Stability analyses for the European LFR demonstrator

The development of next-generation Lead-cooled Fast Reactors (LFRs) up to industrial deployment requires the realization of a demonstration plant intended to prove the viability of technology as well as the overall system behavior. The conceptual design of a low-cost scaled-down LFR named ALFRED (Advanced Lead Fast Reactor European Demonstrator) has been undertaken within the European Commissionʹs 7th Framework Programmeʹs LEADER (Lead-cooled European Advanced Demonstration Reactor) project. A simulation tool has been developed in MATLAB® based on a lumped-parameter approach, aimed at investigating the reactor stability and identifying potential regions of instability through relatively straightforward analyses. As a major outcome, ALFRED has turned out to be inherently stable on the entire power range independently of both the fuel burn-up and the value of the coolant density coefficient, which should reach unrealistic high values (nearly 6 pcm K−1) to make the reactor unstable. The results of this study have provided the reactor designers with important feedbacks leading to the finalization of the primary system configuration.