Japan nuclear panel plans reduction in plutonium stockpile, but details remain unclear

Kyodo

A government nuclear panel said Tuesday it expects Japan to reduce its plutonium stockpile in the long term amid international concerns over the nation’s rising quantities of the material, which can be used to make nuclear weapons.

The plan was outlined in a document issued by the Japan Atomic Energy Commission aimed at highlighting the country’s principle of not possessing plutonium without a specified purpose. Japan is the only non-nuclear weapons state in the world that is proceeding with a commercial spent fuel reprocessing project.

While the nation’s nuclear policy has been thrown into disarray following the 2011 Fukushima No. 1 triple meltdown disaster, the government has maintained a long-standing policy of reprocessing spent uranium fuel and reusing the extracted plutonium and uranium as reactor fuel.

As a way to consume the recovered plutonium, Japan has pushed for making ordinary nuclear reactors use plutonium-uranium mixed oxide fuel, known as MOX fuel, for so-called “pluthermal” power generation.

According to the document, Japan had about 47 tons of plutonium as of the end of 2016, down 1 ton from a year before thanks to the start of two reactors that use MOX fuel. Even so, the amount is said to be enough to make thousands of nuclear bombs.

The document noted that more reactors are set to restart once they clear new safety standards introduced in the wake of the Fukushima crisis, while adding that the commission will check the “appropriateness” of plans to use plutonium.

“We will stick to our policy of not possessing plutonium for no specific purpose. It is possible to ensure an appropriate plutonium balance by consuming plutonium through the ‘pluthermal’ project,” the commission said.

But the document did not make clear by how much Japan will be able to reduce its plutonium stockpile and by when.

A key factor that could affect the amount is the start of a fuel reprocessing plant in Rokkasho, Aomori Prefecture.

The plant has encountered a series of problems leading to repeated delays in completion. However, it is designed to reprocess up to 800 tons of spent fuel per year, extracting about 8 tons of plutonium in the process.

The commission, however, said in the document that the plant will not immediately start running at full capacity after its completion and will increase its output “in stages.”

“Although there could be some increase and decrease in plutonium such as through the operation of the Rokkasho reprocessing plant, we believe it is possible to control the material under a certain balance, and we expect that the goal to reduce Japan’s plutonium stockpile will be achieved in the longer term,” the commission said.

An English version of the document is expected to be released in mid-October, according to the commission. The commission has regularly disclosed the stockpile figure every year, but it decided to release an explanatory document to respond to what it calls the “growing global attention on plutonium management.”