Effect of curing time on the fraction of Cs137 from cement matrix

To assess the safety of disposal of radioactive waste material in concrete, curing conditions and time of leaching radionuclides 137Cs have been studied. Leaching tests in concrete were carried out in accordance with a method recommended by IAEA [Atomic Energy Review 9 (1971) 195-207]. Curing conditions and curing time prior to commencing the leaching test are critically important in leach studies since the extent of hydration of the cement materials determines how much hydration product develops and whether it is available to block the pore network, thereby reducing leaching. Results presented in this paper are examples of results obtained in a 10-year concrete testing project which will influence the design of the engineer trenches system for future central Serbian radioactive waste storing center