A warning sign is posted at the AECL plant in Chalk River, Ont. on December 19 2007. Chalk River Laboratories, the Ontario facility that produces most of the medical isotopes used across North America, has been forced to unexpectedly interrupt its supply, triggering a temporary shortage.FRED CHARTRAND/The Canadian Press
An unplanned shutdown of the aging Chalk River nuclear reactor has the country on the verge of a major shortage of medical isotopes, the president of the Canadian Association of Nuclear Medicine said Friday.
Dr. Norman Laurin said the forced shutdown of production at the Chalk River facility comes at a time when two of the world's three other major producers of medical isotopes are also out of operation.
"You have all at once probably over 70 per cent of the world production down. That's the problem," said Laurin, a nuclear medicine physician at the regional hospital in Trois Rivieres, Que.
Laurin said Atomic Energy of Canada Ltd. has said it would know by late Friday or early Saturday whether it can resume operation of the Chalk River reactor this weekend.
If it can restart production, the current shortage should resolve itself within a few days, he said. Otherwise, severe shortages of isotopes will force hospitals to scramble to triage medical tests and find other ways to do essential imaging procedures.
"Everybody in the community is holding his breath right now," said Laurin. "If they're not back on track this weekend, we're in as much trouble as we were in 2009."
In 2009 a protracted shutdown at Chalk River coincided with a shutdown of the generator in the Netherlands, compromising between 60 to 70 per cent of the world's demand for medical isotopes, Laurin said.
Patrick Quinn, director of corporate communications for AECL, said in an email that it was hoped operations would resume shortly.
"It is anticipated that AECL will resume supplying molybdenum-99 to the market over the weekend," Quinn said.
The current unfortunate confluence of closures came about quickly. Production was stopped in early November at the South African Nuclear Energy Corp.'s reactor at Pelindaba, near Pretoria, after a leak was detected from the reactor. And the Nuclear Research and Consultancy Group, which operates the Dutch production facility, announced Nov. 8 that it was shut down because of safety concerns.
It's not clear when either will be back in operation.
"We were in a fragile equilibrium and it changed when the machine in Chalk River went down," said Laurin, who wrote to members of his organization this week to inform them supplies will be tight.
"We would estimate a shortage of at least 30 per cent in the availability of Tc-99m" — technetium isotopes — "on Thursday, November 21 and of 50 per cent on Friday, November 22," Laurin advised in the message.
"For the weekend of Saturday and Sunday, November 23 and 24, the demand would be normally lower and availability will vary depending on suppliers."
Technetium is derived from molybdenum-99 isotopes made by nuclear generators. Technetium is needed for a wide range of medical tests including diagnosing pulmonary embolisms — potentially fatal blood clots in the lung — or blockages in arteries that lead into the heart.
"It is the single most important isotope we have in general nuclear medicine," said Laurin, adding it is used in about 80 per cent of all nuclear medicine procedures that do not involve PET scans.
Laurin said hospitals that have PET scanners will be able to weather the shortage period easier than those which do not. Others will be forced to find other work-arounds.
"We can use what we call mitigation measures if the crisis is going to last long," he said.
"There are alternate procedures that can be done in both nuclear medicine and radiology to try to get around the shortage of technetium.... It's more costly, it's more complex, but it can be done."