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Japan nuclear regulator revises guidelines in bid to reduce plutonium stockpiles

This Nov. 8, 2012 photo shows a floor crane, foreground, and storage pits at the vitrified high-level radioactive waste storage center, a part of the Rokkasho spent nuclear fuel reprocessing plant facilities, run by Japan Nuclear Fuel Ltd. in Rokkasho village in Aomori Prefecture, northern Japan. (AP Photo/Koji Sasahara)

TOKYO -- The Japan Atomic Energy Commission (JAEC) has revised its guidelines for the use of plutonium for the first time in 15 years to clearly state that it will endeavor to reduce the country's stockpiles of the material that can be used to produce nuclear arms.

As part of these efforts, a nuclear fuel reprocessing plant in the Aomori Prefecture village of Rokkasho, currently under construction, will be mandated to extract only the necessary amount of plutonium from spent nuclear fuel that can be consumed at nuclear power plants.

The amended guidelines require electric power companies to join hands in consuming plutonium at Japanese nuclear plants that can use the substance as fuel in an effort to steadily decrease the country's stockpiles.

The revisions are aimed at dispelling concerns among the international community, including the United States, about Japan's possession of a massive amount of plutonium from the viewpoint of nuclear non-proliferation.

The commission's role is to present the long-term direction of Japan's nuclear power policy, and it will inform other countries of its stance through the International Atomic Energy Agency headquartered in Vienna. Plutonium stockpile reduction was incorporated in the New Strategic Energy Plan approved by the Cabinet of Prime Minister Shinzo Abe on July 3.

Plutonium is produced by reprocessing nuclear fuel used at atomic power stations. Japan currently possesses approximately 47.3 metric tons of the material, enough to produce approximately 6,000 nuclear weapons. Power companies that operate nuclear plants and other entities store plutonium in Japan and overseas.

The previous guidelines that were set in 2003 stipulated that Japan must not possess plutonium without the purpose of using the material. The recently revised guidelines mentioned reducing Japan's plutonium stockpile for the first time, but did not set numerical goals or a timeframe. It just stated that the maximum amount allowed "will not exceed the current level."

To achieve that objective, the guidelines limit the amount of plutonium that can be extracted from spent nuclear fuel at the Rokkasho reprocessing plant, which the government plans to put into operation in fiscal 2021, to a sufficient amount to produce mixed oxide (MOX) fuel, usually consisting of plutonium blended with natural uranium, to be burned at nuclear plants.

With regard to about 36.7 metric tons of Japanese plutonium being stored in Britain and France, the guidelines also urge utilities to cooperate closely in steadily reducing the amount. The government wants the companies to use the substance as fuel at nuclear power plants that can use MOX fuel to achieve overall stockpile reductions. The utilities are required to publicize their plutonium usage plans every year.

Japan has been promoting the nuclear fuel cycle project, in which spent nuclear fuel is reprocessed and used as fuel at atomic power stations. For now, the government plans to process used fuel at nuclear plants into MOX fuel, and use such fuel at nuclear plants.

However, the consumption of such fuel has not progressed because only four nuclear reactors that can use MOX fuel for power generation are in operation after the March 2011 outbreak of the Fukushima nuclear crisis.

Once the reprocessing plant in Aomori Prefecture is put into full operation, the amount of plutonium will increase by up to about 8 tons a year. It is estimated that plutonium needs to be used at 16 to 18 nuclear reactors to consume the full amount. Under the current circumstances, operations at the reprocessing plant are bound to be strictly limited.

(Japanese original by Ei Okada, Tokyo Science and Environment News Department)

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