Fractional Release Behavior of Volatile and Semivolatile Fission Products During a Voloxidation and OREOX Treatment of Spent PWR Fuel

Effect of alkali and alkaline-earth chloride addition on electrolytic reduction of UO2 in LiCl salt bath

“…Because of the difficulty in separating CsCl from the LiCl salt bath, the removal of Cs from spent oxide fuels before the electrolytic reduction process is desirable to reduce the amount of salt waste. It has been suggested in the literature that most of the Cs can be removed from spent oxide fuels by volatilization at a high temperature [23,24]. …”

Oxidation kinetics for conversion of U3O8 to ε-UO3 with NO2

“…Those processes consist of oxidation-reduction cycling between UO 2 and U 3 O 8 with the use of air/oxygen and hydrogen [6]. While the crystalline density change is thought to be minimal for the reaction of U 3 O 8 to UO 3 as compared with the 36% crystalline volume change of UO 2 to U 3 O 8 , Brunauer, Emmet, Teller (BET) surface area analysis has shown an increase in surface area that is highly conducive to volatile and semivolatile fission product removal.…”

Simulation of Cs behavior during the high temperature voloxidation process using the HSC chemistry code

“…In addition, it was revealed that the Ar and 4% H 2 /Ar conditions are beneficial for the removal of Cs owing to the formation of gaseous Cs above 1175 and 671°C for each case. Here, it should be reminded that the release fraction of Cs was only 16% at 1000°C and under reducing conditions [4]. The experimental results suggest that the removal of Cs cannot be interpreted by the Cs-O system presumably due to the chemical reactions between Cs (oxides) and other FPs or U oxides.…”

“…The closest results were reported by KAERI [4], where the oxidation and reduction of oxide fuel, which is the socalled the OREOX process, was investigated as a part of the DUPIC (Direct Use of spent Pressurized water reactor fuel In Canada deuterium uranium) program. In a previous study [4], the release of Cs from the SNF during 500°C heat treatment (air atmosphere) was not observed, while the release fraction of Cs increased to 16% after [5] demonstrated a complete removal of Cs from 47 GWd/tU PWR fuel (6 years cooling) by heating up to 2527°C, and suggested that the release rate of Cs was significantly increased to above 2527°C.…”