Nuclear data needs for advanced reactor systems. A NEA nuclear science committee initiative

The Working Party on Evaluation Cooperation (WPEC) of the OECD Nuclear Energy Agency Nuclear Science Committee has established an International Subgroup to perform an activity in order to develop a systematic approach to define data needs for Gen-IV and, in general, for advanced reactor systems. A methodology, based on sensitivity analysis has been agreed and representative core configurations for Sodium, Gas and Lead cooled Fast Reactors (SFR, GFR, LFR) have been defined as well as a high burn-up VHTR and a high burn-up PWR. In the case of SFRs, both a TRU burner (called in fact SFR) and a core configuration with homogeneous recycling of not separated TRU (called EFR) have been considered. The methodology, the systems considered and the sensitivity approach are consistent with the work reported in ref. (1). For the present study, the approach has been extended to the ABTR Na-cooled core, recently studied within the GNEP initiative (2). Sensitivity coefficients (in a 15 energy group structure) have been calculated at ANL with the ERANOS code system (3) for all reactors and for the parameters most sensitive to nuclear data uncertainties: Multiplication factor, Power peak, Burn-up Δk/k, Coolant void reactivity coefficient, Doppler reactivity coefficient, Nuclide density at end of cycle (transmutation potential), Neutron source at fuel fabrication, Dose in a repository.