Noise Two Frequency One Detector Reactivity System (NTFODRS)

摘要

A reactivity measurement method (the NTFODRS) was experimentally verified on the University of New Mexico (UNM) AGN-201M thermal reactor to obtain the absolute steady-state reactivity and demonstrate the feasibility of acquiring the transient reactivity. A detailed description of the NTFODRS hardware and software is given in this paper. The NTFODRS obtains the absolute and net reactivity by manipulating the frequency domain components inherent in the neutron detector signal current. The ratio of the average high frequency to the average low frequency components (empirically set) is used to determine the reactivity. The NTFODRS was successfully used to determine an unknown AGN-201M steady-state reactivity, with a relative error of 18%. THRNTFODRS transient curves as a function of reactivity are apparently different from the steady state curves. The transient curves are also a function of the rate of reactivity insertion. It can be shown that a modified/faster NTFODRS could be used for fast reactors. NTFODRS is not presently a practicable reactimeter. However, with more research and development and modifications, it could be used for practicable nuclear industry applications such as monitoring nuclear power plant spent/fresh fuel pools. (ERA citation 11:020834)