An extended series of exponential experiments was carried out utilizing 233UO2-ThO2 fuel elements in uniform arrays in light and heavy water. In this series the principal parameters measured were material buckling (), reflector savings (λ), dysprosium disadvantage factor (ζ Dy), ratio of epicadmium to subcadmium capture in thorium (), and ratio of 232Th fission to 233U fission (). A total of 29 clean and poisoned lattices was measured.