A system (1, 2) comprising: - a radiation body comprising a radiation exit window, wherein the radiation body is configured to receive radiation that at least comprises UV radiation, and to radiate at least part of the radiation to the exterior of the radiation body via the radiation exit window; - a radiation arrangement configured to provide the radiation, comprising at least one UV radiation source (21, 22) configured to emit UV radiation; - a detector arrangement configured to detect an internal radiation intensity of radiation in the radiation body at at least one detector position; and - a controller arrangement, functionally coupled to the radiation arrangement and the detector arrangement, configured to set a normal state of the at least one UV radiation source (21, 22) as a default, in which state the at least one UV radiation source (21, 22) provides the UV radiation with an intensity at a maintenance level, and configured to receive input from the detector arrangement and to apply a controller algorithm that involves i) determining at least one safety test value that is representative of a parameter of the internal radiation intensity detected by the detector arrangement at the at least one detector position, ii) assessing whether the at least one safety test value is inside or outside of a safety range of values associated with the at least one detector position, and iii) after occurrence of a disturbance incident involving a shift of the at least one safety test value from inside the safety reference range of values to outside of the safety reference range of values and a subsequent restoration incident involving a shift of the at least one test value in opposite direction, temporarily setting a disinfecting state of the at least one UV radiation source (21, 22), in which state the at least one UV radiation source (21, 22) provides the UV radiation with an intensity at a level that is increased relative to the maintenance level. - a radiation body comprising a radiation exit window, wherein the radiation body is configured to receive radiation that at least comprises UV radiation, and to radiate at least part of the radiation to the exterior of the radiation body via the radiation exit window; - a radiation arrangement configured to provide the radiation, comprising at least one UV radiation source (21, 22) configured to emit UV radiation; - a detector arrangement configured to detect an internal radiation intensity of radiation in the radiation body at at least one detector position; and - a controller arrangement, functionally coupled to the radiation arrangement and the detector arrangement, configured to set a normal state of the at least one UV radiation source (21, 22) as a default, in which state the at least one UV radiation source (21, 22) provides the UV radiation with an intensity at a maintenance level, and configured to receive input from the detector arrangement and to apply a controller algorithm that involves i) determining at least one safety test value that is representative of a parameter of the internal radiation intensity detected by the detector arrangement at the at least one detector position, ii) assessing whether the at least one safety test value is inside or outside of a safety range of values associated with the at least one detector position, and iii) after occurrence of a disturbance incident involving a shift of the at least one safety test value from inside the safety reference range of values to outside of the safety reference range of values and a subsequent restoration incident involving a shift of the at least one test value in opposite direction, temporarily setting a disinfecting state of the at least one UV radiation source (21, 22), in which state the at least one UV radiation source (21, 22) provides the UV radiation with an intensity at a level that is increased relative to the maintenance level.