From 2009 to 2010, the world experienced a severe, worldwide shortage of the radioisotope technetium-99 (tech99) when the Chalk River Plant in Ontario, Canada shut down for more than a year due to water leaks. The Canadian plant, along with one in Petten, Netherlands, is responsible for two thirds of the world supply of the radioisotope. Technetium-99 is used in millions of medical procedures around the world, most commonly in identifying and treating cancer and heart diseases. The shortage meant delays in nuclear medicine tests and forced the use of substitute isotopes that were inferior. The shortage was compounded again when the Netherlands reactor went offline for several months as well. The situation left the worldwide medical community scrambling.
The isotope tech99 is crucially important in nuclear medicine for two main reasons: 1) It has a short half-life, so it breaks down quickly, exposing the patient to a small dose of radiation. 2) It emits easily detectable gamma rays making it ideal for diagnostics. However, the production requires molybdenum 99 (moly99) made in nuclear reactors using weapons-grade uranium. The fifty-four year old Chalk River plant that supplies half of the tech99 for the US is currently running again, yet its license expires in four years. Canada has tried to build two replacement reactors, but they have not turned out to be usable. Nuclear medicine is pushing to find an alternative to production that does not rely on outdated reactors that use enriched uranium.
|Device: Radiation Counter|
Manufacturer: Packard Instrument
Model: Cobra II Auto-Gamma 5010
|Device: Radiation Counter|
General Electric came up with one solution. The US-based company found a way to “harvest” moly99 from high neutron flow reactors. They are testing their technique on Exelon’s Clinton plant in DeWitt County, Illinois. However, GE then decided to scrap its plans for financial reasons. Another company based in Atlanta, Georgia, named Perma-Fix, came up with a resin that could expedite the decomposition of moly99 into tech99. Perma-Fix announced plans for production, which, unlike GE, does not rely on US government subsidies for its business.
Many officials have cited government subsidies to enriched uranium plants as a major obstacle to providing an alternative means of production. The US government’s National Nuclear Security Administration (NNSA) has backed GE, as well as other companies such as Northstar Medical Radioisotopes. Northstar uses an accelerator to create gamma rays that change moly100 to moly99. The NNSA also backed the Morgridge Institute for Research in Wisconsin, whose research focuses on a means of production using non-weapons grade uranium. The US department of Energy is financing a research program at Babcock & Wilcox to develop a new kind of reactor, in which uranium is split by fission into moly99 and then made into tech99.
Canadian scientists at TRIUMF, a national nuclear physics laboratory in Vancouver have found a way to upgrade cyclotrons to make tech99. Cyclotrons are small particle accelerators found at hospitals across the world used for producing isotopes in PET scans. Reported in CBC news in February 2012, Canadian officials believe the method will help supplement reactor-produced tech99 to prevent sudden shortages.