Regulators are in the process of deciding which reactors are sitting on active faults, but the experts involved say there is clearly room for improvement.

Fault exams at three nuclear power plants are proceeding in parallel. The first one to be finalized by an expert panel was accepted by the Nuclear Regulation Authority on Wednesday.

NRA Chairman Shunichi Tanaka fully backed the assessment, which said that a fault beneath reactor 2 of the Tsuruga plant in Fukui Prefecture is active.

“We reached a judgment in line with our mission to decide issues in a scientific and neutral manner so as not to see a nuclear accident like the one in Fukushima happen again,” he said at a press conference.

But he also admitted that the NRA needs to learn from the fault assessment process because it needs to complete similar studies on at least five more facilities, including Kansai Electric Power Co.’s Oi plant in Fukui and Hokuriku Electric Power Co.’s Shika plant in Ishikawa Prefecture.

Members of the panel that signed off on the fault study at Japan Atomic Power Co.’s Tsuruga plant are dissatisfied with how discussions proceeded over the past six months.

“At first, I was expecting this to end in some three months, but I got quite anxious because the prospects became unclear,” Koichiro Fujimoto, an associate professor at Tokyo Gakugei University, said at a meeting the panel held a week ago to finalize the fault assessment.

NRA Commissioner Kunihiko Shimazaki said Japan Atomic Power was to blame for the prolonged assessment. Progress at the investigation site, which was supposed to provide important input, was “sluggish,” he said.

The members, including Shimazaki, inspected the premises but basically had to rely on data provided by Japan Atomic Power to reach a conclusion.

Shunji Matsuoka, a Waseda University professor researching nuclear regulations from a social perspective, said the NRA should be given sufficient authority, manpower and financial resources to conduct field surveys on its own, not just to gain access to data it needs, but also to improve expertise.

“The NRA secretariat still does not have enough human resources with technical knowledge to support the organization’s independence. . . . And simply preparing documents for (outside) experts and asking them to make a decision is unlikely to help improve expertise,” he said.

Meanwhile, another panel member complained about the stress generated by the discussions, which created public suspense because the conclusion they reached would alter the fate of reactor 2.

“There were various pressures once the mission started. . . . I often got depressed because of criticism and negative attacks, even though I was doing my best,” said Takahiro Miyauchi, a professor at Chiba University.

No one may be willing to join the panel in the future unless some improvement is seen in the way things are managed, he suggested.

The NRA itself also appears to have made some oversights.

The watchdog failed to carefully plan what kind of steps should be taken to reach a conclusion on an assessment.

Instead, it abruptly decided to have the panel’s assessment checked by other experts after Japan Atomic Power said the procedure was unfair.

But Waseda’s Matsuoka defended the NRA, saying the regulator’s perceived immaturity should be tolerated, given that the authority is still in a “trial and error process” after being established last September. The regulatory body it replaced was widely criticized for being to close to the central government and other staunch promoters of nuclear power.

Matsuoka added that coming up with scientific assessments is not the end of the NRA’s job. He said communicating its views to the public is also crucial.

“There will always be some experts who cannot share the NRA’s view because there is no such thing as 100 percent certainty in science,” Matsuoka said. “So I think what is important for the NRA is to explain sufficiently to the public why it has reached a certain decision.”