The undetected malfunction of an incorrectly installed and calibrated component at Bruce “B” Unit 7 during a restart procedure in December of 2002 has been termed a “serious event” by the Canadian Nuclear Safety Commission.
The malfunction went undetected for 3 weeks, according to the CNSC report.
Bruce Power CEO Duncan Hawthorne described the event as “a technical breach”. He told the Toronto Star, “The operators caught it quickly.”
The incident appears to have been more than a minor event. According to the CNSC report, a “…backup trip was also impaired, representing a reduction of the defence in depth.”
This latest incident comes a scant two months following Bruce Power’s admission that Bruce “B” Unit 6 had been out of operation over the peak demand summer season when maintenance equipment malfunctioned. The malfunction created an electrical arc that burned a hole through a pressure tube (normally containing uranium fuel but empty at the time) and through another tube (the calandria tube) in which the first tube is enclosed.
While admitting that Unit 6 was down for maintenance for an unexpectedly long period, Bruce Power did not publicly admit to the severity of the event until late September. The company said radioactivity was contained.
The public sector owners and previous operators of the facility Ontario Hydro, later OPG, were required to post publicly available accident reports. But the private sector lease holder/ operator, Bruce Power, does not appear to have to make such reports available. One wonders when the federal regulator, the Canadian Nuclear Safety Commission, was told of the "events" by Bruce Power.
Meanwhile, Cameco Corp. announced that it has a stake in Bruce Power to thank for offsetting last year’s losses in other parts of the company’s operations. The company pointed to a fatal accident at Kumtor gold mine in the former Soviet republic of Kyrgyzstan for hampering its profitability.
Cameco went on to predict that high production at and increased ownership in the Bruce complex (as well as a hoped for turn around in Asia) will boost the company’s profits in the year to come.
These announcements came the day before the CNSC released the latest Bruce Power accident report. The world’s largest uranium producer might well have wished it had held off making the bright pronouncement.
It should comfort Cameco shareholders, as well as those at TransCanada Pipeline and OMERS pension plan holders, to know that even with this latest serious event (which has been described as a violation of the Bruce station’s operating principles), the profitability of the plant has been not only been maintained, it has increased over the previous year.
Cameco's head office is in Saskatoon, TCP is in Calgary and OMERS is in Toronto.
Bruce Power is in the hamlet of Inverhuron, Ontario on the Lake Huron shore, 300 kms west of Toronto.