Los Alamos National Laboratory to lead study of molten-salt nuclear reactor materials

$9.25 million DOE nuclear energy research program aims to improve safety and efficiency of sustainable nuclear energy

August 15, 2022

2022-08-16 News Standard Article Feature

Los Alamos National Laboratory has been selected by the Department of Energy as the lead on a $9.25 million, five-year collaborative project in nuclear energy research. The Scientific Discovery through Advanced Computing (SciDAC) program aims to advance modeling the behavior and properties of structural materials under molten salt conditions by using high-performance computing. Molten-salt nuclear reactors are a reactor design with potential advantages in efficiency, waste and safety over conventional reactors.

“Over the next 30 years, the energy production in the United States will have to change,” said Laurent Capolungo, scientist with the Laboratory and the lead researcher on the project. “Molten-salt reactors can be transformative for society — cheaper, safer and more thermodynamically efficient, meaning they generate more energy from the fissile material and produce less waste.”

Molten salt in a reactor environment

The viability of the molten-salt reactor depends on the degree to which metals in the extreme environment of the reactor respond to molten salt over time. The environment couples the corrosivity of the molten salt with the high irradiation of the fission-generating energy under high temperatures and moderate mechanical loads. The team seeks to understand the corrosion and irradiation effects from the atomistic scale to the micron scale. That insight can inform the design and safety analysis for future reactor projects.

Key challenges in the development of molten-salt reactor technology are that laboratory-scale experiments cannot cover the whole spectrum of conditions the materials will experience in real reactors, and materials cannot be tested at an experimental reactor for decades before certification.

The SciDAC program represents a potential breakthrough to overcome those challenges, employing new multiscale, multiphysics modeling tools. The SciDAC program uses new, advanced scientific computing techniques and algorithms to conduct thousands of simulations to understand the microstructure evolution and mechanical responses of metals — that is, the damage that can occur to metals at microscopic scales — when they are exposed to salt corrosion, irradiation and fatigue over many years.

“We will be able to connect fundamental models of atomic-scale phenomena into significantly modernized tools that can help us understand the materials response over large physical scales and large time-scales,” said Capolungo. “In this project, we want to understand what will happen to the material in 20 years or longer. The grand objective is to demonstrate that the capabilities we will develop can be used to predict the behavior of metals. Then we will be able to potentially adapt our tools to various commercial technology being proposed.”

The Lab is partnering with Idaho National Laboratory, Lawrence Berkeley National Laboratory, Sandia National Laboratories and Carnegie Mellon University on the SciDAC program.