The Archbishop of Canterbury prayed for the release of his envoy, Terry Waite, "a beacon of light" who disappeared one year ago in Lebanon. The 15-minute special prayer service by Robert A. K. Runcie, head of the Church of England, was held in the stone crypt chapel of Lambeth Palace, the church's headquarters. Waite's wife, Francis, and 25 family members and friends attended the tribute to Runcie's 6-foot 8-inch personal envoy. "He's a big man in every way. . . ," Runcie said. Waite, 48, was working to free Western hostages when he disappeared in Beirut on Jan. 20, 1987.