Coupling Subroutine Version of ELOCA Code for High-Temperature Fuel Behaviour to CATHENA System Thermalhydraulics Code

Abstract

This paper describes the coupling of the CATHENA two-fluid code for safety thermalhydraulics with a subroutine form of the latest version of the ELOCA code for high-temperature, thermalmechanical and fission-product release fuel behaviour. The main features of the component codes are described, followed by an outline of the thermal and geometric coupling that exists between the thermalmechanical behaviour of the fuel and the channel thermalhydraulics during a postulated LOCA. Requirements for minimum changes to the component codes and flexibility of application to other code systems, has led to an elaborate code coupling architecture, involving a number of inteface routines. The code coupling methodology is described, with the main emphasis on CATHENA and ELOCA. Work done to verify the methodology is outlined. Finally, a sample CATHENA/ELOCA application is given to illustrate the potential impact of using the coupled approach in thermalhydraulic safety analyses.