Radiolytic hydrogen absorption behavior on tantalum in nitric acid solutions under -ray irradiation

Ishijima, Yasuhiro ; Ueno, Fumiyoshi  

Explosion-bonded metal joint has been used at the spent nuclear fuel reprocessing plant in Japan. The metal joint is made of zirconium, tantalum and stainless steel. And the radiolytic hydrogen is known to be generated in the spent nuclear fuel solution. Also, tantalum is known to be highly susceptible to hydrogen embrittlement. Therefore, evaluating the radiolytic hydrogen absorption behavior of Tantalum in nitric acid solution (HNO) is essential. In this study, immersion tests were conducted on tantalum in nitric acid solutions under -ray irradiation to evaluate its radiolytic hydrogen absorption behavior. Results showed that there was no hydrogen absorption of tantalum after immersion. The reason was considered that the passive film generated by immersion in nitric acid solution inhibited hydrogen absorption.