The cause of the damage to several fuel rods at Cattenom 3 is still unknown, requiring the unit to remain offline for several more weeks (see NEI June 2001, p6). The French nuclear safety authority (DSIN) has ordered Electricité de France to fulfil new conditions for fuel reloading, including launching a programme to examine the damaged rods to get to the root of the problem.
Ninety-two damaged rods were discovered during a refueling and 10-year inspection outage. The primary circuit was also highly contaminated. EdF and Framatome have proposed fretting due to rod vibration, but have not been able to identify the origin of the vibration.