EDITORIAL | Is NRA in a Rush on Tsuruga Power Station No 2 to Shut It Down?

Japan's Nuclear Regulatory Authority has been carrying out a mandatory safety review of the No.2 reactor at the Tsuruga Nuclear Power Station in Fukui Prefecture. Operations at the 165 MWe Japan Atomic Power Company (JAPC) facility have been suspended as it undergoes period inspection. However, the NRA may be setting up to deliver a final report unfavorable to JAPC's plans for restarting the reactor.

At a review meeting at the end of May, the NRA announced that it was "difficult to deny" a fault located in the vicinity of the reactor is active. It was a roundabout way of declaring that it considered the fault in question to be currently active.

Furthermore, the NRA is expected to release its conclusions concerning the physical "continuity" of this fault. That is expected sometime in July. If it concludes that it is "difficult to deny continuity," then a combination of the "activeness" and "continuity" factors would essentially mean that it thinks an active fault runs directly under the No.2 reactor.

Tsuruga No 2 Should Not Be Decommissioned

Should that happen, the Tsuruga No 2 reactor would be considered non-compliant with the new regulatory standards. In effect, it would abort plans to restart that reactor. That is because the new nuclear regulatory standards do not allow the construction of reactors directly above an active fault. The standards were adopted after the March 2011 accident at the Tokyo Electric Power Co's Fukushima Daiichi nuclear power station.

Currently, ongoing discussions at the NRA's review meetings seem to point in that direction. Is their ultimate goal to force decommissioning of the reactor? We cannot stand by in silence as this is happening.

The focus is on a reverse fault. Referred to as a "K," it runs beneath the Tsuruga station site to the north of the No 2 reactor. JAPC has dug a mammoth exploratory trench, 70 meters long by 70 meters wide and 45 meters deep. It says it is closely examining the geological strata and earthquake faults in the area. Meanwhile, over the past 12 years, the company has sought to prove that the "K" fault has not impacted the No 2 reactor.

Accumulated Evidence

As a result of its many years of careful investigation, JAPC has accumulated considerable scientific evidence supporting its claim that the cracks in the mass of rock running beneath Unit 2 do not constitute an active fault. However, some data is lacking. That is due to land erosion caused by construction work about 40 years ago and other reasons.

We get the distinct impression that the NRA and its secretariat have latched onto this gap in data. They seem set to justify the rejection of JAPC's position and declare that the "possibility of activeness cannot be entirely denied." In other words, they want to require proof of what inherently cannot be proven. However, it is extremely inappropriate to apply this rhetorical device known as the "devil's proof" (probatio diabolica) to the world of engineering.

NRA's conclusion concerning the "K" fault is expected to be released by the end of July. Regardless of its outcome, JAPC should continue its meticulous investigations. Why does the NRA seem in such a hurry to bring the curtain down on its review of the situation? We can't help concluding that its strategy here is to deprive JAPC of the time it requires to prepare a rebuttal.

*Tsuruga Port in Fukui Prefecture. (Photo provided by the Tsuruga Port Office of the Hokuriku Regional Development Bureau)*

What Happens if Restarting is Blocked?

What if the NRA finds that the Tsuruga No 2 reactor is not in compliance with the new regulatory criteria? For one, that would not directly lead to scrapping the reactor. However, there is no doubt that it would cause JAPC financial difficulties. It would also mark the first time that a nuclear power plant hoping to restart had failed the required inspection.

However, the NRA's role is to enhance safety in the use of nuclear power. It is counter to the NRA's job to prevent the restarting of existing facilities. Nonetheless, only 12 nuclear power plants have been restarted since the Great East Japan Earthquake of 2011.

Many experts have lamented that the NRA seems more concerned with "stopping nuclear power operations than ensuring their safety." Far from listening to these outside voices, the NRA could through its review force the closure of the Tsuruga No 2 reactor.

NRA's Great Rush

The question is why is the NRA rushing to release its conclusions by the end of July. If the justification offered is that the review has already been going on for 12 years, there would be no great difference in waiting. For example, why not give JAPC the additional six months it is asking for to follow up the NRA's investigation?

Insisting on an end-of-July deadline may engender suspicion that the NRA commissioners currently reviewing the fault issue are rushing the decision before their terms expire in September. Moreover, if they hand down their decision in late July, the Diet will be in recess. Therefore, these NRA officials would not have to answer questions from Diet members.

And if the findings are released on the eve of the opening ceremony for the Paris Olympics, they are not likely to garner much interest among the public. It would be outrageous for the schedule to be manipulated in such a fashion.

Japan's Energy Security

We should never forget that nuclear energy remains an indispensable source of energy for resource-poor Japan. Furthermore, the government has identified the maximum possible use of nuclear power as a core component of its Green Transformation (GX) basic policy. It aims to achieve both economic growth and decarbonization.

Amidst an increasingly tense international situation, the importance of energy security is growing. Meanwhile, the spread of artificial intelligence (AI) is expected to lead to a significantly increased demand for electricity.

Although the NRA has been granted independence, it is still an administrative agency of the nation. Its mission is to enhance the safety of nuclear energy operations. If it is determined to terminate nuclear power plants under the guise of increasing safety, then it is mistaking "dogmatism" and "self-righteousness" for "independence." Moreover, it is perverting the whole rationale for the NRA's existence.

The NRA should not wind up the safety review of the Tsuruga Unit 2 reactor prematurely. We expect NRA Chairman Shinsuke Yamanaka to show leadership in that regard. And Prime Minister Fumio Kishida and his Cabinet should not stand idly by either.

(Read the editorial in Japanese.)

Author: Editorial Board, The Sankei Shimbun