Spanish contribution in the design of the alfred reactor inside the ESNII+ Project

Significant efforts are being devoted in order to boost R&D on advanced nuclear reactors due to their sustainability and improved safety characteristics. The main drawbacks for the industrial deployment of a Lead-cooled Fast Reactor (LFR) are the lack of operational experience and the technological uncertainties. In order to measure the robustness of the design and improve the safety characteristics of the ALFRED reactor -the demonstration reactor of the European LFR technology- a detailed analysis is envisaged within the EU FP7 ESNII+ project (project to support the European Sustainable Industrial Initiative) (ESNII+, 2013). One key research goal for ALFRED is the demonstration of favourable transient behaviour under accident conditions. Such behaviour depends primarily on the reactivity coefficients of the core. For evaluation of those coefficients, computational tools capable of providing results with a high level of accuracy are available. But the results will be affected by different sources of uncertainty, such as uncertainties on the engineering design, on the nuclear data, model uncertainties, etc. The objective of this work is to perform a sensitivity/uncertainty analysis of ALFRED reactor to assess the impact on the core reactivity of the uncertainties in nuclear data as well as the uncertainties in geometrical tolerances. This will allow having an exhaustive picture of their influence on the core performance, identifying key parameters and proposing specific R&D actions to achieve an improved safety level.