Heavy ion irradiation of UMo7/Al fuel: methodological approach

Heavy ion irradiation with an 80 MeV 127I beam is used as out-of-pile technique in order to simulate the in-pile growth of the UMo/Al interaction layer. However, irradiation conditions used in 2005-2006 do not fully allow reproducing the characteristics of the in-pile interaction layer (IL). In this paper, a study focussing on the influence of the different irradiation parameters on the thickness, nature and composition of the interaction layer, is presented. The results are in excellent agreement with SRIM calculations. The interest for heavy ion irradiation is supported by the evidence for a phase transition γ-UMo(a) + α-U → γ-UMo(b) as observed in pile (in this reaction, γ-UMo(a) has a higher Mo content than γ-UMo (b)). (author)