Japan's Nuclear Regulation Authority (NRA) announced Wednesday it is suspending the relicensing process for two reactors at the Hamaoka nuclear power plant after Chubu Electric Power Co., the plant's operator, admitted to fabricating seismic hazard data. The revelation raises concerns about the integrity of safety assessments as Japan slowly reactivates its nuclear power plants following the 2011 Fukushima Daiichi disaster.

The NRA was alerted to the potential data manipulation by a whistleblower in February 2023, but the issue only became public this week when regulators halted an evaluation process that could have allowed a reactor restart at Hamaoka. Chubu Electric Power Co. subsequently issued a press release detailing how the company manipulated the seismic safety data. According to an English translation of the release, the company appears to have scaled up ground motion to evaluate seismic risks.

The Hamaoka plant's location on the coast near an active subduction fault, similar to the Fukushima Daiichi plant, amplifies the gravity of the situation. The Fukushima disaster, triggered by a massive earthquake and tsunami, led to a nationwide shutdown of nuclear power plants and a reassessment of safety standards. The current scandal undermines public trust in the nuclear industry and the regulatory oversight designed to prevent future accidents.

The use of AI in seismic risk assessment is becoming increasingly prevalent. AI algorithms can analyze vast amounts of geological data, including historical earthquake records and fault line characteristics, to create more accurate models of potential ground motion. However, the Hamaoka case highlights the critical importance of data integrity, regardless of the analytical tools employed. If the underlying data is flawed or manipulated, even the most sophisticated AI system will produce unreliable results.

The incident raises questions about the effectiveness of regulatory oversight and the potential for similar data manipulation at other nuclear facilities. The NRA is expected to conduct a thorough investigation into the matter and implement measures to prevent future occurrences. The suspension of the relicensing process for the Hamaoka reactors will remain in effect until the NRA is satisfied that Chubu Electric Power Co. has addressed the data integrity issues and implemented robust safeguards. The future of nuclear power in Japan hinges on restoring public confidence and ensuring the highest standards of safety and transparency.