Virginia's Ralph Sampson was named the winner of the Anthony J. McKelvin Award yesterday as the Atlantic Coast Conference's athlete of the year.

Sampson, the 7-foot-4 Cavalier center who dominated college basketball opponents for four years, was named on 51 of 118 ballots cast by members of the Atlantic Coast Sports Writers Association.

North Carolina's Sue Walsh, a national backstroke swimming champion, placed second with 24 votes. Others receiving votes were Clemson's Mike Eppley (13), a starter in both football and basketball; North Carolina State's Betty Springs (12), a national distance running champion; Wake Forest's Bill Merrifield (7), a two-time ACC baseball player of the year, and Duke's Joe Ulrich (4), the national collegiate soccer player of the year.

Also receiving votes were Georgia Tech's Mark Price (4), the basketball rookie of the year, and N.C. State's Thurl Bailey (2) and Sidney Lowe (1), mainstays on the Wolfpack's 1983 national championship team . . .

Ricky Byrdsong, an assistant basketball coach at Arizona, will have his salary cut 50 percent in 1983-84 because a player was given an airline ticket last fall, according to Cedric Dempsey, the school's athletic director.

Also, Byrdsong's wife, Sherialyn, an assistant coach of the women's basketball team, will be reprimanded, Dempsey said.

Dempsey said both the NCAA and the Pac-10 were notified of the actions. The school's football program recently was put on three years probation by the NCAA for recruiting violations . . .

Oregon State's basketball program is being investigated for possible violations of NCAA rules, school officials confirmed. A report on the preliminary probe was published Friday by the Seattle Times.