Groundwater Treatment Goals Met Early
WC Monitor
8/22/2014
Pump and treat systems at Hanford have removed more than 680 pounds of hexavalent chromium from groundwater near the Columbia River so far this fiscal year. The Department of Energy’s goal was to remove about 550 pounds by the end of the fiscal year on Sept. 30, an objective that DOE and CH2M Hill Plateau Remediation Co. met four months early. In fiscal 2012 more than 1,000 pounds of chromium were removed from near the river at Hanford and in fiscal 2013 about 871 pounds of chromium were removed, beating a goal set that year of 500 pounds of chromium. Goals are set that are lower than previous years’ work because as the concentration of chromium in the plumes near the rivers decreases, it takes more effort to remove the same amount of chromium from the groundwater, according to Hanford officials. Chromium was used as a corrosion inhibitor added to the river water used to cool Hanford reactors when the reactors were producing plutonium. Some of the chromium spilled or leaked from pipes.
Work to treat groundwater and an aggressive effort to dig up contaminated soil has reduced concentrations in the groundwater. The largest source of chromium contamination near the Columbia River at Hanford has been removed after workers dug up contaminated soil down to groundwater 85 feet deep in the area near the former D and DR reactors. In addition, “our contractor removed more chromium than forecasted this year by pulling more groundwater from the areas of highest contamination,” said Briant Charboneau, director of DOE’s Hanford soil and groundwater division. New wells were added and moved to the places where contamination was high, said Jim Hanson, the DOE project lead for groundwater contamination at the K East, K West, D, DR and H Reactor areas.
CH2M Hill also has improved the performance of the five pump and treat systems near the river, in no small part because of input from its operations, maintenance and engineering staff, said Bill Barrett, CH2M Hill director of operations for soil and groundwater cleanup. DOE added two new pump and treat systems in 2010 and 2011 that use a resin to strip chromium out of the water. The resin needs to be replaced less often that the resin previously used at Hanford, which has reduced down time for the systems. The three older systems also have been switched to the new resin. That has allowed modifications in how they are run, allowing one of them to operate at 150 percent of its design, Barrett said. The newer plants also have had minor modifications to allow throughput to be increased, he said. DOE and Hanford contractors have removed nearly 3 tons of chromium from groundwater since treatment systems began operating in the mid-’90s.
Eight More Hanford Pu Finishing Plant Buildings Torn Down
WC Monitor
8/22/2014
Eight more buildings at Hanford’s Plutonium Finishing Plant are gone as workers make way for the eventual teardown of the production portion of the plant. “As we prepare to demolish the facility, we’re ensuring that there is enough space around the main buildings to bring in heavy equipment and stage demolition debris,” said Mike Swartz, CH2M Hill Plateau Remediation Co. vice president for the Plutonium Finishing Plant. The eight buildings gone over the past month bring the total to 61 buildings demolished or removed at the plant since 2008. Recent work has included tearing down the long, 13,302-square-foot administration building built in the 1990s. An old security building that was original to the plant, which started operating in 1949, also was torn down. It covered 3,924 square feet and was sided with shingles containing asbestos that had to be removed before the building was demolished, Swartz said. The Department of Energy has a Tri-Party Agreement milestone to have the plant demolished to slab on grade in 2016.
Efforts to Find Unexploded Ordnances Continue
WC Monitor
8/22/2014
Workers trained to handle unexploded ordnance have been scouring 115 acres near Hanford’s Gable Mountain in the summer heat for bullets, rifle grenades and other debris left from an early firing range. The Hanford Patrol used the north side of the mountain from World War II through the early 1950s, firing into its slope for target practice and other weapons training. That left the area littered with bullets, casings, flares and the occasional smoke or tear gas grenade, some of them unexploded. “It’s not a radioactive site, but it is unique,” said Cathy Louie, the Department of Energy deputy project director for the river corridor. “It’s a significant footprint and a specialty sort of cleanup.” Work was done starting in 2008 to clean up the 55 acres used for a pistol range, a rifle range, a machine gun range and a range for firing grenades from rifles. The work underway now is to clean up the doughnut-shaped 115 acres around the firing range where bullets and grenades landed amidst the sagebrush. The site is reached down a 1.5-mile dirt road that is seldom used because Gable Mountain is considered a sacred tribal site and access to it by Hanford workers is restricted. Signs have been posted that warn “Danger — Unexploded Ordnance — Keep Out.”
Washington Closure Hanford has subcontracted with Terranear to bring in former military and civilian ordnance technicians to search the acreage around the former shooting ranges. It’s been hot work this summer, made more hazardous by rattlesnakes, scorpions and spiders. But the workers, some who have been in Afghanistan, are used to challenging conditions, according to Hanford officials. The technicians have a different look that most Hanford workers. They wear sun hats and snake gaiters instead of the hard hats and neon-orange safety vests required nearly everywhere else at Hanford. Hard hats could fall off and hit an unexploded ordnance as workers bend their heads to search the ground and the orange safety vests attract bees, said Traci Snyder, Washington Closure project safety representative. Two teams of seven technicians each search grids of 100 feet by 100 feet, starting by marking out five-foot-wide lanes to make sure no ground is missed. On flat areas that are clear of brush they can use a commercial-grade metal detector on wheels to search for ordnance. But much of the area is searched with hand-held devices because of the sage and sloping hillside of Gable Mountain.
