Canadian medical reactor back in use

An ageing Canadian nuclear reactor that had produced one-third of the world's supply of medical isotopes before it closed for repairs last year was restarted on Tuesday.

Its restarting was authorized last month and Atomic Energy of Canada Limited (AECL) said on Tuesday that it had concluded low-level tests on the reactor.

"The reactor is now operating at high power and can begin to create medical isotopes," the agency said in a statement.

The half-century old National Research Universal reactor in Chalk River, Ontario, 185 kilometers (115 miles) northwest of Ottawa, was shut down in May 2009 after a leak of radioactive water inside the reactor.

Atomic Energy of Canada Limited had initially estimated the stoppage would last only a few months.

Medical isotopes produced by the reactor are used to diagnose cancer and heart disease in patients around the world. The shutdown led to a global shortage of the precious radioactive material.