Technology


How it Works

The Kairos Power FHR (KP-FHR) is a novel advanced reactor technology that leverages TRISO fuel in pebble form combined with a low-pressure fluoride salt coolant. The technology uses an efficient and flexible steam cycle to convert heat from fission into electricity and to complement renewable energy sources.

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Coolant

Coolant

Flibe is a molten salt with excellent heat transfer properties and fission product solubility.

Modular Design

Modular Design

The reactor is right-sized for enhanced manufacturability and constructability.

Power Conversion System

Power Conversion System

A high temperature superheated steam cycle produces electricity efficiently, cleanly, and reliably.

Fuel

Fuel

The fuel kernel has its own dual containment within the fuel pebble, creating a defense-in-depth mechanism.

Safety

Safety

The synergy between triso fuel, salt coolant, and passive safety mechanisms create an inherently safe design.

KP-FHR Specifications

POWER OUTPUT

140 MWE

NET EFFICIENCY

45%

MAIN/ REHEAT TEMPERATURES

585°C/ 585°C

MAIN STEAM PRESSURE

19 MPA

REACTOR OUTLET TEMPERATURE

650°C

REACTOR OPERATING PRESSURE

NEAR ATMOSPHERIC PRESSURE

REACTOR STRUCTURAL MATERIAL

316 STAINLESS STEEL

FUEL ENRICHMENT LEVEL

19.75%

INTERMEDIATE SALT

"SOLAR" / NITRATE SALT

REFUELING TYPE

ONLINE

DEPLOYMENT CONFIGURATION

SINGLE / MULTI-MODULE

BACK-UP POWER SUPPLY

AUTOMATIC SAFE SHUTDOWN; PASSIVE COOLING UPON LOSS OF POWER

How We Are Achieving This

Kairos is set apart by its integrated design philosophy, testing program, and licensing approach to deliver its mission of reliable, responsible, and competitive power. The FHR is being designed with characteristics important to our customers: License-ability, constructability, operability, responsibility.

Kairos Power has developed a model-to-learn process that supports ongoing planning, designing, building and testing to better enable the transition to clean energy. This agile strategy will reduce costs while allowing Kairos Power to build smarter and faster, developing innovative nuclear technologies to transform the worldwide energy landscape.

 

Kairos Power's test program enables component development by narrowing the design space through progressive test cycles. Through these accelerated test cycles and applied engineering, teams are empowered to collaborate and learn, building on ongoing achievements. Unique experimental facilities and capabilities support Kairos Power's rapid technology demonstration. The test program also provides validation and qualification data to support the licensing basis for the KP-FHR.

Kairos Power's licensing strategy reduces licensing risk and facilitates licensing certainty for customers via active pre-application engagement with the Nuclear Regulatory Commission (NRC) during the design process prior to plant construction. Licensing process improvements are anticipated by implementation of the Licensing Modernization Project (LMP), which provides a methodology for the identification and focus on safety significant portions of the design and safety analysis during the licensing review. The pre-application engagements further support the focus on key technical and analysis issues and utilize a phased licensing approach, including submission of topical and technical reports and a preliminary safety information document.

Common Questions

How Does Kairos Power's Reactor Differ From The Conventional?

Rather than water, as used in conventional nuclear reactors, the Kairos Power reactor uses molten fluoride salt as a coolant. Molten fluoride salts have excellent chemical stability and tremendous capacity for transferring heat at high temperature and retaining fission products. Various U.S. reactor studies confirm the compatibility of molten fluoride salts with conventional high-temperature structural materials (e.g. stainless steel), thus enabling commercially attractive reliability and service life.

What Fuel Does Kairos Power’s Reactor Use?

Kairos Power’s reactor uses fully ceramic fuel, which maintains structural integrity even at extremely high temperatures. This fuel will be undamaged to well above the melting temperatures of conventional metallic reactor fuels. Proven methods for fabricating and testing these fuels have been demonstrated at U.S. National Laboratories. By using pebble-type fuel, Kairos Power reactors can refuel on line, enabling exceptional reliability and availability.

What Is Fluoride Salt Coolant?

Kairos Power’s reactor uses molten fluoride salt coolant. Molten fluoride salts have outstanding capability to transfer heat at high temperature, excellent chemical stability, and the ability to retain radioactive fission products that might be released from fuel. Extensive experience and design information exists from the early U.S. reactor development program that studied and tested liquid-fueled molten salt reactors. These studies confirmed the compatibility of these salts with Kairos Power’s high-temperature structural materials, enabling commercially attractive reliability and service life.

What Does Kairos Power Mean By Passive Safety?

Passive safety means that Kairos Power reactors do not require electricity to remove heat from the core after shutting down. Kairos Power reactors have uniquely large safety margins based on the selected combination of fuel and coolant, which allows emergency cooling to be driven by fundamental physics rather than engineered systems. In Kairos Power’s reactor, there is no need to provide for make-up coolant (since the coolant cannot boil away), and the fuel tolerance for extremely high temperatures allows orders of magnitude more cooling capability under accident scenarios compared to water-cooled reactors. High-temperature fuel and coolant dramatically simplifies emergency cooling under all conceivable accidents.

What Are The Benefits Of A Low-Pressure Reactor?

The intrinsic low pressure in Kairos Power reactors enhances safety and eliminates the need for bulky and expensive high-pressure containment structures.  Kairos Power technology leverages key U.S. federal investments in design, structural materials, and components for low-pressure pool-type reactors, including critical updates to the ASME Boiler and Pressure Vessel Code for design at our service conditions.

Is This A Thorium-Fueled/Fluid-Fueled Reactor?

No. While the use of thorium in a breeding reactor provides potentially attractive benefits, the current challenges with baseload generation do not stem from the price or availability of uranium. Using high-temperature fuels and fluoride salt coolants simplifies licensing, operation, and corrosion control of Kairos Power reactors, while maintaining all relevant safety aspects of molten-salt-fueled reactors.