REACTOR CORE OF LIGHT WATER REACTOR

摘要

PURPOSE:To obtain a reactor core in which a nuclear reactor operating characteristic supervising reactor monitor is properly arranged by separating the difference of height of reactor instrumentation and an inclusion area measuring the output in the time of high output operation such as a local output range monitor up to constant value or more while providing at least a low area (inclusion area) of fissionable nuclide concentration. CONSTITUTION:A fuel assembly is vertically arranged and the height H of its effective part (including an inclusion area) is 3.6-3.7m. In the case where the inclusion area of only a stage is arranged, the H/3-H/6 from fuel effective part upper end (TAF) is proper and this position makes the largest effectiveness from the point of the improvement of a reactor stop margin. Channels A-D of a local output range monitor 4 (LPRM) are arranged at regular intervals (not much exceeding H/4) and the increase of instrumentation errors can be prevented because the channels are separated from the inclusion area up to constant distance or more. Further, a neutron source range monitor (SRM) used in the time of nuclear reactor starting is arranged in the inclusion area and high sensitivity measurement in which rise is utilized can be performed by the inclusion area of thermal neutron flux.