June 9, 1997
The Georgia Department of Natural Resources (DNR) has released a low-level radioactive waste disposal site in Lullwater for unrestricted use, following a comprehensive clean-up by the University. The site is located in the southeast corner of Lullwater, to the north of the walkway that parallels the railroad tracks.
"The Environmental Protection Division of DNR recommended in the fall of 1995 that Emory remediate the radioactive site in Lullwater," said Frank Lisella, director of environmental health and safety. All burials in the site, which was in operation from 1960 to 1975, were carried out in accordance with Atomic Energy Commission, Nuclear Regulatory Commission and Georgia laws and regulations. Clean-up at the site was conducted between April and October 1996 by Nuclear Fuel Services, a contractor hired by Emory.
"It was basically a treasure hunt," said Lisella in describing clean-up procedures used on the three quarters of an acre site. "We know that the contractors removed all of the radioactive materials because of multiple factors; the documentation relating to the disposals, the recollections of eye witnesses, the comprehensive excavation, and the sampling performed after excavation," said Lisella. "There were precise records on the millicuries (mCi) of radioactive materials buried there and 99.9% of the material was tritium and carbon-14, which occur naturally in the environment.
"We also brought back retired facilities management staff who had actually operated the backhoes to bury the materials in this site and they pointed out exactly where and how deeply they had buried the materials," said Lisella.
Emory had a radiation officer as early as 1960. In 1981, Henry C. Karp, who was the University Radiation Safety Officer, put the quantity of radioactive material in the burial site in perspective in a letter to John Palms, then vice president for arts and sciences. Karp said, "There is a total of 312.7 mCi of H-3 at the site. A back-lighted liquid crystal wrist-watch (over one million sold) contains up to 200 millicuries. One household smoke detector contains between .05 and .1 mCi of Am-241. We buried .01 mCi. Seventy pounds of Jekyll Island sand contains .001 mCi of Ra-226, which is the same quantity of radium that was disposed of at the Emory site before radium became a regulated material. The Cs-137 buried is equivalent to a few truckloads of earth from Hartwell Dam."
Even though they knew where everything was buried, the contractors took a series of samples across the site and where they had hits, they did an area dig, in which everything in the area was removed, including soil up to 18 feet. "Most of the materials, as far as radioactivity goes, were at background level or below after all this time," said Lisella. Nonetheless, all the material, including soil, was removed and filled in with clean soil.
During the clean-up, the site was visited by the State Radioactive Materials group and members of the Nuclear Regulatory Commission. "These sites are so infrequently remediated that these folks wanted to watch the process we used to get some experience," said Lisella.
The contractors rehabilitated the site when the excavation was complete. That process included bringing in new soil and planting grass. The contractors also used miniaturized equipment, such as track backhoes to minimize damage to existing trees while they were excavating.
Lisella said the disposal of radioactive materials now in use by researchers is overseen by staff in the environmental health and safety office. The office has a program in place to decay short-lived radioactive isotopes through 10 half-lives, which is the state's requirement for the time it takes for the material to become nonradioactive. That material is then disposed of as biomedical waste. Other materials with longer half-lives are shipped immediately as radioactive waste to disposal facilities.
In addition to closing the books on this low-level radioactive waste site, Emory has been working to clean up two other sites in Lullwater since the early 1990s. In 1992 Emory disposed of a cesium irradiator by relocation to a permanent storage site in Nevada. The irradiator had been placed in Lullwater in 1962 by the biology department and was used for researching the effect of radiation on plants and organisms until 1970. A second site, consisting of discarded chemicals that were buried in 1974 when the chemistry department moved from the Humanities Building into its present quarters, was remediated in 1996. The official clearance of that site is pending review by the Hazardous Site Response component of the Environmental Protection Division. Lisella says that notice could come tomorrow or in a couple of years.
Return to June 9, 1997 Contents Page