How much sludge can be dumped into a double-shelled radioactive waste tank before flammable gas might build up in a big bubble?
That's the question managers and scientists at the Hanford Nuclear Reservation are asking. And they are working against the clock to solve the possible new problem.
At Hanford's C-Farm, workers are pumping the radioactive sludge out old tanks with single shells into more-stable double-hulled tanks. This radioactive witch’s brew constantly generates hydrogen and other flammable gases. Scientists and engineers aren’t sure now how much the newer massive double-hulled underground tanks can hold before the sludge burps up a major flammable gas bubble.
This all matters because a legally-binding deadline is next September. That’s when all the sludge in this tank farm needs to be transferred.
“That issue can be solved long term," says Tom Fletcher, assistant manager for Hanford’s tank farms. "But from a perspective of meeting the 2014 milestone and being complete with C-Farm it’s critical to solve to make that milestone.”
Fletcher says that deadline to cleanup C-Farm is possibly in jeopardy.
There’s a total of 56 million gallons of radioactive sludge at Hanford that is left over from making plutonium for bombs during World War II and the Cold War.