Two More Japan Nuclear Units Will be Decommissioned

Kansai Electric Power Co. (KEPCO) announced it will permanently close two older nuclear reactors in Japan, rather than invest nearly 100 billion yen ($900 million) to bring the units up to the country’s new safety regulations. Japan’s Nuclear Regulation Authority (NRA) created new standards for the country’s nuclear plants after the meltdown at the Fukushima Daiichi plant in March 2011.

KEPCO on December 22 said it will decommission reactors No. 1 and No. 2 at the Oi facility in central Japan over the next year. Each unit has a generation capacity of 1,175 MW. The reactors, which came online in March 1979 and December 1979 respectively, will be the largest decommissioned in the country since the Fukushima disaster, which occurred when a 9.0-magnitude earthquake caused a massive tsunami that flooded the Fukushima plant in the northeastern part of the country. The resulting release of radiation was the largest since the Chernobyl meltdown in Russia in 1986.

Japan idled all 50 of its remaining nuclear units after the Fukushima incident. Only a handful have been cleared to restart, with about two dozen applications for restart pending. Tokyo Electric Power Co. (TEPCO) in September 2017 was given conditional approval by the NRA to restart two reactors at Kashiwazaki-Kariwa plant.

The two Oi units bring to 14 the number of reactors announced for decommissioning as of late December 2017. Nuclear energy today provides about 2% of Japan’s power, down from 30% before the Fukushima disaster.

Under the new safety rules from the NRA, the operating life of nuclear reactors in Japan is limited to 40 years, but they may be able to remain online for another 20 years if operators upgrade equipment to enhance safety, and if the units pass inspection from the NRA. Two newer units at Oi, each with 1,127 MW of capacity, have not operated since being taken offline in 2013 as Japan reconsidered its use of nuclear power in the wake of Fukushima.

KEPCO in a statement said, “We decided to decommission as we are prioritizing safety and quality in future operations, after we were unable to find an effective technological solution” to ensure the safety of the reactors under emergency conditions. A spokeswoman for KEPCO who did not want to be named told local media: “The containment vessels of these reactors are smaller than other reactors in Japan, and a need to beef up the walls to meet the standards would make the work zones even more cramped, making it difficult for prompt repairs in case of troubles.”

Japan’s Prime Minister, Shinzo Abe, has said he still sees nuclear power as important for the country. His government’s current plan calls for 20% of the country’s generation to come from nuclear power by 2030.

The goal may prove difficult as public opinion has turned against nuclear power after Fukushima, and residents in areas near nuclear plants have filed numerous court challenges to permanently half their operation. In the most recent case, the Hiroshima High Court overturned a lower court ruling, saying operation of Unit 3 at the Ikata nuclear plant—owned by Shikoku Electric Power Co.— should be suspended. The 846-MWe pressurized water reactor resumed commercial operation in September 2016 after being idled since April 2011.

The Ikata case is the first time a higher court has overruled a lower court in cases regarding nuclear restarts. Unit 3 is currently offline for maintenance and had been scheduled to resume operation January 22, 2018.

Darrell Proctor is a POWER associate editor (@DarrellProctor1, @POWERmagazine).