In a move that has sparked major controversy, Japan has announced earlier this month that it will pursue a nuclear fuel recycling program involving plutonium extraction from spent fuel waste. The decision has created controversy in the context of Japan’s traumatic World War II history, as well as the fact that the country is already in possession of a huge stockpile of unused separated plutonium measuring over 45 tonnes, which can also be used to make nuclear weapons.
Permitted to separate plutonium under the International Atomic Energy Agency (IAEA) safeguard rules, Japan is the only non-nuclear weapons nation that carries out this extraction process for peaceful purposes. The country has pledged not to possess excess plutonium and to put a limit on its amount of extraction from spent nuclear fuel.
Announcing the decision of Japan’s new government led by Prime Minister Suga Yoshihide, the Chief Cabinet Secretary Kato Katsunobu said: “The government will firmly promote our nuclear energy policy and fuel cycle programs,” adding that the country will make efforts to reduce the volume and toxicity of high-level nuclear waste, and extract plutonium from spent fuel with the aim of resource conservation.
Earlier this year, Japan’s Nuclear Regulation Authority granted a safety approval for the Rokkasho fuel reprocessing plant located in northern Japan and operated by Japan Nuclear Fuel Ltd, which is expected to start operations in 2022. The regulator also granted a preliminary approval for the Rokkasho MOX fuel production plant that is also expected to be completed in 2022.
The major portion’s of Japan’s stockpile of separated plutonium is stored overseas in France and the UK, where spent fuel from Japanese nuclear plants has been reprocessed and stored because Japan currently lacks a plant to produce MOX fuel for reuse. Japan also lacks an underground depository for disposal nuclear waste. The problem of accumulating nuclear waste came to the fore after the 2011 Fukushima nuclear power plant disaster caused by the tsunami.
Earlier this month two remote towns in northern Japan, struggling economically, applied for allowing preliminary government research on whether its land would be suitable for highly radioactive waste storage for thousands of years. Various countries have been planning the building of final disposal sites for their nuclear waste, but, till date, no country has actually created one of these. According to a report in the Japan Times, Finland and Sweden are the only countries that have selected final disposal sites.
Earlier this year, an American firm came out with a detailed analysis on one of the few proven methods of nuclear waste management over the long term through what is known as “deep borehole disposal”. The company, called Deep Isolation, has prepared a Post-Closure Safety Analysis (required by law in the US) for the deep borehole disposal of nuclear waste by drilling into the earth’s surface.
This particular safety analysis shows that spent fuel from nuclear reactors can be safely disposed off using the deep borewell method, which would allow ample compliance with the US regulatory maximum annual dose requirement for a person of potentially (in the distant future) contaminated surface drinking water at the well over the waste at 10 millirem (mrem) per year. This figure is well within the regulatory standards laid down. The potential contamination time taken into account by the analysis starts with the sealing of the repository, includes the thermal period when the deposits are still hot, and then extends to 10 million years.
Instead, on the issue of the MOX fuel, World Nuclear News recently reported that the process of closing the nuclear fuel cycle will hit another milestone when the fourth unit of the Beloyarsk nuclear power plant (NPP) in Russia will be completely switched to uranium-plutonium MOX fuel in 2022. The 789 MW BN-800 fast neutron reactor is currently fuelled by a “hybrid core” consisting of a mix of uranium and plutonium oxides arranged to produce new fuel material as it burns. The transition to MOX fuel assemblies will start in the first half of 2021, the report said.
Citing Vladimir Shaloumov, the head of nuclear safety and reliability at the Beloyarsk NPP, the report said that the MOX fuel is currently being produced by the Mining and Chemical Combine in Russia’s Krasnoyarsk region and comprise uranium dioxide and plutonium dioxide in the form of pellets to be used as fuel. The BN-800 reactor is designed to use the MOX fuel as one of the stages on to the development of a closed nuclear fuel cycle.