A Northern Virginia bingo operator whose illegal games earned an estimated $1 million in Fairfax County was sentenced to two years in prison and a $20,000 fine yesterday in Fairfax Circuit Court.

Noting that operator Alva Ford Thompson, 46, had skimmed $346,000 from bingo profits and that $80,000 of the proceeds are still unaccounted for. Judge Thomas J. Middleton truned aside Thompson's plea that he be placed in a work-release program rather than be sent to prison.

"It's very sad that a man has to be sentenced who has been as successful as you have," Middleton said in imposing the sentence.

Thompson was sentenced earlier this month to a similar two-year prison term and $20,000 fine in Alexandria for running illicit bingo games in that city. Middleton ordered yesterday that the two prison terms run consecutively.

Thompson pleaded guilty to felony gambling charges in both jurisdictions after undercover Alexandria police officer Kathleen Bralove penetrated Thompson's firm, United Charities Inc.

Thompson was accused of keeping two sets of books for games conducted on behalf of three local charities at the Bonanza Playhouse, 7520 Richmond Hwy., in 1977 and 1978. Fairfax County auditors have testified that Thompson understated the games' receipts by $346,000.

Deputy Fairfax prosecutor Steven Merril said last month that the charities -- the Mount Vernon Youth Association, the Pioneer League Baseball Club and the Lee District Basketball Club -- received only $22,000 from the Thompson-run games.

"If this court would let me work," the baldish, heavy-set Thompson pleaded yesterday, "let me contribute for what I have done wrong... please try to consider some type of program for me."

But Middleton rejected the emotional appeal, saying, "It was your brainchild and your culpability."

Thompson could have received a maximum penalty of 10 years in prison and a $20,000 fine. He was freed yesterday on $20,000 personal bond until he begins his prison terms March 12.