A brief shutdown at the aging Chalk River nuclear reactor in Ontario is expected to force health care facilities in British Columbia to reschedule medical exams that aren't urgent, health officials announced Monday, though the disruption was expected to be short-lived.

Chalk River was unexpectedly shut down last week, but Atomic Energy of Canada Ltd. announced over the weekend that repairs had been completed.

Still, Health Shared Services BC, which co-ordinates some services across B.C.'s six health authorities, said it would take a few days for the fresh supply of isotopes to reach B.C.

Susan Larson, operations director for medical imaging in the Vancouver-area, said one of the agency's suppliers, Lantheus Medical Imaging, has already started shipping isotopes, which should start arriving by Tuesday.

Health Shared Services BC said it would receive an update from its other supplier, Mallinckrodt Pharmaceuticals, later in the day on Monday and expected similar news.

"Those patients that absolutely had to have their tests done today are having their tests done today," Larson said during a conference call with reporters on Monday.

"The backlog would have only stared this morning for those sites that are at a reduced activity at this time. ... I would anticipate that there are very few patients who had their exams rescheduled this morning."

The isotopes are used for procedures such as bone, thyroid, lung and liver scans.

Larson did not know how many tests were expected to be rescheduled.

The Chalk River facility is one of the world's largest producers of material used for medical isotopes and the problem at the aging plant occurred at the same time there were troubles at plants in South Africa and Holland.

It's not known when the Dutch and Pretoria-area reactors will be back in operation.

Larson said the disruption was nothing compared to a widespread shortage in 2009, when a protracted shutdown at Chalk River coincided with the shutdown of a generator in the Netherlands compromising between 60 to 70 per cent of the world's demand for medical isotopes.

"It lasted for months, so that's a completely different scenario than we're dealing with," she said.