Hanford workers evacuated after waste leak
Published Saturday, July 28th, 2007
By Annette Cary, Herald staff writer
A mix of radioactive and hazardous chemical waste leaked onto the ground in central Hanford Friday morning as it was being pumped between underground tanks.
Workers in the 200 West Area of central Hanford were ordered into buildings or other structures and remained there until being allowed to leave the site midafternoon.
No worker was contaminated and the waste did not become airborne, according to the Department of Energy.
“There was no hazard to the public,” said Steve Wiegman, senior technical adviser for DOE. “I believe the action for the employees was very conservative.”
Because Friday was a day off for most Hanford workers, few people were in the 200 West Area.
The leak occurred at the transfer pump above Tank S-102, one of 142 underground single-shell tanks prone to leaks that are being emptied of high-level radioactive and hazardous chemical waste.
Waste emptied from the tank is transferred in an above-ground line to a newer double shell tank, Tank SY-102.
Workers had just started up the transfer pump early Friday morning, when the pump clogged, said Joy Shoemake, spokeswoman for DOE contractor CH2M Hill Hanford Group. While they were fixing that problem they noticed some unusual instrument readings and began a visual inspection of the line.
That’s when workers found liquid waste that had spilled into an above-ground pump pit box and the nearby ground. DOE also reported that environmental monitoring in the area picked up readings indicating radioactive material was present.
“They stopped work immediately and backed out of the farms,” Shoemake said. The workers also called for help in evaluating the spill.
Friday evening DOE reported that the spill was about 15 to 18 feet in diameter. Waste in the tanks is managed as high-level radioactive waste, but its content varies and the exact content of the spill was not available Friday evening.
Friday afternoon workers were preparing to put a fixative or soil cement on the spill, Wiegman said. That would prevent any waste from becoming airborne in windy weather until further cleanup plans are made.
Work also was under way to check the perimeter of the tank farm to make sure none of the contamination had spread. The spill is about seven miles from the Columbia River.
Although DOE initially reported that workers in the area took shelter later in the morning, it revised that to say they took shelter soon after the discovery of the leak.
In addition to the underground tank farms, the 200 West Area includes the Plutonium Finishing Plant, T Plant, temporary burial grounds for transuranic waste, the Waste Receiving and Processing Facility and the nearby Environmental Restoration Disposal Facility are in that area.
Retrieval of 464,000 gallons of waste from the Tank S-102 began in December 2004. About 10 percent of the waste remained in March when a pump being used to retrieve the tank broke. A new pump was recently installed and preparations have been under way to restart getting waste from the tank.