Methods and Applications for Assessing of Time-Dependent Failure Rates (IAEA No I31030)

The successful deployment of advanced WCR technologies includes the development of design certification probabilistic safety assessment (PSA) studies that among other aspects must also address piping reliability in multiple contexts. Based on five decades of extensive and documented national operating experiences on the pipe failure rates in current Water Cooled Reactors (WCRs) fleet, a new methodology to predict pipe failure rates in advanced WCRs will be suggested. In the absence of operating experience data of the advanced WCRs there is not yet a consensus technical approach of how to predict pipe failure rates in advanced WCRs. This CRP will provide Member States with an open access to a strong technical basis for establishing plant piping reliability parameters in support of design certification PSA studies, in-service inspection programme development, and operational support. It this way it will bring together the current state-of-knowledge on piping degradation and failures, and will address important area of the predictions of pipe failure rates in suggesting a new methodology consistent with required standards and relevant to deployable advanced WCRs where coordination by the Agency will provide significant added value. Although the focus is on statistical models of piping reliability on the basis of operating experience data in the current WCRs fleet, other approaches to piping reliability parameter estimation, such as probabilistic fracture mechanics approaches, are not precluded from consideration. Additionally, this CRP will enable objective evaluation and the benchmark studies by the participating Member States. The research activities supported by this CRP will foster national excellence and international cooperation, promote sharing of newly developed knowledge and contribute to capacity building in developing countries.

Objectives
Assist the IAEA Member States in assessment of pipe failure rates in advanced WCRs for improved safety design, promote international cooperation among IAEA Member States through the sharing of expertise and participation in the common benchmark calculation.

Specific objectives

• Develop course syllabi for training early-career engineers and scientists, and establish the opportunities for PhD dissertations.
• Collect data and analyze the best practices of the existing piping reliability analysis methodologies across the Member States.
• Successfully complete the benchmark sets and document lessons learned.
• Develop new methodology to predict pipe failure rates in advanced WCRs.

Coordinator: International Atomic Energy Agency