(Editor's note: This story has been corrected.)
The cost estimate to clean up leaked mercury at the Oak Ridge Y-12 nuclear weapons plant in Tennessee have been released and it won't be cheap. According to the U.S. Department of Energy (DOE) it will take between $1 billion and $3 billion to clean up the toxic chemical that escaped during the lithium-separation processes used during the Cold War development of hydrogen bombs.
Frank Munger, editor of Atomic City Underground, writes that from 1950 to 1963 about 11 million kilograms (24,251,000 pounds) of mercury were used during production at the Oak Ridge plant. Spills were not uncommon and DOE estimates that 700,000 pounds were lost to the environment, including tons of airborne releases and mercury that still hides in the cracks and crevasses of buildings. The government still cannot account for about 1.3 million pounds of the mercury stockpile.
The DOE says mercury discharges at the Y-12 nuclear weapons plant have declined in recent years, due in part to a Recovery Act-funded project in 2011 that cleaned out and repaired the plant’s storm sewer system. The Oak Ridge plant currently discharges about 3.7 grams of mercury per day into the East Fork River, which originates inside Y-12 and flows through much of Oak Ridge’s west end before joining Poplar Creek and ultimately the Clinch River and downstream reservoirs.
According to samples taken last year, the concentration of mercury in the river as it leaves the plant's property is about 840 parts per trillion in water - well above the 51 parts per trillion required to comply with the Clean Water Act standards.
As part of the West End Mercury Area cleanup project, workers have already removed about 54 pounds of elemental mercury from Y-12’s stormwater collection system and sealed cracks and holes in the concrete that had allowed mercury contamination to infiltrate the system and reach the creek at Outfall 200 — the point where the underground pipelines converge.
The cleanup plan also calls for a research laboratory near the creek for field studies on mercury.