A nuclear regulator has said that operators of European atomic plants must plan for the possibility that they may have chosen the wrong reactor design.

Philippe Jamet told an industry seminar in Brussels that the accident at Fukushima in Japan last year had changed the safety mindset.

“The important lesson from Fukushima is that you might be wrong on your design basis,” he said. “So you need an extra layer [of safety precautions] for when you are wrong on how your design basis copes with unpredictable external events.”

Following the Fukushima disaster, the EU carried out stress checks on all 143 of its nuclear installations, co-ordinated by European regulator Ensreg.

Initial checks were followed by peer reviews by international teams, and Ensreg delivered its final peer review report to the European Commission in April.