The EFTTRA-T4 experiment on americium transmutation

In the EFTTRA-T4 experiment the irradiation behaviour of a target containing americium dispersed in MgAl2O4 was studied. Pellets containing 10–12 wt% 241Am were fabricated by the infiltration method. However, it was found that the americium, intended to be present as AmO2−x, formed a compound, probably AmAlO3, during sintering. The T4 target was irradiated in the High Flux Reactor (HFR) Petten from August 1996 to January 1998 (358.4 fpdʹs). Post-test burn-up calculations indicated that the 241Am concentration is reduced to 4% of the initial value at the end of the irradiation. The fraction of the initial americium atoms that were fissioned is 28%. Non-destructive and destructive examinations of the target indicated that swelling of the target pellets occurred. This is attributed to accumulation of helium, produced by alpha decay of 242Cm that occurs in the transmutation scheme of 241Am.