Westinghouse has completed zero-power criticality testing of its eVinci microreactor, validating its core design models.
The test was conducted on August 24 at the National Criticality Experiments Research Center (NCERC), a National Nuclear Security Administration facility at the Nevada National Security Site in Nevada. Los Alamos National Laboratory and Idaho National Laboratory worked with Westinghouse on the testing.
The test did not generate electricity. Instead, zero-power criticality testing allows engineers to examine the nuclear behavior of a reactor core without operating it at full power. The results are being used to validate the models and assumptions behind the eVinci design.
Westinghouse said the milestone is part of an iterative development process that combines physical testing, computer modeling, simulation and design changes. The approach is intended to identify technical issues earlier while the company continues developing and demonstrating the reactor.
Core design faces reality
“This zero-power criticality milestone reflects Westinghouse’s heritage of innovation and pushing to the next frontier of nuclear,” said Dr. Lou Martinez Sancho, Westinghouse Chief Technology Officer. “We appreciate the support and collaboration of our partners at the U.S. Department of Energy, NNSA, Los Alamos National Laboratory, Idaho National Laboratory and NNSS in achieving this important milestone.”
The eVinci is designed around a compact reactor architecture that uses heat pipes to move heat from the reactor core. Its design also combines TRISO fuel, graphite core materials and control drums.
Rather than relying on a conventional large reactor configuration, the microreactor is intended to provide a compact source of electricity for locations where building traditional power infrastructure can be difficult or impractical.
Westinghouse says the system could provide electricity continuously for up to eight years without refueling. The company is targeting applications in remote locations as well as defense and space missions, where reliable power can be difficult to provide.
Built for remote missions
The zero-power test is one part of a broader development program. Westinghouse plans to use information from prototype testing and demonstrations to refine the reactor’s design and assess its performance, operation and manufacturability.
That testing approach could be particularly important for a microreactor, where reducing the size of the system does not eliminate the need to demonstrate how its nuclear components behave together.
The eVinci’s heat-pipe system is central to the design. Heat pipes can transfer energy from the reactor core without the large pumping systems used in some conventional reactor designs, potentially helping simplify the overall architecture.
Westinghouse is also developing the reactor for uses beyond conventional electricity generation. Its compact format could make it suitable for isolated communities, industrial sites and other locations where transporting fuel or building grid connections can be challenging.
The company has not announced a commercial operating date for the eVinci microreactor. The latest criticality test instead marks a technical validation step as Westinghouse moves toward additional testing, prototypes and demonstrations.
For now, the result gives engineers experimental data to compare with their models before the reactor progresses to later stages of development.