Benchmarking activity on ENEA available tools for the dynamic analysis of LBE cooled sub-critical systems

Following the large interest aroused in the world on accelerator-driven systems (ADS), the TRASCO Italian national research programme for nuclear waste transmutation has paid special attention to the development of suitable numerical tools for studying operational transients and accidental sequences of ADS-like systems. At present a multi-group dedicated neutronic code for sub-critical systems coupled with a simplified thermal-hydraulic code (NILO-TIESTE) and a modified version of the RELAP5/PARCS code are both available. The aim of this work is to test and compare these two coupled codes against a set of typical transients for lead-bismuth cooled sub-critical systems under cover gas injection enhanced natural circulation. (author)