In the event that a licence to operate the nuclear power plant is granted for a term longer than ten years the licensee shall carry out a periodic safety review.

The renewal of the operating licence always involves the same assessment than a periodic safety review of the facility. STUK assess in the periodic safety review the condition of the facility, paying particular attention to the ageing management of the  components, systems and structures. In STUK's assessment, the licensee’s organizational capabilities to continue safe operation of the facility is also assessed.