DEVELOPMENT OF PIN-LEVEL NEUTRONICS/THERMAL-FLUID ANALYSIS COUPLED CODE SYSTEM FOR A BLOCK-TYPE HTGR CORE

Yuk Seungsu,Chang Jo Keun,Tak Nam-Il,M Margulis,P Blaise

doi:10.1051/epjconf/202124702041

Yuk Seungsu, Chang Jo Keun + Show 3 more

Open Access

https://doi.org/10.1051/epjconf/202124702041

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Abstract

Recently, the coupling between computer codes that simulate different physical phenomena has attracted for more accurate analysis. In the case of high-temperature gas-cooled reactor (HTGR), the coupling between neutronics and thermal-fluid analysis is necessary because of large change of temperature in the reactor core. Korea Atomic Energy Research Institute (KAERI) has developed the coupled code system between a reactor physics analysis code CAPP and a thermal-fluid system safety analysis code GAMMA+ for a block-type HTGR. The CAPP/GAMMA+ coupled code system provides more accurate block-wise distribution data than CAPP or GAMMA+ stand-alone analysis. However, the block-wise distribution data has the limitation in order to predict safety parameters such as the maximum temperature of the nuclear fuel. It is necessary to calculate refined distribution, for example, pin-level (fuel compact level) distribution. In this study, we tried to solve this problem by coupling CAPP and a high-fidelity thermal-fluid analysis code CORONA. CORONA can perform a high-fidelity thermal-fluid analysis of Computational Fluid Dynamics (CFD) level by dividing a block-type HTGR core into small lattices. On the other hand, CAPP can provide a pin power distribution. It is expected that the refined, more accurate distribution data for a block-type HTGR can be obtained by coupling these two codes. This paper presents the development of coupled code system between CAPP and CORONA, and then it is tested on a simple HTGR column problem with encouraging results.

Highlights

High-Temperature Gas-cooled Reactor (HTGR), or Very-High-Temperature Reactor (VHTR) is one of the next-generation reactor types that guarantees high passive safety
Korea Atomic Energy Research Institute (KAERI) has developed key reactor core design codes such as reactor physics analysis code CAPP [3,4,5], high-fidelity thermal-fluid analysis code CORONA [6,7], and thermal-fluid/system safety analysis code GAMMA+ [8,9], which are targeted at block-type HTGRs
A test problem is chosen to determine whether the CORONA/CAPP coupled code system works well

Summary

INTRODUCTION

High-Temperature Gas-cooled Reactor (HTGR), or Very-High-Temperature Reactor (VHTR) is one of the next-generation reactor types that guarantees high passive safety. Korea Atomic Energy Research Institute (KAERI) has developed key reactor core design codes such as reactor physics analysis code CAPP [3,4,5], high-fidelity thermal-fluid analysis code CORONA [6,7], and thermal-fluid/system safety analysis code GAMMA+ [8,9], which are targeted at block-type HTGRs. Through these, it is possible to perform the reactor core analysis and the safety analysis for block-type HTGRs. In recent years, there are many attempts to perform more precise calculations by coupling between the analysis codes simulating different physical phenomena. KAERI developed a coupled code system between CAPP and GAMMA+, which can obtain the block-wise power and temperature distribution on HTGR cores at once [10,11]. The CAPP/GAMMA+ coupled code system provides more accurate solution than CAPP or GAMMA+ stand-alone analysis. This enables more precise core analysis and safety analysis. We tried to solve this problem by coupling CAPP and CORONA

CAPP Code

CORONA Code

Coupling Strategy

NUMERICAL RESULTS

CONCLUSIONS