You can effectively wield weapons made out of thorium.

Prerequisite:Str 15, proficiency with simple weapons, base attack bonus +1. 

Benefit: You are proficient with thorium versions of any weapon with which you are otherwise proficient; and when wielding a thorium weapon you may add an additional one-half your Strength bonus to damage rolls. 

Normal:A character who is not proficient  with thorium weapons takes a –4 nonproficiency penalty on attack rolls with one and receives her normal Strength bonus on damage rolls.