George Mason University yesterday unveiled its new 10,000-seat sports and entertainment arena, Northern Virginia's first major coliseum, at graduation ceremonies where 2,204 degrees were awarded.

Crews had scrambled 24 hours a day for weeks to prepare the $16 million arena in time for the ceremony, university officials said. The work paid off, as the event proceeded smoothly, and thousands of graduates, relatives and friends got their first glimpse of the inside of the arena, called the Patriot Center.

University President George W. Johnson said the coliseum, located off Braddock Road on the southern end of the state university's Fairfax County campus, said the new facility "symbolizes our growing university." The 18-year-old university, which lately has started a number of programs, is in the midst of a public relations campaign boasting of its accomplishments.

Washington Bullets basketball player Tom McMillen, a University of Maryland graduate and former Rhodes Scholar, gave the commencement address, sounding themes that resembled the call for new ideas by Sen. Gary Hart (D-Colo.) in last year's presidential primaries.

A businessman in the off-season, McMillen also is an activist in Prince George's County Democratic politics and has considered running for office.

"What we need in America is a new attitude, a new resurgence, a renewed quest for our birthright -- the hope that our children's lives will be better than our own," McMillen said.

He repeatedly called for a new emphasis on education, both for low-achievers with low test scores and those heading for high-tech jobs. He said that when there is "public outcry" against minimum scholastic achievement as a requirement for participation in school sports -- as has happened in Prince George's -- "surely we should realize our priorities are not in order."

Of the 2,204 degrees conferred, there were two doctoral degrees, 125 juris doctor degrees, 447 master's degrees and 1,630 bachelor's degrees.

The coliseum, clean and well designed, is still unfinished, with painting, flooring and landscaping half completed.

"If you'd seen this place Monday, you'd be stunned at what it looks like now," said university spokesman Helen Ackerman. "We've had crews working day and night cleaning."

The Patriot Center, with 9,200 permanent seats and 800 bleacher seats, will be home to George Mason's basketball team, the Patriots, and will host concerts and other events to try to pay off its revenue bonds. It is larger than the 9,000-seat gym of its sister University of Virginia in Charlottesville and comparable to Richmond's Robins Center.

The fears some nearby residents have expressed that the center will cause traffic jams in the area seemed to be justified after yesterday's ceremony when long back-ups occurred at traffic lights on Rte. 123 in Fairfax City.