Milestones
- NRC certifies 50 MWe US600 designJan 2023Complete.
- UAMPS Carbon Free Power Project cancelledNov 2023Complete.
- NRC approves 77 MWe US460 designMay 2025Complete.
- ENTRA1/TVA programme of up to 6 GW announcedSep 2025Complete.
- First firm construction contractNowCurrent milestone.
Most important updates
- Sep 2025
- May 2025
- 8 Nov 2023
- Jan 2023
- 28 Aug 2020
Current obstacles
- Cost per kilowattSmall reactors lose big plants' economies of scale; NuScale needs factory production and repeat builds, which haven't started.
Physics limits
- Small cores leak neutronsThe smaller the core, the more neutrons escape through its surface instead of causing fission, so small reactors burn their fuel less completely per load.
- Buoyancy alone limits power per moduleWithout pumps, flow comes only from hot water rising and cool water sinking, so each module's power is capped by its height and temperature difference.
- Water reactors run cool, so efficiency is lowPressurised water runs at about 300 °C; at that temperature only about 30% of the heat can become electricity, lower than hotter advanced reactors.
How it works
Reactor and steam generator in one can
Each module is a steel vessel about 23 m tall holding the core and steam generator, sitting in a large water pool below ground.
No coolant pumps
Water heated by the core rises through a central riser, cools on the steam generator tubes and sinks back, circulating without pumps.
The pool is the backup
If power is lost, the module sheds heat into the surrounding pool, which can cool it without operators, power or added water.
Up to six modules
A US460 plant holds up to six 77 MWe modules (462 MWe), each with its own turbine, so modules can be added or serviced one at a time.
Update log
Sep 2025
- Major: PressCommercial
May 2025
- Major: RegulatorRegulatory
Wed 8 Nov 2023
- Major: PressCommercial
Jan 2023
- Major: RegulatorRegulatory
Fri 28 Aug 2020
- Major: PressRegulatory
About NuScale Power
NuScale Power
Light-water SMR, 77 MWe modules, NRC-approved
Oregon company making the NuScale Power Module, a small water-cooled reactor that moves its coolant without pumps. It holds the only NRC-approved SMR designs, including the 77 MWe US460 (May 2025), but its first project, with UAMPS, was cancelled in 2023.
- First SMR design certified by the NRC (50 MWe, 2023); the 77 MWe US460 was approved in May 2025.
- Its first project, with UAMPS, was cancelled in Nov 2023 after expected power prices rose.
- ENTRA1 Energy and TVA announced up to 6 GW of NuScale plants in September 2025.
- Founded
- 200719 yrs
- Headquarters
- United States
- Status
- Public
- Listed
- SMR (opens google.com)NYSE
- Valuation
- public
- Works in
- EnergyFission
- Coverage
- 1 program · 5 updateslatest 1 Sep 2025checked 25 Sep