Estimation of trace element concentration and neutron induced radioactivity in rock samples of different geological compositions for neutron shielding

Abstract

Rock samples of different geological compositions intended for use as coarse aggregates (CA)  in self-compacting concrete (SCC)  have been analysed for concentrations of the elements Sc, Co, Fe, Cs, Ta  Eu. These elements give rise to long-lived radioactivity in concrete used as neutron shields, consequent to long-term neutron irradiation. This study has been performed on all the eleven samples of different geological compositions to compare their low-activation characteristics and determine their suitability for developing SCC based neutron shielding. The collected samples quartzite rock exhibits lowest induced activity on neutron irradiation. But it failed the fresh property tests for SCC as observed in an earlier study (Pai B H V, et al.,) [communicated to Journal of The Institution of Engineers (India): Series A]. Among the CA samples suitable for SCC composition), dolomite rock produces lowest activity for all the isotopes studied. Concretes having low radioactivation  properties will facilitate mitigating the prevailing radiological waste management problems during decommissioning of nuclear facilities.