University of Tennessee, ORNL lead national team to study nuclear fusion reactors

September 11, 2012

Power from nuclear fusion reactors has the promise to be safe, sustainable and limitless. But science has not been able to bring fusion energy to the commercial energy market. This is partly because the operating limits of the reactor materials are not known.

A team of researchers at the University of Tennessee, Knoxville, and Oak Ridge National Laboratory, in collaboration with seven other institutions, is trying to change that.

Led by Brian Wirth, UT-ORNL Governor's Chair for Computational Nuclear Engineering, the Scientific Discovery through Advanced Computing (SciDAC) project will receive $2.3 million from the Department of Energy for the first year with plans for a total of $11.5 million over five years. ORNL and UT will receive $850,000 for the first year with plans for a total of $4.1 million over five years.

Nuclear fusion promises an almost limitless supply of clean and safe energy. Unlike the nuclear fission reactors used today, it doesn't come with the challenge of managing used nuclear fuel containing very long-lived radioactivity. This is because the process to create the energy is different. In nuclear fission, an atom is split into two smaller atoms which remain radioactive for hundreds to many thousands of years. In fusion, two or more smaller atoms are fused into a larger atom that is not radioactive.

"However, the fusion process currently pursued unleashes a very high-energy neutron that is believed to produce more damage to reactor materials than in fission," Wirth said. "Now is the right time to examine this impact of fusion reactions on materials as we determine whether we can really make fusion work as a practical energy source."

The researchers will examine how the surfaces of materials which comprise the reactor respond when being bombarded by energetic neutrons and ions. Using high-performance computers such as ORNL's Jaguar and UT's Kraken, the researchers will try to accurately predict materials' performance and evaluate materials systems and component design for the fusion reactor environment. The team will then be positioned to use their computational tools to evaluate new materials and component designs to enable fusion energy.

"A fusion reactor works by introducing plasma -- a hot, electrically charged gas that serves as the reactor fuel -- into a vacuum vessel," Wirth said. "The plasma is then confined using electric and magnetic fields into a central, vacuum region."

The problem, he said, is that ions from the plasma escape and bombard the material surfaces, in addition to the high-energy neutrons. This combination causes significant damage and changes the properties of the reactor materials.

"It's likely materials do not exist today that could be used to build a reactor that would contain the plasma," Wirth said.

The material property changes are driven by many processes that occur in less than a nanosecond. Yet, it is the cumulative interaction of such processes over much longer times that determine the precise value of these changes. Wirth and his team aim to develop models which stretch this interaction over the period of many decades to evaluate their long-term effects.

"We are trying to identify and model numerous microscale defect and impurity interaction processes that occur over rapid time scales which can span less than a nanosecond," Wirth said. "And then we are trying to integrate these into a model that can predict the material response over the years and decades for which a plasma reactor needs to operate."

Wirth notes that making these goals more challenging is the fact that no current experimental facilities exist that accurately represent the environment these materials are expected to face.

"Our research will address one critically important aspect toward getting to fusion energy," Wirth said. "I'm optimistic about the potential for fusion energy, but realistic in understanding how difficult it will be to realize."
The Department of Energy's Office of Fusion Energy Sciences and Office of Advanced Scientific Computing Research are jointly funding this SciDAC project. Collaborating institutions include Argonne National Laboratory; Los Alamos National Laboratory; Pacific Northwest National Laboratory; University of California, San Diego; University of Illinois at Urbana-Champaign; University of Massachusetts, Amherst; and General Atomics.

University of Tennessee at Knoxville

Related Plasma Articles from Brightsurf:

Plasma treatments quickly kill coronavirus on surfaces
Researchers from UCLA believe using plasma could promise a significant breakthrough in the fight against the spread of COVID-19.

Fighting pandemics with plasma
Scientists have long known that ionized gases can kill pathogenic bacteria, viruses, and some fungi.

Topological waves may help in understanding plasma systems
A research team has predicted the presence of 'topologically protected' electromagnetic waves that propagate on the surface of plasmas, which may help in designing new plasma systems like fusion reactors.

Plasma electrons can be used to produce metallic films
Computers, mobile phones and all other electronic devices contain thousands of transistors, linked together by thin films of metal.

Plasma-driven biocatalysis
Compared with traditional chemical methods, enzyme catalysis has numerous advantages.

How bacteria protect themselves from plasma treatment
Considering the ever-growing percentage of bacteria that are resistant to antibiotics, interest in medical use of plasma is increasing.

A breakthrough in the study of laser/plasma interactions
Researchers from Lawrence Berkeley National Laboratory and CEA Saclay have developed a particle-in-cell simulation tool that is enabling cutting-edge simulations of laser/plasma coupling mechanisms.

Researchers turn liquid metal into a plasma
For the first time, researchers at the University of Rochester's Laboratory for Laser Energetics (LLE) have found a way to turn a liquid metal into a plasma and to observe the temperature where a liquid under high-density conditions crosses over to a plasma state.

How black holes power plasma jets
Cosmic robbery powers the jets streaming from a black hole, new simulations reveal.

Give it the plasma treatment: strong adhesion without adhesives
A Japanese research team at Osaka University used plasma treatment to make fluoropolymers and silicone resin adhere without any adhesives.

Read More: Plasma News and Plasma Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to