Analysis of natural circulation loop in MTRs using CONVEC code

Abstract Natural circulation is an important process in core cooling and decay heat removal of Material Testing Reactors (MTRs). Analysis of an open pool natural circulation loop (NCL) was performed using the CONVEC V3.4 code developed for steady state analysis of MTRs during natural convection. Verification and Validation of code calculations for similar natural circulation loops were provided. The code calculations were carried out to investigate the geometric parameters that enhance the natural loop cooling capacity or increase the margin to Onset of Nucleate Boiling (ONB) as a limiting condition. The results describe the operating envelop in terms of core power without ONB and pool temperature for various dimensions of loop components including the fuel element and pool depth. This paper is useful for the researchers working on the research reactor design.