FLAMANVILLE, France  It looks like an ordinary building site, but for the two massive, rounded concrete shells looming above the ocean, like dusty mushrooms.

Here on the Normandy coast, France is building its newest nuclear reactor, the first in 10 years, costing $5.1 billion. But already, President Nicolas Sarkozy has announced that France will build another like it.

Flamanville is a vivid example of the French choice for nuclear power, made in the late 1950s by Charles de Gaulle, intensified during the oil shocks of the 1970s and maintained despite the nightmarish nuclear accidents of Three Mile Island and Chernobyl.

Nuclear power provides 77 percent of France’s electricity, according to the government, and relatively few public doubts are expressed in a country with little coal, oil or natural gas.