I write in response to the editorial "Build the tunnel" in last week's edition of the Northern Pen, which suggested the Muskrat Falls' Labrador-Island Transmission Link should be built in conjunction with a transportation tunnel across the Strait of Belle Isle.
The Labrador-Island Transmission Link is a proposed 1,100 km transmission line that will connect Muskrat Falls to Soldiers Pond on the Avalon Peninsula. On its way from central Labrador to Soldiers Pond, the transmission link will cross the Strait of Belle Isle.
After careful examination of a seabed crossing (placing cables on the seafloor and protecting them with rock) and a cable tunnel crossing (placing cables in a 4-metre diameter conduit under the Strait), Nalcor decided on a seabed cable crossing.
In our assessment, we engaged consultants from North America, Iceland and Norway. We specifically looked at Norwegian tunnels that have been constructed at a lower cost. The difference between Norwegian tunnel costs and the Straits comes down to one major factor - rock quality for low-cost Norwegian tunnels is far better than that in the Strait of Belle Isle.
There are numerous faults or cracks, as well as porous sedimentary rock under the Strait that would require significant cost, effort, and time to reinforce the tunnel for safe construction and operation. As the tunnel diameter grows, this problem worsens.
Nalcor's chosen alternative - to place cables on the seabed and protect them with rock - is commonly used. It's used on the Grand Banks for offshore installations, and represents a low-risk and cost-effective solution.
It has also been suggested that if constructed at the same time, the cost of the cable tunnel could help reduce the cost of the transportation tunnel. The problem is timing. Pending environmental approval, Nalcor will be ready to start constructing the Strait of Belle Isle cable crossing in 2013. However, a transportation tunnel will require eight to 10 years of preparation (business case, funding, environmental assessment, etc.) before construction can begin.
This kind of delay would result in Nalcor incurring significant additional costs, including the installation of scrubbers and precipitators at the Holyrood Thermal Generating Station to reduce the facility's emissions (cost: about $600 million). There would also be the continued cost of burning fuel at the Holyrood plant, as well as increased maintenance on the aging facility.
For these reasons, the seabed cable crossing is the best choice for the Labrador-Island Transmission Link. It's technically preferred, has lower safety risks and is financially responsible.
Nalcor works closely with the Department of Transportation and Works, sharing information on the Strait of Belle Isle so that Government can better assess the merits of a transportation tunnel. At this time, however, the concept has not developed to where it could meet our province's need to bring power across the Strait of Belle Isle to the island.
Vice president, Lower Churchill Project