Hanford's one leaking single-shell radioactive waste tank is now six leaking tanks — and possibly more.
The fix-it measure: That's a mystery for now.
But it might get revealed in the next few days. Gov. Jay Inslee wants remedial work to start as quickly as possible.
"We need an action plan at Hanford in a variety of ways," said Inslee Friday afternoon when he announced the new leaking tanks in a phone press conference. Inslee was in Washington, D.C., and had just been briefed by Secretary of Energy Stephen Chu.
There is no immediate health danger, Inslee said.
Central Hanford has 149 single-shell tanks and 28 newer double-shell tanks holding 53 million gallons of highly radioactive fluids, sludges, gunk and crusts — all underground. There are 18 clusters of tanks — dubbed "tank farms" — seven to 14 miles from the Columbia River. Sixty-seven of the single-shell tanks have been designated leakers or suspected leakers for decades. Hanford's tanks have design lives of roughly 20 years.
Hanford has pumped almost all the liquids from the single-shell tanks into the double-shell shells, finishing that task in 2005. The single-shell tanks still hold sludge, gunk and crusts, plus tiny pockets of fluids.
Tests were being conducted on several single-shell tanks to see whether rainwater was leaking into them through possible cracks. Those tests showed a dip in fluid levels in Tank T-111, which is in the northwest corner of central Hanford's tank farms. Engineers extrapolated that drop into a leak of 150 gallons to 300 gallons annually for an undetermined number of years. All 177 stainless steel tanks, ranging from 500,000 gallons to 1.2 million gallons in size, are buried beneath 10 to 20 feet of soil. All the testing and pumping are conducted through narrow pipes between the tanks' interiors and the ground's surface. The tanks are roughly 100 feet to 200 feet above the aquifer.
Inslee learned a week ago about Tank T-111. On Friday, Chu told him the number of leaking single-shell tanks is now six, and tests are being conducted to see if more are leaking. Some of the new leakers are outside of the tank cluster that includes Tank T-111 —meaning the problem is geographically wider than one small spot in Hanford. The newly discovered leaks are believed to be equal to or smaller than Tank T-111's leak, said Dieter Bohrmann, spokesman for the Washington Department of Ecology.
The U.S. Department of Energy is looking at ways to remove the wastes from the leaking single-shell tanks, with Inslee saying the feds might narrow the choices in one or two weeks. He declined to list the options. "I'm not at liberty to talk about that until next week," Inslee said.
One possibility would be to dig through the soil and cut a big enough hole in the top of a single-shell tank to scoop, vacuum or sluice the radioactive gunk out of the tanks. Tank T-111 holds 447,000 gallons of sludge and crusts.
A problem with this approach would be dealing with vast amounts of radioactive dusts, vapors, and debris from the disturbed solid wastes. Another problem is what to do with the extremely radioactive wastes after the material is removed.
Or the wastes could be sluiced out through the narrow pipes in the tanks. A problem with this approach would be the forcing of a huge volume of water for weeks into a highly radioactive environment that already leaks. Another problem be would be where to put hundreds of thousands of gallons of super-radioactive fluids that would be outside of the tanks. The 28 double-shell tanks are already almost full.
The Tri-City Herald recently reported that DOE has been thinking about shipping the wastes from Tank T-111 to a huge manmade underground cavern near Carlsbad, N.M., where the feds have been storing thousands of barrels of highly radioactive junk. A problem with this approach would be the tank wastes being much more radioactive than the contaminated junk currently being sent to New Mexico. Also the volumes from Hanford's tanks would be vastly greater than what is currently trucked to Carlsbad. And the massively extra-radioactive wastes and huge volumes would have to be allowed to cross the states between Washington and New Mexico, which have agreed only to allow drastically less volumes to cross their borders.
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