Similarity Assessment of the BFS-109-2A Axial Expansion Experiment Using a Novel Jacobian Matrix Method

摘要

For a metal fueled SFR(Sodium-cooled Fast Reactor), the negative reactivity feedback due to thermal expansion of the fuel has been known as a principal safety mechanism to guarantee the passive shutdown of the reactor after undercooling accidents. To validate the thermal expansion effect in the metal fueled blanket-free core, measurements of the fuel expansion reactivity were performed during the BFS-109-2A reactor physics experiment in the Russian BFS-1 critical assembly. However, owing to the considerable difference in the geometry between a critical experiment model and the real target reactor, a different geometric self-shielding effect is expected. Therefore, the assessment of a similarity is essential work, especially for an innovative reactivity phenomenon experiment such as the fuel expansion reactivity.