An overview of the Canadian corrosion program for the long-term management of nuclear waste

David S Hall,Peter G Keech

doi:10.1080/1478422x.2016.1275419

Abstract

ABSTRACTThe Nuclear Waste Management Organization (NWMO) has developed a comprehensive Proof Test Plan to evaluate the feasibility and safety of its deep geological repository solution for nuclear waste. This work plan includes many active research programs to build confidence in the Canadian used nuclear fuel container design, a copper-coated steel vessel that is optimised for the CANDU waste form. Ongoing research within the Proof Test Plan includes several programs to evaluate the possible extent of damage that may be caused by various corrosion mechanisms: the anoxic corrosion of copper in pure water, concentrated chloride solutions, and in the presence of sulphide; a comparison of the corrosion behaviour of copper coatings on steel with wrought copper; the localised corrosion and surface roughening of copper; the γ-radiolysis-induced corrosion of copper; the galvanic corrosion of through-coating defects; and the localised corrosion of the internal steel weld region.This paper is part of a supplement on the 6th International Workshop on Long-Term Prediction of Corrosion Damage in Nuclear Waste Systems.

Highlights

The Nuclear Waste Management Organization (NWMO) was formed in 2002 to manage the long-term care of Canada’s used nuclear fuel [1]
The choice of copper as a corrosionresistant material was originally based on its thermodynamic stability under predicted deep geological repository (DGR) conditions and is supported by decades of corrosion research and by examples of archaeological and natural copper that have remained intact in the earth for hundreds/thousands or millions/billions of years, respectively [3]
Whereas early waste container predictions allowed for a tolerance of pitting corrosion [17,18], more recent reports suggest that only general copper corrosion is expected in a DGR environment(s) [8,19]

Summary

Introduction

The Nuclear Waste Management Organization (NWMO) was formed in 2002 to manage the long-term care of Canada’s used nuclear fuel [1]. The NWMO has initiated a program to assess the corrosion rates of copper containers in anoxic groundwaters, including pure water and a range of chloride concentrations.

Results

Conclusion