Chalk River reactor idled to late 2009 or longer:

The Chalk River nuclear reactor will be shut down until at least late 2009

CBC News: July 8, 2009

The nuclear reactor at Chalk River, Ont. — normally a major world supplier of medical isotopes — will be out of service until at least late 2009, Atomic Energy of Canada Ltd. officials said Wednesday.

The reactor could be closed even longer if there are delays in the inspection and repair process, according to the president of the Crown corporation, Hugh MacDiarmid.

"We are now able to advise that the [reactor] will not return to service before late 2009," MacDiarmid said during a news briefing.

"We are very conscious of the impact of an unplanned reactor shutdown, and we recognize the concerns and planning needs of the health community, patients and isotope producers."

A leak of radioactive water was detected inside the reactor on May 15, forcing a shutdown that AECL officials initially estimated would take about three months to fix. Since then, workers have been visually inspecting the leak by lowering cameras through small holes at the top of the reactor.

The 52-year-old Chalk River reactor normally produces about a third of the world's supply of medical isotopes, which are required for cancer and heart disease tests around the world.

Raitt, Aglukkaq 'disappointed'

The federal health and natural resources ministers issued a joint statement Wednesday saying they are "disappointed" with the announcement of the delay and warned the health-care industry to prepare for further shortages of medical isotopes.

"We expect a period of more critical shortage during the month of August," said the statement from Health Minister Leona Aglukkaq and Natural Resources Minister Lisa Raitt.

"For this reason, careful management of available supplies by the health-care community and the successful identification of alternatives will remain essential."

The government has directed AECL to give "paramount priority" to bringing the Chalk River reactor back to service as "quickly and safely as possible," said the ministers.

3-phase return

MacDiarmid said the first phase of a three-phase return-to-service schedule should be completed by the end of July. That includes an assessment of the condition of the National Research Universal (NRU) reactor and a decision on which repair method to use.

Roughly 60 per cent of the NRU's circumference has been examined. Inspectors have found thinning of the wall at the leak site, as well as nine other "areas of interest."

Phase 2 includes the actual repair and will take at least two months.

During the final phase, officials will restart and test the NRU, as well as reload its fuel supply. This process, which will eventually lead to the production of isotopes, will take roughly two months, he said.

MacDiarmid defended earlier public suggestions the NRU could have been up and running by the end of August. In late May, AECL senior vice-president and chief nuclear officer Bill Pilkington said that preliminary inspection data suggested the NRU could be operational within three months.

"The original guidance that we gave on the minimum three months was at a very early stage in the project," MacDiarmid said.

"We had not at that time yet made the decision to remove the fuel and the water from the reactor. We did not know fully the extent of the repair that would be required.… We felt it was still conceivable that a repair technique could be effective that would allow us to return to service in as little as three months."

When asked whether the delay in operations could stretch into 2010, MacDiarmid said he would not engage in "speculative questions" but said he is confident the reactor will be restarted.

"All evidence to date suggests the reactor can be returned to service," said MacDiarmid.

Currently, nuclear reactors in Europe and South Africa are producing about 70 per cent of the world's supply of medical isotopes.

Medical isotopes: What are the alternatives?

CBC News: July 8, 2009

The Chalk River, Ont., reactor is pictured in this handout photo. (Canadian Press)Think the medical isotope shortage of 2007 was bad? Brace yourself for anticipated bumps and shortages ahead.

In July, Atomic Energy of Canada Ltd. said it would need longer than initially expected to repair the 52-year-old Chalk River reactor, which has been down since the middle of May. The reactor will be closed until at least late 2009. Meanwhile, a 48-year-old reactor in Petten, Netherlands, will be closed for four weeks of maintenance.

The closure of the world's two main isotope-producing nuclear reactors in mid-July 2009 is expected to exacerbate an already critical shortage of nuclear isotopes.

"We wish to be clear to Canadians," said Federal Minister of Health Leona Aglukkaq and Minister of Natural Resources Lisa Raitt in a statement. "The unplanned shutdown of the NRU will result in a significant shortage of medical isotopes in Canada and in the world this summer."

Chalk River produces about a third of the world's supply of medical isotopes, handling most of North America's demand. Petten produces a little more than 30 per cent of the world's supply.

While both facilities are down, reactors in South Africa, Belgium and France will be hard-pressed to meet worldwide demand.

No new reactors are scheduled to come online until the middle of the next decade.

"We're teetering on the brink of disaster," Dr. Christopher O'Brien, president of the Ontario Association of Nuclear Medicine, told CBC News.

"The medical isotopes we use look at the disease at the cellular level," O'Brien said. "We're able to detect the disease before it even starts to change the appearance of the organ — and that's why it has a significant impact in detecting early spread of cancer such as breast, lung and prostate cancer."

