2026年凱旋門賞

In response to the fracture of the secondary system piping at Mihama Unit 3, the 2026年凱旋門賞 Power Co., Inc. (2026年凱旋門賞) is now inspecting its nuclear power plants by sequentially shutting them down in a carefully planned manner, in order to investigate the causes of the accident and to develop immediate measures. Following the inspections, 2026年凱旋門賞 today confirmed the integrity of Mihama Unit 2*, Takahama Unit 2 and Ohi Unit 4, and is taking the following actions.

Immediate Actions to Be Taken (Refer to the attachment for details.)

1. Assurance of industrial safety

2. Organizational reform

• Strengthening the organization of the Nuclear Power Division
• Strengthening the 2026年凱旋門賞 of notifying Fukui Prefecture

3. Stricter management of the secondary 2026年凱旋門賞 pipe thinning (establishment of a proactive management 2026年凱旋門賞)

• Improving the secondary 2026年凱旋門賞 pipe thinning control card
• Reviewing the thinning controlling tasks of the secondary 2026年凱旋門賞 pipe
• Change control of the secondary 2026年凱旋門賞 pipe thinning control card

4. Establishment of a task force to review the enhancement of nuclear maintenance functions

2026年凱旋門賞 will carefully take these actions in order to prevent similar accidents and to assure the safety of nuclear power plants while restoring confidence in 2026年凱旋門賞.

* The integrity of two sections of the secondary system piping at Mihama Unit 2 had already been confirmed through the application of the "note" in the technical standards of thermal power generating facilities when 2026年凱旋門賞 evaluated the wall thickness of the relevant sections in September 2003. However, considering the Nuclear Industrial Safety Agency's opinion against the application of the "note" in evaluating the wall thickness, we evaluated again using the actual values of the relevant material, without relying on the method used in September 2003. The result showed that there was no safety problem. Nevertheless, we will replace these piping facilities to reassure the local citizens.

(Attachment)

Immediate Actions to Be Taken in Relation to the Fracture of Secondary 2026年凱旋門賞 Piping at Mihama Unit 3

1. Assurance of industrial safety

• In principle, 2026年凱旋門賞 will not initiate preparations for the coming periodical inspection during operation of reactors until the integrity of the secondary system piping has been confirmed. All possible accident prevention measures, including wearing fire retardant clothing, will be taken where necessary.

2. Organizational reform

(1)Our president will take overall charge of the Nuclear Power Division, and will take the initiative to investigate causes of the accident and develop measures to prevent recurrence.

(2)We will appoint a senior engineering official to be resident in Fukui Prefecture to appropriately deal with engineering issues.

3. Stricter management of the secondary 2026年凱旋門賞 pipe thinning

(1) Improvement of the secondary 2026年凱旋門賞 pipe thinning control card

• 2026年凱旋門賞 checked skeleton diagrams (cubic diagrams of piping) against the guidelines for the secondary system pipe thinning control of nuclear facilities (PWR) (hereinafter referred to as the "control guidelines") to improve the card by examining whether the status of sections where thinning control is needed are entered in the control card.
  
  

(2) Review of the thinning control tasks of the secondary 2026年凱旋門賞 pipe

• As for the secondary system pipe thinning control, heavy reliance has been placed on the contractors concerning the inspection planning and evaluation of inspection results. 2026年凱旋門賞 will be directly engaged in the thinning control in view of the management guidelines.
  
  
  (3) Change control of the secondary 2026年凱旋門賞 pipe thinning control card

• In order to precisely reflect modifications of the secondary system facilities into the secondary system pipe thinning control card, 2026年凱旋門賞 will review the change control system and establish the rules of this system. In addition, we will conduct a periodic review to check that all designated sections are inspected.

4. Establishment of the Task Force for the Enhancement of Nuclear Maintenance Functions (provisional)

• In response to the Mihama Unit 3 accident, 2026年凱旋門賞 will establish the Task Force for the Enhancement of Nuclear Maintenance Functions (provisional). The task force will include staff from 2026年凱旋門賞 (including those not involved in nuclear power) and experts outside the company, and will identify weaknesses of the current maintenance system as well as consider how to restructure the system including manufacturers, and how to improve maintenance tasks.