Migration of radionuclides from the coolant of a BR-10 reactor into stainless steel and the deactivation method

This paper presents the radionuclide distribution measured across the wall thickness of the pipelines of the first circuit of a BR-10 reactor and the measured deactivation of the specimens cut from different segments of the pipelines of the first circuit. The pipelines worked in sodium for nearly 120,000 h, and were thrice deactivated in 1961, 1971, and 1980. The pipelines of BR-10 were made from the 12Kh18N9T steel. In all, 12 specimens were cut out. The specimens contained Mn-54, Cs-137, Cs-134, and Co-60. No other long-lived radionuclide was observed. Mn has the maximum activity