Water corrosion tests on mechanically jacketed and pinholed thorium slugs show that these slugs fail in a manner similar to that observed for mechanically jacketed and tested uranium slugs. The proposed mechanism for the water corrosion of these jacketed slugs is analogous to the water corrosion mechanism of jacketed uranium slugs presented in the project lecture. A bare thorium slug appeared to be more resistant to corrosion by water than a mechanically jacketed slug during the first half of the autoclave test. After approximately 90 hours of testing both the bare and the mechanically jacketed thorium slugs were severely corroded by water.