CHALK RIVER, Ont. - Canada's medical community could be faced with another shortage of diagnostic isotopes after another shutdown of a nuclear reactor at Chalk River, Ont.

Atomic Energy of Canada Ltd. says its NRU reactor was shutdown last Thursday after a power outage in parts of eastern Ontario and western Quebec.

However, a heavy water leak was detected within the facility the following day, and AECL estimates the reactor will be out of service for more than a month while repair options are considered.

The agency says the heavy water is being contained and stored in drums, and there is no threat to workers, the public, the environment or nuclear safety as a result.

The aging facility provides about half the global supply of isotopes used in medical imaging.

AECL says it has enough medical isotopes for the coming week, but will unable to meet demand by Saturday.