Failed element monitoring in organic cooled nuclear boiler

Complex of works in design and experimental justitication of the system of failed fuel element control (FFEC) is carried out for an organic cooled nuclear boiler. Gaseous fission products, which yield of defect fuel element is a 10-1000 time as much as yield of other fission products, are chosen as a reference set for FFEC. Structural scheme of the FFEC is developed; the scheme comprises branches of fuel element rejection after reactor shutdown and continuous fuel element control on operating reactor according to activity of coolant and gas released from a deaerator. Standard scintillation detectors are used as transducers of the FFEC system. Increase of the effect-background ratio is attained by the selection of gamma radiation detection range, which is realized in the measuring channel. The technique for mathematical simulation and determination of FFEC system parameters is developed. Experimental checking of investigations conducted at the nuclear boiler confirmed the truth of the decisions have been come. Selected methods and facilities provided essential scope of the FFEC during the reactor operation and shut-down