Comparison of Measured and Calculated Control Rod Reactivity of the RSG-Gas Core

Abstract

COMPARISON OF MEASURED AND CALCULATED CONTROL ROD WORTH OF THE RSG-GAS WORKING CORE CONFIGURATION.The reactivity worth of the RSG-GAS core control rod is a very important reactor parameter and is closely related to operational safety. The reactivity worth of the RSG-GAS core control rod must be determined during the beginning of cycle (BOC) of the new core configuration. Measurement of control rod reactivity by various methods has been carried out in the RSG-GAS core. The measurement used today is paired one by one compensation. The reactivity worth of each control rod has been proven by calculations using the Batan-3DIFF diffusion codes and the results are very satisfying. The results of measuring the reactivity of control rods have never been compared with the results of calculations using the Monte Carlo method. In this work, the total reactivity worth of the control rods of the G.A Siwabessy Multipurpose Reactor (RSG-GAS) core measurement results will be verified with the calculation results for the new core configuration. The calculations were carried out by diffusion and Monte Carlo methods using computer codes Batan-3DIFF and MCNP5. The total reactivity values of the control rods were obtained 17.54 $, 17.03 $ and 17.87 $ by measurement, MCNP5 and Batan-3DIFF calculations, respectively. The relative difference between the measurement value and the calculated control rod reactivity value is approximately 3.0%, which indicates a good fit between the measurement and calculation methods.