  The expected radiation background in the CMS RPC system has been studied
using the MC prediction with the CMS FLUKA simulation of the detector and the
cavern. The MC geometry used in the analysis describes very accurately the
present RPC system but still does not include the complete description of the
RPC upgrade region with pseudorapidity $1.9 < \lvert \eta \rvert < 2.4$.
Present results will be updated with the final geometry description, once it is
available. The radiation background has been studied in terms of expected
particle rates, absorbed dose and fluence. Two High Luminosity LHC (HL-LHC)
scenarios have been investigated - after collecting $3000$ and $4000$
fb$^{-1}$. Estimations with safety factor of 3 have been considered, as well.
