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rely on outdated reactors that use enriched uranium.
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.
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