Nuclear Power Generation in Canada: How It Works
- What Is Nuclear Power Generation in Canada and How Does It Work?
- Where Are Canada’s Operating Nuclear Reactors?
- How Much of Canada’s Power Generation Comes From Nuclear Energy?
- What Role Does Nuclear Power Play in Canada’s Electricity Grid?
- How Is Nuclear Power Generation in Canada Changing?
- Why Can Homes Still Lose Power When Nuclear Plants Are Running?
- Plan Backup Power Around the Loads Your Home Needs
- FAQs
Nuclear power generation in Canada uses controlled uranium fission to create heat, steam, turbine movement, and electricity. In its June 2026 Nuclear Energy Strategy, the federal government reported that 17 CANDU reactors supplied about 13% of Canada’s electricity.
All current commercial reactors are in Ontario and New Brunswick. Their steady output supports the grid, but electricity must still pass through transmission and local distribution equipment before reaching a home.
For circuit backup, consider the EcoFlow DELTA Pro Ultra Whole-Home Backup Power (UL 9540 Certificated). A properly integrated system can support selected circuits when grid delivery stops.
Nuclear power generation in Canada uses controlled uranium fission to create heat, steam, turbine movement, and electricity. In its June 2026 Nuclear Energy Strategy, the federal government reported that 17 CANDU reactors supplied about 13% of Canada’s electricity.
All current commercial reactors are in Ontario and New Brunswick. Their steady output supports the grid, but electricity must still pass through transmission and local distribution equipment before reaching a home.
For circuit backup, consider the EcoFlow DELTA Pro Ultra Whole-Home Backup Power (UL 9540 Certificated). A properly integrated system can support selected circuits when grid delivery stops.
To understand that difference, start with how reactor heat becomes electricity for the grid.
What Is Nuclear Power Generation in Canada and How Does It Work?
Nuclear plants use controlled fission to produce heat. That heat creates steam, which turns a turbine connected to an electrical generator.
Canadian commercial plants use CANDU reactors. CANDU means Canada Deuterium Uranium, and the design uses natural uranium fuel and heavy water. Heavy water serves as a coolant and moderator.
The full electric power generation process works like this:
Natural uranium fuel is placed inside the reactor.
Controlled fission splits uranium atoms and releases heat.
Heavy water carries heat through the reactor system.
That heat turns normal water in a separate system into steam.
Steam spins turbines connected to an electrical generator.
The generator converts turbine movement into electricity.
Transformers raise the voltage before transmission begins.
The Canadian Nuclear Safety Commission’s plant explanation separates the heat-transport, steam, and condenser-cooling systems. These systems move heat without sending reactor water through the turbine.
Nuclear energy therefore becomes electricity only after the turbine drives the generator. The reactor supplies heat, while the electrical generator supplies electricity.
Power output at one moment is measured in watts or megawatts. Energy produced over time is measured in watt-hours, kilowatt-hours, or terawatt-hours. A nuclear plant feeds the grid, but it is not the grid itself.
Where Are Canada’s Operating Nuclear Reactors?
Canada’s 17 operable commercial reactors are located at four active sites in Ontario and New Brunswick. A reactor is one generating unit, while a site may contain several reactors and stations.
Nuclear site | Province | Operable reactors in the June 2026 snapshot | Operator |
Bruce A and B | Ontario | 8 | Bruce Power |
Darlington | Ontario | 4 | Ontario Power Generation |
Pickering | Ontario | 4 | Ontario Power Generation |
Point Lepreau | New Brunswick | 1 | NB Power |
Bruce A and Bruce B are separate stations at the same Bruce site. Sixteen reactors are in Ontario, while Point Lepreau is the only operating commercial reactor outside that province.
Quebec’s Gentilly-2 facility is shut down, so it is not part of the operating count. Research reactors also serve different purposes and are not included in this commercial electricity total.
Operating and operable do not always mean that every unit is producing electricity that day. A unit may be offline for planned maintenance or refurbishment.
Pickering Units 5–8 remain authorized to operate through December 31, 2026. OPG has applied for permission to refurbish them, but that decision is still before the CNSC. Their status should be checked again whenever this article is updated.
How Much of Canada’s Power Generation Comes From Nuclear Energy?
Nuclear supplies about 13% of Canada’s electricity, but its role is much larger in Ontario and New Brunswick. The difference reflects each province’s plants, demand, and wider supply mix.
The federal Energy Fact Book reports that Canada produced about 623 terawatt-hours of electricity in 2024. Hydroelectricity remained the largest source at about 55%. The June 2026 strategy uses 13% as the national nuclear share.
That national figure does not describe the electricity mix at every home. Power generation in Canada changes greatly by province, and electricity also moves between provinces and across the Canada–United States border.
Ontario’s IESO reports that nuclear provided about 48.2% of the province’s actual electricity output in 2025. NB Power says Point Lepreau supplied about one-third of New Brunswick’s electricity that year.
Different current sources may show nuclear shares near 13%, 14%, or 15%. Reporting years, annual plant outages, total generation, imports, exports, and rounding can change the result. This article uses the federal June 2026 figure consistently.
These figures also show why power generation must be dated. A reactor outage or change in demand can shift one year’s percentage without changing the number of licensed sites.
What Role Does Nuclear Power Play in Canada’s Electricity Grid?
Nuclear plants provide large amounts of steady electricity. More flexible sources help grid operators respond when demand changes during the day.
