Double-ended break probability estimate for the 304 stainless steel main circulation piping of a production reactor

The large break frequency resulting from intergranular stress corrosion cracking in the main circulation piping of the Savannah River Site (SRS) production reactors has been estimated. Four factors are developed to describe the likelihood that a crack exists that is not identified by ultrasonic inspection, and that grows to instability prior to growing through-wall and being detected by the ensuing leakage. The estimated large break frequency is 3.4 {times} 10{sup {minus}8} per reactor-year.