18 Novembre 2016
November 17, 2016
The Nuclear Regulation Authority on Nov. 16 gave the green light to Kansai Electric Power Co.’s application to extend operations of the aging No. 3 reactor at its Mihama nuclear power plant for up to 20 years. The plant in Fukui Prefecture will reach its 40-year-lifespan at the end of the month.
The Mihama No. 3 unit is the third reactor to be granted a license renewal by the nuclear safety watchdog following the No. 1 and No. 2 reactors at the same utility’s Takahama nuclear power plant, also in Fukui Prefecture.
In the aftermath of the disaster at Tokyo Electric Power Co.’s Fukushima No. 1 nuclear power plant in 2011, the law was revised to set 40 years, in principle, as the lifespan of nuclear reactors. The licenses for reactor operations can be renewed once for up to an additional 20 years, but license renewal is supposed to be highly exceptional.
We are deeply concerned that the NRA’s decision to approve the extended operation of an aging reactor could set a trend, gradually eviscerating the principle. We feel obliged to express again our opposition to the decision.
There are reactors that have been in service for more than 40 years in the United States and Europe. But experts have warned about a possible significant decline in the level of safety due to such aging issues as deterioration of the reactor vessel, which cannot be replaced.
The No. 3 reactor at the Mihama nuclear plant had a serious accident in 2004 when 11 workers were killed or injured by high temperature steam blowing out of a worn-out pipe in a turbine facility.
One of the factors behind the deadly accident was inadequate inspection over many years.
Older nuclear power plants require more careful maintenance and safety checks.
The extended operation of the aging reactors will impose a heavy burden on Kansai Electric Power, which is responsible for securing their safety.
The utility has promised to raise its estimation of ground motion due to possible earthquakes that might strike areas around the plants and take appropriate measures to bolster the quake-resistance of the reactors by spring 2020. It will also have to take additional safety measures, including steps to make electric cables less flammable.
The company will have to spend more than 380 billion yen ($3.47 billion) to meet the requirements to extend the operation of the three reactors. This sum doesn’t include the costs of building new facilities to respond to terrorist attacks required under the new stricter safety standards.
The amount of money involved could have covered the entire cost of building a 1,000-megawatt nuclear power plant before the Fukushima disaster.
Still, Kansai Electric Power claims the massive investment makes economic sense. It said it plans to also seek license renewal for the No. 1 and No. 2 reactors at its Oi nuclear power plant, which will reach the 40-year legal lifespan in three years.
Of the 11 reactors it owns, the utility has decided to decommission only the two oldest--the No. 1 and No. 2 reactors at the Mihama plant.
Before the 2011 accident, Kansai Electric Power promised local communities that it would replace the aging Mihama No. 3 reactor with a new one. This promise seems to have played a role in its decision to keep the Mihama No. 3 unit running.
The license renewals offer no respite from concerns about the situation in areas around Wakasa Bay in Fukui Prefecture, which are dotted with many aging reactors.
Instead of making decisions only from a business point of view, the utility should opt to decommission these reactors to lower the risk of nuclear accidents.
The NRA’s stance toward the issue is also questionable.
The three reactors at the Takahama and Mihama plants faced decommissioning unless their licenses were renewed before the expiration of the 40-year term.
The NRA gave precedence to the inspections of these reactors for license renewal and allowed the utility to delay required earthquake-resistance tests for important equipment until after the completion of the planned work.
These actions indicate the nuclear regulator tried to complete the license renewal review process before the expiry dates kicked in.
The pools for storing spent nuclear fuel at the nuclear plants operated by Kansai Electric Power are close to reaching their capacity.
The utility says it will build an interim storage facility outside Fukui Prefecture. But there is no workable and specific plan to realize this idea.
The utility is acting in an irresponsible manner by deciding to extend the operation of these aging reactors without solving the key problem.
The catastrophic accident at the Fukushima plant has radically changed the Japanese public’s perceptions of nuclear power generation.
It is hard to believe that continued use of old reactors will open up a new energy future for this nation.
Kansai Electric Power should stop to reconsider whether extending the operation of these reactors is really necessary.
November 16, 2016
The Nuclear Regulation Authority (NRA) has allowed Kansai Electric Power Co. to continue running the No. 3 reactor at its Mihama Nuclear Power Station in Fukui Prefecture beyond the 40-year limit.
This is the third nuclear reactor in the country that will have been allowed to continue to operate beyond the 40-year limit -- following the No. 1 and 2 reactors at the Takahama plant also in Fukui Prefecture.
The move contradicts rules stipulating that nuclear reactors should be decommissioned after being operated for 40 years, in principle.
It had been viewed as extremely difficult to extend the lifespan of Mihama's No. 3 reactor because of its old design and difficulties in improving the reactor's quake resistance as the plant operator is required to largely increase the estimate of the scale of the maximum earthquake that could hit the plant.
As such, the NRA once hinted that it would discontinue examinations of the reactor to see if it meets the new regulatory standards.
However, Kansai Electric Power spent 165 billion yen on measures to enhance the safety of the reactor. The NRA increased its personnel to accelerate the examination of the plant, and managed to approve the continuation of its operation by the deadline.
Six aging nuclear reactors across the country are set to be shut down and decommissioned. Their operators voluntarily decided to decommission these reactors, whose outputs are small, considering the units' cost-benefit performance.
However, if power companies apply for permission to extend the lifespan of nuclear reactors, the NRA will almost certainly grant permission.
The rules limiting the operation of a nuclear reactor to 40 years, in principle, was established with the aim of reducing Japan's reliance on atomic power stations following the outbreak of the Fukushima nuclear crisis in March 2011. Both the NRA and power companies should go back to the fundamentals of the rules.