May 2018, the Board of Audit announced that
1.13 trillion yen (approx. 10 billion USD) had been invested in the plant. Furthermore, it is said that thecost of decommissioning the plant may exceed the government’s initial estimated figure of 375 billion yen(approx. 3.3 billion USD).
（2）The shift to fast reactors
The Japanese government announced the decommissioning of the Monju plant and simultaneously
released a cabinet decision stating that it will adhere to the policy of promoting a nuclear fuel cycle whileremaining committed to policy regarding the research and development of fast reactors. It should be
noted that the objective of research and development in the government’s statement is not fast breeder
reactors, but rather fast reactors. Fast reactors are similar to those in the Monju plant in that they arenuclear reactors that use fast neutrons from plutonium; however, they do not breed plutonium. It is said
that by using fast reactors, the lifetime of radioactive materials in spent fuel can be shortened by 300-400
years through nuclear fission, while reducing waste toxicity. Nevertheless, there are still technicalchallenges with fast reactors, and there has yet to be any anticipation of practical application.
（3）ASTRID -- Collaborative research with France
Shortly after deciding to decommission the Monju plant on 20 March 2017, the Japanese government
announced its intention to consider strengthening the Japan-France partnership on ASTRID, a fast
reactor for industrial demonstration.
ASTRID’s scheduled start date moved from 2006 to 2020, but in 2016, it was announced that the datewould be further postponed to 2030.
Moreover, at a meeting of the Ministry of Economy, Trade and Industry’s “Fast Reactor Strategic
Working Group” on 1 July 2018, Nicolas Devictor, Programme Manager for the Nuclear Energy Divisionof the French Atomic Energy Commission, explained that “the need for commercial deployment of fastneutron reactors is seen as much less urgent, due to the current context of the uranium market” and that
“France is considering reducing output to 100,000 to 200,000 kilowatts (from an initial planned output of600,000 kilowatts).” These changes have destabilized the future of the Japan-France partnership on fast
reactor development.

ND Policy
icy Brief
ief

3Vo l.

Neww Diplomacy Initiative
Ini ive

NOVEMBER
R 2018018

ND Policy Brief

Pluthermal cycle（1）Emergence of a new nuclear fuel cycle
Another nuclear fuel cycle that is different than the fast breeder reactor cycle is the “pluthermal cycle”.
Pluthermal power generation produces electricity by using mixed oxide (MOX) consisting of plutonium asfuel in light-water reactors. The pluthermal method came after the concept of fast breeder reactors andwas specifically mentioned for the first time in the “Long-term Program for Research, Development, andUtilization of Nuclear Energy” published by the Atomic Energy Commission of Japan in 1972. While thepractical application of fast breeder reactors was being called into question, more weight was put on thepluthermal cycle policy. In the 1994 Long-Term Program, the fast breeder reactor cycle was regarded as
the future of nuclear fuel recycling, however, at the same time, a concrete plan to implement thepluthermal cycle was established. In 1997, the cabinet approved measures regarding the promotion of animmediate nuclear fuel cycle and stated that the pluthermal cycle was the most reliable way of using
plutonium to date, and it must be put into motion as soon as possible.
（2）Pluthermal cycle’s lack of economic viability
The pluthermal cycle is not a complete alternative to the fast breeder reactor cycle. Recycling degradedplutonium recovered from the pluthermal process is difficult, and can only be done one to two times atmost. Reprocessing technology for MOX fuel used in the generation of pluthermal power has not been
put to practical use, and as a result, spent fuel must undergo geological disposal as is. Moreover, when
Japan imported MOX fuel from France, the price France declared to customs was about ten times that ofuranium fuel. The pluthermal cycle is simply a limited cycle and has no economic rationality.
（3）Current challenge of restarting reactors in Japan
According to the Federation of Electric Power Companies’ “Plans for the Utilization of Plutonium,”
released in September 2010, 16 to 18 light-water reactors were to use MOX fuel, and 5.5 to 6.5 tons offissile plutonium were to be consumed each year.
However, in light of the accident at the Fukushima Daiichi Nuclear Power Plant in March 2011, alllight-water reactors in Japan were stopped. Of the light-water reactors that are currently in operation,
only four are generating power using the pluthermal method --Takahama reactors No. 3 and No. 4, theIkata No. 3 Reactor, and the Genkai No. 3 Reactor. It remains uncertain whether the Ohma Nuclear
Power Plant, which is capable of loading MOX fuel in all of its reactor cores (process known as fullMOX), will be restarted.
In order to promptly consume plutonium as the Federation of Electric Power Companies has outlined, itis essential that reactors resume operations as early as possible. Nonetheless, the majority of Japanesecitizens want to abandon nuclear power generation. Furthermore, while nuclear reactors fail to restart,
the number of nuclear reactors capable of handling the pluthermal cycle remains uncertain.

