The shutdown of the Chalk River nuclear reactor that has caused a shortage of medical isotopes is still expected to last at least three months, Atomic Energy of Canada Limited said Tuesday.

AECL announced it has started removing fuel rods from the 52-year-old National Research Universal Reactor that was shut down in mid-May because of a small leak of the heavy water used in the reaction process.

Removing the rods will take an estimated three to four weeks, according to AECL.

"Further guidance on a return to service date beyond the current estimate of at least three months will be provided when a final decision has been made with respect to the repair technique chosen," AECL said in a statement.

Natural Resources Minister Lisa Raitt told a House of Commons committee that the three-month shut down is the minimum, suggesting it could last longer.

"The duration of the outage will not be known until the investigations are completed and the repair options are identified," she said.

Also Tuesday, Liberal Leader Michael Ignatieff accused the federal government of not having a plan to deal with shutdown.

"Why does the government pretend it has a supply when it doesn't have any isotopes?" Ignatieff said in question period.

Prime Minister Stephen Harper replied that the shutdown was unexpected and that the government is working with isotope suppliers around the world as well as with the medical community to manage the situation.

"The fact of the matter is, the reactor has had to be shut down for safety reasons, and those safety reasons must be paramount," Harper said.

"There will be challenges, but steps are being taken to deal with those challenges."

Inadequate foreign supplies

Dutch and South African reactors do not have the capacity to make up for the shortfall, and both are down for maintenance next month, Ignatieff said.

Raitt said she is talking with the four other countries — The Netherlands, South Africa, France and Belgium — that make medical isotopes, but this week, only one is up and running.

'The reactors are built; they've actually been powered up; experts say that they're safe; and experts have good reason for saying these reactors can be completed. '— Steve West, president of isotope distributor MDS Nordion.

The South African reactor, a relatively small supplier, will be back up on June 8. But the Dutch reactor that supplies 30 per cent of the world market will be taken out of service from July 18 to Aug. 18.

MDS Nordion takes medical isotopes made in Chalk River and sells them around the world for use in diagnostic imaging to detect conditions such as cancer and heart disease.

Look at restarting MAPLE reactors, isotope firm urges

MDS Nordion has been trying to find alternative solutions, and so far the shelved MAPLE project is the only one, company president Steve West said Monday.

West called on the federal government to let in a team of international experts to see if they can finish the job at the MAPLE 1 and MAPLE 2 reactors, which never worked well enough to be put into commercial production.

Minister not receptive

"The reactors are built; they've actually been powered up; experts say that they're safe; and experts have good reason for saying these reactors can be completed," said West.

Last July, MDS Nordion filed a filed a $1.6 billion court claim against AECL and the Government of Canada over their decision to cancel the MAPLE 1 and MAPLE 2 reactors. The government cited design flaws and escalating costs.

West said the call is not about the lawsuit but finding a quick replacement while the NRU reactor is down.

Raitt did not seem receptive to the idea.

"MAPLES 1 and 2 over 12 years, and hundreds of millions of dollars, never produced a single medical isotope."

Consider all options, opposition urges

The federal government is setting up an expert panel to look for options, and report back in the fall.

NDP natural resources critic Nathan Cullen said Monday the federal government needs a plan now.

"They've dismissed the MAPLEs outright, and now we have a committee that hasn't been even struck that's going to report sometime in the fall, with no real short-term results for people needing the treatment right now."