The Advanced Test Reactor (ATR) is a 250-MW^th flux-trap reactor located at the Idaho National Engineering Laboratory (INEL). Within the reflector are four 124-mm-diameter I-holes, which are available for silicon irradiation. Two large irradiation volumes of 0.5 m × 0.4 m × 1.2 m and 0.5 m × 0.2 m × 1.2 m are also available for transmutation doping. Thermal fluxes in these locations range from 0.56 to 23.0 × 10¹² nt/cm³-s. Use of the ATR for providing neutron transmutation doping (NTD) services in sizes not available elsewhere in the United States may be feasible.