Radames Leon, a staff member accused of abusing a juvenile at Oak Hill, the maximum-security institution where the District houses 150 juvenile delinquents, will keep his job, according to a ruling by David Rivers, director of the Department of Human Services.

Rivers reversed a recommendation from Oak Hill Superintendent Rayford Myers that Leon be fired after he allegedly locked an 18-year-old youth in his room on Aug. 2, 1984, and poured ammonia under the door. The youth, who said he began to choke from the noxious fumes, banged on his window until it broke and was punished for destruction of property.

However, Rivers said yesterday that while he was "concerned about . . . the protection of our kids," he felt the allegations against Leon were unsupported "and not enough to recommend dismissal."

Leon denied pouring the ammonia under the door or abusing the youth. He also questioned the youth's credibility and that of a counselor who said he had overheard Leon threaten to harm the boy. That counselor is currently serving time in a federal prison on a drug possession conviction.

"They don't have no proof or anything, nothing but a criminal's word. They come and try to take my job," Leon said.

The youth who filed the complaint was acquitted of the charges that brought him to Oak Hill. He and his mother said they were disappointed by Rivers' action and said they stood by the allegation.

"I think it's a disgrace," the mother said. "You're supposed to punish, but to use ammonia , to me that's torture."

Attorney Diane Shust, who runs the juvenile services program for the D.C. Public Defender Service, also criticized Rivers' decision. Shust said she mentioned the incident to Oak Hill officials after an initial investigation of her own.

"I found the youth to be credible. I interviewed his witnesses. I found them to be credible," Shust said.

Leon, who is Puerto Rican and the only Hispanic employe at Oak Hill, also said he felt his firing was racially motivated. Officials at the Laurel-based facility denied Leon's claim of discrimination.

Leon learned that he had won his appeal in a letter from Rivers dated Oct. 23. Leon provided a copy of the letter to The Washington Post on Monday.