Unit 3 of the Ohi nuclear power plant in Japan’s Fukui Prefecture today resumed commercial operation, Kansai Electric Power Company announced. The reactor is the sixth to be restarted after clearing the country’s revised safety regulations.

Following the shutdown of all of Japan’s reactors after the March 2011 accident at the Fukushima Daiichi plant, Ohi 3 and 4 were given permission to resume operation in August 2012. However, the two 1180 MWe pressurized water reactors (PWRs) were taken offline again for Nuclear Regulation Authority (NRA) inspections in September 2013.

Ohi 3 is the sixth of Japan’s 42 operable reactors which have so far cleared inspections confirming they meet the new regulatory safety standards and have resumed operation. The others are: Kyushu’s Sendai units 1 and 2; Shikoku’s Ikata unit 3; and Kansai’s Takahama units 3 and 4. Another 18 reactors have applied to restart.

In August 2017 the IEEJ in its Economic and Energy Outlook for FY2018 said that it expected at least ten reactors to be online by March 2019, generating 65.6 TWh/yr and representing 7% of total electricity. These would contribute JPY 500 billion to GDP. In a high case scenario, 17 reactors are online then, providing 99 TWh/yr.

The reactor restarts are facing significant implementation costs ranging from US$700 million to US$1 billion per unit, regardless of reactor size or age. From FY 2011 to March 2017 the total cost is estimated at JPY 1900 billion ($17.4 billion) for eight companies, according to a JAIF survey.

Impact of the nuclear shutdowns

Japan has increased fuel imports are costing about ¥3.8 to 4.0 trillion ($40 billion) per year.
Generation cost was up 56% from ¥8.6/kWh to 13.5/kWh in FY 2012.

About 100 million tonnes per year more CO2 is being emitted than when the reactors were operating, adding 8% to the country’s emissions. Emissions from electricity generation accounted for 486 Mt CO2 (36.2%) of the country’s total in fiscal 2012, compared with 377 Mt (30%) in 2010.