RALEIGH, N.C. (AP) — Utilities in North and South Carolina are adding to the list of states in the U.S. reporting trace amounts of radiation from a nuclear reactor in Japan that was damaged by an earthquake and tsunami.Progress Energy and Duke Energy in North Carolina and South Carolina Electric and Gas Co. all operate nuclear plants and say they've detected trace amounts of radiation.Nuclear experts and health officials say there's no public health risk. The U.S. Environmental Protection Agency says people are exposed to much more radiation on an international airline flight.Progress Energy says it picked up low levels of iodine-131, a radioactive byproduct of nuclear fission, at its nuclear plant in South Carolina and a Florida plant.Massachusetts, Nevada and other Western states also have reported minuscule amounts of radiation.