Medical isotopes can be the most effective — and cheapest — tools in diagnosing cancer. The detailed information they provide — what's happening at the cellular level — helps patients and health-care providers determine the most effective way to treat an illness.

Technetium-99 is the most widely used isotope for diagnostic imaging. It accounts for as many as 20 million diagnostic nuclear medical procedures every year. It is used for getting a detailed look at the heart, kidneys, lungs, liver, spleen and bones as well as for blood flow studies through single-photon emission computerized tomography (SPECT) scans.

Forty per cent of technetium-99 is used for cardiac purposes. Another 40 per cent is used for cancer assessment. The remaining 20 per cent is used for everything else.

There are alternatives for some of the tests. Not all are ideal and not all are readily available.

Turning to older technology

When the isotope supply is low, a CT scan — also called computerized tomography — may be an option. A CT scan is similar to an X-ray, except it reveals much more detail.

A CT scan will provide pictures not only of bones and organs, but also their inner structure and detailed shots of the pancreas, adrenal glands, kidneys and blood vessels.

It is useful in diagnosing cancer. But it's not for everyone. Some are allergic to the "contrast fluid" patients must either drink or have injected before undergoing a CT scan. The reaction can be severe.

However, CT scans may not be able to detect cancer as early as nuclear medicine scans that use the isotopes that are now in short supply.

It's similar for MRI — magnetic resonance imaging — a technique that uses a magnetic field and radio waves to create detailed images of organs and tissues. This process creates 3-D images that allow health-care professionals to examine organs, tissues and the skeletal system.

It can be used to diagnose tumours in the lungs, liver, kidneys, spleen, pancreas, uterus, ovaries, prostate and testicles. It can also be used, in addition to mammography, to help detect breast cancer, especially in women who have dense breast tissue.

While the test is non-invasive, people who suffer from claustrophobia can have difficulty with MRIs. Patients have to lie fairly still for up to an hour inside a small, cylindrical chamber.

Like CT scans, MRI images may not be able to detect cancer as early as nuclear medicine scans.

After Chalk River went down in 2007, Health Canada and provincial health ministries recommended that where possible, hospitals should switch to thallium 201 for cardiac imaging, in the event of another isotope shortage.

A thallium stress test is used to detect blocked arteries, causes of chest pain, whether a patient has had a heart attack and the level of exercise a patient can safely perform. A small amount of thallium is injected into the patient's bloodstream during a stress test.

It's a very effective test — and the production of thallium does not rely on a nuclear reactor. The isotope is produced in individual hospitals in cyclotrons, a type of particle accelerator.

But there is a problem: only a limited number of hospitals have access to cyclotrons. So thallium can be expensive.

The same is true of iodine 123, which is primarily used to generate images of the thyroid. It's also produced in a cyclotron, so it's expensive and can be difficult for some hospitals to acquire.

PET projects?

SPECT scans rely on isotopes produced in nuclear reactors. Dr. O'Brien says positron emission tomography (PET) scans are a good alternative — except they're not widely available in Canada and they're expensive. They use isotopes produced by cyclotrons — not aging nuclear reactors.

Thomas Ruth, a research scientist at Canada's national particle and nuclear physics lab, says he believes the future will be with PET, "primarily because PET has better resolution and sensitivity in human scanning."

But the chemistry adjunct professor at the Vancouver-based TRI-University Meson Facility (or TRIUMF) says getting there is still a few years away. The necessary infrastructure is not yet in place.

Currently, only a few dozen hospitals — and a few private clinics — across the country have PET scanners.

"If we could use PET, there is a network of cyclotrons developing that could cover approximately 75 per cent of the Canadian population," Ruth said. "This network is still months to a bit more than a year away."

Ruth notes that the isotopes PET scanners rely on have even shorter half-lives than the isotopes SPECT scanners use — so each PET scanner should be located close to a cyclotron.

At the end of May, the federal government announced it was setting up an expert panel to study other ways to produce isotopes.

"We would like to have seen something sooner," O'Brien said. "We are happy it's here finally but at the same time, we've lost a year and a half getting things organized."

Even with the Chalk River and Petten reactors off-line at the same time for part of July and August, there may be some short-term relief. The organization representing European reactors says Belgium and South Africa operate their reactors at maximum capacity in July. That's expected to meet between 50 to 80 per cent of the global demand.

Still, the Canadian affiliate of International Physicians for the Prevention of Nuclear War says there's another reason to get away from isotopes produced at reactors like the one at Chalk River. The reactor uses highly enriched uranium to produce the molybdenum-99 that is used to produce medical isotopes.

It's the only grade of uranium from which it is possible to produce a plutonium bomb directly.