Evaluation of the Decay Heat Limits in Electrorefiners for Reprocessing Spent Metallic Fuels

Design limits on the accumulated decay heat in the molten salt of an electrorefiner (ER) are proposed based on two-dimensional steady-state calculations. It was found that forced convection cooling of the outer surface of the ER allows ~30 to 40% larger decay heat than that for natural circulation cooling. The validity of a steady-state calculation is confirmed by comparison with a one-dimensional non-steady-state calculation. Estimated decay heat limits are compared with that of NaCl resulting from the bonding Na in the spent metallic fuel and the lanthanides concentration in the salt. These comparisons suggest that consideration of the decay heat is very important for the continuous usage of the salt in the ER.