Some Performance Indicators of PWR Steam Generators

Abstract

The monitoring of operational performance is a crucial aspect of the management of equipment operation and maintenance in many industries, including nuclear and thermal power plants. Monitoring involves the collection and analysis of data on the operation. PWR steam generators operating experience is sufficiently abundant to enable a systematic analysis of steam generator degradation and failure mechanisms, allowing for development of corrective measures and overall improvement of power plant effectiveness and safety performance. Raw data used in the analysis come from experience at various nuclear power plants collected in the IAEA Power Reactor Information System (PRIS) and published in the agency's annual reports on operating experience since 1971.

In this paper we analyzed steam generators in operation, e.g., their malfunctions during the plant life cycle with the aim of identifying characteristics of failure rate and repair rate. These are necessary parameters if we are to determine the reliability and availability of steam generators and their effect on the safety and efficiency of the nuclear power plant. We analyzed IAEA available data for period from 1971 to 2000. Each steam generator was analyzed individually during plants' lifetime. The data on steam generator failures are presented in uniform format, allowing the consistency in failure classification and data reporting. Operational presence of the analyzed steam generators is tracked through a plant lifetime: the failure rate λ and repair rate μ with associated boundaries, were calculated. The empirical probability distribution of failure rates and repair rates were observed and general trends in performance indicators (λ,μ) analyzed, from the point of their influence on plant reliability and availability.