[en] The interaction between particle beams and accelerator components is at the origin of a wealth of effects requiring a careful evaluation at the stages of machine design, operation, and dismantling.Such an interaction is triggered by different scenarios, i.e. either regular or accidental beam losses on beam intercepting devices (targets, collimators, dumps, stoppers, stripping foils, etc.), dust fall into circulating beam, particle debris generation inside the detectors of a collider, nuclear reactions on the residual gas in the vacuum chamber, synchrotron radiation, gas Bremsstrahlung. Multipurpose Monte-Carlo codes like FLUKA represent an essential tool, allowing us to evaluate macroscopic quantities through the microscopic description of particle transport and interaction in matter. This paper presents an overview of FLUKA studies in CERN accelerator design and operation, with special emphasis on the validation opportunities already offered by the first Large Hadron Collider (LHC) runs