Moderator heat recovery of CANDU reactors

A moderator heat recovery scheme is proposed for CANDU reactors. The proposed circuit utilizes all the moderator heat to the first stages of the plant feedwater heating system. CANDU-600 reactors are considered with moderator heat load varying from 120 to 160 MW_th, and moderator outlet temperature (from calandria) varying from 80 to 100°C. The steam saved from the turbine extraction system was found to produce an additional electric power ranging from 5 to 11 MW. This additional power represents a 0.7–1.7% increase in the plant electric output power and a 0.2–0.7% increase in the plant thermal efficiency. The outstanding features and advantages of the proposed scheme are presented.