Shielding calculations for the upgrade of the HFIR HB 2 beam line

Experimental facilities at the Oak Ridge National Laboratory's High Flux Isotope Reactor are being upgraded through the redesign of beam tubes supplying neutrons to those facilities. In support of the shield design for one of the beam lines HB-2, calculations were performed to determine dose rates outside the shielding as well as background radiation levels at various locations around the instrumentation. Lowpower (10 % power) as well as full-power measurements were made at key locations, and calculated results were compared with corresponding measured results. This paper describes the calculations and compares the measured and calculated results. Most of the measured results, when normalized to the full-operating-power level, compared favorably with the calculated results. One differed by a factor of 2.5, and another differed by a factor of 6. Based on this agreement, one can infer that reasonable calculations for some three-dimensional shield designs can be performed using two-dimensional methods and two-dimensional approximations to the three-dimensional geometry. The results confirmed the adequacy of the design.