Court rules against bid to halt Ohma construction

A Japanese court today rejected a lawsuit seeking to stop construction and subsequent operation of Japan Electric Power Development Corp's (J-Power's) Ohma nuclear power plant, being built in Aomori prefecture.

More than 1100 residents of Hakodate city filed a suit and claims for damages with the Hakodate District Court against J-Power and the government in July 2010. A further eight complaints have since been filed with the court.

The lawsuit focused on whether there is an active seismic fault in the seabed near the Ohma plant site and the risk of volcanic eruptions in the area. The plaintiffs also expressed concerns about the plant using purely mixed-oxide (MOX) fuel. Ohma 1 would be the first Japanese reactor built to run solely on MOX fuel incorporating recycled plutonium.

"Until now, we have asked the court to dismiss the claims, and we have carefully insisted on and verified that the safety of the Ohma nuclear power plant is secure," J-Power said.

The company announced today that the Hakodate District Court had "recognised" its argument and ruled in its favour. The ruling dismisses both the injunction on the plant's construction and the claims for damages, it noted.

Presiding Judge Chikako Asaoka was quoted by the Asahi Shimbun as saying: "At the moment, it is difficult to readily recognise the tangible danger of a grave accident likely to occur at the plant."

"We will continue to respond appropriately to the conformity assessment by the Nuclear Regulation Authority (NRA) to the new regulatory standards and we will work throughout the entire company to create a safe power plant," J-Power said. "In addition, we will strive to provide information about the plan of the Ohma nuclear power plant to the people concerned."

The start of construction of the Ohma plant was originally due in August 2007, with commercial operation planned for March 2012. However, the imposition of more stringent seismic regulations put back the start of construction to May 2008 and commercial operation to November 2014.

Work to build the first unit at Ohma - a 1383 MWe Advanced Boiling Water Reactor - was about 40% complete in March 2011 when a tsunami caused the accident at the Fukushima Daiichi plant. Construction of Ohma 1 was suspended following the accident, but was resumed in October 2012. At that time, J-Power said it would strive to establish a safe power plant by, among other things, ensuring reinforced safety measures are implemented that take into account the lessons learned from the Fukushima accident.

In December 2014, J-Power submitted an application to the NRA to make changes to Ohma 1's reactor installation to strengthen the unit's protection. These measures - including tsunami countermeasures, ensuring power supplies, ensuring heat removal functions, and severe accident responses - were originally expected to be completed by the end of 2020.

However, in September 2015, the company announced a one-year delay in the start of safety equipment construction, pushing back the start of operation to around 2021. This delay was attributed to the prolonged screening process by the NRA after the company was requested to submit additional information about its plans.

A year later, J-Power said it expects a further delay of around two years in the completion of the NRA's review and approval process for Ohma 1. It now expects construction of the safety upgrades to begin this year and to be completed in the second half of fiscal year 2023.

"We are doing all we can for the start of operations in the 2024/25 business year," a J-Power spokesman told Reuters.

Researched and written
by World Nuclear News