Japan's Ikata nuclear plantShikoku Electric Power Co’s Ikata 3 in Japan’s Ehime Prefecture,  was shut down on 26 December in preparation for the removal of used mixed oxide (mox) fuel, a first such operation in Japan.

Shikoku Electric plans to take out 37 used fuel rods in January, 16 of which are mox, and will load five new mox fuel rods. It will also replace the reactor's control unit, before restarting it in late March and resuming commercial operation in late April.

Shikoku Electric has said it will temporarily store the used mox fuel in a cooling pool within the Ikata plant, as Japan currently does not have the necessary reprocessing facilities.

The Japan Atomic Energy Commission (JAEC) is under pressure from the international community to reduce Japan's stockpiles of plutonium and sees the use of mox fuel as a solution.

Japan is the only country without nuclear weapons that is permitted to reprocess used nuclear fuel and has consequently accumulated plutonium.

In 2018 the government announced a goal to decrase the total volume of plutonium, which is stockpiled both in Japan and overseas, from 47t. The stockpiles, under the government's plan, must be reduced before a reprocessing facility in Rokkasho, Aomori Prefecture, goes online in 2021 to extract more plutonium.

The JAEC in 2018 issued new plutonium guidelines to try to reduce the nation's stockpiles, with restrictions placed on the Rokkasho facility so that it can only produce the amount of plutonium required for mox fuel needed for Japan's nuclear plants.

In March, Kansai Electric Power Co said it will transport 32 mox fuel assemblies from France to Japan as early as 2020, to reduce its stockpiles held overseas. Kansai intends to use the mox in units 3 and 4 of its Takahama plant in Fukui Prefecture. This will reduce  plutonium stored overseas by one ton from around 11, Kansai Electric said.

Photo: Ikata nuclear power plant  (Photo Newsliner/CC BY-SA 2.5)