ICONE23-1001 THE COMPONENT OPERATIONAL EXPERIENCE DEGRADATION AND AGEING PROGRAM (CODAP) : REVIEW AND LESSONS LEARNED (2011-2014)

Abstract

The structural integrity of piping systems is crucial to continuous and safe operation of nuclear power plants. Across all designs, the pressure boundary and its related piping and components, form one of the many levels of defense in the continuous and safe operation of a nuclear power plant. It is therefore necessary to identify, understand, evaluate and catalogue all of the various degradation mechanisms and failures that affect various piping systems and components across all nuclear power plants (NPP's). This need was first recognized in 1994 by the Swedish Nuclear Power Inspectorate (SKI) which launched a five-year Research & Development (R&D) project to explore the viability of creating an international pipe failure database (SKI-PIPE) (Riznic, 2007). The project was considered to be very successful and in 2002, the Organization for Economic Co-operation and Development (OECD) Pipe Failure Data Exchange (OPDE) was created. OPDE was operated under the umbrella of the OECD Nuclear Energy Agency (NEA) and was created in order to produce an international database on the piping service experience applicable to commercial nuclear power plants. After the successful completion of OPDE, the OECD, as well as other nternational members, agreed to participate in OPDE's successor: the Component Operational Experience Degradation and Ageing Program (CODAP). The objective of CODAP is to collect information on all possible events related to the failure and degradation of passive metallic components in NPP's. With CODAP winding down to the completion of its first phase in December 2014, this report will focus on the conclusions and the lessons learned throughout the many years of CODAP's implementation. There are currently 14 countries participating in CODAP, many of whom are industry leaders (France, Canada, U.S.A., Germany, Japan, Korea etc.). This cooperation on an international scale provides a library of OPerational EXperience (OPEX) for all participating NPP's (Lydell et. al., 2008). CODAP also allows for the sharing of valuable information on a wide range of reactor types such as Pressurized Heavy Water Reactors (PHWR), Pressurized Water Reactors (PWR) and Boiling Water Reactors (BWR). The use of CODAP/OPEX and knowledge databases can and have resulted in a number of significant inspection changes at NPP's worldwide. For example, Canada has already utilized CODAP to address thermal stratification and piping material fatigue issues. Korea has collected and used information for piping failure events to identify sites of potential concern in their in-service inspection programs. Currently there are over 4500 recorded events on pipe failures affecting all ASME Code Classes and non-safety related piping. These events encompass all known modes of damage/degradation and their respective failure modes.