ND Policy
icy Brief
ief

3Vo l.

Neww Diplomacy Initiative
Ini ive

NOVEMBER
R 2018018

ND Policy Brief

Japan’s plutonium policy（1）The plutonium stockpile
Although the fast breeder reactor cycle was not put into practical use, Japan has continued to separate
plutonium from spent nuclear fuel at its Rokkasho reprocessing plant and reprocessing plants in Franceand England. Japan’s full reprocessing policy has resulted in the accumulation of 46.9 tons of plutonium(as of 2017). Plutonium can be converted for military purposes, and 46.9 tons is enough to create
approximately 6,000 nuclear warheads.
For this reason, the accumulation of plutonium is an issue from a non-proliferation perspective. Japan’s
possession of a large amount of plutonium has resulted in security concerns from the international
community. There is also the issue of the increased possibility of plutonium getting into the hands ofterrorists.
（2）Japan’s ongoing façade—denying the accumulation of excess plutonium
Japan maintains that it does not have a surplus of plutonium. In the 1991 paper entitled “Nuclear Fuel
Recycling in Japan” (Atomic Energy Commission), it was stated that Japan “has a principle of notpossessing surplus plutonium”. Thereafter, in 1997, Japan submitted a written commitment to the IAEA
and international community entitled “Plutonium Utilization in Japan,” in which it promised to “upholdthe principle of no surplus plutonium”. In the Basic Energy Plan of 2014, it is said that the government
remains committed to the policy of not possessing plutonium without specific purposes.
However, as mentioned above, 46.9 tons of plutonium have accumulated in Japan as of the end of 2017.
Accordingly, more people has recognized that the government’s principles alone are insufficient.
（3）Reducing Japan’s plutonium stockpile
On 31 July 2018, the Atomic Energy Commission decided on a new policy for Japan’s plutonium
inventory. The current amount of around 47 tons would be set as the upper limit, and going forward, theplutonium stockpile would not be increased and reduction efforts would take place. Prior to this, the sameobjective was clearly stated in the Basic Energy Plan. As this was the first time that plutonium inventory
reduction was clearly mentioned, it can be interpreted as a step in the right direction regarding
government policies. That being said, the full reprocessing policy is still being adhered to, and as specificand effective measures have not been identified, it is not certain whether reduction efforts will take place.

Proposal
Based on the Fukushima Daiichi nuclear disaster, when the future of nuclear power became uncertain,
the Atomic Energy Commission recommended a switch to a flexible nuclear fuel cycle. It is shown that if

ND Policy
icy Brief
ief

3

Vo l.

Neww Diplomacy Initiative
Ini ive

NOVEMBER
R 2018018

ND Policy Brief

the number of reactors decreases, the policy of direct disposal and storage, rather than total reprocessing,is economically advantageous. However, under the current Designated Radioactive Waste Final Disposal
Act, disposal of spent nuclear fuel (that has not been reprocessed) is not permitted. If direct disposal
remains illegal under the law, other disposal methods cannot be applied.
One possible option for the existing plutonium is to transfer it directly to the United Kingdom, which has
already proposed taking over and disposing plutonium for a fee. The Japanese government should takethis opportunity to seriously consider specific and feasible measures to reduce its plutonium stockpile.

ND Policy
icy Briefief3Vo l.