FREDERICTON - NB Power is seeking an extension of its licence to operate Atlantic Canada's only nuclear power plant but it could be six weeks before a decision is announced.

Officials with the utility appeared before a hearing of the Canadian Nuclear Safety Commission in Ottawa on Wednesday asking that the operating licence for the Point Lepreau reactor be extended by one year to the end of June 2012.

The utility would normally seek a new five-year licence but NB Power spokeswoman Kathleen Duguay says they're only looking for a one-year extension because the reactor is still being refurbished, which won't be completed until next year.

"Our current licence covers the refurbishment project and we haven't completed the refurbishment project," she said. "The condition of the licence is not changing because we are still in refurbishment so it makes sense to ask for an extension to that licence."

The refurbishment of the aging reactor by Atomic Energy of Canada Ltd. is three years behind schedule and $1 billion over budget.

When the project started, the reactor was expected to be back in service in the fall of 2009.

A glitch recently required the removal of 380 new calandria tubes from the heart of the reactor. Each calandria tube contains a pressure tube, which in turn holds the uranium fuel bundles used to power the reactor.

Tiny scratches caused by wire brushes raised concerns that the joints might not remain reliable over the next 25 years.

Duguay said if the licence extension is granted, NB Power will seek approval for the next steps in the project.

"We're going to need permission to refuel the reactor and that's going to be happening in the fall, and then we'll apply for our five-year power operating licence," she said.

NB Power expects to have the power plant back in operation by the fall of 2012.