This work was carried out within the Euratom collaborative project: 'Central Design Team for a Fast-spectrum Transmutation Experimental Facility (CDT/FASTEF)' inserted in the 7° EU Framework Program. The project aims to demonstrate an efficient transmutation of high level wastes and associated technology through a system working in subcritical and/or critical mode: the main objective is the advanced design of an irradiation experimental facility cooled by Lead-Bismuth Eutectic (LBE), to be built at SCK-CEN research centre in Mol (B). Starting from the XT-ADS (eXperimenTal-ADS) sub-critical core summarily designed during the IP EUROTRANS project (6° EU FP), this report identifies the main design modifications due to the critical operation mode. Several neutronic calculations were performed by considering the introduction of a primary and a secondary shutdown systems. In the beginning the main XT-ADS features were maintained, as: the FA architecture (with fuel peliet / clad made of MOX 35 wt. % Pu / FMS T91), the core layout and the 8 irradiation positions (foreseen for experimental rigs). The net result of these scoping investigations consists of a couple of sketches for the critical core adapting the XT-ADS FA (analysed in Appendixes B-D). In parallel with these preliminary evaluations, to further increase the fast neutron flux, a detailed study was carried out by assuming different LBE inlet / outiet temperatures and FA / core geometries (Appendixes E-F). This analysis identifies some design modifications able to provide a higher flux by respecting the actual technological constraints. Based on this study and by adopting a different safety approach (that allows more relaxed specifications on the care pressure drop at 100 MW nominal power, par. 3), a reduced pin pitch can be possible (even with a different clad material, 15-15 Ti SS). As a final result, a first sketch of the FASTEF FA and a range of feasible configurations far the critical layout are proposed (par. 5-7). This range takes into account the current lack of information (as: pin diameter, hollow or solid pellet, 30-35 wt. % Epu) and supplies a large data set useful to address the WP2 phase.
|Titolo:||Analysis of MYRRHA/FASTEF to operate in a critical mode|
|Data di pubblicazione:||29-nov-2010|
|Appare nelle tipologie:||5.2 Documento in Garanzia della Qualità|