ORNL Transuranic (TRU) Waste Tanks Remediation and Closure

RSI led a task to remediate and close three subsurface TRU waste tanks at ORNL. The waste tank capacities ranged from 13,000 to 15,000 gal and contained over 675 curies of TRU waste sludge and supernatant. The tanks waste consisted of spent ion exchange resin, reactor pool treatment system blow down, and mineral solids. The remediation scope included preparation of the sites for access to the underground tanks, supernatant removal and transfer to an active on site waste treatment facility, mixing of tank sludge, retrieval and transfer of sludge to an active solid waste treatment facility, and grout stabilization of the empty tanks. RSI developed subcontracts for site preparation and waste mixing and transfer activities, and participated in the evaluation, negotiation, and award of both contracts. The waste mixing and transfer operations employed unique pulse jet mixing and waste extraction technologies developed via DOE’s EM-50 research and development program. RSI acted as the technical lead for evaluation of these technologies as well as the design and optimization of a progressive cavity waste slurry pumping system. RSI responsibilities for this task included day-to-day management of mobilization, operations, waste transfers, equipment decommissioning, and secondary waste disposition. RSI was responsible for project schedule and budget compliance. The task was completed with a cost avoidance of over $2 million and 6 months ahead of schedule.