Comparison between standard solid fuel and a new annular fuel performance in the core of a PWR

Abstract

In new generation PWR the annular fuel has been proposed as one of the options to achieve higher power density, larger safety margin and reduced electricity generation cost. In the current work, RELAP5 code is used to compare the thermal hydraulic parameters for both solid fuel and internally and externally cooled annular fuel in a core of a PWR. MCNP6 code is used to evaluate the neutronic design and basic safety parameters of the annular fuel. To accomplish this goal, RELAP5 input files for both solid and annular fuels are developed. In these files, a 13 · 13 array annular fuel design is used while the 17 · 17 standard array design is used for the solid fuel. A 100% core power, steady state normal operation is assumed in the current investigation. Also, MCNP6 code input files for both fuels are prepared. It is found that annular fuel has lower peak fuel temperature than the standard solid fuel, which is an important advantage of the annular fuel rather than the solid one. Also, comparisons were performed for reactivity feedback coefficients of the two fuel types at BOC. Burnup calculations were performed to study the energy conversion capability of the annular fuel as well as rim effects.