Demonstration Experiment on Durability of Concrete Containers Storing Incineration Fly Ash Contaminated with Radionuclides and Technical Requirements of such Containers
Concrete Journal, Vol.56, No.4, Apr. 2018
- Synopsis
- Concrete containers have been developed to safely store a significant amount of waste contaminated by radioactive cesium generated in nuclear power plant accidents. In this study, assuming the most severe conditions for concrete containers, hydrated incineration fly ash was put in a full-sized container, and the container was exposed to outdoor weather for about two years to evaluate the durability of concrete containers. It is found that in ordinary concrete, calcium oxychloride is formed by the reaction of CaCl2, in incineration fly ash and Ca(OH)2 in hardened cement pastes, leading to a relatively early onset of mortar scaling and delamination. On the other hand, in the case of fly ash concrete, ingress of chloride ion and calcium oxychloride formation are inhibited. Thus, use of fly ash concrete is effective concerning material durability. The technical requirements of concrete containers are summarized based on the results of the exposure tests.
- Keywords:
- concrete container, durability, incineration fly ash, calcium chloride (CaCl2), calcium oxychloride (3CaO·CaCl2·15H2O), fly ash
