Abstract
When the dry low-level radioactive wastes(LLW) including even slightly aluminum are solidified with mortar, it is necessary to evaluate the effect of gas evolution from aluminum on the performance of solidified dry LLW. Experiments were conducted to measure the opening ratios in the waste packages which were prepared by using simulated dry LLW and several kinds of mortars. The decrease of opening ratio due to gas evolution in mortar was observed in the case of aluminum being in contact with carbon steel. Under the above condition, the relationship between Fe/Al surface area ratio and the opening ratio in mortar was consistent with that between Fe/Al surface area ratio and the amount of gas evolution in the simulated mortar environment, namely, in the solution equilibrated with mortar. Furthermore, authors proposed an estimation method of opening ratio in waste package by using measured data such as physical properties of mortar and gas evolution rate from aluminum. The opening ratios produced from gas evolution in several kinds of mortars were estimated by the proposed method. Estimated values of opening ratios were less than 1% even under the most conservative condition, including aluminum being not in contact with carbon steel.
