Progress has been made toward restarting a nuclear power plant, but a number of challenges still lie ahead, making it important for the parties concerned to steadily prepare to resume operations through such efforts as winning the consent of local governm
The Nuclear Regulation Authority (NRA) on Wednesday approved a draft safety screening report that concluded that safety measures for the Nos 1 and 2 reactors at Kyushu Electric Power Co’s Sendai nuclear power plant “meet new safety standards”
With the NRA’s approval, the Sendai plant has effectively passed the safety examination, a precondition for restarting. Kyushu Electric hopes to resume operating the power plant this autumn.
The new safety standards call for a nuclear power plant operator to take strict safety measures based on lessons from the nuclear crisis at Tokyo Electric Power Co’s Fukushima No 1 nuclear power plant.
It is significant that the Sendai plant has become the first nuclear power plant to clear the new safety standards and have its safety confirmed. One focal point of the safety screening was the magnitude of earthquakes and the scale of tsunami the nuclear plant operator would assume for the plant.
Kyushu Electric has raised its assumptions for the maximum height of a tsunami by 50 per cent and for the maximum impact of an earthquake on the reactors by 15 per cent. On the basis of these assumptions, the utility will take measures against possible flooding and introduce quake-resistant reinforcement of the facilities and equipment.
Measures to prevent crisis
Another focal point was what sort of measures the plant operator would take to prevent such major accidents as those triggered by the loss of cooling functions for reactors, as happened at the Fukushima plant.
Kyushu Electric has won the NRA’s recognition of its countermeasures, such as the expansion of its emergency power sources and the reinforcement of intake pumps, as well as multiplexing pipework for cooling the reactors.
The NRA will examine the construction plan for the facilities and equipment, and its regulations for maintenance and safety checks. It is expected to take at least two to three months to complete all these screenings, including inspections following the completion of the work.
Winning the understanding of the local governments is also important. In addition to Kyushu Electric, the government must also responsibly explain to officials concerned about the safety of the Sendai nuclear power plant and the necessity of restarting it.
The evacuation plan, to be followed in case of an accident at the plant, also needs to be fully known among local residents.
It is also crucial for the screening conducted at the Sendai plant to be utilised to facilitate the checking of other nuclear power plants. In addition to the Sendai plant, applications for the NRA’s safety screening have been made for 17 reactors at 11 nuclear power plants. So far, however, there are no prospects for any of them to pass.
This is primarily because the NRA’s screening has been quite inefficient, with utility companies repeatedly asked to submit more data.
The NRA’s draft safety screening report gives a detailed account of how the safety measures against accidents have been screened by the authority. Power companies should do their utmost to prepare appropriately for the screening by referring to this account.
On the other hand, there was hardly any description of how the NRA made its judgement regarding the assumed impact of earthquakes and tsunami. We think the NRA has a responsibility to clearly specify the grounds for its decision.
The supply of electricity remains precarious as soaring power rates have directly hit ordinary households and businesses. The NRA needs to accelerate its safety screenings and get the restart of nuclear power plants on track.