Chlorination reaction behavior of Zircaloy-4 hull waste was investigated by using HSC chemistry code as a function of decladding
ratio. The Zircaloy-4 hull waste and residual spent nuclear fuel (SNF) remaining in the hull waste after oxidative decladding
process were considered as reactants of the chlorination reaction. It was assumed that the hull waste and residual SNF is
fed into the chlorination reaction after oxidative decladding at 700 °C, which might have cause partial/full oxidation of
the hull waste and residual SNF components. Reaction temperature for the theoretical calculation was set at 330 °C. The simulation
results suggested that solid phase chlorides (BaCl2, SrCl2, NdCl3, LaCl3, and RhCl3) are produced prior to formation of ZrCl4(g) and HfCl4(g). Although ZrCl4(g) is produced later than the solid products, it was expected that ZrCl4(g) can be easily separated from other chlorides as it is a gas phase at 330 °C. Therefore, it was concluded that the decladding
ratio might not affect formation of ZrCl4(g) when sufficient chlorine gas was supplied. Equilibrium composition analysis suggested that highly pure ZrCl4(g) with 0.006 mol.% of HfCl4(g) might be recovered from the hull waste via the chlorination reaction method.