Dissolution Behavior of Simulated Spent Nuclear Fuel in LiCl-KCl-UCl3 Molten Salt

Sang-Kwon Lee,Eun-Young Choi,Sung-Wook Kim,Jun-Hyuk Jang,Min Ku Jeon,Guglielmo Lomonaco

doi:10.1155/2021/9048775

Abstract

Considering the necessity of the development of methods to reduce the burden of storage and disposal of high-level radioactive waste, in this study, we propose a nuclide separation technique using molten salt immersion. The dissolution behavior of simulated spent nuclear fuels (SSFs) immersed in a LiCl-KCl-UCl3 (LKU) molten salt at 500°C was investigated using a combination of thermodynamic and experimental studies. Surrogates of transuranic elements (TRUs), that is, rare earth elements (REs), in the SSFs were dissolved into the molten salt without any damage to the UO2 structure of the SSFs. The results suggest that the LKU salt technique can be used to separate REs and, potentially, TRUs from actual spent nuclear fuels (SNFs). It is thought that this technique is advantageous over the conventional TRU recovery techniques because the majority of the SNFs (i.e., UO2) remained stable, thus reducing the process burden. Several SNF treatment process options using this technique were suggested. This study will serve as a guide for future studies on the management of high-level waste discharged from nuclear reactors.

Highlights

Is study will serve as a guide for future studies on the management of high-level waste discharged from nuclear reactors
transuranic elements (TRUs) are the most dangerous nuclides owing to their exceptionally long-lived and strong radioactivity, they can be utilized as fuels in various nuclear reactors, including Generation IV (Gen IV) reactors such as sodium-cooled fast reactors (SFRs), high temperature reactors (HTRs), and gas-cooled fast reactors (GCFRs) [4,5,6,7,8,9]
TRUs generated from the light water reactors (LWRs) can be transmuted into stable nuclides in the Gen IV reactors to minimize the amount of the high-level radioactive wastes, which is beneficial on the long-term underground disposal [4,5,6,7,8,9]

Summary

Introduction

Is study will serve as a guide for future studies on the management of high-level waste discharged from nuclear reactors. Coupling of back-end fuel cycle of the commercial light water reactors (LWRs) to the fuel cycle of the Gen IV reactors is an attractive option for the management of the LWR SNFs. TRUs generated from the LWRs can be transmuted into stable nuclides in the Gen IV reactors to minimize the amount of the high-level radioactive wastes, which is beneficial on the long-term underground disposal [4,5,6,7,8,9]. Science and Technology of Nuclear Installations the SNF management burden by decreasing radiotoxicity and to maximize resource usage Driven by these considerations, various wet and dry processes have been developed to recover valuable nuclides (especially TRUs) from SNFs [4, 11, 12]. The nuclides in the SNFs are dissolved in chloride molten salts (e.g., an LiCl and LiCl-KCl mixture) to allow them to be chemically and electrochemically recovered [4]

Methods

Results

Conclusion