Advanced scientist, Hanford Engineering Development Laboratory, Richland, Wash.
Pages: 15 Published: Jan 1979
The major sources of helium production in stainless steel irradiated in a fast reactor are (n, α) reactions in nickel, iron, chromium, and impurities such as nitrogen and boron. The corresponding reaction cross sections are generally of the threshold type with threshold energies about 1 MeV. Two important exceptions are the cross sections for the two-stage nickel reaction and the boron-10 reaction. Athough lifetime helium concentrations are low, they may be an important consideration, when applying material property change data obtained from the experimental breeder reactor II (EBR-II) core to high-temperature out-of-core fast breeder reactor (FBR) structural components. The ratio of atomic parts per million (appm) helium to displacements per atom is larger for the soft out-of-core spectra than for the harder in-core spectra in which most irradiation data are obtained. These differences should be kept in mind when applying data obtained in EBR-II to FBR out-of-core components.
helium, nickel 59, cross sections, spectra, stainless steel, fast reactor, structural components, displaced atoms
Paper ID: STP38176S