Structural Review of the San Onofre Nuclear Generation Station Unit 1 Containment Structure under Combined Loads. Systematic Evaluation Program

摘要

This report is a structural assessment of the containment structure of the San Onofre Nuclear Generation Station Unit 1, performed for the Nuclear Regulatory Commission as part of the Systematic Evaluation Program (SEP). The San Onofre assessment focused on the overall structural integrity of the containment structure under a safe shutdown earthquake an a postulated design basis accident. The safe shutdown earthquake was represented by the Housner Spectra, scaled to 0.67 g peak ground acceleration. The postulated design basis accident was either a loss of coolant accident or a main steam line break. Several combined stresses were evaluated for their adherence to the 1980 edition of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code allowables. All the calculated stress intensities were found to be acceptable according to this code except the general primary membrane stress due to combined dead and pressure loads under level A service limits. Because the containment structure was previously tested under combined dead and pressure loads for a higher peak pressure than the one used here, this study concluded that it was acceptable. (ERA citation 08:000643)