The grids have been seeded with short pieces of piping as a quality control measure to make sure teams stay focused on the sometimes monotonous work. If a team finishes the grid without finding all the pipes, the grid has to be surveyed again. “To date they have not missed one,” said Nathan Metzler, a URS employee and the project lead for Washington Closure. “They are very good.” Work started April 7 and is about 80 percent complete, he said. So far workers have found about 30,000 bullets, four tear gas grenades that would have been fired out of a launcher and one partial smoke grenade. The grenades, about nine inches long, are shaped like bombs with fins. When a metal detector gets a reading, workers use a shovel to investigate, often finding fencing, nails and fence staples. They also have found old barrels used for target practice until they were turned into Swiss cheese, Metzler said. Earlier, when work was being done to clear the center of the area, flares and the links that hold strings of bullets together for machine guns also were discovered. The grenades have been found aboveground. They are surrounded with a barricade, and when work is completed the Army explosive ordnance disposal team will be called in to blow them up.
Testing Results Promising on Buried Research Waste Cleanup System
WC Monitor
8/22/2014
Results are promising from the initial testing of a system planned to clean up research waste dropped down the 94 vertical pipe units at Hanford’s 618-10 Burial Ground, according to Hanford officials. The burial ground just off the main Hanford highway north of Richland is believed to be one of the two highest hazard burial grounds in the river corridor. Some of the worst of the research waste generated at Hanford’s 300 Area just north of Richland was dropped down the pipes in containers ranging from the size of juice cans to buckets from 1954 to 1963.The Department of Energy and Washington Closure Hanford are planning to pound steel overcasings into the ground to surround each VPU and then crush and mix both the waste and the VPU surrounded by the overcasing. Mock VPUs have been installed by Washington Closure near the 618-10 Burial Ground to test the system, and initial testing has been done on two types of the units with testing yet to be done on the potentially most challenging type of VPUs. As cleanup planning began, all the VPUs were believed to be made of five 50-gallon drums without tops and bottoms welded together to form a pipe. But the first 27 VPUs were made from corrugated pipes 12 to 14 inches in diameter buried in the ground. In addition, some of the pipes now are believed to be made of steel and may be different sizes.
The initial testing has been done on mockups simulating a VPU made of drums and another of corrugated piping. Steel overcasings 30 feet long and 48 inches in diameter were driven into the ground with a hydraulic hammer around the units. Then an auger pulverized the mock waste and the original pipes, using water for dust suppression, and mixed it up with some of the soil surrounding the original pipes. “It was very, very good size reduction,” said Mark Buckmaster, project manager for the 618-10 vertical pipe units. “It comes out looking like sand and gravel.” Washington Closure plans to start work as soon as next month to learn more about the quantity of each type of VPUs in the burial ground, before proceeding with more testing, which will include the first tests of the system on one of the steel VPUs. Workers will dig down enough to uncover the top of 30 of the VPUs, which were sealed earlier with concrete plugs. No more than two are expected to be uncovered at a time. Photos of construction of the vertical pipe units show what type of pipes were used for the other 64 units.
Hanford officials already have some knowledge of what’s in the VPUs after four narrow steel cylinders were pushed into the ground around each of them, allowing radiation detectors to be lowered to take readings. Some of the data showed that some waste likely was cesium 137, which likely indicates highly radioactive fuel or pieces of fuel from Hanford reactors. Others have indications of cobalt 60, likely from radioactive reactor parts that failed and then were brought to the 300 Area for testing. Generally there were one or two isolated very hot spots in each pipe, Buckmaster said. Plans call for pulling up samples of the waste after it is augered, using the hollow center of the auger, to learn more. There is no good way to sample the waste before it is crushed and mixed by the auger, according to Hanford officials.
Some of the waste is expected to be classified mixed low level waste, which can be mixed with grout and sent to the Environmental Restoration Disposal Facility in central Hanford. If waste is low level, early plans call for injecting grout through the hollow stem of the auger and then digging up the grout and any surrounding soil or soil at the bottom of the column that may be contaminated. However, some of the VPU waste may be classified as transuranic waste and sent to the Waste Isolation Pilot Plant. For VPUs with transuranic waste, Washington Closure plans to build an enclosure on the ground at the top of the pipe and then use heavy equipment operated outside the enclosure to scoop out the waste. It would be packaged into drums and then taken to central Hanford for further characterization to make sure it meets WIPP requirements.
A Hanford Advisory Board committee heard an update on plans for the burial ground recently, and several members had concerns. “I am concerned about releases in the environment,” said Shelley Cimon. Now the waste is contained in cans, but it would be released and mixed, she said. Other members were concerned that waste that would be considered transuranic before the waste is mixed together, could be at levels classified as low level after the waste is crushed and mixed with other waste in the overcasing. That would allow it to be sent to ERDF. Questions also were raised by board members about the wisdom of pulverizing containers, some of which contain liquids. “The amount of liquids is very minor,” Buckmaster said.
Plans are being made now for more testing of the system on the mockup VPUs. Among refinements could be work to make sure the waste is evenly spaced from top to bottom after it is crushed and mixed in the overcasing. The cleanup work on the actual VPUs could start in the summer of 2015. The Tri-Party Agreement calls for the cleanup to be finished in 2018. The 618-10 Burial Ground also has 12 trenches where bottles of laboratory waste and drums of radioactive waste were buried in the soil. Work to clean up the trenches is about 80 percent complete, according to DOE. The high-hazard 618-11 Burial Ground also was used to bury research waste and the method developed for the VPUs at the 618-10 Burial Ground also will be used there. The 618-11 Burial Ground, which is just off the parking lot of Energy Northwest’s commercial nuclear power plant, has three 900-foot-long trenches, 50 VPUs and four caissons.
