Thorium Ceramic is used in high temp Crucibles as described by Richardson (1935) whereby Thorium Oxide, with the addition of Zirconium Oxide, was used to produce small crucibles that could withstand temperatures of 2300 C for the melting of pure metals with no evidence of contamination.
Richardson, H.K., Presented at a joint meeting of the Electrochemical Society and the American Ceramic Society, Asheville, N. C., April 26, 1934.

Anti-Fowling Boat Hull and Keel
Alpha emissions can prevent Bio-film