Exelon Corp., the biggest U.S. nuclear power producer, boosted the Dresden 3 reactor in Illinois to 95 percent of capacity from 18 percent yesterday, according to a report from the U.S. Nuclear Regulatory Commission.

The 867-megawatt unit was taken offline Nov. 6 to repair a turbine valve, the company said yesterday.

The Dresden plant is 60 miles (97 kilometers) southwest of Chicago. Another reactor at the site, Dresden 2, began a planned refueling and maintenance outage Nov. 2, according to the company.