A spokesperson for the Office for Nuclear Regulation (ONR) said: "We note EDF's announcement of its intention to extend the operating life of Heysham 1 and Hartlepool power stations.
“As the independent nuclear regulator, we are conscious of the nation's energy challenges and government aspirations to achieve net zero.
"We will always try to regulate in an enabling manner, working constructively with EDF on their plans to extend the life of their nuclear plants, 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.
“Several safety cases at each station are likely to require updating to achieve EDF’s stated ambitions, together with investment in plant to sustain equipment reliability, all while ensuring that the necessary people and skills are available.
“The ongoing safety of operations at any nuclear site must be fully demonstrated to us as part of ongoing regulation which will be informed by our extensive inspection and assessment regime."