Post irradiation examination of reactor operated pressure tube S-07 of KAPS-2

An irradiated Zr–2.5% Nb pressure tube removed from Kakrapar Atomic Power Station unit #2 (KAPS-2) after eight effective full power years was subjected to post irradiation examination in BARC hot cells facility. The examination included visual examination of outer and inner surface, gamma scanning, measurement of internal diameter, measurement of oxide thickness on the inner surface and analysis of hydrogen content in the tube. Examination revealed satisfactory performance of the pressure tube in the reactor. The maximum oxide thickness on the inside surface was found to be less than 15 μm at 4 m from the inlet end and maximum hydrogen pick up at the peak location was 6 ppm. The maximum increase in internal diameter was 0.82 mm at 3.2 m from the inlet end.