PROMOX: The French R and D programme on MOX fuel

To improve the knowledge of mixed oxide fuel rods behaviour, two prototype assemblies have been irradiated in the fourth core of the CAP reactor (Chaudiere Avancee Prototype) in Cadarache. The irradiation campaign started on the 29th of September 1985 and ended on the 2nd of July 1987, reaching 419 effective full power days, without any rod failure. The average burn-up of the MOX rods is evaluated at 20 GWd/tM, which is roughly equivalent to two commercial reactor cycles. Moreover, the reactor was operated under load following and frequency control mode. As a consequence, the MOX rods have undergone power cycles similar to those in an EDF commercial reactor. After irradiation, both assemblies were dismantled in the reactor handling and storage pool, and rods were shipped to CEN Saclay for post-irradiation examinations. This paper presents some preliminary results obtained on six MOX fuel rods examined in the hot cells of the LECI (Laboratoire d'Etude du Combustible Irradie). (author). 6 refs, 5 figs