NRU Main Cooling Circuit Heat Exchangers - Life After 50 Years of Operation

Abstract

Continued operation of the National Research Universal (NRU) reactor is recognized as essential for AECL and the wider research community to sustain existing programs of national research, isotope production, and fuel and materials testing. To support its continued operation beyond December 2005, AECL initiated a NRU Licensability Extension (LE) Program, of which the NRU LE Plant Life Management (PLiM) Project is one of the major components. As part of the NRU LE PLiM Project, a life assessment of the NRU heavy water main cooling circuit heat exchangers was performed. These heat exchangers have been in operation for 50 years and have provided excellent operational service to date. Inspection results show that the heat exchangers are still in good condition and the outcome of a rigorous and systematic assessment is that they have a good prognosis to achieve a further 10 to 20 years of service life. While recommendations have been made to support their continued operation, no concerns were identified as life limiting. This paper will provide an overview of the integrated assessment of the NRU heat exchangers and the strategies that were applied in support of a further 10 to 20 years of service life.