Electricité de France (EdF) has begun a major maintenance outage at its Tricastin 3 unit, which it says will be the most extensive ever performed at any French nuclear plant in terms of volume of work.

The four-and-a-half month outage will cost more than r100 million and involve the replacement of three steam generators and three low-pressure turbine rotors. Other work will include testing the water tightness of the primary circuit, inspecting welds in the reactor vessel and testing the reactor containment. EdF said the length of the outage was “exceptional” but necessary in view of the “nature and importance of the maintenance operations and control programmes” being carried out. Additional safety reinforcement measures will also be put in place.

French nuclear power units have no pre-ordained operating lifetime limits, but are required to undergo a particularly stringent review once every 10 years. EdF must also demonstrate to the national safety authority, the DSIN, that the work carried out during outages has paved the way for a further ten years of safe operation.