Design and Performance of CANDU Steam Generators

Abstract

The recirculating U-tube steam generators at Ontario Hydro's Pickering and Bruce CANDU Nuclear Generating Stations have demonstrated excellent reliability over many years of operation. Tube failures have been rare, contributing to high plant capacity factors. Of the approximately 390,000 steam generator U-tubes at the Pickering and Bruce plants, one tube leak has occurred at Pickering to date and 12 tubes have leaked at Bruce in a total of 89 reactor years of operation. The success of these units is attributed to an age old respect for steam generation equipment, an ongoing pursuit of research and design advancements, and extensive cooperative efforts on the part of the utility, the system designer, and the supplier. The supplier's involvement began with the steam generator design and manufacture for the very first CANDU plant. The utility's involvement began with their direct participation in the earliest stages of nuclear plant design, The utilities' contribution to the success of these units relates to the rigorous approach used in definition of requirements, in understanding the supplier's design in detail and in making every effort to operate, monitor, and service the equipment with appropriate care. This paper presents the supplier's and the utility's approach to achieving these remarkable results. In order to present these viewpoints separately and in some detail, this paper is divided into two parts: Part 1: The Equipment Supplier Perspective and Part 2 : The Utility Perspective.