Physical Design of the Radiation Shielding for the CMS Experiment at LHC

The design of the radiation shielding for the CMS experiment at the LHC requires a simulation of the radiation environment using a model of the CMS experimental setup, accelerator components and the experimental hall infrastructure. The radiation simulations are used to optimise the design of the CMS detectors components and also the interface of the CMS detector with LHC accelerator. The Beam Radiation Instrumentation and Luminosity Project of CMS is responsible for giving important input into the optimisation and upgrade of radiation shielding used in CMS and also the radiation environment simulations software infrastructure. This contribution describes the organization of this work, the simulation software environment used for this part of CMS experiment activity and recent radiation simulation results used to optimise the forward shielding for CMS.