# Westinghouse eVinci microreactor development > Live situation record from CLSTR: https://clstr.news/situations/westinghouse-evinci-microreactor-development > Updated: 2026-09-15T22:14:07.000Z. Sources: 4. Developments: 2. Westinghouse Electric Company has reached key milestones in the development of its eVinci microreactor through testing at the National Criticality Experiments Research Center in Nevada. On August 24, 2026, the company completed zero-power criticality testing in partnership with Los Alamos National Laboratory and Idaho National Laboratory. This initial phase validated the reactor’s computational models and core design assumptions by confirming that physics predictions accurately reflected real-world neutron behavior. Subsequent testing achieved criticality at 1,225 degrees Fahrenheit. During these experiments, researchers recorded a peak core temperature of 1,852 degrees Fahrenheit, which set a new temperature record for reactivity measurements at the facility. The data gathered from these tests is intended to help engineers refine analytical models and improve the prototype design. The eVinci microreactor utilizes a compact architecture featuring heat pipes, a graphite core, and TRISO fuel, designed for resilient energy production in remote or challenging environments. ## Timeline ### 2026-09-15: Westinghouse eVinci microreactor achieves criticality milestone Westinghouse Electric Company successfully completed high-temperature criticality testing for its eVinci microreactor in Nevada, providing key data to advance its commercial nuclear design. 2 sources. https://clstr.news/cluster/westinghouse-evinci-microreactor-achieves-criticality-milestone ### 2026-09-01: Westinghouse completes zero-power criticality test for eVinci microreactor Westinghouse successfully completed zero-power criticality testing for its eVinci microreactor, validating core design assumptions and computational models for the advanced nuclear technology. 2 sources. https://clstr.news/cluster/westinghouse-completes-zero-power-criticality-test-for-evinci-microreactor --- Cite as: Westinghouse eVinci microreactor development. CLSTR, https://clstr.news/situations/westinghouse-evinci-microreactor-development