Concept of off-Gas Purification in Reprocessing Plants

摘要

Concepts and individual processes for the off-gas purification in reprocessing plants are described which are suited to achieve a better retention of the gaseous and volatile radionuclides sup 129 I, sup 85 Kr, sup 14 C, and tritium. Improved and new process steps have been developed to the cold pilot plant scale. Essential individual process steps are an efficient iodine desorption from the dissolver solution, improved and new off-gas scrubs with nitric acid, a cryogenic as well as a selective absorption process for rare gas recovery plus the required prepurification steps and a process for the continuous and pressure-free fixation and storage of krypton in a metal matrix. Individual facilities have been selected and combined to investigate integrated dissolver off-gas systems. Advanced concepts based on a process using low flows and loads of all off-gas streams including the cell ventilation off-gas are briefly discussed. (ERA citation 11:012831)