IFPE/CONTACT REV.1, PWR Fuel Performance Tests Siloe Reactor

Description: The CONTACT series of experiments was a programme of in-pile tests conducted in the Siloe reactor, Grenoble. They were short rods of Zr-4 clad UO2 pellets of typical PWR 17x17 design. The purpose of the experiments was to improve the understanding of fuel rod performance. Two designs of fuel pellet were investigated in separate tandem rods. The experiments described here are those employing only standard commercial quality Framatome pellets. Each rod contained 5 enriched pellets with an Al2O3 insulator pellet at each end of the column. The plenum at the top of the rod contained an Inconel spring to mechanically restrain the column. The rods were irradiated in a pressurized water loop whose location could be moved during irradiation in order to maintain the desired power level in the experimental rod. In this way, near constant power was maintained throughout each experiment. CONTACT 1 was irradiated between October 1978 and July 1980 at a constant power level close to 40 kW/m to a discharge burn-up of ∼22 MWd/kgU. During irradiation, the internal pressure was 1 MPa of helium. CONTACT 2 was irradiated between January 1979 and November 1979 at a constant power of ∼25 kW/m and an internal helium pressure between 0.1-0.2 MPa. The rod was discharged early because of a failure at a burn-up of ∼5.5 MWd/kgU and replaced with the identical design rod CONTACT 2bis. CONTACT 2bis commenced irradiation in April 1980 and was discharged in June 1981 at a burn-up of 12.4 MWd/kgU after the accidental introduction of a quantity of air into the water loop. During irradiation the power was maintained at ∼25 kW/m and the internal pressure was 0.1-0.2 MPa helium