A simulated experimental study on eutectic reaction of core materials using Pb-Sn couple

Abstract

Studies on the eutectic reaction of core materials are important for more accurate evaluation of progression of a reactor severe accident since such reactions provide significant input to the followed in- and ex-vessel phenomena. In this study, motivated to obtain some knowledge and database for enhanced understanding on this reaction, a series of simulated experiments was performed using the Pb-Sn couple due to their lower eutectic point. The experiments were conducted in a self-designed experimental system, which mainly consists of a sample holder and a visible resistance furnace. To acquire relatively comprehensive understanding, different experimental parameters such as the reaction temperature (463–483 K), contact pressure (0.43–1.15 MPa) and the contact geometry (square, upright and inverted isosceles trapezoids) were varied. Based on the experimental observation and quantitative data obtained, influence of experimental conditions on the reaction rate as well as the chemical composition and specific heat capacity of reaction product was analyzed. It is found that the reaction temperature and contact pressure have noticeable impact on the reaction rate, while the role of contact geometry seems to be insignificant. As for the composition of reaction product, despite an evident effect of reaction temperature and contact geometry, non-remarkable impact of the contact pressure is found. Although the composition of reaction product is varied at different conditions, the change in macroscopic specific heat capacity of the reaction product is confirmed to be limited over present scope of experimental parameters. The obtained results in this work to some degree have confirmed the good applicability of our experimental system developed, thus providing us with promoted confidence for future investigations on eutectic interaction using actual reactor materials. Knowledge and fundamental data from our work might be also utilized for the future development and verifications of eutectic-reaction models in reactor severe accident analysis codes.