Need for replacement parts will stall Muskrat Falls turbine commissioning

The company installing the four power generating turbines at Muskrat Falls has encountered a mechanical problem that will delay first power by "days and weeks, not months," according toa Nalcor official.

It's the latest hiccup in a list of challenges that have shadowed the controversial and vastly over-budget Lower Churchill Project.

Contractors arealready struggling to complete the computer software needed to safety and efficiently operate the 1,100-kilometre transmission line from central Labrador to Newfoundland's Avalon Peninsula, and repair vibration and jamming issues with three synchronous condensers at the Soldiers Pond switchyard.

New metal strips being fabricated

The first turbine has been undergoing testing for several monthsand has operated at full speed with water passing through the power station.

But technicians withAndritzHydro Canada have discovered a problem with steel strips known as "keys" that are part of the rotor rim assembly.

These strips are about two metres long, and are supposed to fit snugly together. But there's a space between the strips, and new ones are now being fabricated for all four turbines.

"We expect that Andritz will pause testing for approximately two weeks while the new parts are installed," said a Nalcor spokesperson.

"This is not a major issue," said the spokesperson,who added it's"to be expected" when commissioning a turbine unit that weighs 1,100 tonnes and comprises thousands of precisely engineered parts.

Andritz contract flagged during inquiry

Andritz is responsible for supplying the partsand covering any costs associated with the delay, according to Nalcor.

The company describes itself as one of the leading suppliers of electro-mechanical equipment and services for hydropower plants in Canada.

It was awarded the $200-million-plus contract known as CH0032in 2013 to supply and install the powerhouse and spillway hydro-mechanical equipment at Muskrat.

But this contract is one of six singled out during the Muskrat Falls inquiry for contributing to a dramatic increase in the construction cost, which has grown from $6.2 billion to $10.1 billion. These figures do not include interest costs during construction, which pushes the final forecast cost to $12.7 billion.

The current value of the Andritz contract was not revealed during the inquiry last year because the work isongoing, and it was deemed commercially sensitive.

• Muskrat Falls power this winter? Nalcor CEO updates on project's software struggles

Like most components of the project, the Andritz contract is behind schedule.

Nalcor CEO Stan Marshall told reporters in October that turbine No. 1 would be energized in November, and that it would be ready to supply electricity in January.

Then in December, Marshall said first power was delayed until February.

Marshall was not available for an interview Wednesday, and it's unclear when the first turbine, capable of generating more than 200 megawatts of electricity, will be in operation.

A Nalcor official said the testing process will continue for months, and the lessons learned on turbine No. 1 can be helpful duringthe commissioning process for the remaining three turbines.

• Nalcor announces another setback for Muskrat Falls transmission software
• Employee fatigue, software bugs responsible for new Muskrat delays, says Marshall

Meanwhile, there has not been a change to the completion schedule, with full commercial power of 824 megawatts planned for later this year.

Read more from CBC Newfoundland and Labrador