Deuterium permeation properties of beta-irradiated and unirradiated poly(vinyl alcohol) and polystyrene shells

We measured the permeability of IF fuel shells made of poly (vinyl alcohol) (PVA) and polystyrene (PS) with deutrium. Activation energies were determined using permeability coefficients measured over the temperature range 25 to 1000C for PVA, and minus 100 to 200C for PS shells. We then exposed this same batch of shells to intense beta-irradiation from tritium and repeated the permeation measurements. Comparing permeabilities of the same shells before and after irradiation, we obtained a measure of the effect beta-irradiation has on fuel retention characteristics of the polymers. Our results show that irradiation does change the permeability of PVA, while the permeability of irradiated PS is relatively unchanged. 3 refs., 6 figs