25 Juin 2018
June 17, 2018
Japan to cap plutonium stockpile to allay U.S. concerns
THE ASAHI SHIMBUN
Japan plans to boost measures to curb surplus plutonium extracted from the reprocessing of spent fuel at nuclear power plants, including capping the country’s stockpile of the highly toxic material.
The move followed the U.S. and other countries' calls for Japan to reduce excess plutonium in light of nuclear nonproliferation and the threat of terrorist attacks involving nuclear materials.
The Cabinet Office’s Japan Atomic Energy Commission will incorporate the measures in the five-point basic nuclear policy expected at the end of this month, the first revision in 15 years.
A reduction in the volume of plutonium held by Japan will also be specified in the government’s basic energy plan, which will be revised next month.
Japan possesses about 10 tons of plutonium inside the country and about 37 tons in Britain and France, the two countries contracted to reprocess spent nuclear fuel. The total amount is equivalent to 6,000 of the atomic bomb that devastated Nagasaki in 1945.
In the policy, announced in 2003, the government vowed not to possess plutonium that has no useful purpose. The government has pledged not to have surplus plutonium to the International Atomic Energy Agency.
But the prospect for substantially curtailing the country’s plutonium stockpile is becoming increasingly murky as the Monju prototype fast-breeder project has been abandoned.
The government decided in 2016 to decommission the Monju reactor in Tsuruga, Fukui Prefecture, which has seldom been in operation over the the past two decades due to a slew of problems.
Monju was designed to use plutonium recovered from spent fuel from other reactors as a key component of the government’s nuclear fuel recycling program.
Japan can reprocess spent nuclear fuel under the Japan-U.S. Nuclear Cooperation Agreement.
The 30-year pact is expected to be automatically extended beyond its expiration on July 16.
After the expiration, however, the pact will be scrapped six months after either Japan or the United States notifies the other side of its intention to do so.
Foreign Minister Taro Kono has expressed concern about the "unstable" future of the agreement after July, and Japan has worked to meet a request from Washington to clearly spell out steps to reduce Japan’s plutonium stocks.
The government's draft policy calls for allowing retrieval of plutonium strictly based on the projected amount to be used at conventional nuclear reactors as mixed plutonium-uranium oxide fuel, commonly known as MOX fuel.
It will also step up oversight on utilities with the aim of reducing the amount of plutonium to a level allowing the nuclear reprocessing plant under construction in Rokkasho, Aomori Prefecture, and other facilities to operate properly.
In addition, electric power companies will cooperate with each other in the use of MOX fuel, so that the amount of Japan’s surplus plutonium that is now overseas will be reduced.
For example, Kyushu Electric Power Co. and Kansai Electric Power Co., two utilities that began using MOX fuel ahead of other utilities, will consider using more MOX fuel at their nuclear plants for the benefit of Tokyo Electric Power Co., whose prospect of bringing its Kashiwazaki-Kariwa nuclear power plant in Niigata Prefecture back on line remains uncertain.
When the 2.9 trillion yen ($26.37 billion) reprocessing plant in Rokkasho goes into full operation, about eight tons of new plutonium will be added annually as Japan’s surplus plutonium.
The Federation of Electric Power Companies of Japan, an electric power industry group, estimates that MOX fuel should be used at 16 to 18 reactors to keep the amount of Japan’s plutonium from rising.
But of nine reactors that have resumed operations following the introduction of more stringent safety standards after the Fukushima No. 1 nuclear disaster in 2011, only four can use MOX fuel.
The operation of the Rokkasho plant will likely be significantly curtailed even if it is completed amid that environment.
(This article was written by Yusuke Ogawa, Rintaro Sakurai and Shinichi Sekine.)