Geopolymers from fly ash and their gamma irradiation

In order to assess the suitability of geopolymers produced from fly ash for use in nuclear waste encapsulation, their behaviour when exposed to gamma radiation has been examined. Irradiation (400 KGy at 4 kGy/h) was found to have had minimal effect on the porosity of bulk samples. Radiolytic hydrogen production from the pore water exhibited a dose rate effect (9 kGy/h up to 280 kGy and 24 kGy/h up to 700 kGy). An effect of surface area was observed with a decrease in hydrogen production corresponding to a decrease in surface area; the effect of pore chemistry was not ruled out.