RICHLAND, Wash. -- In light of a leak recently found in of the Hanford site's underground double shell waste tanks, Washington River Protection Solutions says they have started video inspections of six other tanks similar to the tank with the leak.
Video inspection of the first of these tanks, AY-101, was finished last week and the project manager says no leak was found.
The original leak, in tank AY-102, was announced in October after tests confirmed a small amount of chemical and radioactive waste is getting into the 30-inch space between the two shells of the tank, but not into the environment.
A pump is in place inside AY-102 that is capable of pumping liquid supernate from the primary tank. Another supernate pump and connectors are staged should the tank annulus require pumping.
AY-102 was the first double-shell tank constructed at Hanford, going into service in 1970. A 444-page Leak Assessment Report released in November documented a number of “first-of-a-kind construction difficulties and trial-and-error repairs,” including welds that didn’t meet specifications and had to be repaired, some several times; buckling and bulging of the steel plates that were welded together to form the bottom of the secondary shell creating voids between the secondary shell bottom and the concrete-like refractory that the primary shell sits on, and problems with the stress-relieving process as the result of cold weather and rainwater.
AY-101 was the second double-shell tank constructed at Hanford. Because lessons learned from AY-102 were applied to AY-101, it did not have the number or severity of construction difficulties experienced with AY-102.