Comsol Case Studies Researching a New Fuel for the HFIR: Advancements at ORNL Require Multiphysics Simulation to Support Safety and Reliability

	Researching a New Fuel for the HFIR: Advancements at ORNL Require Multiphysics Simulation to Support Safety and Reliability Comsol

Researching a New Fuel for the HFIR: Advancements at ORNL Require Multiphysics Simulation to Support Safety and Reliability

Comsol

Technology Category	Analytics & Modeling - Predictive Analytics Analytics & Modeling - Real Time Analytics Application Infrastructure & Middleware - Data Visualization
Applicable Industries	Healthcare & Hospitals National Security & Defense
Applicable Functions	Product Research & Development Quality Assurance
Use Cases	Predictive Maintenance Process Control & Optimization Remote Asset Management
Services	Software Design & Engineering Services System Integration Testing & Certification
Challenge	The High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL) is undergoing a conversion from highly enriched uranium (HEU) to low-enriched uranium (LEU) fuel to meet the Global Threat Reduction Initiative's requirements. This conversion presents a complex challenge due to the unique fuel and core design of the HFIR, as well as its high power density. The primary challenge is to ensure that the new LEU fuel can maintain the reactor's performance, safety, and reliability. Researchers need to evaluate the impact of the fuel change on various aspects such as neutron scattering, isotope production, irradiation experiments, and neutron activation analyses. Additionally, the HFIR will need to operate at a higher power level (100 MW) to maintain the same neutron flux, which increases the demands on the reactor's thermal margin and safety. Read More
About Customer	Oak Ridge National Laboratory (ORNL) is a multi-disciplinary research facility located in Oak Ridge, Tennessee, USA. It is managed by UT-Battelle for the U.S. Department of Energy. ORNL is known for its cutting-edge research in various fields, including nuclear science, materials science, and energy production. The High Flux Isotope Reactor (HFIR) at ORNL is a key facility that provides neutron scattering capabilities, stable and radio isotopes, and unique irradiation experiment facilities. The HFIR is used by over 500 researchers from around the world each year and is one of the highest steady-state neutron flux reactors globally. ORNL's mission includes advancing scientific knowledge, supporting national security, and contributing to technological innovation. The laboratory collaborates with academia, industry, and government agencies to achieve its research and development goals. Read More
Solution	Researchers at ORNL are using COMSOL Multiphysics® simulation software to explore the impact of converting the HFIR from HEU to LEU fuel. The new fuel design involves reducing the uranium-235 enrichment from 93% to 19.75%. To accommodate changes in nuclear characteristics, density, and thermal properties, the HFIR core fuel meat must be redesigned. Preliminary studies indicate that the HFIR will need to operate at 100 MW to maintain the same neutron flux, increasing thermal demands. The COMSOL Multiphysics software is used to conduct fluid-structure interaction (FSI) simulations to evaluate the safety and performance of the new fuel design. These simulations help predict fuel plate deflections and ensure that the reactor can maintain the required coolant flow rate. Validation studies are conducted to prove the accuracy of the COMSOL code, ensuring that the models are reliable and meet safety standards. The fully-coupled FSI approach in COMSOL has shown excellent agreement with experimental results, providing confidence in the new fuel design. Read More Log in to view content
Contents

Technology Category

Analytics & Modeling - Predictive Analytics

Analytics & Modeling - Real Time Analytics

Application Infrastructure & Middleware - Data Visualization

Applicable Industries

Healthcare & Hospitals

National Security & Defense

Applicable Functions

Product Research & Development

Quality Assurance

Use Cases

Predictive Maintenance

Process Control & Optimization

Remote Asset Management

Services

Software Design & Engineering Services

System Integration

Testing & Certification

Challenge

The High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL) is undergoing a conversion from highly enriched uranium (HEU) to low-enriched uranium (LEU) fuel to meet the Global Threat Reduction Initiative's requirements. This conversion presents a complex challenge due to the unique fuel and core design of the HFIR, as well as its high power density. The primary challenge is to ensure that the new LEU fuel can maintain the reactor's performance, safety, and reliability. Researchers need to evaluate the impact of the fuel change on various aspects such as neutron scattering, isotope production, irradiation experiments, and neutron activation analyses. Additionally, the HFIR will need to operate at a higher power level (100 MW) to maintain the same neutron flux, which increases the demands on the reactor's thermal margin and safety.

About Customer

Oak Ridge National Laboratory (ORNL) is a multi-disciplinary research facility located in Oak Ridge, Tennessee, USA. It is managed by UT-Battelle for the U.S. Department of Energy. ORNL is known for its cutting-edge research in various fields, including nuclear science, materials science, and energy production. The High Flux Isotope Reactor (HFIR) at ORNL is a key facility that provides neutron scattering capabilities, stable and radio isotopes, and unique irradiation experiment facilities. The HFIR is used by over 500 researchers from around the world each year and is one of the highest steady-state neutron flux reactors globally. ORNL's mission includes advancing scientific knowledge, supporting national security, and contributing to technological innovation. The laboratory collaborates with academia, industry, and government agencies to achieve its research and development goals.

Solution

Researchers at ORNL are using COMSOL Multiphysics® simulation software to explore the impact of converting the HFIR from HEU to LEU fuel. The new fuel design involves reducing the uranium-235 enrichment from 93% to 19.75%. To accommodate changes in nuclear characteristics, density, and thermal properties, the HFIR core fuel meat must be redesigned. Preliminary studies indicate that the HFIR will need to operate at 100 MW to maintain the same neutron flux, increasing thermal demands. The COMSOL Multiphysics software is used to conduct fluid-structure interaction (FSI) simulations to evaluate the safety and performance of the new fuel design. These simulations help predict fuel plate deflections and ensure that the reactor can maintain the required coolant flow rate. Validation studies are conducted to prove the accuracy of the COMSOL code, ensuring that the models are reliable and meet safety standards. The fully-coupled FSI approach in COMSOL has shown excellent agreement with experimental results, providing confidence in the new fuel design.

Impact #1	The use of COMSOL Multiphysics has enabled ORNL researchers to accurately predict the fluid-structure interactions and deflections of the HFIR fuel plates.
Impact #2	The fully-coupled FSI approach has improved the stability and accuracy of the simulations, ensuring reliable results.
Impact #3	The validation studies have confirmed the accuracy of the COMSOL code, providing confidence in the safety and performance of the new LEU fuel design.

Impact #1

The use of COMSOL Multiphysics has enabled ORNL researchers to accurately predict the fluid-structure interactions and deflections of the HFIR fuel plates.

Impact #2

The fully-coupled FSI approach has improved the stability and accuracy of the simulations, ensuring reliable results.

Impact #3

The validation studies have confirmed the accuracy of the COMSOL code, providing confidence in the safety and performance of the new LEU fuel design.

Benefit #1	The HFIR will need to operate at 100 MW instead of 85 MW to maintain the same neutron flux.
Benefit #2	The uranium-235 enrichment will be reduced from 93% to 19.75%.

Benefit #1

The HFIR will need to operate at 100 MW instead of 85 MW to maintain the same neutron flux.

Benefit #2

The uranium-235 enrichment will be reduced from 93% to 19.75%.

Download PDF Version

Overview

Researching a New Fuel for the HFIR: Advancements at ORNL Require Multiphysics Simulation to Support Safety and Reliability

Operational Impact

Quantitative Benefit