Atomic Energy of Canada Ltd. has pushed back its deadline again on when it will complete the installation of 380 calandria tubes at the Point Lepreau nuclear power plant in New Brunswick. (CBC)

The $1.4-billion refurbishment of the Point Lepreau nuclear reactor in New Brunswick is continuing to miss deadlines set by Atomic Energy of Canada Ltd., CBC News has learned.

The reactor is scheduled to be restarted next February, 16 months behind schedule, but is facing even more problems.

AECL had planned on installing 380 calandria tubes in the nuclear reactor by the start of February, a deadline that was pushed back until the end of March. Now, the federal nuclear agency has postponed the completion date yet again and set a new target for the end of April.

AECL had expected that installing the tubes, which contain pressure rods that hold uranium fuel bundles, would take about eight weeks, but after 11 weeks the installation is still only 25 per cent complete.

When AECL changed its schedule last fall, it built in a degree of flex time just in case there were further delays.

Calandria tube installation is a three-step process involving inserting the tubes, attaching collars at each end to fasten them in place and then testing the assembly to ensure the unit is air-tight.

Internal reports at Atlantic Canada's only nuclear power plant show less than half of those requiring collars have been installed and even fewer have passed the air-tightness test.

October deadline in place

As of March 10, 191 calandria tubes had been installed and the rest are to be in place by late April, AECL spokesman Dale Coffin said in an email to CBC News.

The agency still intends to have its part of the refurbishment complete by October, Coffin said, in time to hand over the reins to NB Power for the final testing and commissioning before the revamped reactor starts producing power in February 2011.

Inserting the new tubes is the first major step in rebuilding the reactor, which was shut down in March 2008 for what was supposed to be an 18-month refurbishment.

However, dismantling the old reactor took 32 weeks longer than expected as remote-controlled tools continually malfunctioned in the radioactive environment.

Cleaning and inspecting the reactor shell ran another 14 weeks late, with calandria tube installation problems adding to those delays. There are two major jobs left for AECL: fuel channel and lower feeder installation, each originally budgeted to take about two months.

The Point Lepreau reactor generates about 30 per cent of New Brunswick's electricity, and the extended shutdown has resulted in significant cost overruns for the province.

The federal and provincial governments have been locked in a war of words over who should cover the costs of the delays, which the New Brunswick government says are the fault of AECL.

The Point Lepreau project is the world's first refurbishment of a Candu-6 facility, and AECL had hoped it would act as a model process that could be sold to other countries that purchased the same kind of reactor.