Assessment of Offsite Power Reliability for Nuclear Power Plants by Fault Tree Analysis

Abstract

and Radiological Regulatory Authority ABASTRACT The reliability of offsite power for a nuclear power plant (NPP) is assessed using fault tree (FT) analysis. The method combines alternating current (AC) load flow analysis with FT technique. The probability of loss of offsite power (LOOP) initiating event is assessed based on the unreliability of the power delivered to the house load of the NPP. Based on the quantitative and qualitative analysis of the constructed FT, the probability of the LOOP initiating event is assessed. The FT results include the importance measures which enable identification of the most important elements of the power system from the aspect of nuclear safety. The impact of changes in the power system to the safety of the NPP is evaluated. The verification of the method was performed on the IEEE test system.