It was 52 years ago, in August of 1958, that the nuclear powered submarine USS Nautilus passed directly under the North Pole. Two days later, the Nautilus emerged, completing a four day 1,830-mile voyage under the Arctic ice cap.

The Nautilus relied solely on power from its nuclear reactor, which propelled the big sub at a steady 20 knots. The design of the Nautilus pressurized water nuclear reactor, supervised by Adm. Hyman Rickover and his team, was the prototype for most of our current fleet of 104 civilian nuclear power plants.

Whether at sea or on land, those nuclear reactors provide clean, safe power with the highest reliability and availability factor of any fuel source. U.S. nuclear plants generate 800 billion kilowatt-hours (kWh) per year, 20 percent of our electric needs.

With its consumer bills during 1Q 2010, Xcel Energy included an insert titled "Your Electricity," which listed all of its power plant fuel sources by cost and reliability. Nuclear power led both lists as the lowest-cost and most-reliable power source for our largest utility.
   
High capacity
Minnesota's nuclear reactors at Prairie Island and Monticello have a capacity factor (uptime percent) of 90 percent, stopping only every 20 months or so for refueling and maintenance. By contrast, all U.S. wind farms in 2009 produced 72 billion kWh, which is 1.75 percent of total U.S. electric power at a capacity factor of about 27 percent.

Like Minnesota, Canada's Ontario Province had a warm July. On July 8, 2010, the City of Ottawa hit 95 degrees and the province was using 25,000 megawatts (MW) of electric power. Gas and coal plants furnished 10,200 MW; nuclear 9,200 MW; and hydro 3,600 MW. Ontario's 1,100 MW of wind capacity managed just 107 MW on that day.

Wind tends to be lowest on those hot summer days when there isn't a "breath of air," and air conditioners run hard. For July as a whole, Ontario wind averaged output at 10-20 percent of name plate capacity.

It's probably time for the Minnesota Legislature to join the world nuclear renaissance and lift our state's ban on new nuclear power plants. Like the postman, neither snow nor rain nor heat nor other vagaries of weather stays those plants from the swift completion of their obligations.
 
Rolf Westgard is a professional member of the Geological Society of America and American Nuclear Society. He is a guest lecturer on energy subjects for the University of Minnesota College of Continuing Education.