Investigations on metal matrices for nuclear fuel waste disposal

The Canadian Nuclear Fuel Waste Management Program is investigating the use of low-melting-point metals and alloys, such as lead, zinc and aluminum-7 wt.% silicon as cast matrices inside used-fuel disposal containers. This paper reviews casting development and corrosion work conducted on those matrices. The overall picture that has developed from the program to date indicates that all candidate matrix materials can be successfully cast to produce high-integrity matrices, using the appropriate techniques developed in the program. Corrosion tests conducted in granitic groundwaters over a range of possible vault temperature and pressure combinations indicate that lead has the greatest potential to provide an additional barrier to radionuclide release