Shielding considerations for the 750-MeV electron accelerator at the University of Illinois

This report summarizes some of the calculations that were carried out to provide shielding data for the 750-MeV electron accelerator under construction at the University of Illinois. All of the results described herein were obtained for a 300-MeV and/or 750-MeV electron beam. All calculations deal with doses produced by the particle beam during operation and do not include secondary radiation sources, i.e., induced radioactivity. The dose equivalents were obtained as a function of shield thickness so that various accident scenatios could be considered, i.e., various percentages of beam loss during operation. The calculated results that were considered included: (1) the earth shielding thickness (and iron door) surrounding the accelerator vault, (2) the earth shielding thickness around the beam transport tunnel, (3) an estimate of the thickness and composition of the movable shielding door in the general purpose electron beam experimental area, (4) the shield thickness around the beam dump in the bremsstrahlung irradiation facility, (5) skyshine dose from some of the experimental areas, and (6) dose rates inside and outside the tagged photon facility. The programs and cross section data bases used in the calculations, as well as the source neutron spectra calculations, are presented. The results of the dose calculations are presented and discussed