The scientist, Siegfried S. Hecker, a Stanford professor who previously directed the Los Alamos National Laboratory, said in an interview that he had been ¡°stunned¡± by the sophistication of the new plant, where he saw ¡°hundreds and hundreds¡± of centrifuges that had just been installed in a recently gutted building that had housed an aging fuel fabrication center, and that were operated from what he called ¡°an ultra-modern control room.¡±