NEW DISCOVERY RAISES ADDITIONAL QUESTIONS AT HANFORD DOUBLE-SHELL TANK

More material has been found between the primary and outer shells of a Hanford double-shell tank, increasing concerns that Tank AY-102 may be deteriorating and leaking waste from its primary shell. In early August, radioactive material was found in two spots outside the tank’s primary shell, a first for one of Hanford’s 28 double-shell tanks, which may be needed to hold waste until the last of it is treated in 40 years. Last week, in one of the initial steps to learn more, a video camera was lowered through a different riser to begin additional video inspections and found the third spot with material. A photo taken of the same area in 2006 showed it to be clean. “We just have got to think it’s not encouraging to find another spot that clearly was not there in 2006,” said Cheryl Whalen, cleanup section manager for the Washington State Department of Ecology’s Nuclear Waste Program.

Suspicions were raised in early August that the inner shell of Tank AY-102 might be leaking when a video camera lowered into the space between the inner and outer shells of the tank and then a video camera lowered for a more in-depth look found unexpected material there. The cameras showed two side-by-side areas of contamination, one a dry mound about 24-by-36-by-8 inches. A sample of the material was collected, showing it was radioactive. DOE launched an investigation then, with plans to send cameras down the 10 risers that allow access from above ground into the space between the tank’s shells. The area around the first additional riser checked last week turned up the third spot of material. It has not been determined yet if the material is radioactive, said Lori Gamache, DOE spokeswoman. “We are continuing our investigation, including gathering additional information from other tank risers,” DOE said in a message to workers late last week. DOE also is investigating whether the radioactive material may have come from a pit with pumps or piping serving the AY Tank Farm where there could have been a spill.