Federal regulators give a thumbs up to bring the nation’s newest nuclear reactor on—line. The Tennessee Valley Authority says it will soon fire up the unit 2 reactor at its watts bar plant north of Chattanooga. It will be the only nuclear power generation unit added to the nation’s power grid in the past 20 years. Construction on the reactor started in 1973. All told the unit cost some $6 billion to complete. TVA president Bill Johnson says the reactor should provide clean and reliable electricity for the next 80 years. Unit 2 will churn out about 1,150 megawatts of the blue spark—enough to power 650,000 homes.