AECL to Discontinue Development of the MAPLE Reactors

Production of Medical Isotopes to be Maintained through NRU Reactor

Mississauga, 2008 May 16 — Atomic Energy of Canada Limited (AECL) is announcing that, after careful review and analysis, it will discontinue development work of the MAPLE reactors located at its Chalk River Laboratories, effective immediately.

This decision is based on a series of reviews that considered, among other things, the costs of further development, as well as the time frame and risks involved with continuing the project.

"We are making the right business decision given the circumstances," stated AECL's President and Chief Executive Officer Hugh MacDiarmid. "This was a difficult choice given the tremendous efforts expended by our people on development of the MAPLE reactors. Nevertheless, our Board of Directors and senior management have concluded that it is no longer feasible to complete the commissioning and start-up of the reactors."

The decision to discontinue development of the MAPLE reactors will not impact the current supply of medical isotopes as commercial agreements between MDS Nordion and AECL provide for isotope production to continue through AECL's National Research Universal reactor (NRU) and associated facilities in Chalk River. NRU currently has an operating site licence from the Canadian Nuclear Safety Commission (CNSC) that is valid until October 31, 2011. AECL will work closely with CNSC and MDS Nordion on the requirements for continued production beyond that date.

Mr. MacDiarmid added, "We recognize the important role that NRU plays in the supply and delivery of medical isotopes to patients in North America and around the world. AECL is committed to supplying medical isotopes from NRU in a safe and reliable manner."

For further information:

Dale Coffin
Director, Corporate Communications
Atomic Energy of Canada Limited
(905) 403-7457