SMR-300
About
The SMR-300 is a 300 MWe SMR with PWR technology that can be deployed for flexible electricity production and cogeneration. The SMR-300’s process heat applications are particularly well suited for desalination and district heating, given the reactor’s operating temperature of 300 degrees Celsius.
| Developer | Holtec |
|---|---|
| Country of Origin | United States |
| Size | Small |
| Type | Pressurized Water Reactor (PWR) |
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Analysis
3
Deployment Timescale
Score Justification
The SMR-300 is under design review in the United Kingdom and is based on established PWR technology. Despite being modular, the design still requires on–site construction for its containment structure, which can introduce delays.
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 expected overnight costs for the SMR-300 are moderate, given its relatively small size. As a PWR, the reactor does not need exotic specialized components, but it requires robust nuclear-grade construction related to containment.
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)
3
Operational Cost
Score Justification
The SMR-300’s Operational Cost benefits from predictable waste management and fuel costs, given the reactor’s standard-assay LEU UO₂ fuel. As a PWR, its high pressure and corrosive coolant contribute to higher maintenance costs than many similarly sized non-PWRs.
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) - 2/4 Maintenance Cost
What is the expected annual maintenance cost for the reactor and balance of plant systems, including consumables? (25% of total score) - 3/5 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
The lack of a prototype reduces Cost Predictability for the SMR-300, in addition to the potential for construction delays and cost overruns related to containment. Once a prototype establishes a baseline, modularity could improve cost predictability.
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
Holtec has incorporated security by design by siting the reactor below grade, sealing hatchways for the spent fuel pool, and storing dry spent fuel in an underground silo. The containment, including spent fuel storage areas, is sealed during operation. The SMR-300 uses LEU fuel. Its thermal spectrum is not optimized to produce weapons-usable nuclear material.
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 SMR-300’s safety case is under review in the United Kingdom, but the reactor does not use accident-tolerant fuel. As a PWR, the SMR-300 requires robust containment, but Holtec’s design goes further by providing double containment. The coolant (light water) is mildly chemically reactive.
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 SMR-300 uses standard–assay LEU UO₂ fuel, which has been licensed and qualified for disposal in multiple countries. This familiar spent fuel form can usually be transferred to interim storage within five years. The reactor does not introduce novel waste streams that require separate treatment and handling beyond past practice.
By indicator
- 1/1 Spent Fuel Licensing Precedent
Has the spent fuel form been previously licensed for disposal? (20% of total score) - 3/4 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 SMR-300 is based on traditional LWR technology, so its supply chain is robust.
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)