New RELAP5-3D Lead and LBE Thermophysical Properties Implementation for Safety Analysis of Gen IV Reactors

Abstract

The latest versions of RELAP5-3D©code allow the simulation of thermodynamic system, using different type of working fluids, that is, liquid metals, molten salt, diathermic oil, and so forth, thanks to the ATHENA code integration. The RELAP5-3D©water thermophysical properties are largely verified and validated; however there are not so many experiments to generate the liquid metals ones in particular for the Lead and the Lead Bismuth Eutectic. Recently, new and more accurate experimental data are available for liquid metals. The comparison between these state-of-the-art data and the RELAP5-3D©default thermophysical properties shows some discrepancy; therefore a tool for the generation of new properties binary files has been developed. All the available data came from experiments performed at atmospheric pressure. Therefore, to extend the pressure domain below and above this pressure, the tool fits a semiempirical model (soft sphere model with inverse-power-law potential), specific for the liquid metals. New binary files of thermophysical properties, with a detailed mesh grid of point to reduce the code mass error (especially for the Lead), were generated with this tool. Finally, calculations using a simple natural circulation loop were performed to understand the differences between the default and the new properties.

Post-test simulation of a PLOFA transient test in the CIRCE-HERO facility

“…The main dimensions of the thermal-hydraulic model are summarized in Table 1. , 2015) and integrated in R5-3D, as presented in Balestra et al (2016). In the MULTID component, the three-dimensional momentum equations are used.…”

Pre-test analysis of protected loss of primary pump transients in CIRCE-HERO facility

“…Previous analysis was carried out using thermophysical properties correlations implemented in R5-3D. The same simulations are repeated using the most recent correlations derived from [9], which have been implemented in Relap5-3D [10]. Figure 7 and Figure 8 show the comparison between R5-3D and NEA properties correlations on case 4.…”

STH-CFD Codes Coupled Calculations Applied to HLM Loop and Pool Systems

“…The application of STH codes to GEN-IV system required the implementation of thermophysical properties and correlations for new kind of fluids (e.g., liquid metals). Balestra et al at the University of Rome, in collaboration with the Idaho National Laboratory (INL), developed a tool for the generation of new properties binary file needed by the code RELAP5-3D [15] and implemented thermophysical properties for LBE and Lead recommended in [16].…”