And much of the world's supply is produced in Canada. Testing.

The National Research Universal (NRU) reactor went fully online at Chalk River, Ont., on Nov. 3, 1957. It has been used for scientific research, including the development of nuclear medicine. It remains the biggest single source in the world of the isotope cobalt-60, which has been used in cancer treatment for more than half a century.

Chalk River's importance gained worldwide attention in 2007 when the reactor was shut down for maintenance, causing a worldwide shortage of medical isotopes. And it was underscored again in August 2008 when the other four major producers of isotopes

And much of the world's supply is produced in Canada.

The National Research Universal (NRU) reactor went fully online at Chalk River, Ont., on Nov. 3, 1957. It has been used for scientific research, including the development of nuclear medicine. It remains the biggest single source in the world of the isotope cobalt-60, which has been used in cancer treatment for more than half a century.

Chalk River's importance gained worldwide attention in 2007 when the reactor was shut down for maintenance, causing a worldwide shortage of medical isotopes. And it was underscored again in August 2008 when the other four major producers of isotopes

And much of the world's supply is produced in Canada.

The National Research Universal (NRU) reactor went fully online at Chalk River, Ont., on Nov. 3, 1957. It has been used for scientific research, including the development of nuclear medicine. It remains the biggest single source in the world of the isotope cobalt-60, which has been used in cancer treatment for more than half a century.

Chalk River's importance gained worldwide attention in 2007 when the reactor was shut down for maintenance, causing a worldwide shortage of medical isotopes. And it was underscored again in August 2008 when the other four major producers of isotopes

And much of the world's supply is produced in Canada.

The National Research Universal (NRU) reactor went fully online at Chalk River, Ont., on Nov. 3, 1957. It has been used for scientific research, including the development of nuclear medicine. It remains the biggest single source in the world of the isotope cobalt-60, which has been used in cancer treatment for more than half a century.

Chalk River's importance gained worldwide attention in 2007 when the reactor was shut down for maintenance, causing a worldwide shortage of medical isotopes. And it was underscored again in August 2008 when the other four major producers of isotopes