The Environmental Protection Agency has called the uncontrolled spread of small amounts of radioactive waste at Hanford “alarming” after a Nov. 17 windstorm.
Surveys six miles north of Richland after the winds subsided found specks of contamination had spread beyond Route 4, the public highway from Richland out to the Wye Barricade secure entrance to Hanford.
The contamination had blown from the 618-10 Burial Ground, which is being cleaned up on the west side of the highway.
The search also turned up previously undiscovered specks of radioactive waste believed to have been spread by plants or animals outside known contaminated areas.
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Hanford officials brought in a street sweeper to collect the sand and dirt from a stretch of highway near the burial ground. Tests of the sweepings plus a survey of the road turned up no contamination on the public highway. It is heavily traveled by Hanford and Columbia Generating Station employees driving to and from work.
The pieces of material found were small, just specks or grains, and the contamination level on them was very low, according to the Department of Energy.
This is a matter that is alarming to EPA and requires further investigation and discussion.
EPA letter to DOE
“The workers and public were not at risk of exposure because of the spread of contamination,” said Bryan Foley, DOE deputy project director for Hanford work near the Columbia River, at a recent Hanford Advisory Board committee meeting.
The Washington State Department of Health agrees that the spread of waste did not pose a threat to the public. Its concern is that control of the contamination was lost and that a more serious spread of contamination is not allowed to occur, said John Martell, of the department’s Office of Radiation Protection.
EPA, in a letter to DOE, said the spread of contamination “is a matter that is alarming to EPA and requires further investigation and discussion.”
It has given DOE until the third week of April to prepare a report on its loss of control of radioactive material. DOE is required to describe for EPA, a Hanford regulator, what actions and technology it plans to prevent a recurrence.
DOE and its contractor, Washington Closure Hanford, have had problems with contamination spread at the 618-10 Burial Ground as early as summer 2014, according to the weekly staff reports of the Defense Nuclear Facilities Safety Board.
In one of the incidents described by defense board staff, a windstorm spread small pieces of plastic outside the burial ground’s boundary fence. The plastic, used to wrap contaminated equipment, can become brittle and break.
Winds as high as 75 mph swept over the burial ground, spreading contamination.
Workers at the burial ground near Route 4 in southern Hanford are digging up contaminated debris and drums of waste from trenches to be treated and taken to a lined landfill in central Hanford for disposal.
In recent months, drums have been excavated that are lined with concrete and have a pipe nested in the center to hold waste with higher levels of radioactivity than typically found in unlined drums used for waste disposal. The waste came from research and uranium fuel fabrication work at Hanford before 1964.
Heavy equipment is used to place the concrete-lined drums in boxes partially buried in the burial ground soil and filled with a soupy grout mixture. The drums are then munched up within the grout bath. Water misters are used at the burial ground to make sure the grout does not dry out during processing and before it is loaded into boxes to be trucked to the central Hanford landfill.
“Keeping surfaces wet and minimizing any drying of grout is really important,” Foley said.
Grouting work was done Nov. 16 and surveys after the work that day found specks of contamination at the burial ground. Windy weather, common at Hanford, was forecast for Nov. 17 and workers prepared for it by applying more fixative — what they call “rhino snot” — to the soil before the storm arrived.
But winds were worse than usual, hitting 70 to 75 mph at the burial ground, and Hanford officials knew they were going to have issues.
Contamination is believed to have been spread not only by the wind, but by plants and animals.
“Washington Closure Hanford went out and started surveying to understand how far the contamination had spread,” said Stacy Charboneau, manager of the DOE Richland Operations Office, at the Hanford Advisory Board meeting.
They found sandy grains of contamination that had spread toward the road and two grains on the east side of the road. Contamination was cleaned up as it was discovered.
Washington Closure told the EPA on Nov. 24 that all radiological material had been collected.
But on Dec. 11 the state Department of Health conducted a follow-up survey on behalf of EPA and found four specks of contamination that had spread outside of areas of radiological control. Three were on the west side of the highway and one was on the east side.
DOE determined that they likely were specks of contamination from the urine of animals that had gotten into contaminated areas or bits of contaminated tumbleweeds. The weeds have long roots that can intrude into contaminated areas.
They are not so much new controls, but better implementation of existing controls.
Bryan Foley, DOE deputy project director
Part of the issue that contributed to the spread from the 618-10 Burial Ground was the type of waste in the concrete-lined drums. The waste had high levels of radioactive isotopes that grout does not bind well, said Dennis Faulk, EPA Hanford program manager.
The letter sent by EPA to DOE said the loss of control also was due to inadequate measures for controlling small debris and possibly not applying enough water where the drums were being treated.
Some changes have been made to procedures, including revising how grout and waste mixtures are sampled. A plastic bag is used to keep the mixture from being exposed to the atmosphere.
But the improvements being made “ are not so much new controls, but better implementation of existing controls,” Foley said.
The report required by EPA is expected to address not only issues directly related to the 618-10 Burial Ground but the spread of contamination by plants and animals.