The Evaporation Behavior of Volatile Fission Products in FLiNaK Salt

Masami Taira,Yuji Arita,Michio Yamawaki

doi:10.11131/2017/101315

Abstract

Molten salt reactor (MSR) was suggested for the one of the nuclear power plant concepts planned for generation IV. However, little study had been done on the severe accident at MSR. The one of the severe accident at MSR is considered that the molten salt with fuel will be exposed to air and some fission products will release to environment. The molten FLiNaK salt (LiF-NaF-KF: 46.5–11.5-42 mol%) with CsI(FLiNaK- CsI: 99-1 mol%) was evaporated and released gases were measured by mass spectrometry. The evaporated gases from above sample were mainly CsI and KI. The value of vapor pressure for CsI was low about ten to the first ∼ second power of vapor pressure for pure CsI at same temperature. Therefore, it is expected that FLiNaK prevents the release of CsI. On the other hand, despite KI were not included in original sample, KI released significantly.

Highlights

Molten salt reactor (MSR) is one of the nuclear power plant concepts planned for Generation IV systems [1]
The most interesting point about MSRs is that the nuclear fuel was dissolved into molten salt of primary loop, and the molten salt served as coolant
It means that from a mixture of LiF-NaF-KF (FLiNaK) is difficult to be evaporated because of stable salt, the measuring temperature was decided to 1284K

Summary

Introduction

Molten salt reactor (MSR) is one of the nuclear power plant concepts planned for Generation IV systems [1]. MSR were first developed in the Oak Ridge National Laboratory (ORNL), United States in around 1950s to 1970s. In this term, the experimental reactor was constructed and operated [2, 3]. The heat generated by nuclear fission will be transported by primary molten salt. At heat exchanger, this heat is transported to the secondary loop, in which the molten salt of second loop doesn’t contain fissile elements-. This heat is transported to the secondary loop, in which the molten salt of second loop doesn’t contain fissile elements- This heat makes steam and converted to electricity

Methods

Results

Conclusion