BWRX-300
About
The BWRX-300 is a 300 MWe BWR that relies on natural circulation for core cooling and emphasizes passive safety functions, which makes it ideal for grid electricity generation and repeat deployment at single-unit or multiunit sites. With an outlet temperature of about 300 degrees Celsius, the BWRX-300 also can serve desalination and district heating needs.
| Developer | GE Vernova Hitachi |
|---|---|
| Country of Origin | United States |
| Size | Small |
| Type | Boiling Water Reactor (BWR) |
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Analysis
3
Deployment Timescale
Score Justification
The BWRX-300 has made regulatory progress, including a Canadian construction license and ongoing NRC review activities for U.S. deployment. Its technology basis is strongly anchored in BWR operating experience, though as a first-of-a-kind SMR, it still faces schedule risk from licensing completion and site execution.
By indicator
- 2/4 Regulatory Engagement
To what extent has the reactor developer engaged with a recognized nuclear regulatory authority in the licensing process? (30% of total score) - 4/6 Technology Precedent
Has the reactor design, or a sufficiently similar design, been certified anywhere in the world? (10% of total score) - 2/3 Modularity
What share of total reactor systems can be manufactured off-site in controlled factory environments rather than constructed on-site? (15% of total score) - 2/4 Specialization
To what extent do construction activities and components require lengthy qualification processes? (15% of total score) - 5/5 Supply Chain
How mature and available are suppliers for key reactor components and fuel services? (30% of total score)
2
Overnight Cost
Score Justification
The BWRX-300’s overnight costs are relatively high for an SMR because it still requires a full nuclear island, containment, and major civil works. Although the design is simplified compared with the design of traditional BWRs, site-specific construction keeps capital intensity out of a fully modular cost frame.
By indicator
- 2/4 Component Cost
What is the expected cost of the reactor’s major components? (40% of total score) - 3/6 Construction Cost
To what extent does the design reduce construction cost and risk through modular fabrication and limited nuclear-grade specialization? (60% of total score)
4
Operational Cost
Score Justification
As an LWR, the BWRX-300’s high pressure and corrosive coolant contribute to higher maintenance costs than many similarly sized non-LWRs. Fuel costs remain low because the BWRX-300 uses standard-assay LEU fuel, while waste management remains broadly comparable with that of other BWRs.
By indicator
- 3/3 Fuel Cost
What is the estimated cost of nuclear fuel per unit of electricity generated, including enrichment, fabrication, and back-end costs? (15% of total score) - 3/4 Maintenance Cost
What is the expected annual maintenance cost for the reactor and balance of plant systems, including consumables? (25% of total score) - 4/5 Staffing Level
How many full-time personnel are required to safely operate and maintain the reactor unit? (40% of total score) - 3/5 Spent Fuel & Radioactive Waste Management Cost
What are the expected operational costs associated with managing spent fuel, including interim storage, transport, disposal, or recycling? (10% of total score) - 4/5 Decommissioning Cost
What are the total lifetime contributions required for decommissioning, regardless of funding mechanism? (10% of total score)
2
Cost Predictability
Score Justification
Cost predictability is limited because there are no operating prototypes or commercial units yet. Even with active projects underway, first-unit procurement, supply sequencing, and site learning curves can drive first-of-a-kind overruns.
By indicator
- 0/5 Prototype
To what extent has the reactor design been built, demonstrated, or commercially deployed in practice? (75% of total score) - 2/3 Modularity
What share of total reactor systems can be manufactured off-site in controlled factory environments rather than constructed on-site? (25% of total score)
5
Security
Score Justification
The BWRX-300 uses LEU fuel, and its thermal spectrum is not optimized to produce weapons-usable material. The design incorporates security-by-design principles such as minimized access points, hardened and steel-reinforced structural elements, and protected routing of critical systems.
By indicator
- 3/3 Fuel
What is the enrichment level and composition of the reactor fuel? (40% of total score) - 4/4 Nuclear Material Production
What is the potential for the reactor to produce weapons-usable nuclear material? (40% of total score) - 1/1 Security by Design
Has the reactor developer built in security by design? (20% of total score)
3
Safety
Score Justification
The design of the BWRX-300 emphasizes passive safety features, including natural-circulation and long-duration decay heat removal without immediate operator action. The design also includes diverse shutdown capabilities (control rods plus an independent boron injection pathway). However, the reactor relies on conventional UO₂/zircaloy fuel rather than accident–tolerant fuel.
By indicator
- 1/2 Safety Case
How mature and publicly established is the reactor’s safety case with the regulator? (40% of total score) - 1/2 Shutdown Mechanism
How diverse, independent, and passive are the reactor’s shutdown systems? (20% of total score) - 0/1 Fuel With Safety Characteristics
Does the reactor use fuel with accident tolerance or inherent safety characteristics? (10% of total score) - 3/4 Pressure & Containment
How well does the reactor’s containment strategy protect from the release of radioactive material? (10% of total score) - 2/3 Passive Heat Removal
How long can the reactor remove core heat without operator intervention? (10% of total score) - 3/4 Coolant Reactivity
How chemically reactive is the reactor coolant? (10% of total score)
3
Spent Fuel & Radioactive Waste Management
Score Justification
The BWRX-300 produces conventional spent fuel with well-established storage, transport, and disposal pathways. At a storage milestone of 50 years, the decay heat from the BWRX-300’s spent fuel is less than that of a fast reactor’s because it does not produce as many long-lived fission products and actinides, which eases repository constraints. As with most LWRs, the spent fuel can usually be transferred to interim storage within five years.
By indicator
- 1/1 Spent Fuel Licensing Precedent
Has the spent fuel form been previously licensed for disposal? (20% of total score) - 2/4 Waste Streams
How many distinct waste streams require separate conditioning or handling pathways? (20% of total score) - 2/3 On-Site Storage
How much on-site area is required for interim spent fuel storage? (10% of total score) - 2/3 Spent Fuel Volume
What volume of spent fuel is produced per unit of electricity generated? (15% of total score) - 1/2 Decay Heat
What is the decay heat output of spent fuel at the 50-year interim storage milestone? (20% of total score) - 2/2 Time to Interim Storage
What is the average time until spent fuel can be transferred to interim storage? (15% of total score)
5
Supply Chain
Score Justification
The BWRX-300 leverages widely available supply chains for fuel services and many major components, reducing single-point dependencies. Although first-unit manufacturing and qualified module suppliers may be bottlenecks for early builds, the overall supply chain is far more mature than those of most advanced reactors.
By indicator
- 2/2 Key Component Availability
To what extent are commercial or pilot-scale suppliers available for the reactor’s major components? (60% of total score) - 4/4 Fuel Availability
Are suppliers available for both fuel fabrication and enrichment required by the reactor design? (40% of total score)