Measurement of thermal properties of ferro siliceous sacrificial radiation shielding concrete using semi-infinite transient heat conduction model

The accurate measurement of thermal properties of ferro siliceous sacrificial concrete (FSSC) is quite difficult but essential to study the radiation shielding behavior and molten core corium interaction (MCCI). The present study aims to propose a step-wise transient method based on a semi-infinite medium principle to measure the different thermal properties of FSSC using transient temperature measurement and a simple data processing approach. Various thermophysical properties such as specific heat, thermal conductivity, thermal diffusivity and thermal effusivity are determined, which can be helpful to understand the ablation behavior of the FSSC during molten core-corium interaction in nuclear power plants. The results of specific heat of the FSSC vary from 760 to 770 J/ kg.K, while the value of thermal conductivity lies in the range of 7.0-7.4 W/m.K. The average value of thermal diffusivity and thermal effusivity is found to be 2.51 x 10-6 m2/s and 3900.5 Jm-2K -1s-1/2,respectively. The specific heat obtained using semi-infinite assumptions is predicted well by the rule of mixture. The results of thermal conductivity obtained from the present model are compared with the results of the Serial, Parallel and Lichtnecker models available in the literature. These models under predict the value of thermal conductivity obtained from the experimental results.

Automated summary

This study proposes a step-wise transient method based on a semi-infinite medium principle to measure the different thermal properties of ferro siliceous sacrificial concrete (FSSC) using transient temperature measurement and a simple data processing approach. The measured thermophysical properties provide insights into the ablation behavior of FSSC during molten core-corium interaction in nuclear power plants. The results show variations in specific heat, thermal conductivity, thermal diffusivity, and thermal effusivity, and demonstrate discrepancies with existing models.