Effect of pellet radial power and temperature distributions on fuel assembly neutronics

Recently, the resonance self-shielding module of the PARAGON code has been enhanced with the capability of subdividing the fuel pellet into multi-regions. A gradient of temperature can be associated to these micro-regions to better account for the spatial temperature distribution. The purpose of this paper is to validate this module when a profile of temperature is used in the fuel pellet Comparison to MCNP code will be performed We will also study the effect of this gradient of temperature on reactivity and power distribution for different types of fuel pin cells and assemblies. We will compare the results to the current Westinghouse core design methodology where a flat temperature is used throughout the pellet Since the radial temperatures depend on the radial powers and vice-versa, iteration between PARAGON and the fuel rod design code PAD will be performed. (authors)