LONG-LIFESPAN IN-CORE INSTRUMENT

摘要

A long-lifespan in-core instrument having an extended lifespan due to an enhanced combustion lifespan of an emitter according to the present invention comprises: a central tube; an outer sheath tube distanced from the outer circumferential surface of the central tube; self-powered neutron detectors placed between the central tube and outer sheath tube, and each comprising an emitter of a material having a reaction cross section with neutron that is comparatively smaller than that of rhodium; a background detector for compensating for the background noise signal; core exit thermocouples for detecting the core exit temperature; and filler wires filling in the space between the self-powered neutron detectors, background detector and core exit thermocouples, and as such, the present invention can markedly reduce the amount of spent in-core instrument waste, which is high-level radioactive material, and thus can contribute in securing a utility space for the high-level waste material, as well as in reducing radiation exposure of the nuclear power plant personnel.