Kansai applies to decommission Ohi 1 and 2

Kansai Electric Power Company has applied for Japanese government approval to decommission units 1 and 2 of its Ohi nuclear power plant. The company will later submit a detailed decommissioning plan for the two 1175 MWe pressurised water reactors.

Kansai Electric Power Company has applied for Japanese government approval to decommission units 1 and 2 of its Ohi nuclear power plant. The company will later submit a detailed decommissioning plan for the two 1175 MWe pressurised water reactors.

Ohi units 1 and 2 (Image: Kansai)

Kansai announced on 22 December that it had decided not to seek permission to restart the two units in Japan's Fukui Prefecture. At that time, it informed Ohi town and Fukui Prefecture of its decision to decommission the units, which began operating in March 1979 and December 1979, respectively.

Ohi 1 and 2 - which have been offline since July 2011 and December 2011, respectively - are the only reactors in Japan to feature ice condenser emergency cooling systems. These systems employ blocks of ice in a basket installed around the containment vessel to rapidly cool steam generated to reduce pressure in the event of an accident. Kansai said that to comply with new safety standards, the walls of the containment buildings of Ohi 1 and 2 would had to have been thickened. Kansai estimated it would have cost some JPY830 billion (USD7.3 billion) to make safety upgrades for the units to meet the required standards.

Kansai announced today that it had submitted an application to Japan's Ministry of Economy, Trade and Industry seeking approval to decommission the units. The application states that Ohi units 1 and 2 will officially be classed as shutdown as of today and that the overall rated generating capacity of the plant will be reduced from 4.75 GWe to 2.36 GWe.

The utility will now formulate a detailed decommissioning plan for Ohi 1 and 2, which it will submit to the Nuclear Regulation Authority for approval. Its plan will outline the facilities and equipment to be dismantled and a timetable for completing the work.

Following the shutdown of all of Japan's reactors after the Fukushima Daiichi accident, Kansai was given permission to resume operation of the newer units 3 and 4 of the Ohi plant in August 2012. However, the two 1180 MWe PWRs were taken offline again for inspections in September 2013. The utility has received all the necessary approvals to restart both units. Kansai has already reloaded fuel into unit 3 and plans to return both units to commercial operation by mid-2018.

Researched and written
by World Nuclear News