Calculation of 3-D flux distributions in CANDU reactors using lattice properties which include the history of the lattice

A refinement is proposed to the current method of evaluating lattice properties for use in core-tracking calculations in CANDU reactors. This refinement takes into account the individual past history of each bundle, including flux/power level, fuel temperature, and coolant density and temperature that the bundle has seen during its stay in the core. Previously core-average or locally appropriate values were used for the lattice parameters, and the past history was not taken into account. This new method provides a means of much more accurately following the power and burnup history of a CANDU reactor core, both locally and globally.