Development of process simulation code for a reprocessing plant and analysis of solvent degradation and reduction of solvent washing waste

摘要

A process simulation code for an entire nuclear fuel reprocessing plant was developed. The code can be used on a personal computer. Almost all of the equipment in the reprocessing plant is included in the code and the mass balance model of equipment is based on the distribution factors of flow-out streams. Each model of equipment is connected between the outlet flow and the inlet flow according to the process flow sheet. We estimate the amount of DBP from TBP degradation in the entire process by using the developed code. The DBP concentration at the Pu refining process becomes the highest, which is generated from the TBP degradation caused by a radiation from the extracted Pu in solvent. On the other hand, very little of DBP is generated in the U refining process. We therefore propose simplification of the solvent washing process and volume reduction of the alkali waste solution in the U refining process. We also analyzed the amount of DBP when high burnup UO{sub}2 fuels and LWR-MOX fuels are reprocessed. It is concluded that two times amount of DBP is generated during the high burnup UO{sub}2 fuels and LWR-MOX fuels reprocessing but this amount of DBP is not so much to affect the process performance.