Coupled Thermal-Hydraulic Analysis and Species Mass Transport in a Versatile Experimental Salt Irradiation Loop (VESIL) Using CTF

Samuel A Walker,Robert K Salko,Abdalla Abou-Jaoude,Zack Taylor,Wei Ji

doi:10.3390/jne2030025

Abstract

With the resurgence of interest in molten salt reactors, there is a need for new experiments and modeling capabilities to characterize the unique phenomena present in this fluid fuel system. A Versatile Experimental Salt Irradiation Loop (VESIL) is currently under investigation at Idaho National Laboratory to be placed in the Advanced Test Reactor (ATR). One of the key phenomena this proposed experiment plans to elucidate is fission product speciation in the fuel-salt and the subsequent effects this has on the fuel-salt properties, source term generation, and corrosion control. Specifically, noble gases (Xe & Kr) will bubble out to a plenum or off-gas system, and noble metals (Mo, Tc, Te, etc.) will precipitate and deposit in specific zones in the loop. This work extends the mass transfer and species interaction models in CTF (Coolant-Boiling in Rod Arrays—Two Fluids) and applies these models to give a preliminary estimation of fission product behavior in the proposed VESIL design. A noble metal–helium bubble mass transfer model is coupled with the thermal-hydraulic results from CTF to determine the effectiveness of this insoluble fission product (IFP) extraction method for VESIL. Amounts of IFP species extracted to the off-gas system and species distributions in VESIL after a 60-day ATR cycle are reported.

Highlights

The Versatile Experimental Salt Irradiation Loop (VESIL) shown below in Figure 1a, is a proposed fuel-bearing integrated effect experiment currently under investigation at IdahoTest Reactor (ATR)
Deposition model [3] and helium bubbling model [4] are coupled to determine what species will be extracted in an off-gas system
The current VESIL design was chosen after several thermal-hydraulic analyses conducted at Idaho National Laboratory (INL) using STAR-CCM+ and SAM [7]

Summary

Introduction

The Versatile Experimental Salt Irradiation Loop (VESIL) shown below in Figure 1a, is a proposed fuel-bearing integrated effect experiment currently under investigation at IdahoTest Reactor (ATR). The Versatile Experimental Salt Irradiation Loop (VESIL) shown below, is a proposed fuel-bearing integrated effect experiment currently under investigation at Idaho. As the fuel-salt is irradiated, the process of insoluble fission product (IFP) species migration, accumulation, and deposition will occur during the 60-day ATR cycle. This work applies the species mass transport capabilities currently under development within the subchannel thermal-hydraulics code CTF [2]. It acts as a feasibility study of the salt-loop in light of these complex transport phenomena. A previously developed NM deposition model [3] and helium bubbling model [4] are coupled to determine what species will be extracted in an off-gas system.

Methods

Results

Discussion

Conclusion