Welcome to the

Website

This site is a resource for ARIANT (AlgoRIthm for Analysis of Network Thermalhydraulics) users to enable them to access documentation, report problems, note code behaviour, and provide contact information to the ARIANT Code Development group within CNL.

An Introductory ARIANT training course has been scheduled for July 23 to 25, 2024 in Deep River, ON.

ARIANT is a generalized, one-dimensional, non-equilibrium, two-fluid, two-phase system thermalhydraulics code. The range of application includes, but is not limited to, pressurized heavy water power reactors (PHWR), nuclear and electrically heated experimental test facilities. The code supports a variety of coolants, including H2O, D2O, molten salts (LiF-BeF2, NaBF4-NaF, LiF-NaF-KF, and NaF-ZrF4), liquid metals (Potassium (K) and Sodium (Na)) and noncondensable gases ('AIR', 'N2', 'H2', 'AR', 'HE', 'CO2').

ARIANT can simulate two-phase flows and heat transfer over a wide range of temperature and pressures, including both sub- and supercritical pressures. The primary focus of development has been on the analysis of the consequences of postulated upset scenarios in CANDU reactors. The code has also been successfully applied to a wide range of problems from test facilities (e.g., RD-14M, CWIT, LOBI, etc.). ARIANT is currently being revised to support applications in Small Modular reactors such as the molten salt or the high temperature, gas cooled reactors. ARIANT incorporates various modules enabling the user to perform complete simulations of power plants or experimental facilities. For example, a highly detailed heat transfer module enables the user to model a fuel bundle in three-dimensions to any desired resolution. The code includes a point neutron kinetics model for basic neutronics calculations; however, it can also be interfaced with third party codes to develop a more detailed representation of core physics. ARIANT incorporates a complete control system module that provides all the necessary tools required to simulate the control systems in a power plant such as various trip functions, controls required for power maneuvering.

ARIANT has been written in Fortran 95/2000 language and as a result is highly modularized. ARIANT also uses dynamic memory allocation, which means the problem size is only limited by the size of local computer memory. The code employs a fully-implicit numerical integration scheme using Newton’s iterative method. ARIANT is being developed by the Thermalhydraulics and Safety Analysis Branch (TSAB) of the Advanced Reactors Directorate (ARD), which is part of CNL's Science and Technology (S&T) Organizational Unit.

Please see the Updates page for recent additions to the website.