Embalse Refurbishment - Aging, Safety Assessment, and the Path Forward

Abstract

The Embalse Nuclear Power Station has been engaged in Pre-refurbishment activities for two years. The primary focus has been on the first phase Pre-Project Condition Assessment Program (PCAP). This phase of the Refurbishment and Life Extension (RLE) project consists of all preparatory activities that are required to define the refurbishment scope and costs, and for input into the utility business case for the RLE project. As part of an overall Plant Life Management (PLiM) program, the following activities have been performed: 1. Systematic and rigorous condition assessments / life assessments (including Health Prognosis and Recommendations) 2. Assessment of design and safety analysis features at Embalse, relative to current technology and licensing practices 3. Pre-Project activities related to: Retube, Steam Generator replacement, and Digital Control Computer (DCC) replacement The program has been a joint effort of Embalse NPS-NASA, AECL, ANSALDO and several other support organizations. Details of the planned program were addressed previously in a paper presented at the 28th CNS Conference (2007), entitled “Embalse Refurbishment – Pre-Project Condition Assessment Phase 1”. Since that time, significant progress has been made towards completing the assessment program and planning for the next steps. This paper presents the progress of Refurbishment and Life Extension (RLE) Program at Embalse Nuclear Power Station with specific emphasis on the PCAP efforts. This includes a discussion of the benefits and lessons learned from RLE project’s perspective, and an overview of some key conclusions of the aging assessments. Finally, this paper outlines the path forward. It should be noted that results of assessments presented in this paper are very conservative. This is driven largely by the fact that there are currently uncertainties in equipment condition that can be addressed through the activities recommended as an outcome of these assessments.