Japan’s Nuclear Regulation Authority (NRA) has been unable to reach a decision on whether to approve the government’s plan to extend the operating life of nuclear reactors beyond 60 years.

At a recent NRA meeting, four of the five NRA commissioners, including Chairman Shinsuke Yamanaka, supported the extension plan but Akira Ishiwatari, opposed it. Further discussions are scheduled for later in February.

Under current regulations, the maximum operating period for nuclear reactors is set at 40 years in principle or 60 years if approved by the regulator. The government is working on a bill to effectively allow nuclear reactors to operate beyond the 60-year limit by excluding periods when reactors are halted for safety inspections or other reasons.

Akira Ishiwatari, the NRA Commissioner in charge of examining earthquakes and tsunamis, said removing the operating period limit “cannot be said to be a safe modification”. He also noted that regulation of the operating period is to be transferred from the jurisdiction of the NRA to the Ministry of Economy, Trade & Industry.

The NRA meeting discussed the results of an opinion poll on the reactor operating period. A total of 1,749 opinions were received, NHK reported. These included many dissenting opinions including “the 40-year rule that was imposed in the wake of the Fukushima Daiichi Nuclear Power Plant accident should be observed” and “there are limits to inspections and evaluations of ageing”.

In response to this, the NRA said, “Since the degree of deterioration of nuclear installations varies depending on how they are used and how they are managed, we need to understand the specific deterioration situation at the appropriate time and comply with the standards based on the results. It is necessary to check each one to see whether they are doing so.”

NRA Chairman Shinsuke Yamanaka told a press conference: “It was good that the committee had an opposing opinion in the sense that it extended the discussion, but I think that Commissioner Ishiwatari was misunderstood.” He added: “It is not wrong for the committee members to have different opinions, and I would like to discuss it further.”

Image: Akira Ishiwatari, a commissioner of the Nuclear Regulation Authority, has opposed the Japanese government's plan to extend the operating life of nuclear reactors beyond 60 years (courtesy of NHK)