Influence of molten salt composition on the fluorination of UF4

Evaporation behavior of 2LiF–BeF2–ZrF4 molten salt with irradiated nuclear fuel

“…UF 4 and ThF 4 targets, loaded separately in sealed acrylic (polymethyl methacrylate) boxes, were irradiated using a photoneutron source (PNS) at the Shanghai Institute of Applied Physics, CAS, China. The PNS was derived from a 15 MeV electronic accelerator.…”

“…2LiF–BeF 2 –ZrF 4 salt (LiF–BeF 2 –ZrF 4 : 65–30–5 mol%) was prepared according to the procedures described in our previous work. 4 Certain amounts of fluorides (UF 4 , ThF 4 ) and FLiBe–ZrF 4 with a mass ratio of 2 : 2 : 26 were mixed in a nickel crucible (Ni purity > 99.96%, Sinopharm Chemical Reagent Co., Ltd.), which was placed inside the furnace vessel. After the vessel was sealed by covering the lid and screwing tight, it was first heated to 523 K and maintained for 2 h to remove trace moisture.…”

“…3 In the last ten years, Shanghai Institute of Applied Physics (SINAP) has undertaken a thorium-based molten salt reactor (TMSR) programme, and developed the pyro-processing methods to separate uranium and recover the carrier salt from spent nuclear fuel, mainly based on the uoride volatility method (FVM), low-pressure distillation and high-temperature electrochemistry. [4][5][6][7][8][9][10] Briey, the discharged fuel salt was rst reacted with uorine, which would result in removal of uranium as a volatile UF 6 . The salt would then be fed to a low-pressure (approximately 1 Torr) single-stage still where the 7 LiF and BeF 2 would be vaporized and recovered.…”

“…The 2LiF–BeF 2 –ZrF 4 (expressed as FLiBe–ZrF 4 ) molten salt with irradiated ThF 4 and UF 4 fuels was first treated by fluorination process, where UF 4 was reacted with F 2 and the product, UF 6 , was adsorbed by the adsorbant NaF at 823 K as our previous work. 4 Then the mixture salt was transferred to the low-pressure distillation equipment and the evaporation experiment was carried out at 1223 K and 30 Pa. The specific activity of radioactive nuclides was measured by a high-purity germanium detector HPGe gamma spectrometer.…”

On the Structures of Thorium Fluoride and Oxyfluoride Anions in Molten FLiBe and FLiNaK

“…19 The thorium fluoride and oxyfluoride species identified in molten FLiNaK−ThF 4 correlate well with those in molten FLiBe−ThF 4 , although there is an intrinsic difference between the two fluoride melts. 20 ■ EXPERIMENTS AND THEORETICAL METHODS All the chemicals were handled in an argon atmosphere glovebox with oxygen and water contents less than 1 ppm. The eutectics of FLiNaK (46.5 mol % LiF, 11.5 mol % NaF, 42.0 mol % KF) and FLiBe (66.7 mol % LiF, 33.3 mol % BeF 2 ) were prepared as described previously.…”