Applicability of X-ray radiography for integrity assessment of aged pipes in the JMTR

Ito, Masayasu ; Taguchi, Taketoshi ; Miyauchi, Masaru; Sozawa, Shizuo

It has been 45 years since the first criticality of JMTR in March 1968, and unfortunately, two contaminated water leakages from the stainless steel pipes occurred in 2012. Results of the investigation showed that the cause of the leakages was cracks due to stress corrosion cracking (SCC) from the outer surface, and crevice corrosion from the inner surface, respectively. Although visual inspection for these pipes had been carried out as regular inspections before the leakages occurred, these cracks were invisible to the naked eye. Since the X-ray radiography can detect internal flaws/cracks, was investigated as a non-destructive inspection to assess the integrity of the aged liquid waste transfer pipes in the JMTR. In this presentation, observation results by the X-ray radiography and the X-ray CT will be reported, and the applicability of the X-ray radiography.