Westinghouse's eVinci Microreactor Hits Criticality at Record Temperature
Event summary
- Westinghouse achieved zero-power high-temperature criticality for its eVinci microreactor on September 3, 2026.
- The test reached criticality at 663°C and recorded a peak core temperature of 1,011°C, a record for NCERC.
- The milestone was completed in partnership with Los Alamos National Laboratory and NNSS.
- Westinghouse leveraged AI and digital engineering tools to accelerate prototype design.
The big picture
Westinghouse's achievement marks a critical step in advancing microreactor technology, positioning the eVinci as a potential solution for remote and defense applications. The company's iterative, evidence-based development model aligns with broader industry trends toward smaller, more deployable nuclear reactors. The milestone also underscores the strategic importance of U.S. government partnerships in driving nuclear innovation.
What we're watching
- Technical Validation
- How the high-temperature data will strengthen analytical models and reduce technical risk.
- Deployment Timelines
- The pace at which Westinghouse can transition from prototype design to commercial deployment.
- Regulatory Support
- Whether continued U.S. Department of Energy backing will sustain the eVinci program's momentum.