An attorney for the Nuclear Regulatory Commission in Bethesda was indicted by a federal grand jury here yesterday in connection with an alleged scheme to launder credit-card payments made to two Washington prostitution operations.

The 52-count indictment on charges of interstate transportation in aid of racketeering/prostitution, was returned in U.S. District Court against John Cleveland Carr, 38, of Springfield.

The maximum penalty for each charge is five years in jail and a $10,000 fine. Neither Carr nor his attorney could be reached for comment last night.

According to the indictment, Carr received completed customers' credit-card slips from George Glenn, the operator of two out-call services, The After Dinner and The Stripe, at 735 Kennedy St. NW. Carr then would have the slips taken to a Mechanicsville, Md., pharmacy where they were processed so it would appear that purchases had been made there, the indictment stated.

Using this type of operation, Glenn received the face value of the charge-card slips, minus 20 percent that went to Carr, the indictment alleges.

FBI agents searched the two out-call services on Oct. 15, 1981. On March 16, 1982, Glenn pleaded guilty to two counts of interstate transportation of women for the purpose of prostitution. He received two years' probation.