Completion report for the isolation and remediation of inactive liquid low-level radioactive waste tanks 7562, H-209, and T-30 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

A human health risk analysis was conducted on inactive tanks 7562, H-209 and T-30 to determine the method for remediating the tanks. Risk analysis results indicated that the health risk associated with these tanks were within or below the EPA range of concern of 1 {times} 10{sup {minus}4} to 1 {times} 10{sup {minus}6}. On the basis of these results, and with regulator approval, it was determined that either no action or in-place stabilization of the tanks would satisfy risk-based remediation goals. Therefore, a decision was made and approved by DOE to remediate these tanks in-place as a maintenance action. Tanks H-209 and T-30 were isolated from associated piping, electrical systems, and instrumentation and grouted in-place. Due to regulatory concerns over the location of tank 7562 relative to an area of subsurface soil contamination, tank 7562 was isolated from associated piping and instrumentation and left in-place empty. Completion of these maintenance actions has met the intent of the Federal Facility Agreement (FFA) for remediation of inactive tanks H-209 and T-30. EPA and Tennessee Department of Environment and Conservation (TDEC) will be requested to approve a change to the FFA removing tanks H-209 and T-30 from the Appendix F list of inactive tanks. The request for removal of tank 7562 from Appendix F will be submitted pending final disposition of the tank. Since the associated tank piping systems remain in-place, it will further be requested that these systems be included as individual sites in Appendix C of the FFA for future remedial consideration