Meeting the nation’s demand – LANSCE extends run cycle for medical radioisotopes
by Clay Dillingham of Communication, Arts, and Services (IRM-CAS)
The national demand for radioisotopes is extraordinary. Radioisotopes are vital to medical treatment and research, industry, agriculture, environmental science, and for defense appli-cations. To meet the high demand for the strontium-82, a medical isotope critical for cardiac imaging, the Department of Energy asked the Isotope Production Facility (IPF) at the Laboratory to stay in production beyond its normal run cycle schedule and run overtime.
“If we hadn’t run the IPF facility in an unprecedented dedicated mode, there would have been a nationwide shortage of strontium-82,” said Kevin John of Inorganic Isotope and Actinide Chemistry (C-IIAC), acting site-program-manager for the National Isotope Program.
“Strontium-82 is used in Positron Emission Tomography (PET) to help diagnose heart disease. Hospitals nationwide diagnose about 400 patients every day using PET. By staying in production, we produced a five-to-six-week supply, enough to support more than 10,000 patients.”
The accelerator-based isotope production facility at the Los Alamos Neutron Science Center (LANSCE) is one of only two such facilities in the United States — the other is at Brookhaven National Laboratory in New York, which also is supported by the DOE.
The production of isotopes at Los Alamos requires a number of steps, beginning with the linear accelerator at LANSCE, which accelerates a beam of protons to 40 percent the speed of light, to an energy of 100 million electron volts. These high-energy protons are steered onto a special target at the IPF. Like a pool queue ball traveling at 40 percent the speed of light and smashing the other racked balls to begin the game, the protons’ intense impact breaks apart the target’s atoms and sends subatomic particles scattering throughout the target. These subatomic particles are absorbed by other atoms, creating isotopes. Chemistry Division then extracts the isotopes from the target material and prepares them for shipment to cus-tomers nationwide.
The shortage of isotopes developed because the demand for strontium-82 is rising, and the increased demand hasn’t allowed production facilities to shut down for regularly scheduled mainte-nance work.
Normally, these isotope production facilities schedule shutdowns in a sequence that maintains a steady supply of medical isotopes. This year, however, the demand outstripped the predicted supply. With other production facilities down for regularly scheduled maintenance, and the nation’s supply of strontium-82 running out, the DOE’s Office of Nuclear Energy asked the Lab to postpone its scheduled shutdown and dedicate an additional 14 days of operation to mass producing the critical isotope.
The Isotope Production Facility, which can produce about 100 dif-ferent isotopes for use in research, industry, and defense, focused its efforts on producing enough strontium-82 to meet the nation’s med-ical needs for the next month or so, until an isotope facility in Russia starts up again this month.
“We need to do the maintenance, which takes months to complete, and we will. But the need for a steady supply of isotopes is more important, so we stepped in and did a dedicated production run, and filled the isotope-gap,” said Kevin Jones of the Accelerator Operations and Technology (AOT) Division. “It was really a heroic effort on the part of our employees. We had to work 24-7 for two weeks to do it.”
Los Alamos’ IPF was commissioned in 2004 to help the nation reduce its dependence on foreign isotopes. Radioisotopes, which decay, have become a critical resource for medicine, research, industrial, agricultural, and defense applications. Radioisotopes decay by giving off subatomic particles, like positrons. This decay helps to distinguish the isotope from the normal, often more stable form of the element. The decaying process also makes the isotope visible to instruments, like those in PET. Doctors can inject radioisotopes, such as strontium-82, into patients and track their movement and location to see, for example, if organs, like the heart, are functioning properly. The decay from other radioisotopes is used to bombard and destroy cancer cells. Industry uses isotopes to check the integrity of a weld, to sterilize instruments, and for “well-logging” to detect the presence of certain desirable materials in a well. Isotopes also are used to kill germs and sterilize food.
March 2007. Under LALP 07-001