Uncertainties in the Power Alignment at the Jordan Research and Training Reactor

Abstract

Nuclear research reactors are required to be equipped with an active Reactor Protection System (RPS) that intervenes and shuts down the reactor at pre-set trip set-points, assuring that the reactor operating conditions do not exceed safety limits stated in the reactor Safety Analysis Report (SAR). However, for the RPS to truly prevent the reactor power from exceeding the reactor power safety limits, robust and accurate calibration of the RPS power signals is required.The accuracy of the power alignment at the Jordan Research and Training Reactor (JRTR) was evaluated by estimating sources of uncertainty in the measured thermal power, most significantly induced by assumptions in the thermal power evaluation method, and by the uncertainties in temperature and flow rate measurements.Based on the results of the analyses, a set of recommended modifications to the power alignment procedure and to the Operator Work Stations (OWS) alarm set points are provided to ensure that the RPS satisfies its function of shutting down the reactor without exceeding the safety limits.