1. The new target for the completion of RRP

Considering the time required for the conformity review for Design and Construction Plans, the construction works and the inspections, JNFL has set the new target of the completion of RRP as by the end of FY2026.

(1) Conformity Review for Design and Construction Plans

• JNFL revised the initial ground model for seismic design to the new basic ground model which utilized the latest data because the initial ground model did not fully utilize the latest data adherence to the previously approved contents.
• For the seismic evaluation JNFL considered that the result of previous evaluation could explain the conformity to the technical design standards even if the ground model is revised. However, in analyzing the actual floor shaking of the buildings, JNFL decided to re-evaluate all seismic design items (buildings, equipment, piping, etc.) by using the new basic ground model, in order to explain conformity to the standards.
• For the structural design, etc. JNFL thought that JNFL could explain the conformity to the technical design standards on the assumption that it was comprehensively organized, but there are some cases JNFL could not explain the validity of design concept. Therefore, JNFL decided to self-review all articles, going back to the design concept, in order to explain the conformity to the standards.
• Based on the above, at the conformity review meeting on August 26, 2024, JNFL indicated that the explanation would continue until November 2025. JNFL estimates the conformity reviews would last until March 2026, taking into account the subsequent amendments.

(2) Construction works

• Additional construction works for the tornado, fire and severe accident countermeasures are required if part of the initial design concept is revised to explain the conformity to the technical design standards. However, JNFL estimates at present these additional construction works will not affect the completion of RRP.
• Furthermore, other additional construction works might be expected as a result of the progress of the conformity reviews. However, JNFL will proceed with the additional construction works in a manner that will not affect the completion of RRP.
• JNFL considered the construction works to be carried out after the approval of Design and Construction Plans, such as the works to connect new equipment to existing equipment, the works to switch the route of sea release system, etc., together with inspections.

(3) Inspections

• JNFL scrutinized the time required for inspections to be carried out after approval—4 to 7 months— and, based on the latest inspections results of electric power companies, JNFL estimates that 9 months would be required for inspections after approval, taking into account the time required for training to cope with severe accidents, etc.

Schedule for Completion and Operation of RRP

2. The new target for the completion of J-MOX

Considering the time required for the conformity review for Design and Construction Plans, construction works and inspections, JNFL has set the new target of the completion of J-MOX as by the end of FY2027.

(1) Conformity Review for Design and Construction Plans

• Since it was the first conformity review for Design and Construction Plans of J-MOX, JNFL comprehensively organized the items to be explained such as structural design, etc., in terms of relevance and consistency with RRP. So it took time to reach a common understanding with the NRA about the explanation policy. The conformity review is still ongoing, JNFL estimates the conformity reviews would last until May 2026, taking into account the time required for the explanation on and after the third application, in addition to October 2024 as indicated in the explanation plan for the second application (presented at the conformity review meeting on August 26, 2024).

(2) Construction works and Inspections

• JNFL estimates that construction works and inspections would take approximately one year after the completion of RRP, taking into account the time required for construction after approval of the second application, the time required for connection to RRP after completion of RRP and the time required for inspections and training to cope with severe accidents, etc.

Schedule for Completion and Operation of J-MOX

3. Future actions

JNFL had difficulty explaining in an organized way to the NRA because there was insufficient progress management due to the lack of an overall plan of explanation at the conformity reviews and the lack of the identification of technical issues owing to adherence to the previously approved contents and past designs. Based on these reflections, JNFL has strengthened its structure since last year by accepting a number of people with experience in handling conformity reviews from electric power companies and manufacturers, establishing a steering team and assigning a project manager.
Thus, JNFL became able to clarify the remaining technical issues, including a review of ground model and design concept and presented an “Overall Plan of Explanation” at the conformity review meeting on August 26, 2024.
In order to address the remaining technical issues in a precise and organized way, JNFL will take the following actions:

1. JNFL will continue working with the steering team and the project manager to precisely identify issues and points raised by the NRA during the conformity reviews and inspections, and to enhance the quality of explanations.
2. JNFL will thoroughly manage the progress by having a common understanding with the NRA on the schedule of the conformity reviews, etc., in accordance with the “Overall Plan of Explanation” presented on August 26, 2024, and reviewing it as necessary.

With the continued support from the whole industry, including electric power companies and manufacturers, JNFL will tackle to achieve the new target for the completion together with all the Japanese relevant entities with top priority on safety.