Ontario nuclear plant weld failure ”unprecedented,” documents show

OTTAWA — When the Canadian Nuclear Safety Commission was struggling last December with a shortage of medical isotopes sparked by the Chalk River reactor shutdown, it was also dealing with another Ontario nuclear plant where there had been an “unprecedented” weld failure on one fuel bundle.

In all, 10 defective welds were found on the fuel bundle, a collection of processed uranium rods resembling the barrel of a Gatling gun about a half-metre long.


The rods contain pellets of uranium dioxide – used to generate electricity by heating water into steam to drive turbines.

The defective bundle was discovered at the Bruce Power plant, north of Tiverton, Ont., in June 2007.

Minutes of the Nuclear Safety Commission’s meeting, held Dec. 5 and 6, 2007 and obtained by Canwest News Service, show the commission asking if similar incidents had ever occurred. “CNSC staff responded that weld failures have occurred over the last 10 to 15 years, but that this event of 10 weld failures on one bundle is unprecedented,” the document says.

Canwest News