RETRIEVAL & TREATMENT OF HANFORD TANK WASTE

The Hanford Tank Farms contain 53 million gal of radioactive waste accumulated during over 50 years of operations. The waste is stored in 177 single-shell and double-shell tanks in the Hanford 200 Areas. The single-shell tanks were put into operation from the early 1940s through the 1960s with wastes received from several generations of processing facilities for the recovery of plutonium and uranium, and from laboratories and other ancillary facilities. The overall hanford Tank Farm system represents one of the largest nuclear legacies in the world driving towards completion of retrieval and treatment in 2028 and the associated closure activity completion by 2035. Remote operations, significant radiation/contamination levels, limited access, and old facilities are just some of the challenges faced by retrieval and treatment systems. These systems also need to be able to successfully remove 99% or more of the waste, and support waste treatment, and tank closure. The Tank Farm retrieval program has ramped up dramatically in the past three years with design, fabrication, installation, testing, and operations ongoing on over 20 of the 149 single-shell tanks. A variety of technologies are currently being pursued to retrieve different waste types, applications, and to help establish a baseline for recovery/operational efficiencies. The paper/presentation describes the current status of retrieval system design, fabrication, installation, testing, readiness, and operations, including: (1) Saltcake removal progress in Tanks S-102, S-109, and S-112 using saltcake dissolution, modified sluicing, and high pressure water lancing techniques; (2) Sludge vacuum retrieval experience from Tanks C-201, C-202, C-203, and C-204; (3) Modified sluicing experience in Tank C-103; (4) Progress on design and installation of the mobile retrieval system for sludge in potentially leaking single-shell tanks, particularly Tank C-101; and (5) Ongoing installation of various systems in the next generation of tanks to be retrieved