FROM NEEDS TO DEVELOPMENT, VALIDATION AND APPLICATION (NEEDS): THE VIRTUOUS CYCLE FOR LFR CORE DESIGN

When dealing with the design of the core of a nuclear reactor, the availability of consolidated expertise, validated simulation codes, and consolidated design and analysis procedures, is a mandatory prerequisite for successful accomplishment. Concerning lead-cooled fast reactors, the Laboratory for Design and Analysis of Nuclear Systems of ENEA holds a renowned leading position, acknowledged internationally. This derives from a longstanding experience, historically acquired on sodium-cooled fast reactors through the PEC, PRISM and BN-800 projects, and then shifted to systems cooled by heavy liquid metals within the context of Euratom research projects, national programmes and international collaborations. Despite this, the Laboratory strives to pursue the continuous improvement of its assets, leveraging the activities on which it is engaged to focus the efforts on aspects of primary importance. The identification of the areas of improvement, and the definition of the priorities, are a direct result of the needs emerging as feedback from the activities performed. These needs, generally, involve an extension of the expertise in the pertinent domains (such as neutronics, thermal-hydraulics, thermomechanics, fuel performance) and its subsequent consolidation; the development of new codes (as was the case with ANTEO+, TIFONE and TEMIDE) and methods (such as the burnup sensitivity and uncertainty model for ERANOS), and their validation; the execution of new experiments (either by separate or integral effects) and their consequent assimilation. Examples of the virtuous cycle of improvement of design capabilities, realized by the development of design building blocks, are presented with cases of practical application.