[en] Discrete ordinate calculations are made and the results compared with measurements performed in the startup experiment at the Poolside Facility. Because of the physical size of the simulated surveillance capsule used in this experiment, the analytic procedure is more complicated than one adopted in earlier calculations of the PCA-PVF and PSF. The comparisons indicate the pressure vessel fluences in the long-term irradiation experiments still presently going on at the PSF, and which are geometrically identical to the startup experiment, can only be predicted to within about 20%