Japan is pushing nuclear operators to draft plans to deal with older reactors, including the possibility of scrapping those most vulnerable to disaster.
The proposal affects a quarter of Japan's 48 reactors and, according to newspaper the Nikkei, the government is hoping that by forcing the closure of older units, which are too old or too costly to refurbish to new standards imposed after the Fukushima disaster, it may gain public support to restart newer units.
All Japan's reactors were shut following the 2011 nuclear crisis at Fukushima caused by a major earthquake and tsunami and public opinion turned against nuclear power after the disaster.
But the government wants to restart units deemed safe by a new, more independent regulator and cut Japan's reliance on expensive imports of fossil fuels.
Kansai Electric Power is likely to be the first to consider scrapping two of its ageing nuclear reactors, the Nikkei said – the 340MW No. 1 and 500MW No.2 reactors at its Mihama nuclear facility in western Fukui prefecture.
Both Mihama units are more than 40 years old and have relatively small capacity, so restarting them would bring only a limited profit boost and cost several hundred billion yen for inspections and safety measures, the paper said.
But the company denied the report, saying it was still considering how to respond ahead of a looming application deadline to extend the operations of two ageing plants beyond a 40-year limit.
Kyushu Electric Power will also consider scrapping its 38-year-old 559MW Genkai No.1 reactor, the Nikkei reported later, but a spokesman told Reuters that the company is weighing the extension of operations, rather than decommissioning.
Japanese trade minister Yuko Obuchi said on Friday that operators should decide on their own whether to scrap the reactors, but the government would help with the smooth decommissioning of older units, besides trying to restart nuclear plants that clear the nation's new safety standards.
The new nuclear safety rules make it tougher to upgrade and run older reactors, and as many as two-thirds of Japan's 48 idled nuclear units may not return to operation because of the high costs, local opposition or seismic risks, a Reuters analysis showed earlier this year.
The more stringent safety checks on nuclear facilities adopted in July 2013 limit a reactor's operating life to 40 years in principle, but by clearing tough inspections, they could get a one-time maximum extension of 20 years.
Two reactors in southwest Japan have already won initial clearance to restart under the new safety regime, but hurdles remain.
A dozen reactors will reach the 40-year limit within five years and the government is asking operators to evolve plans to decommission older units by the end of the year, the Nikkei said.