Injunction lifted on operation of Japanese reactor

Ikata 3 was given approval by the Nuclear Regulatory Authority to resume operation in April 2016, having been idle since being taken offline for a periodic inspection in April 2011. Shikoku declared the 846 MWe pressurised water reactor back in commercial operation on 7 September 2016.

Four residents from Matsuyama and Hiroshima filed a request for a temporary injunction against the unit's operation with the Hiroshima District Court on 11 March 2016, the fifth anniversary of the Fukushima Daiichi accident. The plaintiffs claimed that Shikoku had underestimated the potential size of an earthquake that could strike the plant. However, on 30 March 2017, the court ruled that Shikoku has used reliable measures in calculating the basic earthquake ground motion at the site and rejected the petition. The following month, the plaintiffs appealed the decision in the Hiroshima High Court.

In December 2017, that court overruled the district court's decision and ordered the suspension of Ikata 3's operation. Ikata 3 had been taken offline in October 2017 for maintenance and periodic inspections and was scheduled to restart on 22 January. The injunction was effective until the end of this month. Shikoku described the high court's ruling as "extremely disappointing" and promptly filed an appeal against its decision.

The Hiroshima High Court yesterday accepted Shikoku's appeal and cancelled the injunction, allowing the utility to begin the process of restarting the reactor.

Residents in nearby Oita Prefecture had also sought an injunction against Ikata 3's operation with the Oita District Court, claiming that the operator had underestimates the risks posed by a volcano some 130km away. That court also sided with Shikoku, ruling on 28 September that the safety of the plant is secured. The company has claimed there is a low possibility of Mount Aso experiencing a large-scale eruption while the reactor is in operation.

Shikoku said it plans to reload fuel into the core of Ikata 3 between 1 and 4 October. The unit is scheduled to be restarted on 27 October, with power generation expected to resume on 30 October. Commercial operation of the reactor is set to restart on 28 November.

So far, nine of Japan's 39 operable reactors have cleared inspections confirming they meet the new regulatory safety standards and have resumed operation. These are: Kyushu's Sendai units 1 and 2 and Genkai units 3 and 4; Shikoku's Ikata unit 3; and Kansai's Takahama units 3 and 4 and Ohi units 3 and 4. Another 16 reactors have applied to restart.