The IESO classifies nuclear as baseload generation in Ontario because reactors normally operate for long periods at steady output. Nuclear plants produce no greenhouse gas emissions while generating electricity, although their full lifecycle includes mining, construction, fuel processing, and waste management.
Canada’s electricity mix also includes hydro, natural gas, wind, solar, bioenergy, imports, and storage. Reservoir hydro and natural-gas plants can often change output faster than a nuclear unit.
Nuclear stations also have limits. Reactors need planned maintenance, inspections, and major refurbishment outages. Uranium is a finite fuel, so nuclear energy is not classed as renewable. The question of whether nuclear energy is renewable also involves the difference between a low-emission source and a naturally renewed fuel.
Used nuclear fuel requires secure storage and long-term management. Each site also needs regulation, monitoring, cooling, security, and emergency planning. The CNSC oversees these requirements and the systems used to control, cool, and contain the reactor.
Steady nuclear output supports reliability, but it cannot meet every grid need alone. Transmission, flexible generation, storage, reserves, and local distribution equipment remain part of reliable service.
How Is Nuclear Power Generation in Canada Changing?
Canada is extending the life of existing reactors while building one commercial small modular reactor. Governments and utilities are also studying further projects that are not yet operating.
Existing Reactor Refurbishments
Refurbishment replaces major reactor components and can extend a unit’s working life. OPG completed construction work on the four-unit Darlington refurbishment in 2026. Bruce Power’s wider life-extension program remains underway, with work planned across Units 3–8.
Pickering’s four remaining operating units are expected to stop after their current 2026 authorization. OPG has requested approval for refurbishment, but the CNSC hearing and decision process is still underway.
Darlington New Nuclear Project
One BWRX-300 small modular reactor is under construction at the Darlington site. It is a 300-megawatt-electric water-cooled reactor.
The CNSC granted a construction licence for one unit in April 2025. It removed the first regulatory hold point in March 2026. OPG later applied for an operating licence, but the reactor is not operating.
The site plan allows for possible future applications covering up to three more units. Those possible units are not all approved or under construction.
Federal Nuclear Strategy
Canada launched a national nuclear strategy in June 2026. It covers existing CANDU skills, new reactors, small modular reactors, uranium, waste management, workforce development, and Canadian technology.
The strategy sets policy aims rather than guaranteed construction results. Every project still needs financing, regulatory review, site work, and final operating approval.
Why Can Homes Still Lose Power When Nuclear Plants Are Running?
A nuclear plant may keep generating electricity while a fault elsewhere stops it from reaching your home. Generation is only the first stage of the electricity system.
The delivery path includes five main stages:
Generation at the power plant.
High-voltage transmission across long distances.
Substations that direct power and change voltage.
Local distribution lines and transformers.
The service connection and electrical equipment inside your home.
The generation of power occurs at the plant. Transmission and distribution then carry that electricity to customers. High winds, snow, ice, lightning, floods, falling trees, vehicle collisions, equipment faults, and planned work can disrupt those later stages.
Protection systems may also disconnect damaged equipment to limit a fault. In other cases, the problem may be a local transformer or a breaker inside the home. A closer look at how extreme weather affects Canada’s power grid explains why dependable generation cannot prevent every local outage.
Home backup does not repair or replace the public grid. It supplies chosen loads until utility service returns. Size it from essential circuits, running watts, startup demand, voltage, and required operating time, not the province’s nuclear share.
The DELTA Pro Ultra base configuration provides 6,144 Wh of capacity, 7,200 W continuous AC output, and 10.8 kW surge output. It supports 120 V and 240 V output. Automatic circuit-level integration requires compatible equipment, such as EcoFlow Smart Home Panel 2, and installation by a qualified electrician.
For a selected-load plan, consider the EcoFlow DELTA 3 Ultra Series Portable Power Station (3072Wh).
The series provides 3,072 Wh base capacity, 3,600 W continuous output, and 7,200 W surge output. Its 10 ms automatic switchover applies to compatible connected equipment. The DELTA 3 Ultra Plus variant can expand from 3 kWh to 11 kWh with compatible equipment.
Selected loads may include refrigeration, communications, lights, and other compatible appliances. Home circuits still require approved transfer equipment. Runtime depends on the loads, losses, temperature, cycling, battery condition, and available capacity.
Never plug backup equipment into a wall outlet to feed a home. Canadian guidance requires an approved transfer panel and switch installed by a qualified electrician for household connections. Keep equipment dry and follow its manual.
Plan Backup Power Around the Loads Your Home Needs
Check electricity and outage information from your provincial system operator or utility. List the circuits and devices that must stay on, then have a qualified electrician confirm any circuit-level connection method.
Once those loads are clear, explore EcoFlow DELTA Pro Ultra Whole-Home Backup Power for a compatible integrated setup.
FAQs
Does nuclear power mean my home cannot lose electricity?
No, nuclear generation may continue while a fault in transmission, distribution, local equipment, or the home’s electrical system interrupts service.
Can a home battery store electricity generated by a nuclear plant?
Yes, a battery stores electricity received from its charging source. Once grid electricity reaches a home, the battery normally cannot separate nuclear-generated electricity from other grid sources.
Can battery backup power a home during a grid outage?
It can support compatible plug-in devices or properly connected household circuits. Its output, capacity, voltage, and connection method must fit the planned loads.
How much battery capacity does a home need during an outage?
Capacity depends on each load’s energy use and the required operating time. System losses, appliance cycling, temperature, and access to more charging also affect the result.