Comparison of seismic analysis methods within analytical approach

Abstract

Introduction. In the nuclear power industry, ensuring nuclear and radiation safety is of paramount importance, therefore all aspects that may affect safety are considered in a deterministic and probabilistic approaches.
 As part of the safety justification, consideration of earthquakes of various intensity levels is regulated by safety standards. At the same time, the deterministic analysis of the earthquake and the models and calculation methods used are quite well-established, and in the probabilistic way, a relatively large number of different approaches have been developed and used as part of PSA level 1. The results of the evaluation of the conditional probability of failure of system elements, buildings and structures depending on the intensity of seismic impact on the free ground surface of the site depends on the approach used for the calculations.
 Aims. To perform a comparative analysis of various methods for constructing a failure probability curve under seismic impact.
 Materials and methods. A comparative analysis of the use of various approaches to the construction of a failure curve under seismic impact for a relatively simple case is performed. The results of the calculations showed that the scaling method leads to the most conservative results. The use of linearization methods and the method of moments give more realistic estimates, which can have a positive impact on the results of PSA level 1.
 Conclusions. A comparative analysis of some approaches has practical interest and is relevant, since various methods can contribute more than 50% to the core damage frequency, which creates a significant imbalance in the safety of nuclear power plants.