REACTOR COOLANT PUMP PERFORMANCE MONITORINGIN IRIS USING NITROGEN-16 MEASUREMENTS

摘要

Monitoring of 16N produced in the core is expected to provide an effective means tornmonitor the performance of components such as steam generators and reactor coolant pumps,rnwhich are located within the reactor pressure vessel in the IRIS reactor. The concentration ofrn16N at key locations within the reactor pressure vessel will depend on the flow path and rate,rnand can be used to monitor long-term system performance through trending and to monitorrnshort-term transient events. Calculations show favorable 16N count rates for a gamma-rayrndetector located at a pressure-vessel port adjacent to a steam generator location. The gammarayrndose to the detector electronics is within acceptable limits, and the background activity isrnnot expected to interfere with the detection of 16N. Candidate gamma-ray detectors have beenrnevaluated, and demonstration measurements have been carried out with a bismuth germanatern(BGO) scintillator detector. Excellent separation between 16N gamma rays and backgroundrn(60Co) gamma rays was observed.