Abstract: A system and method for monitoring one or more radioactive nuclides present in a stack flow consist of a first detector having a predetermined first sensitivity to gamma radiation and a second detector having a predetermined second sensitivity to gamma radiation and also a predetermined sensitivity to beta radiation. An enclosure proximal to the second detector defines a detection volume and enables the use of calibration factors which are independent of the geometry and material composition of a stack duct. A signal processor with energy window discrimination analyzes the signals from the two detectors. The use of two or more energy windows enables the identification of the nuclide species present in the stack flow and an accurate background-corrected measurement of the released radiation activity concentration for each of the identified nuclide species.

Abstract: A radiation dosimeter records absorbed radiation using a passive radiation sensor having one or more radiation-sensitive elements (RSEs) and a radiation-insensitive element (RIE). Floating gate MOSFET technology is used for both the RSEs and the RIE. A reader is connected to the sensor by means of a switching channel in order to pre-charge the sensor before exposure and to read the sensor voltage signals after exposure to radiation. The voltage signals of the RIE are used to correct for the spurious effect of voltage retention loss in the RSEs.