Introduction

Safety and performance analyses of nuclear reactors involve mathematical and numerical models for the thermal hydraulics. This course provides foundational knowledge of numerical models adopted in the safety and performance analysis codes for nuclear reactors. It includes an introduction of the governing equations, expressed as partial differential equations, used in the safety and performance analysis codes. The course covers numerical methods, including discretization of the partial differential operators and solution schemes of the discretized linear equations. It introduces the finite difference method (FDM) and finite volume method (FVM) for the discretization of the governing equations. Both the semi-implicit and implicit schemes are described for the numerical solution of the discretized linear equations. Additionally, phase coupling schemes are explained for handling the two-phase fluid flow solution, and implicit coupling of the interfacial drag and virtual mass forces are discussed. To enhance understanding, numerical experiments are provided for simple one-dimensional (1D) and two-dimensional (2D) conceptual problems.
The course specifically emphasizes acquiring practical knowledge of numerical methods for nuclear thermal hydraulics. To achieve this, students will learn how to apply these numerical methods in real-world scenarios by developing pilot code for given exercise problems. The Fortran language will be used for writing this pilot code. In addition, students will learn how to write, compile, and execute a Fortran program.

Course Objectives

Course Code: Multi-dimensional Two-phase Flow Analysis for Nuclear Reactors (MS, 2nd Semester)

Introduction

Two-phase flow analyses are essential for the safety and performance evaluation of light water nuclear reactors (LWRs). In safety analysis, the two-phase flow model must address significant phase changes caused by rapid transients in pressure and heat transfer. A multi-dimensional two-phase flow analysis model offers more accurate predictions of thermal hydraulic phenomena and can enhance the safety margin of LWRs. For practical applications of multi-dimensional two-phase flow analysis, parallel computing, which utilizes multiple CPU cores, is critical. In this course, students will learn about parallel computing methods using the Message Passing Interface (MPI) library. To enhance understanding, the course will include the implementation of parallel computing algorithms through a pilot program developed in the first semester.
The CUPID code, developed by the Korea Atomic Energy Research Institute, is designed for multi-dimensional two-phase flow analysis of light water reactors (LWRs). This course introduces the mathematical and numerical models utilized in the CUPID code, equipping students with the knowledge needed to effectively use it. The course will cover CUPID's input specifications, enabling students to generate inputs tailored to their specific applications. Additionally, there will be a session dedicated to utilizing SALOME, a tool for generating computational meshes for use with CUPID.
Recent applications of CUPID for pressurized water reactors (PWRs) and small modular reactors (SMRs) will be introduced in this course. Following this introduction, a conceptual design problem will be presented for students to evaluate using CUPID. Students will be required to develop the necessary inputs, including the computational mesh, and analyze the conceptual design of the SMR.

Course Objectives

Course Code: High Performance Computation of Nuclear Thermal Hydraulics (PhD, 1st Semester)

Introduction

Advanced modeling and simulation are becoming increasingly practical due to rapid improvements in computing performance. Consequently, advanced simulations are anticipated to play a significant role in the development of new Small Modular Reactor (SMR) designs. This course will provide an introduction to the state-of-the-art (SOA) research and developments in the United States, European Union, and South Korea.
Thermal hydraulics presents one of the most challenging aspects of developing advanced simulations for nuclear reactors. This course will provide the fundamentals of numerical methods applicable to nuclear reactor thermal hydraulics. The governing equations used in simulations of nuclear reactor thermal hydraulics will be discussed, followed by an introduction to numerical methods for discretizing these equations. The finite difference method (FDM) and finite volume method (FVM) will be employed for discretization. Numerical solution methods will be covered for both single- and two-phase fluid flow applications. A particular emphasis will be placed on enabling students to gain practical knowledge of numerical methods through the development of pilot programs during the course.
Parallel computing is essential for high-performance computing. This course will introduce the domain decomposition method using the Message Passing Interface (MPI) library. Algorithms for memory communication between neighboring domains will be explained. A simple parallel program will be utilized to enhance students' understanding of these concepts. Subsequently, parallel programming techniques will be applied to the pilot codes developed in the numerical methods class.

Course Objectives

Course Code: High Performance Computation of Nuclear Thermal Hydraulics (PhD, 2nd Semester)

Introduction

The development of a new small modular reactor (SMR) design relies on reliable analysis tools to assess the feasibility of its conceptual design and determine specific parameters essential for design optimization. Consequently, advanced modeling and simulation are expected to play a crucial role in the development of new SMR designs. One of the most efficient ways for students to grasp the design concepts and underlying physics of an SMR is by learning an advanced system analysis tool and applying it to investigate a conceptual design. The CUPID code will be used to explore the SMR design currently being developed in Korea. Relevant physical models required for a specific SMR design will be introduced, and multi-scale, multi-physics analysis methods based on CUPID will also be discussed in the context of SMR applications.
Particular emphasis will be placed on acquiring the practical knowledge necessary for using the CUPID code. The mathematical and numerical models of CUPID will be introduced, followed by a hands-on study that enables students to analyze a small modular reactor (SMR) conceptual design using CUPID.

Course Objectives