Use of Multiple Innovative Technologies for Retrieval and Handling of Low-Level Radioactive Tank Wastes at Oak Ridge National Laboratory

The U.S. Department of Energy (DOE) successfully implemented an integrated tank waste management plan at Oak Ridge National Laboratory (ORNL) (1), which resulted in the cleanup, removal, or stabilization of 37 inactive underground storage tanks (USTs) since 1998, and the reduction of risk to human health and the environment. The integrated plan helped accelerate the development and deployment of innovative technologies for the retrieval of radioactive sludge and liquid waste from inactive USTs. It also accelerated the pretreatment of the retrieved waste and newly generated waste from ORNL research and development activities to provide for volume and contamination reduction of the liquid waste. The integrated plan included: retrieval of radioactive sludge, contaminated material, and other debris from USTs at ORNL using a variety of robotic and remotely operated equipment; waste conditioning and transfer of retrieved waste to pretreatment facilities and interim, double contained storage tanks; the development and deployment of technologies for pretreating newly generated and retrieved waste transferred to interim storage tanks; waste treatment and packaging for final off-site disposal; stabilization of the inactive USTs that did not meet the regulatory requirements of the Federal Facilities Agreement between the DOE, the Environmental Protection Agency (EPA), and the Tennessee Department of Environment and Conservation (TDEC); and the continued monitoring of the active USTs that remain in long-term service. This paper summarizes the successful waste retrieval and tank stabilization operations conducted during two ORNL tank remediation projects (The Gunite Tanks Remediation Project and the Old Hydrofracture Facility Tanks Remediation Project), the sludge retrieval operations from the active Bethel Valley Evaporator Service Tanks, and pretreatment operations conducted for the tank waste. This paper also provides the status of ongoing activities conducted in preparation of treating the retrieved tank waste for final disposition, and the efforts to improve monitoring capabilities for waste collection and storage tanks that will remain in long-term service at ORNL