Inorganic Polymers as safety material for nuclear industry

Abstract

Alkali Activated Materials (AAMs) are interesting alternative binder materials to Ordinary Portland Cement (OPC) for application in nuclear safety structures and radioactive waste management. AAMs have a low Ca content which enables the addition of fluorine to reduce the hydrogen gass production for wastes containing reactive metals. Moreover, neutron activation of Ca to 41Ca can be avoided with Ca-free precursors. Iron-rich AAMs were proven to have a similar gamma shielding capacity to basalt-magnetite concretes. Since dehydration in AAMs is limited, better neutron shielding capacities for AAMs can be obtained compared to aged concrete. The absence of portlandite, the low water content and the high alkalinity, make AAMs interesting candidates for the conditioning of certain radioactive waste streams.

The effect of gamma radiation on Fe-rich inorganic polymers in the very-early age was investigated. Mechanical and microstructural properties were identified. It was found that the compressive strength increased due to gamma irradiation. Also, a decrease in Young’s-modulus and a decrease in creep was observed. The decrease in porosity and the radiation induced oxidation can explain the observations.