Readying for Criticality: Final Design Review Completed

Today, Aalo completed its Final Design Review with independent DOE and NRC reviewers. This represents a major regulatory milestone that we've been working toward for over two years.

The company continues its remarkable run of achievements in record speed. Less than three years after its founding, Aalo has begun fabricating and assembling components for initial criticality: the milestone that marks the company’s first sustained nuclear reaction in a fully Aalo-owned reactor.

In 2025, President Trump released an executive order directing at least three advanced reactors to go critical by July 4, 2026, and Aalo remains on track to meet that directive.

The journey so far has included an acronym soup of regulatory milestones, including SDS, CDR, CSDR, PDR, PDSA, and now FDR (Final Design Review). Safety remains the company’s top priority, even as it meets milestones with great speed.

This week’s FDR was a two-day, sixteen-hour review session with a total of 40 reviewers in attendance.

Led by Co-founder and CTO Yasir Arafat, Aalo engineers presented on the subsystems of our critical facility, with the granularity necessary for kicking off the build. Outside of the design itself, the company also shared its plans for plant operations, security, and other administrative considerations necessary to run a nuclear facility.

Principal Mechatronics Engineer Austin Anthis notes that “we got thorough, constructive feedback from our reviewers. The feedback helps us iterate fast: it sharpens our design, improves our regulatory submittals, and builds confidence as we ramp up fabrication.”

Anthis added that “the engineering team has converged on real, practical solutions to enable us to build and safely go critical by July 4.”

CTO Arafat also thanked reviewers "who brought rigor, candor, and professionalism to this review."

The team’s next step is to incorporate reviewers’ feedback and submit a final Documented Safety Analysis and Readiness Assessment. Once approved, Aalo will have cleared all the regulatory hurdles necessary to turn on our reactor, a.k.a. "achieve criticality" on a system that we designed, permitted, manufactured, installed at a building we constructed, and operated with our own operators.

We started hiring ~2.5 years ago. We're incredibly proud of this pace of execution. Thanks to everyone who has supported us thus far! We are getting close to making history.