By allowing the continued operation of two reactors at the Oi nuclear power plant until September, the Nuclear Regulation Authority signaled the difficulties it faces in forcing utilities to abide by what it calls the "world's most stringent" safety standards for the nuclear industry.
By allowing the continued operation of two reactors at the Oi nuclear power plant until September, the Nuclear Regulation Authority signaled the difficulties it faces in forcing utilities to abide by what it calls the "world's most stringent" safety standards for the nuclear industry.
The nuclear watchdog concluded at a June 20 meeting that it found “no problem immediately posing serious threat to the safety” of the Oi facilities during provisional checks it has been conducting since April, and will allow them to continue operating until they are shut down in September for routine inspections.
The decision allows Kansai Electric Power Co.'s No. 3 and No. 4 Oi reactors to stay online this summer without having to pass the new tougher safety standards, although the NRA expressed frustration with the utility's cooperation. This frustration reveals the potential tug of war the NRA faces in coming years in dealing with plant operators.
Of Japan's 50 nuclear reactors, the Nos. 3 and 4 Oi reactors are the only ones currently online. The two were reactivated last July as the nation's first to do so after the 2011 Fukushima nuclear accident.
The approval was not a surprising one, as the NRA was set from the outset to let the Oi reactors operate until September unless they were found to have serious problems, despite the nuclear watchdog's policy that requires all reactors to meet new safety guidelines before they are restarted.
The guidelines, which will go into effect in July, were drawn up to legally require operators of nuclear power plants to be prepared for a severe accident, such as the one at the Fukushima No. 1 nuclear power plant operated by Tokyo Electric Power Co.
Before the March 2011 triple meltdown following the Great East Japan Earthquake and tsunami at the Fukushima plant, the previous guidelines did not envision a disaster of such magnitude.
All reactors are expected to clear NRA examinations to assess if they meet its new safety guidelines before they are allowed to go back online.
According to experts, the NRA gave the green light to the continued operation of the Oi reactors after "less-than-strenuous" provisional checks partly because it did not have time to conduct detailed studies.
For example, the NRA put off determining if an active seismic fault runs beneath the plant site. Some members of the panel of experts with the NRA pointed out that on-site studies indicated the presence of an active fault under a key facility.
The NRA, however, decided to delay its final assessment because Kansai Electric, which disputes the panel's view, has not finished its own study and the NRA panel was not unanimous in its evaluation.
The NRA also had to accept a sketchy study of the geological structure beneath the plant site and surrounding area, which is necessary to determine the impact of an anticipated quake.
NRA investigators plan to embark on an extensive check of the geological structure when Kansai Electric applies for restarts of the Oi reactors.
The provisional checks also revealed the utility’s reluctance to cooperate with the NRA.
The NRA ordered the utility to determine the size of an expected temblor on the assumption that three active faults in the plant’s vicinity will shift at the same time. But it took the company about a month to agree to the simulation.
The NRA criticized Kansai Electric in a June 20 draft report that said the company “looked as if it were trying to find the lowest possible bar to clear the new safety standards by proposing safeguard measures by piecemeal.”
In an apparent warning to other utilities, the NRA said such an approach would “become an impediment to efficiently conducting inspections.”
Other regional utilities have been closely observing Kansai Electric's cooperation with the NRA during the provisional checks as reference for when they apply for restarts of their reactors in July and later.
The NRA will begin its checks of reactors under the new safety guidelines starting July 8.
Shunichi Tanaka, NRA chairman, said the new standards released June 19, are the “world’s most stringent, as was planned.”
But he also acknowledged for the guidelines to be truly effective hinges on how strenuous the NRA’s examinations will be in line with the new regulations.
Tanaka has sent mixed signals to utilities eager to bring idled reactors back online due to ballooning fossil fuel costs, saying the NRA’s top priority is the safety of reactors, not the bottom lines of the operators, and emphasizing speedy and efficient examinations.
Four electric power companies are expected to apply for restarts of their 12 reactors right after the new guidelines take effect on July 8.
They are the Nos. 1-3 reactors at the Tomari plant in Hokkaido, operated by Hokkaido Electric Power Co.; the Nos. 3-4 reactors at the Oi plant, and the Nos. 3-4 reactors at the Takahama plant, both in Fukui Prefecture, of Kansai Electric; the No. 3 reactor at the Ikata plant in Ehime Prefecture of Shikoku Electric Power Co.; and the Nos. 3-4 reactors at the Genkai plant in Saga Prefecture and the Nos. 1-2 reactors at the Sendai plant in Kagoshima Prefecture of Kyushu Electric Power Co.
All these reactors are the pressurized-water type, different from the Fukushima No. 1 plant.
They are expected to get easy approval from the NRA because they have a five-year moratorium on the installation of the required filtered containment vessel venting system.
Other utilities--Tohoku Electric Power Co., TEPCO, Chubu Electric Power Co., Hokuriku Electric Power Co. and Chugoku Electric Power Co.--are likely to take more time to be ready for applying.
All their reactors are of the boiling water type that are required to be fitted with a filtered containment vessel venting system at the time of application for restarts.
When the Oi reactors are shut down for an inspection in September, the nation will have no reactors online for at least several months.
Experts say that it will be late this year or early next year at the earliest when the first reactor may be reactivated after passing the new safety standards.