# Statistical data analysis of NPP equipment failures in non homogeneous event flow. Part 2

6/21/2017 2017 - #02 Global safety, reliability and diagnostics of nuclear power installations

https://doi.org/10.26583/npe.2017.2.02

### UDC: 519.7:519.23/.24/.25

In the process of its operation, the technical equipment passes through three stages, each of which is characterized by a certain trend in the failure flow parameter (FFP) behavior. During normal operation, the FFP value is approximately constant. In this case, the equipment operation is assumed to be homogeneous and the reliability indices are calculated by classical methods. At the burn-in stage, the FFP decreases with time; at the aging stage, it increases. Therefore, at these stages, the operating times between two successive failures are not identically distributed random values, and the failure flow cannot be considered as recurrent. In calculating the reliability characteristics, it is necessary to take into account the failure flow non-homogeneity in time. The paper describes a method for estimating the NPP equipment reliability indices, which takes into account the possible failure flow non-homogeneity. The specificity of incoming statistical data on failures is noted. A description is given of the normalizing flow function model used for calculating the required reliability indices. As a practical example, data on the Bilibino NPP CPS KNK-56 component failures have been analyzed. The article continues to present the statistical data analysis methods introduced by the authors in their previous work [1].

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failure flow intensity function non-homogeneous event flow normalizing flow function model (NFF) abstract homogeneous flow counting process aging system juvenescent system renewal equation