In PUREX process, spent fuel is dissolved in nitric acid solution. Since the nitric acid solution contains many kinds of oxidizing metal ions eluted from the fuel, the corrosiveness of the solution is very high. In the case of stainless steel-made equipment, corrosion acceleration factor should be solution temperature, composition, concentration, boiling, and oxidizing of metal ions. Among them, the effect of solution boiling has not been fully clarified; it is said that there are both cases of decelerating and accelerating according to the composition of the nitric acid solution. In this study, we focused on the effect of the boiling of nitric acid solution on the corrosion of a stainless steel-made concentrator in reduced pressure in fuel reprocessing plant. In order to perform the simulation test in a non-radioactive condition, nitric acid solution with the addition of vanadium as an oxidizing metal ion were used. Corrosion tests were carried out under the conditions of boiling at reduced pressure, and of non-boiling at normal pressure and several temperatures. As a result, corrosion was accelerated by the solution boiling while it was not by non-boiling at the same temperature. It was also found that the temperature dependence of corrosion rate is the similar to those for the both conditions of boiling and non-boiling. The corrosion accelerating effect will be discussed on the basis of the reaction among nitric acid, NOx and vanadium, etc.