Progress is reported in finaiizing basic design data for the Materials Testing Reactor. The major emphasis at ANL was on issurance of design reports on practically all phases of the MTR project outside the reactor face and low the first fioor level. Operation of the mock-up reacr at ORNL at 10 watts resulted in no major design changes. Topics discussed include the reactor building, wing, and reactor service building; canal and canal facilities; water systems; air exhaust systems; electrical power systems; effluent control; and shielding requirements. 11 drawings. (C.H.)