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August 1, 2018

Editorial: Plutonium reduction does not fit in with nuclear fuel cycle

https://mainichi.jp/english/articles/20180801/p2a/00m/0na/005000c#cxrecs_s

The Japan Atomic Energy Commission (JAEC) has clearly stated for the first time that Japan will try to reduce its plutonium stockpiles. The new policy, incorporated in the commission's revised guidelines, is a reflection of Japan's principle of not holding plutonium without specific purpose of use -- a stance maintained from its standpoint of nuclear nonproliferation.

• 【Related】Japan nuclear regulator revises guidelines in bid to reduce plutonium stockpiles
• 【Related】Japan, US extend nuclear pact amid concern about plutonium stockpile
• 【Related】Editorial: Turn renewal of Japan-US nuclear pact into chance to reconsider reprocessing

Reasserting Japan's position at this juncture is important, as awareness about nuclear security is on the rise and the Japan-U.S. agreement on nuclear cooperation has been extended automatically. However, the first revisions since 2003 are half-baked and do not show a path toward a real reduction. Such measures will not be able to win international trust.

Plutonium is a product of the nuclear fuel cycle. The cycle was conceived out of concerns about uranium depletion, but now there is uranium aplenty. Moreover, fast-breeder reactors, which stood at the core of the cycle, have been found to be difficult to put into actual use and are not viable economically. The United States, Britain, Germany and others have already given up on such projects.

Japan, however has stuck with its nuclear fuel cycle, and to maintain it, the government lets power utilities use plutonium in mixed oxide (MOX) fuel as a stop-gap measure. But this arrangement has faced turbulence in the wake of the 2011 Fukushima nuclear disaster. As a result, the country has been left with stockpiles of about 47 metric tons of plutonium in Japan and overseas.

If a reprocessing plant for spent nuclear fuel that Japan is building in the northern prefecture of Aomori starts operation as planned, its domestic plutonium stockpile is bound to increase. Plutonium can be used to produce nuclear weapons, and it is understandable that Japan's neighbors and the United States have voiced concerns about increases in the amount of the material.

The revised guidelines state that operations at the reprocessing plant will be limited to the level needed to produce enough plutonium for MOX consumption. They also encourage power companies to cooperate in the reduction of overseas stockpiles.

However, the guidelines do not state that reduction is more important than reprocessing, and operation of the reprocessing plant has gone unquestioned. This arrangement is not going to reduce stockpiles.

For a real reduction of plutonium stockpiles, the government should take drastic measures such as freezing operation of the reprocessing plant or discarding plutonium in deep, secure underground locations. Handing over Japan's overseas stockpiles to countries now storing them is an option that merits discussion.

Japan must review the meaning of continuing with reprocessing and its nuclear fuel cycle.

The argument of seeking greater MOX consumption to reduce plutonium stockpiles is preposterous. Plutonium-based fuels are more expensive than uranium fuel. They also create concerns about nuclear proliferation. How to deal with the spent fuel is a tough question to answer, too.

Japan should not delay its departure from the nuclear fuel cycle any longer.