Development of an ASME-NH program for nuclear component design at elevated temperatures

In this paper, we discuss an ASME-NH program that has been developed to overcome the complexity and costs arising from the real application of the ASME-NH rules by hand calculations for class 1 nuclear facility component design for elevated temperature operations. A computerized program is described for implementing all the assessment procedures such as the time-dependent primary stress limits, total accumulated creep-ratcheting strain limits, and the creep–fatigue damage limits by the elastic and inelastic analysis methods complying with the ASME-NH rules. As an example application, a preliminary structural integrity evaluation for a high-temperature reactor vessel design of a typical lead-cooled reactor is described.