There was a recent report produced by the experts at Los Alamos about the fire at the WIPP facilities:
Based solely on the photographic information it appears that some
surfaces on the LANL drum may have reached temperatures of up to 700-870°C10 and the waste in a large portion of the room reached temperatures up to 170°C11 to 230°C12.
The drum in question had recently been transferred. The drums are packed with nuclear grade catt litter, and then compressed to 1/5 their original size.