Reactor operators have filed requests to restart 10 of Japan’s 50 reactors with the Nuclear Regulation Authority (NRA).

The units covered are: Hokkaido Electric Power Company’s Tomari 1&2; Kansai EPC’s Ohi 3&4 and Takahama 3&4; Kyushu EPC’s Sendai 1&2, and Ikata 3, operated by Shikoku EPC.

To date, Ohi 3&4, operated by Kansai EPC are the only reactors that have been allowed to resume operation in Japan following the March 2011 earthquake and tsunami that struck Tepco’s Fukushima Daiichi nuclear power plant. The MHI-designed pressurized water reactors, which restarted last July, are set to continue operation until the next statutory outage, planned for September 2013.

Japanese utilities had been waiting for new regulations to come into force before submitting restart applications. The Act on the Regulation of Nuclear Source Material, Nuclear Fuel Material and Reactors was enacted on 8 July, according to NRA.

The new regulations include design basis safety standards, severe accident management measures and safety requirements relative to earthquakes and tsunamis.

They were developed after "Various investigation reports and studies on Fukushima underlined certain vulnerability and failures in Japan’s existing nuclear safety systems, procedures and standards, including a lack of the back-fit system that applies revised standards to existing nuclear reactors," the NRA said in an overview of the draft standards published in February 2013.

Photo: Ohi 3&4, Japan