Authorities on Wednesday approved for the first time an extension to the 40-year operating life of one of the nuclear power plants affected by the 2011 earthquake and tsunami disaster.
The government’s nuclear watchdog allowed an extension of up to 20 years beyond the Nov. 28 limit for Japan Atomic Power Co.’s Tokai No. 2 plant in Ibaraki Prefecture.
The move, together with previous operating limit extensions at three other aging nuclear reactors, could undermine the 40-year cap the country applies in principle to nuclear complexes. The Nuclear Regulation Authority had said extension beyond that would be “a rare exception.”
The Tokai plant uses the same type of boiling water reactor as the Fukushima No. 1 power plant, which suffered fuel meltdowns triggered by the magnitude 9.0 quake and subsequent tsunami on March 11, 2011.
A 5.4-meter tsunami also left the Tokai plant without an external power source and incapacitated one of its three emergency power generators, although it managed to cool its reactor using the remaining power generators.
In late September, the NRA formally approved the restart of the Tokai plant, which has been idled since the disaster.
But even with the approvals for the restart and extension of its operating limit, it remains unclear when the plant will actually get back online, as construction work to enhance its safety will not be completed until March 2021.
The utility also needs to obtain consent from all of the host and surrounding municipalities, being the sole nuclear power plant in Japan to need approval from local governments beyond its immediate host — the village of Tokai.
The plant also faces the hurdle of having to compile an evacuation plan covering 960,000 residents within a 30-kilometer radius — the largest number of potential evacuees for a nuclear plant in the nation due to its location in a metropolitan region.
Japan Atomic Power applied for the plant’s restart in May 2014 with a plan to construct a 1.7 kilometer-long coastal levee, predicting potential tsunami as high as 17.1 meters.
The cost for safety measures at the plant is estimated to reach some ¥180 billion ($1.6 billion), and the operator, solely engaged in the nuclear energy business, has been struggling, as none of its reactors have been online since the 2011 disaster.
The Tokai plant boasts an output capacity of 1.1 million kilowatts, while the output capacities of the three other nuclear power units given the green light to operate beyond 40 years are 800,000 kilowatts or more.
Japan has decided to scrap nuclear power reactors with an output of around 500,000 kilowatts or lower as these are seen as difficult to turn profitable because of the massive investment required to boost safety.
Kyushu Electric Power Co., the operator of the Genkai No. 2 plant in Saga Prefecture — which has an output of 559,000 kilowatts — will soon face a decision on whether it should be scrapped or have its operating limit extended, as 37 years passed since it went into service.