The Global Picture
Where the ~127 SMR designs tracked worldwide currently stand
2
In commercial operation today
~10
In active construction worldwide
51
In pre-licensing or licensing review
~65
Earlier-stage design & concept
Source: OECD Nuclear Energy Agency SMR Dashboard (2026). 127 designs are tracked, up from 98 in 2024, with 51 in pre-licensing/licensing and 85 active siting discussions worldwide. The construction figure combines IAEA-tracked advanced builds (Argentina, China, Russia) with major Western projects now underway. This directory currently profiles 14 of the most advanced, well-documented programs. See the note at the bottom of this page on expanding further.
How SMR Licensing Actually Works
Every design on this list has to clear a national nuclear regulator before it can be built. The path looks different in each country, but the core idea is the same: prove the design is safe first, then prove the specific site is safe, then prove it's being built and run the way it was approved.
United States (NRC)
Two possible paths
- 1Pre-application engagement, where the company works informally with the NRC for years before filing anything official.
- 2Part 50 path: a Construction Permit is approved first, then a separate Operating License once it's built (used by TerraPower, Kairos).
- 3Part 52 path: a single Combined License covers construction and operation together (used by Oklo).
- 4A separate, reusable Design Certification can also be sought. NuScale is the only SMR with one so far.
Canada (CNSC)
Four-stage licence sequence
- 1Optional Vendor Design Review, an early, non-binding check for "fundamental barriers" in the design (ARC-100 has completed this).
- 2Licence to Prepare Site.
- 3Licence to Construct, which includes public hearings and Indigenous consultation (granted to OPG for BWRX-300 in 2025).
- 4Licence to Operate, issued once construction and testing are complete.
United Kingdom (ONR, EA, NRW)
Generic Design Assessment (GDA)
- 1Step 1: scoping and readiness.
- 2Step 2: fundamental safety, security, and environmental review.
- 3Step 3: detailed design assessment, ending in a Design Acceptance Confirmation (Rolls-Royce SMR is finishing this stage now).
- 4Site-specific permitting still follows. GDA approval alone doesn't authorize construction.
Cost Reality Check
Why "estimated cost" is the least reliable number in this whole directory
~$25.7K
Per kW, BWRX-300 unit 1 at Darlington, the only audited Western SMR cost we have
$5K
Per kW, GE Hitachi's own "fleet mode" target once several units are built
$9.3B
What killed NuScale's original US project. Cost rose 75% before a single reactor was built
$1.8B
Rolls-Royce's advertised fleet price per unit. A vendor target, not a built result
It's not too early to talk about cost, but it is too early to treat any single number as reliable. Two real numbers exist for the same reactor type: a $5,000/kW target and a $25,700/kW actual, because first-of-a-kind builds carry the full weight of licensing, first-time manufacturing, and construction risk premiums that a tenth unit won't. Every other design on this page is even earlier, so most published figures are still vendor targets, not audited costs. Cost is also inherently site-specific. Financing terms, labor markets, local supply chains, and government backing move the number as much as the reactor design does. Sources: World Nuclear News, POWER Magazine, Neutron Bytes, NucNet, howtostoreelectricity.com SMR cost analysis (2026).
