Power and Neutron Flux Distributions in the Core and Shielding

An extensive program of neutronic flux measurements has been carried out during the commissioning of Superphénix. Analysis of the results allowed the comparison of different methods of calculation. The best fit on axial and radial profiles of reaction rates in the core is obtained when control rod reactivity is well reproduced. In the shielding, agreement is improved by the use of experimental correction factors, obtained in clean neutron propagation experiments. A unique feature of the work is the simultaneous analysis of core and shielding experimental results. This feature has a relevant impact on the assessment of appropriate and consistent design calculation routes for liquid-metal fast breeder reactors.