The Federation of Electric Power Companies of Japan has given up on devising a plan by March 31 on how to use 0.6 tons of fissile plutonium to be extracted by reprocessing spent nuclear fuel in the new fiscal year from April, sources said.

The federation cannot meet the end of March deadline because prospects are bleak that the nation's nuclear reactors will be rebooted anytime soon, including those that run on fuel containing plutonium, in view of the Fukushima disaster, the sources said Thursday.

The Japan Atomic Energy Commission has called on utilities to declare how they use extracted plutonium every fiscal year to ensure transparency. Stockpiling plutonium without making clear its uses could invite criticism from the international community, as the material can be diverted for nuclear weapons.

Japan had embarked on a program in which spent uranium fuel was to be reprocessed and the extracted plutonium and uranium reused as reactor fuel. The recovered material is turned into plutonium-uranium mixed oxide (MOX) fuel for pluthermal power generation. That program has effectively been put on hold amid the nationwide reactor shutdown due to the Fukushima crisis and subsequent widespread public opposition to atomic energy.

Japan Nuclear Fuel Ltd. still expects to reprocess about 80 tons of spent fuel in fiscal 2013 by starting up its troubled fuel reprocessing plant in Rokkasho, Aomori Prefecture. The process would produce about two tons of MOX, of which around 0.6 tons would be fissile plutonium, the sources said.

Given the gravity of the issue, the commission wants federation officials to provide an explanation next Tuesday.