Method and System for Stack Monitoring of Radioactive Nuclides

A method for monitoring a stack flow containing one or more radioactive nuclides, comprising the steps of:

• (a) providing an electronic signal processor with energy window discrimination which receives signals from a first detector having a first sensitivity to gamma radiation;
• a second detector having a second sensitivity to gamma radiation and a sensitivity to beta particles produced by the one or more radioactive nuclides;
• and a flow meter for measuring a flow rate of the stack flow;
• (b) pre-determining sensitivity calibration factors for the first and second detectors and for different nuclides;
• (c) calculating a background-corrected, beta-only signal for each energy window;
• (d) identifying one or more nuclide species present in the stack flow by comparing the beta-only signals of different energy windows;
• and
• (e) calculating a background-corrected value of the radiation activity concentration for each of the identified nuclide species.