27 Apr (NucNet): Japan has identified the reprocessing of nuclear fuel as the “essential factor” for the long-term use of nuclear energy, Harukuni Tanaka, senior managing executive officer of Japan Nuclear Fuel Limited (JNFL), said at the World Nuclear Fuel Cycle conference in Prague last week.
Mr Tanaka said the target for the share of nuclear energy in the energy mix in 2030 is under discussion in a special advisory council set up by the government, but nuclear has been identified as one of the “important base-load power generating methods”.
Mr Tanaka said nine nuclear units in Japan plan to use mixed-oxide (MOX) fuel if they are allowed to restart operation by the country’s Nuclear Regulatory Authority (NRA). These are made up of five pressurised water reactors (PWRs) and four boiling water reactors (BWRs), which are under inspection to ensure they meet safety standards introduced following the March 2011 Fukushima-Daiichi accident.
The PWRs are Takahama-3 and -4, Genkai-3, Ikata-3, and Tomari-3. The BWRs are Shimane-2, Hamaoka-4, Tokai-2, and Ohma-1.
Mr Tanaka said JNFL hopes to obtain a licence to operate Japan’s MOX fuel fabrication plant (JMOX) at Rokkasho by October 2017. The facility’s safety design is being assessed by the NRA under the new requirements.
Japan has experience in processing spent nuclear fuel at its Tokai plant which started operation in 1977 and completed its last reprocessing service contract in 2006. The plutonium recovered from processing was sent to France for MOX fuel fabrication.
Fuel from Japan’s reactors has also been reprocessed at Areva’s facilities at La Hague in northern France and the MOX manufactured at Areva’s Melox plant in the Rhone valley.
JMOX will receive MOX powder from JNFL’s Rokkasho processing plant. The two facilities are connected through an underground tunnel to protect the transfer of “sensitive” materials, Mr Tanaka said.
The processing plant is being inspected by the NRA to determine whether it conforms to the new safety standards, but JNFL hopes to obtain an operating licence by March 2016, Mr Tanaka said. JNFL has started upgrading the plant’s safety functions for design-basis accidents as well as severe accidents, he said.
When operational, the processing plant will be able to treat up to 800 tonnes of spent fuel per year. JMOX will have a maximum capacity of 130 tonnes of heavy metal per year.
Mr Tanaka said 12 reactor units were either using or under regulatory review to begin using MOX fuel before the Fukushima-Daiichi accident.
Tokyo Electric Power Company (Tepco) was operating one unit, Fukushima-Daiichi-3, with MOX fuel when the accident occurred.
Tepco had also prepared fresh MOX fuel for its Kashiwazaki-Kariwa-3 unit, but has applied for restart permission from the NRA for Units 6 and 7 only.
A regulatory review was completed of Tohoku Electric’s Onagawa-3 so it can begin using MOX, but the company has not yet submitted an application to the NRA to restart the unit.
MOX fuel consists of a mix of uranium and plutonium oxides recovered from used nuclear fuel. More than 30 nuclear reactors in Belgium, France, Germany and Switzerland use MOX fuel, typically as one third of their cores. Some units can use up to 50 percent MOX and some modern designs could use 100 percent MOX.
