NEW YORK -- Although it's hardly at the heights it once was, NBC's "ER" is still a pretty strong performer in the Nielsens. Including repeats, it's averaging about 12 million viewers a year.

Those numbers would be higher if you took out the repeats -- which is exactly what NBC plans to do next season.

The long-running hospital drama will go rerun-free for its 13th season. It will run for 13 episodes in the fall, leading to a cliffhanger, then return to finish out the season in April 2007. In between, the network will give the highly visible 10 p.m. Thursday spot "The Black Donnellys," a new drama created by Oscar-winning "Crash" writer-director Paul Haggis and the film's co-writer, Bobby Moresco.

"Repeats are tough for any serialized drama, and it's been harder for 'ER' as it got into its 12th season this year, 13th season next year," NBC Entertainment President Kevin Reilly says. "When 'ER' is in originals, it still has the goods."

The move is also a vote of confidence for "The Black Donnellys," which was the first series NBC picked up this year for the 2006-07 season. It follows a quartet of Irish-American brothers in New York whose sense of loyalty to one another leads down a sometimes-dark path.

NBC has a long tradition of airing high-profile and high-quality dramas at 10 p.m. Thursdays. Prior to "ER," the timeslot was home to "L.A. Law" and "Hill Street Blues." Reilly hopes "The Blacke Donnellys" can follow in that tradition.

"I think it's really very special," Reilly says of the show. "It's compelling and different, and I think it's worthy of the night. We want to shine a light on it."