Surface Science Western’s (SSW’s) scientists Rebecca Sarazen and Sridhar Ramamurthy, along with Thalia Standish and Dmitrij Zagidulin from the Chemistry Department, were at the Advanced Photon Source (APS, Chicago) performing micro X-ray tomography (micro-CT) measurements on copper-coated steel samples. Access to APS, located within Argonne National Laboratories (ANL) in Chicago, is based on the review and rating of the proposals submitted by potential users. The proposal submitted by the SSW team rated 1.4, with 1=Extraordinary, 2=Excellent, 3=Good, 4=Fair, 5=Poor.
Copper-coated steel used fuel containers (UFCs) are currently being considered by the Nuclear Waste Management Organization (NWMO) for permanent disposal of used nuclear fuel in a Canadian deep geological repository (DGR). The proposed coating structure consists of an electrodeposited copper coating for the container and cold sprayed copper coating for sealing the final closure weld. Understanding the long-term corrosion performance of UFCs is critical because regulations require containment be achieved for many thousands of years after emplacement.
The use of micro-CT technique allows us to non-destructively determine the nature and the distribution of corrosion damage propagation, especially at the copper/steel interface, under conditions expected in a DGR. The high flux X-ray beam at APS enables one to make a number of measurements within a short period of time. During the current visit to the APS, the SSW team worked continuously for 48 hours monitoring the in-situ corrosion behaviour of 9 samples at various immersion times ranging from 0 to 38 hours. They also analyzed a number of ex-situ samples that were previously subjected to electrochemical experiments.