Stabilization of uranium hexafluoride by hydrolysis method for decommissioning of safeguard laboratory facility

Inagawa, Jun; Hotoku, Shinobu ; Oda, Tetsuzo; Aoyagi, Noboru   ; Magara, Masaaki  

In safeguard laboratory (SGL) facility of Nuclear Science Research Institute of JAEA, uranium hexafluoride (UF) of enriched uranium of various enrichment was used for research and development of a spectrometric method for the determination of the enrichment of uranium in April 1983 through March 1993. After completion of this R&D, the UF has been stored in SGL facility. It was decided that the UF is carried to out of the facility, because the SGL facility will be decommissioning until March 2015. To transport and store in safety after transportation, it is necessary that the UF should be converted to stable chemical form. Hydrolysis of UF to uranyl fluoride (UOF) and evaporation to solid state were selected for the stabilization method. The equipment for hydrolysis and evaporation was installed in the SGL facility. Stabilization was operated in this equipment, and all of the UF in the SGL facility was converted to UOF solid state in October 2012 through August 2013. In this report, results of examination and operation for stabilization of UF were reported.