Photo/Illutration The No. 2 reactor at Japan Atomic Power Co.’s Tsuruga nuclear power plant in Tsuruga, Fukui Prefecture (Asahi Shimbun file photo)

The government’s Nuclear Regulation Authority has decided to suspend safety screening for restarting the No. 2 reactor at the Tsuruga nuclear power plant in Fukui Prefecture in response to a finding that operator Japan Atomic Power Co. (JAPC) had altered survey records.

There is a need to make clear how and why the misbehavior, which fundamentally undermines the screening process, took place and who bears the responsibility. There should also be a rethink of the future course of JAPC, which appears anything but certain.

A large number of geologically active fault lines lie beneath areas around Wakasa Bay, the site of the Tsuruga nuclear plant. An NRA panel of experts pointed out in 2012 that a fault line running directly beneath its No. 2 reactor could be active.

A nuclear reactor located directly above an active fault is not allowed to go online and has no choice but to be decommissioned. JAPC argued, however, that the fault line is not active and filed an application in 2015 for having the reactor screened for a prospective restart.

It was found, however, that documents the company had submitted for an evaluation process contained more than 1,000 errors. It also came to light, during a 2020 meeting for the safety screening, that geological data had been rewritten.

The changes had been made to records of observation of samples collected from geological formations, which represent the very foundation of the scientific survey. If no trust can be placed in that data, there will simply be no meaning whatsoever in discussing the safety of the nuclear reactor.

Similar rewriting of raw data is something strictly warned against in scientific observations or experiments.

JAPC officials have argued the changes were made at the discretion of rank-and-file workers who, in their words, “were unaware that they should not have done so.” The officials have also explained that the workers’ superiors, including an executive in charge of the matter, were in the dark about what was occurring. 

At stake here, however, is the question of management and organizational discipline, including the education of engineers. The NRA was right in rigorously condemning the practice and suspending the screening process.

In addition, some of the alterations, of which there were a total of 80, involved modification of wording to deny the possibility that the fault line had moved in the past--a key piece of information that has a bearing on whether the reactor should be allowed to go back online.

JAPC would not be entitled to operate a nuclear reactor if it had intentionally engaged in the misconduct to turn the screening process to its benefit.

It is impossible to have all submitted documents substantiated in safety screening for nuclear reactors, so regulators have no choice but to trust the goodwill of operators.

Arbitrary data manipulation tarnishes the reliability of screening results, including for other nuclear reactors. JAPC should disclose all relevant documents and materials as well as details of the development.

JAPC, which specializes in operation of nuclear reactors, maintained its business by selling electric power to major regional utilities.

Decisions have been made to scrap two of JAPC’s four nuclear reactors. The company’s survival now hinges on the remaining two--the No. 2 reactor of the Tsuruga plant, and the single-reactor Tokai No. 2 nuclear plant in Ibaraki Prefecture.

The Mito District Court, however, in March ordered a suspension of the Tokai No. 2 plant, which JAPC has been preparing for a restart, for reasons of flaws in emergency evacuation plans.

None of JAPC’s nuclear reactors has been reactivated following shutdowns after the Great East Japan Earthquake and tsunami triggered the Fukushima nuclear disaster in 2011. JAPC has been kept afloat by “basic rates” major regional utilities pay annually based on agreements.

There should, however, be a fresh round of discussions on the company’s future, including on the wisdom of keeping it in business. The utilities that hold stakes in JAPC would be too irresponsible if they were to continue to leave the question unaddressed.

The government should also take an active part in addressing the problem, which is the consequence of Japan’s long-standing nuclear power policy.

--The Asahi Shimbun, Aug. 29