U.S. Environmental Protection Agency
75 Hawthorne Street (AIR-6)
San Francisco, CA 94105-3901

LAWRENCE BERKELEY NATIONAL LABORATORY

TRITIUM ISSUES

MIXED WASTES TREATABILITY STUDY

A treatability study is used to determine if a specific technology can efficiently and effectively treat a particular waste. Such studies are not typically intended to commercially treat or dispose of hazardous waste.

The Lawrence Berkeley National Laboratory generates hazardous wastes that contain spent solvents and tritium ("mixed wastes"). Over the past several years, the Laboratory has found fewer off-site disposal options for mixed waste, and began the process of identifying a means to treat rather than dispose of its mixed waste. In 1996, the Laboratory initiated a treatability study to see if catalytic chemical oxidation could be used to remove volatile organic constituents from tritiated mixed waste. The process converts mixed waste into carbon dioxide, nitrogen oxides, sulfur oxides, hydrogen and tritium.

Under what regulatory authority is the Lawrence Berkeley National Laboratory conducting this study?

The Laboratory conducts the treatability study under two California regulatory exclusions that are very similar to federal hazardous waste exclusions. These are described in Title 22 of the California Code of Regulations, Sections 66261.4(e) and 66261.4(f). The two exclusions allow the Laboratory to conduct a treatability study on its own hazardous waste without having to obtain a treatment permit. The exclusions allow treatment of up to 400 kilograms of any hazardous waste. To date the Laboratory has treated about 13 liters (approximately 20 kilograms) of previously generated mixed waste. The waste contains approximately 2,096 curies of tritium. (A curie is a measurement of radioactive material. A Laboratory emission would be expressed in curies of tritium.)

California is authorized to be the lead enforcement agency to oversee the hazardous waste treatability study. EPA provides the State with technical and program oversight, guidance and other assistance, and helps the State ensure that treatability studies are protective of human health and the environment.

During the treatability study, mixed waste undergoes an extraction process. After completing the extraction of a silica gel sample on July 24, the Laboratory identified discoloration on the sample. Believing that the extraction and treatment process had removed all traces of the mixed waste from the silica gel, the lab collected some silica gel residue and placed it into a kiln to remove the discoloration. The kiln is vented to a stack with a tritium monitor and alarm. While in the kiln the sample released tritium, which activated the alarm. A laboratory technician subsequently shut down the kiln. Stack monitoring showed that 35 curies of tritium were released.

After the release, the Laboratory stopped treating all silica gel wastes in the kiln. The Laboratory conducted a follow-up investigation and prepared an occurrence report that was submitted to the Department of Energy.

Department of Energy staff conducted follow-up visits to the facility after the release occurred, and have recorded the release in their Occurrence Reporting System. Compliance staff from California have also conducted a full investigation of the incident and have requested and received information on the tritium release from the Laboratory. California is currently preparing a report of its investigative findings. Since the release, other personnel from EPA, the State of California and the office of Congress-woman Barbara Lee have also visited the facility.

For more information, please contact Kevin Wong, U.S. EPA Waste Management Division, (415) 744-2041.