ARIANT Assessment against RD-14M Natural Circulation Experiment

Abstract

ARIANT (AlgoRIthm for Analysis of Network Thermalhydraulics) is a CNL (Canadian Nuclear Laboratories) newly developed state-of-the-art system-level code intended for general modelling and analysis of two-phase thermalhydraulic flow and heat transfer for PHWR, light-water reactors and advanced reactor applications. This paper presents ARIANT modelling of the RD-14M experimental facility including all heated sections, headers, primary pumps, steam generators and the pressurizer. Using the model, ARIANT is assessed against an RD-14M natural circulation (NC) experiment, representative of a CANDU NC scenario. ARIANT predictions of pressures, flow rates and temperatures are compared with the steady-state and transient data over the course of the test. It shows that ARIANT can well predict most of the key parameters with reasonable accuracy, the overall behaviour of the transient, and the effects of sensitivity parameters on the steady-state and transient results. The assessments against the RD-14M NC test support ARIANT applicability and accuracy to model natural circulation phenomena associated with CANDU design basis accidents, and demonstrate code applicability as an alternative to existing system thermalhydraulics codes for CANDU safety analysis.