Japanese reactor restarts after lifting of injunction

17 May 2017

Kansai Electric Power Company announced today that it had restarted unit 4 of its Takahama nuclear power plant in Fukui prefecture. The reactor - which together with unit 3 has been offline since March 2016 - is expected to re-enter commercial operation next month.

Takahama units 3 and 4 - 460 (Kansai)
Takahama units 3 and 4 (Image: Kansai)

The company said the 830 MWe (net) pressurised water reactor (PWR) was restarted at 3.00pm today and is expected to achieve criticality tomorrow. Kansai plans to resume electricity generation at Takahama 4 and reconnect it to the grid on 22 May "as the final stage of the periodic outage inspection following various types of tests". It added that "full-scale operation" of the unit will resume in mid-June after the completion of the comprehensive inspection performed by the Nuclear Regulation Authority (NRA).

In late January 2015, 29 residents of Shiga prefecture - part of which lies within 30 kilometres of the Takahama plant - filed a petition with the Otsu District Court for a temporary injunction against operation of Takahama 3 and 4. Four hearings were subsequently held. The court's presiding judge Yoshihiko Yamamoto ruled on 9 March that the safety of the units cannot be guaranteed - despite the NRA saying they meet revised safety standards - and issued an injunction against their operation.

Unit 3 of the Takahama plant had resumed operation on 29 January, 2016. Takahama 4 was restarted on 26 February, but was taken off line on 29 February following an automatic shutdown of the reactor due to a "main transformer/generator internal failure". The injunction has since kept both Takahama 3 and 4 offline. Last August, Kansai removed the fuel from both Takahama units 3 and 4 and placed it in the units' storage pools.

Kansai appealed to the court to temporarily remove the injunction. However, the court ruled last June the injunction would remain in place.

The utility then filed an appeal with the Osaka High Court on 14 July 2016 pointing out the decision of the Otsu District Court was not rational. In late March, the Osaka High Court ruled in Kansai's favour and lifted the injunction. Local media reported the residents that sought the injunction decided not to appeal against the rejection of their demand by the Osaka High Court.

Kansai began reloading the 157 fuel assemblies - including four mixed-oxide (MOX) fuel assemblies - into unit 4 on 28 April and completed the process on 1 May. At unit 3 - also an 830 MWe PWR - fuel loading began on 13 May and was completed yesterday. That unit is expected to be restarted early next month, with commercial operation scheduled for early July.

Kansai president Shigeki Iwane said, "After successfully completing the reactor startup, which is one of the important steps in the process of resuming power operation, we will take sincere and deliberate actions on a continuous basis to support the inspections to be performed by the Nuclear Regulation Authority." He added, "Taking this opportunity, I would like to encourage each and every one of our employees and the employees of all the contractors to renew a resolve to pursue nuclear safety and to make an untiring effort."

Three other Japanese reactors are currently in operation: Kyushu Electric's Sendai units 1 and 2 and Shikoku Electric's Ikata unit 3. Another 19 have applied to restart.

Researched and written
by World Nuclear News