Crews hired by the state of Texas and advised by Los Alamos National Laboratory have recovered three large radioactive sources from high schools in San Antonio, the latest success in the Laboratory’s nationwide effort for the National Nuclear Security Administration’s program to reduce security and other risks associated with radioactive material.
Working with the San Antonio Independent School District, the Texas Department of State Health Services, Radiation Program led the effort to recover the three heavily shielded devices, known as Gammators, which contained four-inch-long rods of cesium-137. The Gammators were removed from Brackenridge, Fox Tech and Lanier high schools, where they had been stored for more than 30 years after a brief career irradiating seeds, cells and other objects with gamma rays for school science experiments.
“We’re most grateful to the National Nuclear Security Administration for funding this effort, and to Andy Tompkins and everyone from Los Alamos for making sure this operation was carried out safely and securely,” said D. Ray Jisha of the Department of State Health Services, who supervised the work.
Over the past 25 years, Los Alamos has recovered more than 10,500 radiation sources of various types from schools, hospitals, research institutes and industrial facilities, such as oil drilling companies. Those sources have contained everything from plutonium to cobalt (see attached fact sheet).
“This represents the National Nuclear Security Administration’s efforts to further prioritize and accelerate the removal of high risk radiological materials that can be used in a dirty bomb,” said Ed McGinnis, acting director of NNSA’s Office of Global Radiological Threat Reduction. “We are working overtime across the nation to remove and secure materials that pose not only a safety hazard but a security risk, and we commend Los Alamos for another job well done.”
The barrel-shaped devices at the three high schools each weigh about 1,850 pounds. Surrounding each radioactive source, which rests on a small turntable, is a welded steel shell filled with lead shielding. Each one-inch diameter rod originally contained about 400 Curies of highly radioactive cesium-137, which has decayed to about half that level over time.
About 150 of the Gammators were supplied to schools across the United States and to other countries in the 1960s and 1970s through the “Atoms For Peace” program. Hospitals used similar devices to irradiate blood.
Crews had to use brute force to wrestle one of the devices down two flights of stairs to reach the truck during the operation, which began with preparations on Saturday (April 9), and concluded the next day.
Because of the heavy shielding, the stored devices posed little risk to students and teachers at the three schools. However, the slim chance of exposure through inappropriate handling made removal of the Gammators a priority for the state, the school district and for Los Alamos.
“Our teams from Los Alamos have gone into hundreds of places all over the country to remove radioactive sources that are no longer needed,” said Tompkins, who works for Los Alamos’ Offsite Source Recovery Project, part of the U.S. Department of Energy’s National Nuclear Security Administration’s Radiological Threat Reduction Program. “Since the 9-11 attacks, we have stepped up our efforts significantly because of the potential threat that any radioactive material might be misused.”
Bill Vinal, science director for the school district, said state technicians frequently tested the three Gammators for leaks.
“Although there was never any danger to the students or teachers, we haven’t needed these in many years and wanted them moved to a safe, secure location,” Vinal said. “There’s just no reason to keep this type of material around.”
