Heavy water—the CANDU moderator

CIM Bulletin, Vol. 76, No. 859, 1983

R.J. TWIGG and S.D. CHANG, Atomic Energy of Canada Limited, Chemical Company

The production of heavy water, the moderator in a CANDU reactor, is examined following a flow sheet of a typical Canadian plant. The process involves the extraction and concentration of deuterium from natural water through a chemical exchange mechanism with hydrogen sulphide. Consequently, corrosion problems associated with sour environments — the use of hydrogen sulphide — are an everyday problem and have led to the development of a highly refined materials selection and testing program to prevent equipment from failing prematurely.
Keywords: Heavy water, CANDU reactor, Deuterium, Hydrogen sulphide, Corrosion, Carbon steel, Austenitic stainless steel, Deposition, Welding