The volatility of a proposed fusion reactor structural alloy, Path-A Prime Candidate Alloy, a modified 316 stainless steel, was investigated. Tests were conducted in nonstatic air at temperatures from 723 to 1473 K (450 to 1200°C) for durations of 1 to 100 h. Results indicate that no significant volatility occurred for any major alloying constituent with the notable exception of molybdenum. The volatility of molybdenum is temperature dependent. An apparent activation energy was determined for the volatility of molybdenum from 1073 to 1473 K.