ON-LINE CONTROL OF THE CANDU-PHW POWER DISTRIBUTION.

On-line spatial control of Canada Deuterium Uranium-Pressurized Heavy Water power distribution is achieved through a redundant multi-purpose control computer system and a virtually continuous flux mapping procedure combined with a liquid control absorber system. This paper discusses in detail the on-line calculational methods, control algorithms, and hardware aspects of spatial control. The detector system of the on-line control consists of about 100 vanadium and 28 platinum detectors. Output from the V detectors forms the input to a flux mapping routine which is executed every two minutes in the on-line computers. The methods used in on-line flux mapping are described. Results from the flux mapping routine are used in part for calibration of the 28 faster responding Pt detectors. Signals from the Pt detectors are in turn fed to individual controllers in the computer. Further details of the control mechanism, including the LCA (Liquid Control Absorber), adjuster rods and MCA (Mechanical Control Absorbers) are provided.