Static and dynamic tests for the chemical durability of nuclear waste glass

Abstract

Different types of durability tests are analyzed in terms of their relevance to flow conditions and their ability to predict the long-term corrosion rates under the most adverse flow and dilution conditions. Results obtained by applying various types of tests to glasses developed for use in nuclear waste fixation show that carefully controlled flow tests are most useful in modelling the entire dependence of corrosion on flow rates and surface-to-volume ratios. Constant-medium tests carried out in buffered media and with limited silica accumulation (up to 10 mg/ L) are easier to perform and are useful both in predicting worst-risk corrosion rates and in supplying data for modelling repository situations. Results of independent constant-medium tests, stagnant tests, and flow tests on simulated nuclear waste glasses show excellent agreement in the determination of the maximum corrosion rates.