Mitigation of Caesium and Cobalt Contamination on the Surfaces of Ram Packages

Abstract

AbstractTechniques for mitigating the adsorption of 137Cs and 60Co on metal surfaces (e.g. RAM packages) exposed to contaminated water (e.g. spent-fuel pools) have been developed and experimentally verified. The techniques are also effective in removing some of the 60Co and 137Cs that may have been adsorbed on the surfaces after removal from the contaminated water. The principle for the 137Cs mitigation technique is based upon ion-exchange processes. In contrast, 60Co contamination primarily resides in minute particles of crud that become lodged on cask surfaces. Crud is an insoluble Fe–Ni–Cr oxide that forms colloidal-sized particles as reactor cooling systems corrode. Because of the similarity between Ni2+ and Co2+, crud is able to scavenge and retain traces of cobalt as it forms. A number of organic compounds have a great specificity for combining with nickel and cobalt. Ongoing research is investigating the effectiveness of chemical complexing agent EDTA with regard to its ability to dissolve the host...