Verification of Stevenson and Associates load coefficient method (LCM) for Catawba Nuclear Station

Stevenson and Associates has spent many years developing a load coefficient method which would produce results that were less conservative than NUREG-0800 Standard Review Plan for the Review of Safety Reports for Nuclear Power Plants. They have analyzed over 150 standard piping segments in the development of a load coefficient method. The results of these analyses have consistently shown that the load coefficient developed is in the range of .8--1.1 time the peak acceleration of the floor response spectra. When using a load coefficient in this range, the stresses, support loads, and valve accelerations have compared favorably on the conservative side with the response spectrum modal analysis. Unfortunately there has been a great deal of criticism in the use of standard models. Critics have said that the use of standard models does not represent the real world. This paper presents the results of a study performed to verify the Stevenson and Associates results using eight piping analysis models for Catawba Nuclear Station. The Duke Power Company study demonstrated that load coefficients which support a value of 1.0 times the peak acceleration of floor response spectra can be developed using Stevenson and Associates load coefficient method. The stresses, support loads, andmore » valve accelerations of Duke Power Company study also compare favorably on the conservative side with the response spectra modal analysis results.« less