PROTEUS integral measurement provides one of the rarest fast reactor nuclear systems data with superior accuracy. The PROTEUS reactor is composed of PuO2/UO2 fuel lattice. A detailed 3-D neutronics model and calculation for the PROTEUS facility has been achieved with the SuperMC code. Most of the calculated fission rates for 238U and 239Pu showed an average deviation less than 3% from the measurement. Calculated neutron spectra in both steel-37 and steel-18/8 at the test regions showed a consistent pattern with the experiment; however, it was noticed that there was a systematic underestimation for the higher energy spectrum. The observation was also consistent with the calculated threshold reaction rate: 103Rh (n, n′) 103mRh, 115In (n, n′) In115m, and 32S (n, p) 32P. The majority of the calculated threshold reaction rates were in agreement with experimental values within total uncertainty at 2σ level. The results demonstrate good consistency of the SuperMC for modeling and calculation for reactor analysis.