A leak has been ruled out as the cause for a drop in the level of liquid inside one of Hanford's huge underground waste tanks holding high-level radioactive waste.
That's been the good news at the Hanford tank farms this summer, as an equipment malfunction has suspended work at the only tank where radioactive waste was being retrieved. Waste from 142 older, leak-prone, single-shell tanks is being transferred to 28 newer double-shell tanks.
The Department of Energy and its contractor CH2M Hill Hanford Group had feared that a leak was responsible for a sudden drop in the liquid level earlier this year in a single-shell tank believed to have leaked radioactive waste into the soil beneath it in the past.
In May, Hanford workers saw a drop of about 1.7 inches in Tank SX-104.
But a leak was the worst-case scenario, with several other possibilities also considered for the fluctuation of the liquid level in the tank.
It turns out, Annette reports, that liquids within the tank were merely settling.