Pyroprocessing technology has been actively developed at Korea Atomic Energy Research Institute (KAERI) to meet the necessity of addressing spent fuel management issue. This technology has advantages over aqueous process such as less proliferation risk, treatment of spent fuel with relatively high heat and radioactivity, and compact equipments. This paper describes the pyroprocessing technology development at KAERI from head-end process to waste treatment. The unit process with various scales has been tested to produce the design data associated with scale-up. Pyroprocess integrated inactive demonstration facility (PRIDE) was constructed at KAERI and it began test operation in 2012. The purpose of PRIDE is to test the process regarding unit process performance, remote operation of equipments, integration of unit processes, scale-up of process, process monitoring, argon environment system operation, and safeguards-related activities. The test of PRIDE will be promising for further pyroprocessing technology development. 1. Introduction Pyroprocessing treatment can reduced the volume, radioactivity, and heat load of the light water reactor (LWR) spent fuels [1]. In addition, pyroprocessing based on the group recovery of transuranic element (TRU) can provide metal fuels for the sodium-cooled fast reactor while keeping higher intrinsic proliferation resistance. Therefore, successful development of pyroprocessing can save disposal space, reduce the radiotoxicity of spent fuels, and increase uranium utilization efficiency. Korea Atomic Energy Research Institute (KAERI) has been developing pyroprocessing since 1997. The concept development, bench scale testing, and demonstration of laboratory scale key unit process had been carried out since 2006. From 2007 to 2011, the focus moved to the design and construction of engineering-scale integrated system. Pyroprocess integrated inactive demonstration facility (PRIDE) was constructed in 2011 and it began test operation in 2012. Process flow diagram consists of head-end processes (decladding, voloxidation, oxide feed preparation), electrochemical processes (electrolytic reduction, electrorefining, electrowinning), and waste treatment processes as shown in Figure 1. Figure 1: Flow diagram of pyroprocessing (PRIDE at KAERI). 2. Unit Process of Pyroprocessing 2.1. Head-End Process The head-end process in pyroprocessing is to convert spent fuel assembly into a suitable feed material which is supplied to the electrolytic reduction process. The first step of head-end process is to disassemble spent pressurized water
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