Before the tsunami in 2011, Japan was generating 30% of its electricity from over 50 nuclear reactors, but all were shutdown within 14 months of the accident. A total of nine units have restarted since 2015, while 17 reactors are in the process of gaining approval to restart.
Tohoku Electric Power Company has received initial regulatory approval to resume operation of unit 2 at its Onagawa plant in Japan’s Miyagi Prefecture. The plant was the closest nuclear power plant to the epicentre of the earthquake and tsunami of 11 March 2011, but sustained far less damage than expected.
The utility applied to the Nuclear Regulation Authority (NRA) in December 2013 for a safety assessment of Onagawa 2 to verify countermeasures taken at the plant meet new safety standards. Tohoku expects to spend JPY340 billion (USD 3.1 billion) on these, which include seismic reinforcement of the unit and construction of a 29-metre high and 800m long sea wall to protect the plant from tsunamis. Work on them is expected to be completed by March 2021.
Today the NRA approved a draft screening document that concludes the plant will meet revised safety standards, introduced in January 2013. Tohoku will still need to obtain the approval of local authorities before it will be able to restart Onagawa 2.