N.B. Power facing $71M bill for generator troubles at idle nuclear plant

A problem in the massive electrical generator at the Point Lepreau nuclear station that has been delaying its return to service will take several more weeks to resolve and cost an expected $71 million in repairs and lost production, N.B. Power estimates.

But the actual problem with the one million horsepower generator, which was discovered nearly a month ago, hasn't been fully diagnosed yet, and the utility warned costs could climb if a fix takes longer than expected.

"You said early September is when you are estimating. Is that sort of a best case scenario?" asked J.D. Irving lawyer Glen Zacher about the Lepreau generator, during N.B. Power's rate hearing on Monday.

"Yes, that would be fair," replied Jason Nouwens, Lepreau's director of regulatory and external affairs.

Nouwens declined to say what a worst case scenario for the repair might be.

The Lepreau plant has been offline since early April for what was supposed to be a $137 million, three-month maintenance shutdown.

No work was done on the station's main generator as part of that program, and according to Nouwens there was no reason to because it was operating normally in the spring. 

"We do have monitoring on the generator," said Nouwens. "Those monitoring systems did not identify that there was an issue and the generator was operating properly when we shut down."

But after sitting idle for three months, the generator showed a problem during routine testing done on all plant equipment prior to being restarted, Nouwens said, and there is no alternative but to keep Lepreau idle until the malfunction is fully diagnosed and repaired.

"It has to be remedied now," he said.

Nouwens said engineers at the plant believe they have traced the problem to what he said was a single "stator bar" in the generator but they still do not know how or why the malfunction occurred.

Currently the generator is being disassembled to retrieve and replace the defective piece and to investigate what caused it to stop working properly.

Once the engineers are satisfied they fully understand what happened, the generator will be pieced back together and the station will be restarted sometime around Sept. 7.  However, that will depend on the puzzling failure being completely resolved.

The problem comes at a difficult time for the financially-battered utility.