Radwaste Solutions | Year: 2011
Removing waste from U.S. Department of Energy's Hanford's storage tanks is one of the most difficult environmental challenges in the entire DOE complex. Tanks are buried under 10 feet of soil and were built to put waste in, not take it out. The new Venturi system safely removes multiple forms of waste solids from the leaking tanks without allowing more liquids to escape. The fluid injected at the head end flows smoothly to the receiver tank at the rate of 70 gpm at a pressure of 100 pounds per square inch. The prototype vacuum retrieval system is attached to a robotic arm. The vacuum system is being tested in a variety of waste simulants ranging from thick sludge to dense sand. The fluidizer nozzles are a fan spray on each side of the head that run between 8 and 30 gallons per minute as needed. They create a water broom to move waste into the head. Currently outfitted with two types of spray nozzles, the system can use fluidizer nozzles to wash waste, such as sludges, into the head, thinning as it goes.
Radwaste Solutions | Year: 2011
Significant advancements in Surface Geophysical Exploration (SGE) technology and improvements in computational capabilities were enabling scientists at the US Department of Energy's Hanford Site in Washington State to explore radioactive and chemical waste plumes in the soil around underground radioactive waste storage tanks. SGE had enhanced the ability of scientists to gather more information about soil contamination so that they took appropriate action to protect the environment. The first application of SGE technology was adapted from the mining industry and after that it improved significantly to find use in other areas. A significant advancement in the technology came when a team of researchers combined SGE with Direct Push technology. The SGE work at SGE work at Hanford had an added benefit as it was driving the development of standard processing software that were used by scientists at such sites around the world.
Radwaste Solutions | Year: 2010
Surface geophysical exploration (SEG) technology has been successfully used by the scientists at the Hanford Site to obtain 3-D images of radioactive and chemical waste plumes. Hanford has used SGE for the past few years to locate these contaminant plumes, and it has proven to be effective, but until recently it has been able to show only the breadth of a plume, not the depth. The plumes were created from tank leaks that occurred decades ago, with the largest in the early 1970 at 1150000 gal. Well casings are used in conjunction with steel probes inserted into the soil to locate plumes of contaminants beneath radioactive waste storage tanks. The use of SGE, especially at depth, is taking us orders of magnitude closer to where we need to be in defining the extent of the problem of these waste plumes in the soil. SGE also gives a starting point which will allows to see if there is movement of the plumes overtime.
Roxburgh R.,WRPS |
Radwaste Solutions | Year: 2013
A leak was discovered in the annulus of one of the Hanford's double shell tanks, AY-102, which contains 850000 gallons of high level waste from the past production of weapons-grade plutonium. Tests performed on samples of material found in the annulus between the inner and outer walls of AY-102 show that HLW has leaked from the primary tank, according to a report prepared by Hanford Tank Operations contractor Washington River Protection Solutions (WRPS). The waste was first discovered in the 30-inch-wide annulus space in early August 2012. To get a clearer picture, video cameras were lowered into the annulus through 10 different access pipes. Images taken with the cameras showed three suspicious spots. The report suggests construction problems coupled with the heat generated by the waste likely led to corrosion of the bottom of the primary shell of AY-102. The report also concluded that it's probable that the bottom of the inner shell is leaking in one place, with the waste coming out in two places through ventilation channels in the refractory used to help cool the tank.