Quantification of initiating event frequencies and component reliability data in level 1 probabilistic safety assessment at Puspati TRIGA research reactor

Abstract

Prior to developing level-I probabilistic safety assessment in Puspati TRIGA Reactor (RTP), collecting and analyzing data is the cornerstone of the probabilistic safety assessment processes. This paper provides on how data quantification is made available for both initial initiating events frequency and components reliability. Taking into consideration on the availability of data, it was decided that generic data to be used in combination with plant-specific data. Methods for estimating the parameters used in quantifying is also presented in this paper. This includes, data treatment by applying Bayesian updates in forming a better refine posterior data. It was found out that, result with the presence of plant-specific data history tends to have high value, loss of offsite power (LOOP) with 1.27E-03. Meanwhile, for other IEs that used generic data, shown lower result with maximum value of 2.68E-06 (loss of flow accident at secondary pump: LOSC-P). As for components data, basic event, No signal from fission chamber 1 (fail to function) is the highest value with 4.07E-01, followed with Manual valve SV1A fail to close (2.75E-01). This publication is perhaps one of the first publically available document providing information on generic and plant specific data for initiating event and components reliability parameters that were used in a Level-1 PSA study for a nuclear research reactor. In addition, this information can be used by PSA technical staff in how to analyze and treat initial incident event data, including, type and what data need to be collected.