Abstract: Shielding is an important measure to ensure that the dose rate and dose outside an accelerator room meet the control objectives. The optimization design of shield thickness generally uses some analytical algorithms and its reliability needs to be verified. Outside the primary shield of an accelerator, 10 sites and another one of flat filter free high doserate mode, are selected to perform dose rate calculation, using analytical algorithms in IAEA Report No.47 and GBZ/T 201.2. The outcomes are then compared withthe measured results. It shows that calculated values with the IAEA approach are higher than those with GBZ/T 201.2 parameters employed, with the latter much closer to measurements. However, there are some individual sites with a measured,higher than calculated dose rate, which's maybe due to insufficient concrete thickness. The analytical algorithm of GBZ/T 201.2 can reasonably estimate the dose rate outside the main shielding area. During the construction process, the project quality should be strictly controlled to ensure that the concrete density and construction thickness are consistent with the design.

Key words: Accelerator, Shield, Dose Rate