Japanese reactors cleared

Kansai's four-unit Takahama Nuclear Power Plant.

TWO units at the Takahama nuclear power plant in Japan received the final approval from the country’s Nuclear Regulation Authority (NRA) for restart, bringing the total number of reactors cleared for restart to four.

The NRA granted Kansai Electric Power Company preliminary permission to make changes to the basic design of the reactor installations of Takahama units 3 and 4 in mid-December 2014. At that time, the NRA said that the applied design and safety features of both the 870 MWe pressurised water reactors met its new regulatory requirements, which were announced in July 2013.

Kansai first applied for permission to restart the units in July 2013. It has since submitted various amendments to its plans to increase the plant’s resistance to extreme events such as earthquakes, tsunamis and tornadoes, in accordance with the regulator’s requirements.

Following a one-month period for public comment, the NRA gave Kansai its final permission to make the required safety upgrades at the units prior to their restart. The NRA said it granted the approval after reviewing some 10,000 pages of documentation from Kansai, holding 67 review meetings, and conducting field investigations for safety assessment. It also took into consideration public comment received following the publication of its draft assessment.

In the next step of the restart process, the NRA will review the detailed design and construction of the nuclear reactors and related facilities as well as operational safety programmes, including organisation systems and procedures for accident responses.

Units 3 and 4 of its Takahama plant in Fukui prefecture have remained offline since being shut for periodic inspections in February 2012 and July 2011, respectively. Kansai reportedly aims to restart the two reactors by November.

On April 17, 2013, a shipment of mixed-oxide (MOX) fuel left the port of Cherbourg in northern France for Kansai’s Takahama nuclear plant situated west of Tokyo. This shipment was the first since the Fukushima disaster. The MOX fuel for Takahama Unit-3 contains around 7 per cent plutonium.

So far, the NRA has only approved the restart of two other reactors, granting Kyushu Electric Power Company permission to make changes to the reactor installations of Sendai units 1 & 2 in September 2014. Local and prefectural government approval is also required before they can restart. Seventeen other reactors have applied for their safety assessment.