No. 80-2273. Argued June 4, 1981. Decided October 1, 1981. James F. Hendricks, Jr., Oakbrook, Ill., for petitioner. Steven Fetter, N.L.R.B., Washington, D.C., Joel A. D'Alba, Chicago, Ill., for respondent. Petition for review from the National Labor Relations Board. Before PELL and SPRECHER, Circuit Judges, and EAST, Senior District Judge. William G. East, Senior District Judge for the District of Oregon, is sitting by designation. PELL, Circuit Judge. North Suburban Blood Center (NSBC or Center)