Original Date: 11/03/1996
Revision Date: 01/18/2007
Information : Head End Treatment System
All process water for Oak Ridge’s Y-12 Plant is treated before it leaves the facility. Currently, the West End Treatment Facility processes 8 million gallons of water per year. During the water treatment, mixed sludge accumulates and is sent to the West Tank Farm (WTF) for storage in three 500,000-gallon tanks before final disposal. Approximately 40,500 gallons of mixed sludge accumulates annually during the water treatment process. At a cost of $1 million per tank, Y-12 needed a way to minimize the volume of radioactive sludge being transported off-site to a certified waste storage facility.
Mixed sludge contains various types of waste: common waste (acidic), basic wastewater (high concentrations of nitrates and heavy metals), and other waste (radioactive). Through additional steps, the Head End Treatment System (HETS) reduces the amount of radioactive waste by segregating the mixed sludge into radioactive sludge and non- radioactive, non-Resource Conservation and Recovery Act (RCRA) sludge. HETS removes heavy metals from the mixed sludge through hydroxide precipitation and neutralization of raw wastewater. The radioactive sludge is stored at the WTF while the non-radioactive, non-RCRA sludge (CaCO3) can be recycled as a treatment chemical or sent to a land disposal.
Since implementation, HETS reduced operational costs at the WTF from $9.5 million in 1993 to $4.3 million in 1995. In addition, the system reduced sludge generation by 30% (a portion of the regenerated sludge can now be readily disposed) and increased the storage life of the 500,000-gallon tanks from 12 years to 57 years.
For more information see the
Point of Contact for this survey.