Conclusion

The major heavy-water systems, the distinguishing feature of the CANDU reactor, have been described with emphasis on the CANDU-6. As with the design of all reactors, the materials of construction of those systems are chosen for their ability to withstand constraints arising from reactor operation under both normal and accident conditions and with some regard to cost. The light-water-cooled secondary system has been described briefly.

The separate fuel channels passing horizontally through the low-temperature calandria vessel are unique to CANDU. They contain the natural-uranium-fuelled bundles that are loaded/unloaded on-power and are the vital components of the reactor. Besides thermalising the fission neutrons, the surrounding moderator D ₂ O helps to adjust the core neutronics with low-concentration chemical shim,...