Superphénix Benchmark Part I: Results of Static Neutronics

Abstract

In the paper, the specification of a new neutronics benchmark for a large Sodium cooled Fast Reactor core and results of modelling by different participants are presented. The neutronics benchmark describes the core of the French sodium cooled reactor Superphénix at its startup configuration, which in particular was used for experimental measurement of reactivity characteristics. The benchmark consists of the detailed heterogeneous core specification for neutronic analysis and results of the reference solution. Different core geometries and thermal conditions from cold “as fabricated” up to full power were considered. The reference Monte Carlo solution of Serpent 2 includes data on multiplication factor, power distribution, axial and radial reaction rates distribution, reactivity coefficients and safety characteristics, control rods worth, kinetic data. The results of modelling with seven other solutions using deterministic and Monte Carlo methods are also presented and compared to the reference solution. The comparisons results demonstrate appropriate agreement of evaluated characteristics. The neutronics results will be used in the second phase of the benchmark for evaluation of transient behaviour of the core.

Superphénix Benchmark Part II: Transient Results

“…The reactivity coefficients and parameters calculated with Serpent 2 [3] are summarized in Table 6 to Table 10. The coefficients are provided without axial profiling and thus, should be used with the core global or region-averaged parameter, i.e.…”

“…A set of values corresponding to the core power level was proposed. The values were evaluated assuming needed compensation of the core reactivity at different power conditions following the CR worth curve obtained in [3]. Evaluated CR worth curve and CR position worth are given in Fig.…”

“…It contains a description of the neutronic and thermal hydraulic (TH) core models for transient analysis including pin geometry, flow, power, reactivity and kinetics parameters, as well as boundary conditions for six selected transients. Specific power, reactivity, and neutron kinetics characteristics of the core were evaluated within the first phase of the benchmark exercise [3].…”

“…• the model input parameters were revised on the basis of the Serpent 2 neutronics calculations from the static neutronics phase [3];…”

“…• definitions of reactivity effects and the suggested set of effects were reconsidered based on results of modelling with Serpent 2 [3,6];…”