Aalo-1
About
The Aalo-1 is a 10 MWe sodium-cooled thermal microreactor deployed in five-unit configurations (the Aalo Pod) for a total output of 50 MWe. It is designed for distributed electricity applications, including industrial and campus-scale deployment. The design uses 8% enriched uranium fuel and emphasizes repeatable modules and multi-unit deployment.
| Developer | Aalo Atomics |
|---|---|
| Country of Origin | United States |
| Size | Micro |
| Type | Sodium-Cooled Thermal Reactor |
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Analysis
3
Deployment Timescale
Score Justification
The Aalo-1 is at an early stage of formal regulatory engagement. Technology Precedent reflects some overlap with sodium-cooled reactor technologies rather than a licensed commercial reference. Once licensed, Aalo Atomics’ factory fabrication can be expected to accelerate construction time.
By indicator
- 1/4 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) - 3/3 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) - 3/5 Supply Chain
How mature and available are suppliers for key reactor components and fuel services? (30% of total score)
5
Overnight Cost
Score Justification
As with many microreactors, overnight costs are reduced not only by smaller output but by simplified systems and minimal balance-of-plant requirements. Construction costs are also relatively low because of a small site footprint and limited large-scale civil works. However, the Aalo-1 still requires significant quantities of specialized sodium-compatible components that require lengthy qualification processes.
By indicator
- 4/4 Component Cost
What is the expected cost of the reactor’s major components? (40% of total score) - 5/6 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
Operational costs are relatively inexpensive for the Aalo-1 because of the limited maintenance and staffing needs of compact plant systems. Decommissioning is also inexpensive because of the transportability of the core.
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) - 4/4 Maintenance Cost
What is the expected annual maintenance cost for the reactor and balance of plant systems, including consumables? (25% of total score) - 5/5 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) - 5/5 Decommissioning Cost
What are the total lifetime contributions required for decommissioning, regardless of funding mechanism? (10% of total score)
3
Cost Predictability
Score Justification
Cost Predictability reflects the Aalo-1’s early-stage deployment maturity but is supported by Aalo Atomics’ completion of a full nonpower prototype that informs construction approach and cost estimation. The Modularity score supports repeatable fabrication and standardized construction once manufacturing processes are established.
By indicator
- 1/5 Prototype
To what extent has the reactor design been built, demonstrated, or commercially deployed in practice? (75% of total score) - 3/3 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)
4
Security
Score Justification
The Aalo-1 uses LEU fuel, and its thermal spectrum is not optimized to produce weapons-usable nuclear material. It does not incorporate an explicit security-by-design framework in its publicly available design materials.
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) - 0/1 Security by Design
Has the reactor developer built in security by design? (20% of total score)
2
Safety
Score Justification
While the Aalo-1 does not yet have an approved safety case for commercial operation from a national regulator, the design incorporates multiple shutdown pathways and operates at low pressure, relying on confinement as opposed to containment. Its use of sodium coolant offers high thermal efficiency and operation at low pressure, but it is chemically reactive and requires careful management in the event of a leak. It does not explicitly credit passive heat removal beyond 72 hours in its publicly available design materials.
By indicator
- 0/2 Safety Case
How mature and publicly established is the reactor’s safety case with the regulator? (40% of total score) - 2/2 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) - 2/4 Pressure & Containment
How well does the reactor’s containment strategy protect from the release of radioactive material? (10% of total score) - 1/3 Passive Heat Removal
How long can the reactor remove core heat without operator intervention? (10% of total score) - 1/4 Coolant Reactivity
How chemically reactive is the reactor coolant? (10% of total score)
3
Spent Fuel & Radioactive Waste Management
Score Justification
The Aalo-1’s sodium coolant waste stream requires an additional treatment step so that it can be chemically stabilized. There is no on-site storage required because the core is simply removed and shipped to an interim processing site.
By indicator
- 0/1 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) - 3/3 On-Site Storage
How much on-site area is required for interim spent fuel storage? (10% of total score) - 1/3 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)
3
Supply Chain
Score Justification
The Aalo-1’s component supply is constrained by the need for specialized sodium reactor hardware and limited qualified vendors, but the design benefits from reliance on established LEU enrichment services.
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) - 4/4 Fuel Availability
Are suppliers available for both fuel fabrication and enrichment required by the reactor design? (40% of total score)