Small Reactors for Low Temperature Heating

Abstract

For regions which do not have abundant long term supplies of oil, gas, or electricity, small nuclear reactors for heating large buildings are a future energy option. In Canada, the first installations might be in remote arctic communities where heating costs are highest. While several European countries are developing heating reactors in unit sizes of 100 MWt and greater, Atomic Energy of Canada Limited is studying the feasibility of much smaller units in the range 2 to 20 MWt. Based on the inherently safe SLOWPOKE research reactor, the proposed heating reactor would produce hot water at temperatures less than 100°C. It would be unattended most of the time, responding automatically to daily variations in load demand. The reactor core would contain enough uranium fuel to last two heating seasons.

Thermohydraulic tests have been carried out on an electrically heated tube simulating a single fuel element, and a 31-element test rig simulating the core and primary coolant circuit is under construction. Preliminary cost estimates indicate that heat from a 2 MWt SLOWPOKE-type reactor compares favourably in cost with heat from electricity and imported oil, but is significantly more expensive than the corresponding energy from natural gas. If the current studies at the Chalk River Nuclear Laboratories confirm technical and economic feasibilty, a 2 MWt prototype reactor will be built at Chalk River in 1984/85.