Design of a Filter Aid and Coagulant Addition System at Three Mile Island Unit 2

The installed defueling water cleanup system filters experienced severely reduced operating life. This was caused by blinding of the filter media due to colloidal material located within the Three Mile Island Unit 2 (TMI-2) reactor vessel. Through laboratory testing, a combination of coagulant and filter aid placed on the filter media was found to extend operating time tenfold. A system of pumps, mixers, tank, and control was developed to apply the coagulant and filter aid to the filters located in the TMI-2 damaged containment.