A discussion of Candu 300 plant life extension

The CANDU nuclear power program recognized from its inception the importance of incorporating maintainability and life extension features into the basic design. This is facilitated by the modular nature of the CANDU design. The Candu 300, in providing a station design life of 100 years, significantly advances plant life extension capabilities. All key components are designed for a minimum 40 year life with the provision for easy replacement. An example of this is the Candu 300 fuel channel. The fuel channel design has been modified to allow the 208 fuel channels to be replaced within a 90 day outage. Even major equipment can be replaced with a minimum of down time (4 weeks for example for steam generators). This is facilitated by the station layout, which provides 360 deg access to the five principal buildings, and by spacious and well organized building internal arrangements. A comprehensive in-service inspection program, in combination with a transient monitoring and recording function within the station control computers is utilized to monitor component status. The Candu 300 has been designed utilizing the Atomic Energy of Canada Limited Candid Engineering system, which incorporates advanced computer aided design and drafting based on 3-dimensional modelling. This has permitted the replacement of all components to be simulated