On the role of validated simulations within the European nuclear fission technology platform

Abstract

This paper highlights the role of validated simulation code systems within the ongoing EURATOM Coordination Action "Sustainable Nuclear Fission Technology Platform" (SNF-TP). The SNF-TP proposes research structures and programs for developing a coherent European strategy for: (i) improving the performance of currently operating (Generation II) and future nearterm (Generation III and III+) Light Water Reactors (LWR) while maintaining a high degree of safety, performing studies regarding the feasibility of novel designs, and establishing a unified approach of LWR life time extension; (ii) establishing a sustainable, closed fuel cycle for electricity production using innovative (Generation IV) fast neutron reactor systems in conjunction with partitioning and transmutation (P&T) technologies; (iii) establishing a commercially viable High Temperature Reactor (V/HTR) for process heat and hydrogen production; (iv) assuring adequate training to preserve and enhance the human competence in the nuclear field, and maintaining/renewing the infrastructure necessary for achieving sustainability of nuclear energy; and (v) implementing a Strategic Research Agenda for conceiving and coordinating the European research and development in nuclear science and technology. Numerical simulations and validation activities comprise transversal activities common to all types of reactors as well as issues which are specific for each type of reactor system. Besides performing specific experiments and developing specific simulation models, essential activities are "code verification" ("is the code solving the mathematical model correctly?"), "code validation" ("does the model represent reality?"), and "code qualification" (certifying that a proposed simulation/design methodology/system satisfies all performance and safety specifications). Code validation and qualification (V&Q) can be attained only by selected benchmarking, taking into account systematically (i.e., using sensitivities) all sources of uncertainties (computational, experimental, etc.). The development of software modules for validation and verification of simulation programs, including global sensitivity and uncertainty analysis, is a generic issue of fundamental importance for the safe operation of all types of reactors while reducing uncertainty design margins. The scope of this paper is to sketch briefly the role of validated simulations in the context of the (above mentioned) strategic elements of the EURATOM Coordination Action SNF-TP.