Proposals are made for improving the homogeneous diffusion procedure for reactor operating and design calculations. The procedure is based on the use of homogeneous properties for the assemblies and on high-order discretization for the reactor diffusion calculations. It proposes to improve the radial leakage model incorporated in the flux calculation and to introduce a super-homogénéisation equivalence technique between the flux and cross-section edit calculations to yield homogeneous diffusion properties consistent with the control rod worth calculations.