KP-FHR
About
The KP-FHR is a fluoride salt-cooled high-temperature reactor with an electrical output of approximately 75 MWe designed to deployed in a minimum configuration of two units for a combined output of 150 MWe. It is well suited for electricity production, and its high operating temperature enables cogeneration for hydrogen production and industrial refining.
| Developer | Kairos Power |
|---|---|
| Country of Origin | United States |
| Size | Small |
| Type | Fluoride Salt-Cooled High-Temperature Reactor |
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Analysis
3
Deployment Timescale
Score Justification
The KP-FHR is engaged in formal regulatory licensing activities with the U.S. NRC, including construction permits for test reactors. There is some global precedent with the HTR-PM as a graphite-moderated TRISO reactor, however there are significant differences, including coolants. The KP-FHR reactor requires some long-lead specialized salt systems, but it does not need the same nuclear-grade containment and cooling structures as a traditional LWR.
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) - 3/6 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) - 3/4 Specialization
To what extent do construction activities and components require lengthy qualification processes? (15% of total score) - 2/5 Supply Chain
How mature and available are suppliers for key reactor components and fuel services? (30% of total score)
4
Overnight Cost
Score Justification
The KP-FHR’s component costs reflect that it uses specialized salt systems, heat exchangers, and reactor internals, and has construction requirements that include below-grade excavation.
By indicator
- 3/4 Component Cost
What is the expected cost of the reactor’s major components? (40% of total score) - 4/6 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
Fuel costs are elevated owing to the use of HALEU TRISO fuel and limited enrichment and fabrication capacity. Maintenance and staffing assumptions reflect a compact plant layout and simplified balance of plant relative to large reactors. Decommissioning costs are reduced by the small thermal inventory and limited plant footprint.
By indicator
- 1/3 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
The KP-FHR’s design has engineering-scale prototypes and test units, including electrically heated salt systems and the licensed Hermes test reactor. It does not yet have an operating nuclear prototype producing power, which limits cost baselining.
By indicator
- 1/5 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 KP-FHR uses HALEU fuel. Its thermal spectrum is not optimized to produce weapons–usable material. The below-grade configuration and plant layout incorporate design-basis security features.
By indicator
- 2/3 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)
4
Safety
Score Justification
Kairos Power has submitted a safety case for test reactor licensing, but it has not yet received approval for a commercial unit. TRISO fuel provides high temperature tolerance and fission product containment. The KP-FHR operates at low pressure; it also has robust containment with its below-grade siting, in addition to a steel and concrete containment. The molten fluoride salt coolant is chemically reactive, which could pose risks in a leak or accident scenario.
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) - 1/1 Fuel With Safety Characteristics
Does the reactor use fuel with accident tolerance or inherent safety characteristics? (10% of total score) - 4/4 Pressure & Containment
How well does the reactor’s containment strategy protect from the release of radioactive material? (10% of total score) - 3/3 Passive Heat Removal
How long can the reactor remove core heat without operator intervention? (10% of total score) - 2/4 Coolant Reactivity
How chemically reactive is the reactor coolant? (10% of total score)
3
Spent Fuel & Radioactive Waste Management
Score Justification
There is no licensed disposal precedent for the KP-FHR’s spent TRISO fuel, though qualification activities are underway. The multi-layered structure of TRISO fuel results in higher spent fuel volume per unit of energy than most LWR fuels. However, spent TRISO fuel retains relatively low volumetric decay heat at long cooling times, which is a significant driver of storage, transportation, and disposal.
By indicator
- 0/1 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) - 2/2 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)
2
Supply Chain
Score Justification
Kairos Power has made notable efforts to address supply chain challenges, including breaking ground on a new salt production facility and entering partnerships to advance TRISO fuel fabrication. Infrastructure for these components remains at a pilot scale, and commercial availability is thus limited.
By indicator
- 1/2 Key Component Availability
To what extent are commercial or pilot-scale suppliers available for the reactor’s major components? (60% of total score) - 2/4 Fuel Availability
Are suppliers available for both fuel fabrication and enrichment required by the reactor design? (40% of total score)