Other Press Conferences
Other Press Conferences
Press Conference by President Hayashi Regarding Inappropriate Handling of Base Earthquake Motion Development in the New Regulatory Standards Compliance Review for Hamaoka Nuclear Power Station
January 05, 2026
Chubu Electric Power Co., Inc.
- It has been confirmed that there is suspicion of inappropriate handling regarding the development of the base earthquake motion for the new regulatory standards compliance review of the Hamaoka Nuclear Power Station.
Background
- First, we will explain the background to this matter.
- Our company is currently undergoing a review by the Nuclear Regulation Authority (NRA) to assess the compliance of Units 3 and 4 of the Hamaoka Nuclear Power Plant with the new regulatory standards.
- In May 2025, we were notified by the Nuclear Regulation Authority (NRA) to investigate our methodology for establishing the design basis earthquake motion.
- Following this, since May 2025, we have provided explanations to the NRA during meetings regarding the evaluation methods and other aspects of establishing the design basis earthquake motion.
- Furthermore, in October, the Nuclear Regulation Authority requested the submission of evidence materials, including reports prepared by our contractor.
- Subsequently, upon reviewing the reports and materials internally, we confirmed suspicions that the selection of representative waves for seismic motion evaluation at the Hamaoka Nuclear Power Station was conducted using methods differing from those explained by our company during the review meeting in January 2019, or through intentional methods.
- We view this matter as extremely serious, as it could significantly impact the review process and potentially undermine the trust in our nuclear power business held by stakeholders, including the local community, thereby threatening the very foundation of this business.
- We sincerely and deeply apologize for causing such an incident and for the significant concern and inconvenience this has caused our stakeholders, including the local community.
- We are truly sorry.
- Next, we will explain how the methods we actually implemented differed from what we explained at the review meeting.
- In January 2019, during the review meeting, we explained that for seismic motion evaluation based on the review guide established by the Nuclear Regulation Authority, we "calculated `2020 sets of seismic motions' with different calculation conditions and selected the wave closest to their average as the representative wave."
- In contrast, we actually selected representative waves using the following two methods:
- The first method involved pre-creating multiple sets of "20 sets of seismic motions and their representative waves" instead of just one set, and then selecting "the representative wave for one set" from among these pre-created sets.
- We have confirmed that this method was implemented prior to 2018, although the exact timing is unclear.
- The second method involved intentionally selecting a wave "that was not the closest to the average" as the representative wave. Subsequently, the remaining 19 sets were selected so that the representative wave would be closest to the average of the 20 sets, thereby creating a set of "20 sets of seismic motions and their representative waves."
- We have confirmed this method was implemented around 2018 or later.
- Last December, it was discovered that representative waves were being selected using these two methods. We initiated an internal investigation and reported this to the Nuclear Regulation Authority.
- Following the inappropriate procurement case disclosed last November, the occurrence of this incident has made us keenly aware that it calls into question our very qualification as a nuclear power operator managing the Hamaoka Nuclear Power Station.
- Today, our Board of Directors resolved to establish an independent third-party committee composed solely of external experts to ensure transparency and fairness in investigating the facts and causes of this matter, and to consider measures to prevent recurrence. We will fully cooperate with the investigation conducted by this third-party committee.
- Separate from the third-party committee, under a meeting body led by myself, we will examine issues such as organizational culture in light of the successive discovery of inappropriate incidents, consider measures to prevent recurrence, and confirm the impact on our business and plans.
- Going forward, we will respond appropriately based on the instructions and guidance of the regulatory authorities and the Nuclear Regulation Authority.
- We once again offer our deepest and most sincere apologies for the occurrence of these incidents.