More than 7,000 people marched through sun-washed streets yesterday, rallying and chanting opposition to nuclear energy on the second anniversary of the Three Mile Island accident, the worst commercial nuclear power accident in the nation's history.

The protestors, most of them young people wearing T-shirts and blue jeans, carried signs depicting pastoral scenes of flowers, trees and -- most of all -- the sun.

Organized labor was a visible presence, with groups from as far away as New Mexico and Indiana.

"I'm here because I think TMI represents locally what is potentially a worldwide problem, certainly a nationwide problem -- which is the long-range dangers inherent in using this form of production of energy," said International Association of Machinists union President William Winpisinger.

Also marching were Quaker youngsters from Pittsburgh, the New York chapter of the Socialist Workers Party and such diverse groups as the New York Public Library Guild, the Audubon Society of Wayne-Pike counties in Michigan and environmental groups from Maryland, Virginia, Missouri, West Virginia, Georgia, New York, Ohio, Massachusetts and Illinois.

The nuclear plant at nearby Three Mile Island leaked radiation and was shut down after the accident March 28, 1979, that crippled one nuclear reactor. Work on a $1 billion cleanup continues.