The corrosion behavior of Type 304L (UNS S30403) nitric acid grade (NAG) stainless steel in boiling 9 M and 1 M nitric acid (HNO₃) and with the addition of 0.03 M sodium fluoride (NaF) and with fluoride complexed with 0.06 M to 0.15 M aluminum nitrate (Al[NO₃]₃) and 0.015 to 0.0375 M zirconium nitrate (Zr[NO₃]₄) has been established. The corrosion behavior has also been studied using potentiodynamic polarization in the same environments at room temperature and at near boiling temperature and correlated to the measured corrosion rates. It was shown that the fluoride addition accelerates anodic dissolution. The surface film formed on stainless steel was analyzed using x-ray photoelectron spectroscopy to show that fluorides do not remain attached to the surface. The effect of different ratios of complexing with Al(NO₃)₃ and Zr(NO₃)₄ has been studied, showing more effectiveness of zirconium. The corrosion behavior of Types 304L, 304L (welded), 310L (UNS S31000) stainless steels and Alloy 690 (UNS N06690) was established in boiling HNO₃ and HNO₃ with complexed fluoride and in its vapor and condensate phases. The corrosion rates were shown to be higher in the vapor phase than in the concentrate phase for all the materials tested. The differences in the corrosion rates measured in 48 h or 120 h exposures have been explained.