Abstract
Molybdenum and its alloys, such as TZM, are widely used today in nuclear reactors and are seriously considered for use in next generation reactor designs. Inclusion of molybdenum or any other material requires comprehensive study of factors such as fuel compatibility, temperature ranges, mechanical stress, radiation exposure, and expected corrosion environment. Next to radiation tolerance, corrosion resistance is perhaps one of the most important factors to consider in predicting the maximum lifetime of a reactor component. Several claims to the improvement of base molybdenum electrochemical behavior by molybdenum-lanthanum ODS and titanium-zirconium-molybdenum alloy have been made and warrant further verification. Electrochemical behavior of pure molybdenum, TZM, and Mo doped with 0.3 wt% lanthanum oxide was explored in aqueous solution at STP. Molybdenum samples were subjected to electrochemical tests in aqueous solutions of 1-13 pH containing 3.5 wt% NaCl. Performance was found to be strongly pH dependent, performance decreasing as pH increased. Neutral and acidic solution tests revealed similar results, with good performance all around. TZM observed increased performance in pH 1 solution while showing similar results to molybdenum at increased pH levels. Mo-La as compared to pure molybdenum observed increases corrosion performance in multiple factors.