Atomic Energy of Canada Ltd. is laying off about 50 employees at its Chalk River facility in eastern Ontario, the union that represents government scientists says.

The Professional Institute of the Public Service of Canada called the layoffs announced Monday at AECL's research and technology division "poorly timed."

The union said that the layoffs, including a dozen people it represents, compromise the future of Canada's nuclear industry.

It also said the move will have serious consequences for the availability of medical isotopes.

The reactor at Chalk River is a combination research tool and medical isotope production facility.

Before it was shut down for repair about a year ago, it was producing a major portion of the world supply of isotopes, used in medical diagnostic tests.

"AECL's only reactor has been down for over a year," said Gary Corbett, the union's president. "World medical isotope availability is in doubt. Research needs are not being met.

"When you consider all of this, how is it a good time to reduce staff?" asked Corbett. "Any cost savings achieved through these layoffs will be dwarfed by the revenues lost as a consequence of the reactor remaining offline."

The union represents about 57,000 professionals across Canada's public sector, including 750 professional engineers and scientists at AECL.