Will Japan react to North Korea's missile and nuclear programmes?
14 May, 2009 09:19 am
The Japan Times, in an article on 20 April 2009, reported that the former Japanese Finance Minister Shoichi Nakagawa suggested, in a speech made at Obihiro, Hokkaido, Japan, that Japan should consider possessing nuclear weapons as a deterrent to a threat from a neighbour, specifically North Korea (1).
According to a report by the Associated Press (2), North Korea has restarted its facility to reprocess plutonium from spent reactor fuel elements, an important step away from North Korea’s agreement at a 2007 Six-Party meeting (the six parties are China, Japan, North Korea, South Korea, Russia, the USA) to disable its nuclear facilities in return for energy aid and other concessions.
Apart from the mining of uranium, Japan is operating all the elements of the complete nuclear fuel cycle, including the design and construction of reactors. Having no uranium that can be mined economically, it imports yellow cake (U3O8) but it has industrial plants to convert and enrich uranium and to fabricate reactor fuel elements. And it is also has a commercial reprocessing plant at Rokkasho-Mura, operated by Japan Nuclear Fuel Limited.
The Rokkasho-Mura Reprocessing Plant (RRP), with an operating capacity of 800 tonnes of spent nuclear power reactor fuel per year, is the world’s most up-to-date reprocessing plant (4). The output of RRP is not the usual plutonium dioxide, but plutonium dioxide mixed with uranium dioxide, or MOX (mixed oxide). But the plutonium dioxide and the uranium dioxides can be separated by straightforward chemistry; the plutonium could then be used to fabricate nuclear weapons.
Japan already has a stockpile of plutonium that could be used directly in a nuclear-weapon programme. About 400 kilograms of plutonium are in critical assemblies at Tokai-Mura,
A critical assembly is designed for studying structures that contain fissile materials (plutonium or highly enriched uranium) in a configuration and quantity sufficient for realization of a nuclear fission chain reaction. Such experiments are necessary for checking the correctness of calculations related to both nuclear reactors and nuclear weapons.
Japan could also use the plutonium produced in its nuclear-power reactors to produce nuclear weapons. It now has a stockpile of civil plutonium (reactor-grade plutonium) totalling more than 43 tonnes; about 20 per cent of the total global stockpile of civil plutonium of about 250 tonnes (6). For an advanced technological country like
Japan plans to use eventually fast breeder reactors (FBRs) fuelled by plutonium and has been developing them for some time. These reactors differ from other types in that they produce more fuel than they consume. Uranium-238 in the core of the reactor and in a ‘blanket’ placed around the core is converted into plutonium-239.
The plutonium can be used to fuel another breeder so that enough nuclear fuel becomes available not only to keep the reactor going but also to fuel a new one of the same size. Eventually, a family of breeder reactors becomes self-sustaining in nuclear fuel, requiring only a relatively small yearly replenishment of uranium-238. Breeder reactors are attractive to
The plutonium recovered from the breeder reactor run in an optimum way is precisely the type of plutonium needed to fabricate the most effective nuclear weapons. The Joyo experimental FBR has been operating since 1977. The Monju prototype FBR started up in April 1994 but it has not operated since December 1995 when a sodium leak occurred and it had to be shut down (8).
Japan has the technical means to build advanced nuclear weapons within months. Whether or not it does so will depend on the political judgment of
Japan is currently defended by the American nuclear umbrella, provided by US nuclear forces in the Asia/Pacific region, and there is no current security need for Japan to acquire nuclear weapons. However, because of events such as the North Korean nuclear and missile developments, the nuclear issue is under discussion and the public seems to being softened up for a possible decision.
This discussion is not new. Since the 1950s, leading politicians have, for time to time, argued that
Nevertheless, Japan may not acquire nuclear weapons unless it feels its security is significantly threatened, particularly by a weakening of the American nuclear umbrella. However, according to a report by the US Congressional Research Service, if it does acquire them it “could set off an arms race with
1. Nakagawa floats sobering option: going nuclear, Kyodo News, 20 April, 2009.
2. Kwang-Tae Kim, NKorea says it has restarted nuclear facilities, Associated Press,
3. Frank Barnaby and Shaun Burnie, Thinking the Unthinkable: Japanese nuclear power and proliferation in
4. GlobalSecurity.org, Rokkasho Reprocessing Plant, see
5. Tadahiro Katsuta and
6. Citizens' Nuclear
7. Richard L. Garwin, Reactor-Grade Plutonium Can be Used to Make Powerful and Reliable Nuclear Weapons: Separated plutonium in the fuel cycle must be protected as if it were nuclear weapons, Federation of American Scientists, August 26, 1998.
8. World Nuclear Association, Nuclear Power in
9. Frank Barnaby and Shaun Burnie, Thinking the Unthinkable: Japanese nuclear power and proliferation in East Asia, The Asia-Pacific Journal:
10.Emma Chanlett-Avery and Mary Beth Nikitin,