BWRX‑300
US
Basics
Reactor Type
Boiling Water Reactor
Boiling water reactor
Heat transport usually with light (normal) water or vapour
Heat transport usually with light (normal) water or vapour
Reactor Description
Loop operated BWR
Boiling water reactor
Heat transport usually with light (normal) water or vapour
Heat transport usually with light (normal) water or vapour
Electric Output (MWe)
300
Thermal Output (MWt)
870
Size
Large
'Large' size
Electric output of between 200 MWe and 300 MWe (or more)
Electric output of between 200 MWe and 300 MWe (or more)
Spectrum
Thermal
Kinetic neutron energy of 0.000…0.025 eV
Slow or cold neutron / moderated neutron spectrum
Slow or cold neutron / moderated neutron spectrum
Developer
GE Vernova
Pilot Site Details
Darlington NPP, Ontario
Details
Use (goal of commercial operation)
power gnenertation
Deployment medium
Land-based
Design Lifetime (Years)
60
Fuel
Fuel class
LEU
Low enriched uranium
Uranium enriched to less than 5 percent U-235
Uranium enriched to less than 5 percent U-235
Fuel Type
UO2 Pellets
Uranium dioxide
Most often used uranium compound for fuel elements
Most often used uranium compound for fuel elements
Fuel Cycle
Open
Refuelling Cycle
N/A
Cooling & Temperature
Reactor cooling of primary loop
Light Water
Deuterium-depleted water
Containing the natural proportion (or less) of deuterium oxide, i.e. about 0.02 percent
Containing the natural proportion (or less) of deuterium oxide, i.e. about 0.02 percent
Reactor moderator
Light Water
Deuterium-depleted water
Containing the natural proportion (or less) of deuterium oxide, i.e. about 0.02 percent
Containing the natural proportion (or less) of deuterium oxide, i.e. about 0.02 percent
Reactor Outlet Temperature (°C)
288
Status
Design status
Detailed design
Licensing status
Canada:
- May...
Canada:
- May 2025 - Ontatio gives go-ahead and CAD20.9bn funding for Darlington SMR project
- Apr 2025 - CNSC issues construction licence to utility OPG to build BWRX-300 plant at Darlington new nuclear project
- Apr 2023 - CNSC confirms applicability of environmental assessment for pilot Darlington project
- Mar 2023 - Completion of phases 1 and 2 of pre-licensing vendor design review (VDR) with Canadian regulator CNSC
- Oct2022 - OPG submits application for licence to construct first unit at Darlington NPP (currently under CNSC review)
- In 2020 - GEH made first submittal to the CNSC for its review of the BWRX-300 design
Poland:
- Dec 2023 - Acquired government decision-in-principle for 6 sites
- Dec 2023 - Acquired pre-licensing general opinion on safety by regulator PAA,
- May 2023 - Environmental assessment scoping process started for 3 sites
US:
- May 2025: TVA applies to BWRX-300 at Clinch River In Tennessee
- Aug 2023: First topical report reviews issued by US NRC
- Apr 2023: TVA preparing construction permit application to submit in 2024 for Clinch River, TN site deployment
- Jan 2020: Engaged with US NRC in pre-licensing activities by submitting topical reports
UK:
- Dec 2025: 2nd step of GDA completed;
- Dec 2024: 1st step of GDA completed; start of 2nd step of GDA
- Jan 2024: 1st step of the GDA started
- Dec 2022: Application submitted for pre-licencing general design assessment (GDA) to UK regulator
Deployment timeline
2028: Pilot deployment at...
2028: Pilot deployment at Darlington NPP in Canada
2029: OSGE in Poland aims for pilot project (reportedly Wloclawek)
2035: Fermi Energia in Estonia aims for deployment
Agreements and Engagement
- May 2025 - Estonia begins planning...
- May 2025 - Estonia begins planning process for SMR deployment
- Feb 2025 - GE invited to submit final bid in UK SMR programme tender (won in Jun 2025 by Rolls-Royce)
- Oct 2024 - Included in shortlist of European industrial alliance on SMR
- Sep 2024 - BWRX-300 makes it into a further stage of the UK government process among four shortlisted candidates
- Jun 2024 - Sweden's Vattenfall shortlists BWRX-300 in competition to build at least two SMRs at Ringhals NPP
- Oct 2023 - UK government includes BWRX-300 in shortlist for first SMR competition among six vendors
- Mar 2023 - TVA, OPG, and Synthos Green Energy sign agreement to collaborate on the standard and detailed design of BWRX-300
- Feb 2023 - Fermi Energia chose BWRX-300 for potential deployment in Estonia in the early 2030s.
- Agreements signed in:
- Poland (OSGE)
- Canada (OPG, SaskPower)
- Sweden (Kärnfull Next)
- Estonia (Fermi Energia)
- US (TVA)
