•Since the inception of nuclear power reactors in the
early 1950's, many designs
have been conceived, quite of few of these designs were actually built and a handful have been successful.
•The figure (next) maps the predominant types that have
persisted over time. The types are
distinguished by the major design features of fuel type, coolant type and moderator type.
•The current market share is held by the Pressurized
Water Reactor (PWR) which
uses enriched fuel, high pressure light water combined coolant / moderator in a pressure vessel. But CANDU,
which uses natural uranium, high
pressure heavy water coolant in pressure tubes, low pressure heavy water moderator, is a viable
competitor.
•In the end, the choice depends on achieving a balance of
technical issues such as cost,
safety, operations, design infrastructure, etc. and non-technical issues such as electrical grid
planning, institutional and
societal preference, international politics, funding arrangements, indigenous resources, etc.