Japan puts fifth reactor back into operation

Unit 3 of the Takahama nuclear power plant in Japan's Fukui prefecture was restarted today, plant owner Kansai Electric Power Company has announced. Takahama 4 - which had also been kept offline since March 2016 by a court injunction - was restarted last month, joining three other reactors in operation.

Unit 3 of the Takahama nuclear power plant in Japan's Fukui prefecture was restarted today, plant owner Kansai Electric Power Company has announced. Takahama 4 - which had also been kept offline since March 2016 by a court injunction - was restarted last month, joining three other reactors in operation.

Takahama units 3 and 4 (Image: Kansai)

Kansai said the 830 MWe (net) pressurised water reactor (PWR) was restarted at 2.00pm today and is expected to achieve criticality tomorrow. The company plans to resume electricity generation at Takahama 3 and reconnect it to the grid on 9 June "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 early July after 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. The court's presiding judge ruled on 9 March that the safety of the units could not 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 then kept both Takahama 3 and 4 offline. Last August, Kansai removed the fuel from both units and placed it in their 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.

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. That unit - also an 830 MWe PWR - restarted on 17 May and reached full generating capacity on 25 May. It is expected to resume commercial operation this month.

At unit 3 fuel loading began on 13 May and was completed on 16 May.

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