Decision and Details
Inappropriate conduct related to the formulation of design-basis ground motions in the review of Hamaoka Nuclear Power Station's compliance with New Regulatory Requirements
To avoid affecting the review and restart schedule, avoid facility impact assessments and construction resulting from individual waves, and resolve difficulties in explaining the matter to the Nuclear Regulation Authority
The report states that the matter could affect the formulation of design-basis ground motions, the restart of Hamaoka Nuclear Power Station, and decisions on facility impact assessments and construction, but does not indicate any monetary impact on earnings.
| Item | Details |
|---|---|
| Matter Covered | Inappropriate conduct related to the formulation of design-basis ground motions in the review of Hamaoka Nuclear Power Station's compliance with New Regulatory Requirements |
| Implementation Date | Conducted from fiscal 2012 through around the time of the Nuclear Regulation Authority's 2025 inquiry, before and after it (details provided for each act) |
| Period Covered | Formulation of design-basis ground motions and responses to the compliance review from fiscal 2012 through 2025 |
| Quantity / scale | Evidence-trail creation method ⑨: 6 cases; evidence-trail creation method ⑩: 58 cases; evidence-trail creation method ⑪: at least 1 case; evidence-trail creation method ⑬: 5 cases; evidence-trail creation method ⑭: 68 cases; total: 225 cases |
| Impact on Business Performance | The report states that the matter could affect the formulation of design-basis ground motions, the restart of Hamaoka Nuclear Power Station, and decisions on facility impact assessments and construction, but does not indicate any monetary impact on earnings. |
| Reason | To avoid affecting the review and restart schedule, avoid facility impact assessments and construction resulting from individual waves, and resolve difficulties in explaining the matter to the Nuclear Regulation Authority |
| Governing Rule | The New Regulatory Requirements, the Recipe, JEAG4601 and other standards are mentioned, but the rule serving as the basis for publication of this investigation report is not disclosed |
| Related previous disclosures | Document 1-1, “Ground-Motion Evaluation of Inland Crustal Earthquakes at Hamaoka Nuclear Power Station (Response to Comments),” from the 624th Meeting on the Review of Compliance with New Regulatory Requirements for Nuclear Power Plants, and materials from the 671st, 685th, 882nd, 1041st and other compliance review meetings |
Items this document does not state (4)
These are items the company does not state in this document. We do not leave them blank, nor fill them in from other sources or by inference.
The reasons the company gives
The company's own explanation, not something inferred from the numbers.The investigation report cites as background the company's desire to avoid affecting the schedule for formulating design-basis ground motions and restarting Hamaoka Nuclear Power Station, avoid assessments of the impact of individual waves on facilities and equipment and any resulting construction, and resolve difficulties in explaining the matter to the Nuclear Regulation Authority.