Analysis of Unit Process Cost for an Engineering-Scale Pyroprocess Facility Using a Process Costing Method in Korea

Abstract

Pyroprocessing, which is a dry recycling method, converts spent nuclear fuel into U (Uranium)/TRU (TRansUranium) metal ingots in a high-temperature molten salt phase. This paper provides the unit process cost of a pyroprocess facility that can process up to 10 tons of pyroprocessing product per year by utilizing the process costing method. Toward this end, the pyroprocess was classified into four kinds of unit processes: pretreatment, electrochemical reduction, electrorefining and electrowinning. The unit process cost was calculated by classifying the cost consumed at each process into raw material and conversion costs. The unit process costs of the pretreatment, electrochemical reduction, electrorefining and electrowinning were calculated as 195 US$/kgU-TRU, 310 US$/kgU-TRU, 215 US$/kgU-TRU and 231 US$/kgU-TRU, respectively. Finally the total pyroprocess cost was calculated as 951 US$/kgU-TRU. In addition, the cost driver for the raw material cost was identified as the cost for Li3PO4, needed for the LiCl-KCl purification process, and platinum as an anode electrode in the electrochemical reduction process.