Improvement Of The Burnup Of the First Fuel Charge In The CANDU-600 MWe Reactor Through Fuel Bundle Shuffling

Abstract

An analysis was performed in an attempt to increase the fuel burnup of the first fuel charge (first 4560 fuel bundles discharged) of the CANDU-600 MWe reactor by altering the fuelling strategy. The fuelling scheme studied involved re-inserting the two last bundles in a channel along with six fresh bundles into each refuelled channel. This scheme was compared to the eight bundle shift scheme in which eight fresh bundles are placed into a refuelled channel. The comparison was done using a coarse mesh reactor model with the FMDP computer code. Reactor operation was simulated from 0 to 350 FPD's (Full Power Days). During this period the fuel burnup of the first fuel charge was increased by 11.1%, from 5075 MWD/Te-U to 5637 MWD/Te-U. To accomplish this a 10.8 increase in the average fuelling machine rate was necessary.