No abstract

Within the frame of the International Source Term Program, VERDON program aims at quantifying the source term of radioactive materials in case of a hypothetical severe accident in a Light Water Reactor (LWR). Tests were performed in a new experimental laboratory (VERDON) built in the LECA-STAR facility (CEA Cadarache). The VERDON-1 test was devoted to the study of a high burn-up UO 2 fuel and FP release at very high temperature (≈ 2600°C) under reducing atmosphere. Post-test qualitative and quantitative characterizations of the VERDON-1 sample led to the proposal of a scenario explaining what might have occurred during the experimental sequence. Hence the fuel and the cladding might have interacted leading to the melt of UO 2-ZrO 2 system. Besides no relocation was observed during the test, it might have been imminent.