Neutron flux measurements were made in the reactor building of the Sandia Pulsed Reactor Facility using threshold detectors for the neutrons with energies greater than 10 kev. Bare and cadmium-covered gold were used for measurement of the thermal neutron fluxes. Midplane measurements were made as a function of distance outward from the reactor vertical centerline in several different directions within the building. In addition, detailed measurements were made on a midplane traverse around the circumference and a vertical traverse from the base of the safety screen over the domed top and to the base on the opposite side. All measurements were free field'' in the sense that no spectrum-perturbing experiments were near the reactor during these measurements. The fluxes above 10 kev follow a (1/r)/sup 2/ attenuation, whereas the thermal fluxes show very little attenuation with distance. The reactor is, to a good approximation, a point isotropic neutron emitter. (auth).