Spill at Chalk River Nuclear Labs happened Dec. 5: Reports
By Tom Spears, Ottawa Citizen January 27, 2009
OTTAWA — There was a leak of mildly radioactive heavy water at Canada's oldest nuclear reactor in early December, but Atomic Energy of Canada Ltd., said Tuesday almost nothing escaped and there's no danger.
The company says that 47 kilograms (fewer than 47 litres) of heavy water leaked from the National Research Universal reactor at Chalk River, Ont., west of Ottawa, on Dec. 5. But the leak stopped of its own accord — before the source could be identified — and so AECL hasn't made any repairs.
"We didn't pinpoint it definitely. We had indication that it was coming from a seal," said Bill Pilkington, AECL's vice-president in charge of the plant.
"Losing 47 kg. of heavy water is not insignificant," he said. "At the same time, we wouldn't characterize it as a large, sustained leak." He said there was no danger to the public.
Most of the leaked heavy water was caught and the radioactive tritium in it will be recovered, he said. A few litres evaporated, but the amount was within one-thousandth of the amount permitted as air emissions under the plant's licence.
Tritium forms when heavy water is exposed to radiation, usually in a reactor. Heavy water is used as coolant in NRU, and also as a "moderator" — something that helps the process of breaking apart uranium atoms.
"In this case, the concentration was quite low," Pilkington said. "We don't consider that there's a safety issue here. There was no significant radiation exposure to workers, there was no release to the environment, there was no exposure to the public." The NRU has been working since 1957, producing medical isotopes.
Last year, AECL abandoned the two new reactors that were supposed to replace NRU. The twin MAPLE-1 and -2 reactors, also at Chalk River, were supposed to have been commissioned years ago, but both ran into repeated technical problems and breakdowns after hundreds of millions of dollars in construction costs. Neither was ever brought into service.
"The NRU continues to operate safely and reliably," Pilkington said.
"However it is not going to operate indefinitely, so there do need to be plans to replace NRU for isotope production at some point."
During question period Tuesday, Liberal MP Geoff Regan asked why Canadians weren't told earlier about the leak.
Natural Resources Minister Lisa Raitt said in the House the incident had no "adverse effect on human health or on the environment."
"The reactor at Chalk River continues to operate consistently and meet(s) all safety regulations and security regulations and we continue to work with CNSC (Canadian Nuclear Safety Comiission) to ensure safety requirements at Chalk River labs continue today," she added.
Also on Tuesday, the Conservative government committed $351 million to AECL. Part of that money, the government says in budget documents, would be to "maintain safe and reliable operations at the Chalk River Laboratories."
Ottawa Riverkeeper Meredith Brown is on an environmental stewardship council set up by AECL to deal with the plant's relationship to its surroundings. But she said she couldn't get anyone at the company to talk to her Tuesday.
"I've tried to get through," she said, but no one at the company would take her call. The council does have a meeting set for next week.
"I did receive a couple of convoluted messages from them (AECL) back in December," she said. "None of it say anything about a spill or a leak. It made it seem like it's ongoing maintenance."
Last year, a panel of experts said the federal government needs to find a replacement, as fast as possible for the aging NRU reactor.
"Canada needs reactors that are designed to expand their production capabilities quickly in response to an emergency," the panel says in a report it submitted to federal Health Minister Tony Clement.
The report, dated May 2008, was posted on Health Canada's website in July.
Clement convened the panel in December 2007 shortly after the Chalk River reactor was shut down by AECL.
AECL took that step because it believed it could not meet safety standards administered by the federal regulator, the Canadian Nuclear Safety Commission.
The shutdown sparked a global medical crisis and forced Parliament to take the extraordinary step of overruling the safety commission to allow AECL to start up the reactor.
© Copyright (c) Canwest News Service
