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.
In mid-2019, the Canadian government started the environmental assessment for this small modular reactor project proposed by Global First Power (GFP) with support from Ultra Safe Nuclear Corporation (USNC) and Ontario Power Generation (OPG). The Micro Modular Reactor is a 15 MW thermal, 5 MW electrical high-temperature gas reactor, drawing on operational experience from pebble bed reactors developed by China, Germany, Japan and the USA.
In mid-2020, a joint venture was formed between Ultra Safe Nuclear Corporation (USNC) and Ontario Power Generation (OPG) to build, own and operate the proposed Micro Modular Reactor (MMR) project at the Chalk River Laboratories site. The joint venture – the Global First Power Limited Partnership – is owned equally by OPG and USNC-Power, the Canadian subsidiary of USNC.
Safer Reactor Core
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 first micro reactor design is for 5 megawatts of electrical power.
The MMR™ facility uses standardized modules. The modules are to be assembled, tested, and commissioned at factories. They will be mass produced at factories.
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.
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. The reactor is designed to safely operate at 600 degrees celsius. This is a higher temperature than current pressurized water reactors which operate at about 315 degrees celsius. Higher temperatures allow for greater energy efficiency. 600 degrees celsius is also matching the temperature of coal power plants. This means new high temperature reactors can replace coal plants and also provide the industrial heat.
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.
- Passively cools in all scenarios
- No active safety systems needed
- No water or power needed
Site Area would only be 5 acres and the reactor could be installed in a few months.
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™.
From Pellets to Fuel Stacks
SOURCES- Ultra Safe Nuclear Corporation, Nextbigfuture.