Atomic Energy of Canada Limited (AECL) is changing its policy and will now voluntarily disclose reportable incidents at its Chalk River nuclear plant, according to an internal government report.
The decision comes in the wake of a year filled with plant shut-downs, maintenance problems and global concerns regarding the supply of medical isotopes.
On Dec. 4, 2008, the National Research Universal (NRU) research reactor was shut down "as a result of unanticipated technical problems unrelated to isotope production." The next day, the AECL notified the Canadian Nuclear Safety Commission (CNSC) that the production of medical isotopes could be affected by the shut down. The AECL thought it might be able to bring the reactor back on line by the following morning, but decided to extend the shutdown after it discovered a small heavy water leak.
AECL estimated that 47 kilograms of heavy water leaked from the reactor, most of which was contained with the exception of 4.5 kilograms which evaporated and went into the ventilation system.
"AECL has reported that this emission amounted to less than one thousandth of regulatory limits," said the report. On Feb. 5, the AECL announced it would slowly release some treated radioactive water back into the Ottawa River. However, the CNSC said that the treated water will still contain tritium, a radioactive isotope of hydrogen that can be dangerous if inhaled or ingested by drinking concentrated amounts, according to T he Vancouver Sun.
The reactor was brought back to stable operation on Dec. 11.
Serge Dupont, associate deputy minister of Natural Resources Canada, said that the AECL promptly informed Canada's nuclear watchdog. However, the organization did not feel it was necessary to let the public know because none of the heavy water leaked into the Ottawa River, reported The Edmonton Sun.
"Since the heavy water leak did not pose a risk to the public or the environment, reports of the leak to the public was not required by either AECL or the CNSC," he wrote. "Given the media interest in the events outlined above, and subsequent public concerns, it is clear that the criteria for public disclosure of non-routine events need to be revisited."