Copper Container Corrosion Model for the In-Room Emplacement of Used CANDU Fuel(Modele de Corrosion des Conteneurs en Cuivre pour le Stockage en Chambres du Combustible CANDU Irradie)

摘要

Copper containers in a Canadian nuclear fuel waste disposal vault are expected toundergo uniform corrosion and, possibly, pitting. The corrosion behavior of the containers will be dictated by the evolution of environmental conditions within disposal vault. The environment will evolve from an early warm, oxidizing phase, during which fast uniform corrosion and pitting may occur, to an indefinite period of cool, anoxic conditions, during which the container will only be susceptible to slow uniform corrosion. The results of corrosion and electrochemical studies of the uniform corrosion of CU in O2-containing CI solutions are discussed and a detailed reaction mechanisms presented. The relevant literature on pitting corrosion is briefly reviewed and models for the prediction of pit depth discussed. The potential for microbially influenced corrosion and stress-corrosion cracking is discussed, as are vapor-phase corrosion and the effects of gamma-radiation. The use of natural analogues for justifying long-term corrosion predictions is also considered. Finally, a model for uniform corrosion and pitting is presented and container lifetimes predicted.