GAIN vouchers go to Constellation, Nano Nuclear, and NuCube

The companies: Of the three companies receiving awards, two are working on microreactors and one is refining its boiling water reactor operations.

• Constellation Energy, of Kennet Square, Pa., will collaborate with ORNL to investigate the underlying physics of moisture carryover phenomena in BWRs, aiming to develop reduced-order predictive models that can be integrated into Constellation’s evaluation tools. Constellation and ORNL will use modeling and simulations, including ORNL’s Virtual Environment for Reactor Applications (VERA), to lower fuel cycle costs and improve capacity factors across Constellation’s BWR fleet, particularly in high power density and uprated cores. Last year, its Dresden and Clinton BWRs had their licenses renewed for 20 more years by the Nuclear Regulatory Commission.
• Nano Nuclear Energy, of New York, N.Y., will collaborate with ORNL to demonstrate safety margins, performance reliability, and licensing readiness of its Kronos microreactor. Nano Nuclear and ORNL will quantify the impact of nuclear data, modeling assumptions, and operational parameters on key reactor physics metrics, including reactivity, power distribution, and temperature coefficients. The University of Illinois–Urbana-Champaign, in partnership with Nano Nuclear, just last week submitted a construction permit application to build a Kronos microreactor to the NRC.
• NuCube Energy, of Idaho Falls, Idaho, will collaborate with Argonne to verify the autonomous operation and remote monitoring systems of its DeccaCell microreactor. NuCube and Argonne will use a digital twin of the reactor to test autonomous control architecture, and Argonne will be adapting its existing autonomous operation and diagnostics framework to demonstrate automated startup, remote monitoring, islanding-mode transitions, and predictive maintenance within a validated simulation environment. The project aims to lower operational costs, enhance safety, and enable commercialization.

All three companies have received GAIN vouchers in the past. The first round of FY 2026 vouchers were announced in December 2025, and proposals for this year’s third round of vouchers are due April 30.