A spokesperson for the Office for Nuclear Regulation (ONR) said: "We regulate in an enabling manner, working constructively with EDF on their plans to extend the life of their nuclear plants by reviewing technical and safety case considerations while ensuring it achieves the required standards of safety and security in the most practical way.
“Although their plant life extension decisions do not need formal regulatory assessment or permissioning by ONR, it is a requirement of the site licence that operations be carried out under a valid safety case. Our regulatory activity evaluates the adequacy of both the safety case, the security plan and their implementation.
“Safety cases at Sizewell B are likely to require updating to achieve EDF’s stated ambition, together with investment in plant to sustain equipment reliability, all while ensuring that the necessary people and skills are available throughout the extended lifetime. Security plans also require updating to ensure they remain robust and responsive to the evolving security landscape.
“The ongoing safety and security of operations at any nuclear site must be fully demonstrated to us as part of ongoing regulation which will be informed by our extensive, proportionate and targeted inspection and assessment regime."