Fifty inmates were transferred from Lorton Reformatory's Youth Center No. 2 yesterday in what D.C. corrections officials said was an effort to reduce tensions caused by overcrowding that led to a disturbance at the facility Friday.

Last week, 190 inmates were moved to the facility from Youth Center No. 1, part of the same prison complex in southern Fairfax County, after two methane gas explosions in a dormitory there seriously injured two prisoners. Youth Center No. 1 remains closed while fire and health officials investigate the source of the gas.

The inmates tranferred to Youth Center No. 2 brought that facility's population to 437, or 187 more than it was built to hold. Corrections officers, who said they were understaffed, complained that the increase led to "an explosive situation" because of poor security and friction between inmates of the two youth facilities. They said tear gas had to be used to quell the disturbance there Friday night.

The 50 Youth Center No. 1 inmates were shifted yesterday to the orientation unit of Lorton's medium-security Central Facility, a fenced-in building completely segregated from the rest of the compound, corrections spokesman Leroy Anderson said. He said the unit "used to have a capacity of 65, but has been upgraded so it now has a capacity of 98," the total number of inmates now housed there.

Anderson said the inmates transferred to the orientation unit were among the 140 who were housed in Youth Center No. 2's gymnasium.

Anderson also said that D.C. Corrections Director James Palmer plans to "double bunk" the 90 Youth Center No. 1 inmates still housed in Youth Center No. 2's gymnasium in that facility's four dormitories.