Number of reactors back online is 14, although one has been temporarily shut down
Japanese regional utility Chugoku Electric Power has told the Nuclear Regulation Authority that it plans to restart Unit 2 at its Shimane nuclear power station in Shimane Prefecture, southwest Japan, on 7 December.
If the restart goes ahead, it will bring the number of reactors able to operate to 14 and boost the nation’s power supply this winter.
Shimane-2, the second boiling water reactor (BWR) unit to restart in Japan since the 2011 Fukushima disaster, was set to resume in August, but the restart was rescheduled due to essential safety upgrade work.
Shimane-2 is a 789-MW BWR unit of the same type as those that suffered meltdowns at the Fukushima-Daiichi nuclear power station following the massive earthquake and tsunami in March 2011. The plant began commercial operation in 1989.
Unit 2 at Tohoku Electric Power Company’s Onagawa nuclear power station in Miyagi Prefecture, northeastern Japan, was restarted on 29 October, becoming the first BWR in Japan to be go back online.
However, it was taken offline on 3 November due to an equipment malfunction. While a generator test was being carried out, an incident occurred in which a device for calibrating the detector that measures neutrons inside the reactor was stopped in the middle of the process.
Tohoku Electric said it had identified the cause of the incident, but has not yet said when it plans to restart the plant.
Before the Fukushima disaster Japan’s fleet of 54 nuclear plants generated about 30% of the country’s electricity, but were all shut down for safety checks following the accident.
Among the 33 operable nuclear reactors in Japan, 13 have now resumed operations after meeting post-Fukushima safety standards. The restarted plants are: Sendai-1 and -2, Genkai-3 and -4, Ikata-3, Mihama-3, Ohi-3 and -4, Onagawa-2 (temporarily offline) and Takahama-1, -2, -3 and -4.
In October, Japan’s new economy minister said the country will need to maximise the use of existing nuclear power plants because AI and data centres are expected to boost electricity demand.
Yoji Muto said the new administration will plan restarting as many reactors as possible so long as they are safe.
Muto’s comments point to a continuation of former prime minister Fumio Kishida’s policy that moved Japan back towards nuclear energy as a major power source.
Newly appointed prime minister Shigeru Ishiba, who succeeded Kishida on 1 October following the Liberal Democratic Party presidential election, had said during his election campaign that Japan should reduce its dependence on nuclear energy, but later said that he would support the restart of existing plants.
