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% Am-241 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 fpd's). Post-test burn-up calculations indicated that the Am-241 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 Cm-242 that occurs in the transmutation scheme of Am-241. (C) 2000 Elsevier Science B.V. All rights reserved.