Fully Ceramic Micro-Encapsulated Fuel
Fuel Based Safety
Fully Ceramic Microencapsulated (FCM®) fuel provides a new approach to inherent reactor safety by providing an ultimately safe fuel. Industry standard TRISO fuel, which contains the radioactive byproducts of fission within layered ceramic coatings, are encased within a fully dense silicon carbide matrix. This combination provides an extremely rugged and stable fuel with extraordinary high temperature stability.
The fuel packaging starts with a Uranium Fuel Kernel measuring less than 1 mm across.
TRISO Particle Fuel
The kernel is coated with special layers designed like tiny pressure vessels. The layers contain fission products inside and ensure mechanical and chemical stability during irradiation and temperature changes. This is called a TRISO Particle. Developed in the 1960’s for gas-cooled reactors, TRISO has enjoyed continued international development resulting in an excellent starting point for the Ultra Safe reactor.
Ultra Safe Nuclear’s breakthrough is encasing the TRISO Particles within a dense Silicon Carbide matrix, which we call Fully Ceramic Micro-Encapsulated Fuel, or FCM® Fuel.
FCM® Fuel Pellets are stacked…
…and placed into Graphite Blocks. Graphite is the moderator which slows down neutrons and increases the likelihood that neutrons will cause fission reactions in the fuel. Cooling channels are built into the Graphite Blocks. Cold helium flows through the cooling channels and picks up heat.
Reactor Core Cartridge
The Reactor Core is made up of several hundred such Graphite Blocks with a few tons of fuel. Various openings and channels are used for control rods and coolant flow.
Benefits of Intrinsic Safety
The Core is placed inside the vessel of the Micro Modular Reactor (MMR®). The FCM® fuel unlocks a number of system benefits including fission product isolation that improves worker and plant safety, enhanced proliferation resistance, and minimized emergency planning zones.
The Micro Modular Reactor (MMR®) system is a 4th Generation nuclear energy system that delivers safe, clean, and cost-effective electricity and heat to remote mines, industry, and communities. It is the leading SMR project in Canada and the first so called "fission battery" concept worldwide.
The buried reactor core consists of hexagonal graphite blocks containing stacks of Ultra Safe’s FCM® fuel pellets. The MMR® reactor core has a low power density and a high heat capacity resulting in very slow and predictable temperature changes.
The Most Benign Cooling Medium Available
Helium gas is the MMR® reactor’s primary coolant. The helium passes through the nuclear core and is heated by the controlled nuclear fission process. The helium then transports the heat away from the core to the Molten Salt System.
The MMR® reactor uses helium as it is an inert gas; a radiologically transparent, single-phase gas with no flashing or boiling possible. Helium does not react chemically with the fuel or reactor core components. It is easy to accurately measure and control the helium pressure in the reactor.
The FCM® fuel ensures the helium is clean and free of fission products.
Genuine Safety Margin
The MMR® reactor is a walk-away safe reactor. In the case of an accident, the MMR® reactor cannot melt down, as all heat dissipates passively into the environment, no matter the scenario.
The plant has no need for active systems to remove heat. Additionally, the plant does not need any outside services, including electrical power, to operate safely.
The fuel safety margin is so large that fission product retention is accomplished entirely by the fuel; no other containment is needed. There are no sudden temperature rises – the reactor shuts down naturally in all accident conditions.
Typical MMR® Layout
The MMR® Energy System consists of two plants, the nuclear plant and the adjacent power plant. The nuclear plant contains the MMR® reactors including all the equipment required to transport the heat to the adjacent plant. The adjacent power plant contains the equipment that converts heat to electricity or process heat as required.
Molten Salt Loop
Fully Dispatchable Nuclear Heat
The MMR® Energy System is simple to operate, and flexible in its outputs. The use of molten salt thermal storage allows for significant flexibility in the supply of both electricity and process heat. While the MMR reactor operates at constant power, electricity and heat are delivered on-demand from the power plant.
Operations are simple with minimal maintenance requirements, and no on-site fuel storage, handling, or processing. The MMR® reactor is fueled once for its lifetime. A fuel cartridge is rated at 20 years of full power. If operation of the Energy System is desired beyond 20 years, a cartridge replacement can be performed.
The MMR®’s high temperature heat has many uses beyond generation of electricity. District heating, desalination, and process heat are all possible with the MMR®.
The MMR® facility uses standardized modules. The modules are to be assembled, tested, and commissioned at our factories.
Easy to Transport
Modules will be sized for standard International Standards Organization shipping containers; this means they can be transported easily by ship, rail or road. This includes ice roads.
Quick to Build
The modules are transported to the site, and then assembled. The construction of the MMR® plant is quick, simple, and scalable.
Scalable and Adaptable
Multiple MMR® reactors can be linked together to provide as much power as needed. The modules can also be combined in different ways for different sites and needs including integration with renewable micro grids.
Total Environmental Protection
The MMR Energy System uses no water. There is no risk of spills with environmental impacts during accidents. The nuclear fission products are locked inside the FCM fuel form during and after power production permanently.
FCM® fuel cannot be re-processed using currently available reprocessing schemes. The MMR® fuel cartridge is sealed at the factory– the fuel cannot be accessed.
The MMR® Energy System can operate as a stand-alone off-grid plant to deliver fully dispatchable and resilient power. Or can be connected to existing grids.