Differential pressure changes of a high airflow-type HEPA filter during solvent fire in reprocessing facilities

Tashiro, Shinsuke ; Uchiyama, Gunzo ; Ono, Takuya ; Amano, Yuki ; Yoshida, Ryoichiro ; Abe, Hitoshi 

A clogging behavior of a high-efficiency particulate air (HEPA) filter at solvent fire accidents for reprocessing facilities has been studied. In this study, the burning rates of 30% tri-butyl phosphate (TBP)/dodecane (DD) mixed solvent and DD solvent and the differential pressure (P) of a high airflow typed HEPA filter applied in the actual facilities in Japan were measured. It was confirmed that the mainly burned was DD at the early stage of the mixed solvent burning and the TBP at the late stage. Furthermore, it was found that the P rapidly rose at the late stage of the mixed solvent burning. The increase of the release ratio of the unburned particulate composition (TBP, its degraded solvent and inorganic phosphorus (PO)) was considered to contribute to the rapid rise. The correlating formulas with the P and the mass of the loading particulates, except for the region of the rapid rise of P, could be induced.