Estimation of safety parameters of equilibrium cycle of Indian Pressurized Water Reactor (IPWR)

The Indian Pressurized Water Reactor (IPWR) is being designed with enriched uranium fuel and light water as coolant in a hexagonal lattice arrangement. The physics design of the core included optimization of 235U content in the fuel to achieve a target discharge burnup of about 50 GWD/T in a multi-cycle batch re-fuelling mode. The burnup reactivity control during the cycle is achieved by soluble boron. IPWR has been designed as per current safety standards where all the reactivity coefficients are negative in all the operating conditions. The kinetic parameters together with the reactivity coefficients are also used in safety analysis. The reactivity coefficients have been estimated from detailed 3D core simulations and the kinetic parameters have been estimated using the conventional perturbation theory expressions which involve weighting by the adjoint flux. Present work reports the estimation of the range of reactivity coefficients over an equilibrium operating cycle to be used to calculate the effective feedbacks and safety margins.