The statistical analysis of the passive system reliability in the Nuclear Power Plants (NPPs)

The probabilistic safety assessment (PSA) has been investigated for the very high temperature reactor (VHTR). It is difficult to make the quantification of the PSA because the operation and experience data are deficient. Therefore, the necessity of the statistical data usage is considered for the basic event. The physical data using the non-linear fuzzy set algorithm are applied to quantification of the designed case. The main model of this study is the mass flow rate in natural circulation. Furthermore, the potential energy in the gravity, the temperature and pressure in the heat conduction, and the heat transfer rate in the internal stored energy are also investigated. For the failure analysis, the values in the probability set and the fuzzy set are compared. In the results, how to use the newly made failure frequency in the propagations is found. It is concluded the artificial intelligence analysis of the fuzzy set could enhance the reliability method than the probabilistic analysis.