Canada isotope reactor idled until October -report

TORONTO, July 7 (Reuters) - A Canadian nuclear reactor that normally produces a third of the world's medical isotope supply will be idled until at least October and likely longer, the Globe and Mail reported on Tuesday, citing unnamed sources.

The Chalk River reactor in eastern Ontario has been out of operation since May 17 because of a heavy water leak.

The Toronto-based newspaper, citing sources close to the situation, said government-owned Atomic Energy of Canada Ltd. plans to hold a briefing on Wednesday, when they are expected to announce they need more time to carry out repairs.

The sources said the most optimistic scenario would see the Chalk River facility up and running by October.

An AECL spokesman could not immediately be reached for comment. Officials tentatively estimated in mid-May that the facility would be down for at least three months.

The unexpected shutdown of the reactor, build in 1957, has sent hospitals in Canada and the United States scrambling to find replacement sources of medical isotopes, which have a short shelf life.

A medical isotope is a very small quantity of radioactive material used to perform nuclear medicine imaging tests. Isotopes are mixed with different solutions and injected into patients, where they give off energy read by a special camera.

Chalk River is one of the few nuclear reactors able to produce the isotopes, and health experts have warned that the other facilities do not have the capacity to make up for the lost Canadian production.

MDS Inc (MDS.TO) (MDS.TO) said in June it was in talks with a Russian producer of medical isotopes as it scrambles to cope with the prolonged shutdown of Chalk River, which had been its main supplier. (Reporting by Jeffrey Hodgson; editing by Rob Wilson)