Health Physics experience during conditioning of medium level liquid waste from reprocessing plant at Tarapur

Spent fuel processing plant (PREFRE) at Tarapur generates High level (HL), Intermediate level (IL) and low-level (LL) liquid wastes. High level and Intermediate level liquid wastes are stored in underground stainless steel and carbon steel tanks respectively. The low level liquid waste generated is relatively large in volume and is routinely treated at Low-level liquid waste treatment plant before discharge to environment. For treatment of Intermediate level waste, a scheme of fixation in Cement -vermiculite matrix in mild steel tanks placed in RCC trenches at Solid Waste Disposal Facility was adopted. This method of treatment is known by acronym 'CLEAR' (Conditioning of Liquid Effluents of low and Intermediate level of Activity from Reprocessing Plant at Tarapur). The scheme consisted of transfer of the liquid waste from PREFRE Waste Tank Farm via pump house facility through underground encased pipe lines to conditioning tanks placed in RCC trenches at SWMF (Solid Waste Management Facility). In-Situ fixation involved addition of vermiculite to the liquid waste, with constant stirring followed by cement addition at controlled rate by remote mechanism. Lastly water proofing of RCC trench was carried out to prevent ingress of rain water. The treatment of Intermediate Level waste was carried out on campaign basis. Health Physics experience gained during the five CLEAR Campaigns is presented in the paper. (author)