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The CNSC offers a range of videos to explain different elements of the fields we regulate.

Visit the CNSC’s YouTube Channel. Check out the CNSC videos explaining the nuclear sector in Canada, and how it remains safe through our regulations. You can explore our "Ask an Expert" video playlists, or catch up on past Commission hearings and meeting presentations.

How does the Independent Environmental Monitoring Program work?

Follow a sample’s journey. Learn how the CNSC’s Independent Environmental Monitoring Program (IEMP) manages the environmental sampling around licensed nuclear facilities, the laboratory analysis of the samples, and the evaluation of results.


A sample’s journey. A nuclear facility. How does the Independent Environmental Monitoring Program (IEMP) work? Select location. Prepare for sampling. Take samples. Ship to lab. Analyze samples. Evaluate results. Post results online. Notify public. To learn more The Canadian Nuclear Safety Commission. Government of Canada

Five layers of defence

Watch this video to see how defence in depth is applied to nuclear power plants.

Transcript (click to expand)

Music: Soft, upbeat music begins.

On screen: (The words “Canadian Nuclear Safety Commission” appear. The Canadian flag pops up above the word “Canadian” in a text bubble. A text bubble showing workers and the words “Nuclear regulator” appears below the word “Commission”. A green shape swirls around the word “Safety” as the other words fade out.)

Narrator: The Canadian Nuclear Safety Commission is Canada’s nuclear regulator, and safety is our top priority.

On screen: (The words “Defence in depth” appear on the screen then disappear to reveal a nuclear plant. The shape of a shield overlays the nuclear plant. The shield disappears and 5 different coloured bubbles animate onto the screen. They begin to move in an orbital path around the nuclear plant.)

Narrator: Defence in depth is a safety concept that aims to prevent and mitigate accidents through 5 independent levels of defence, applied to all nuclear power plants in Canada. Level 1 is about prevention, and encompasses the design, construction, processes and maintenance occurring during normal plant operations.

On screen: (A white ball, labelled Level 1, appears then disappears, revealing a scene of level 1 activities, including workers observing activities, reviewing plans, and using meters outside.)

Narrator: Level 2 represents the measures and systems in place to control and correct any unusual occurrences during normal operations.

On screen: (A white ball, labelled Level 2, appears then disappears, revealing a scene of level 2 activities, including workers inside a nuclear plant reviewing information on computers.)

Narrator: Nuclear power plants operate at these levels for the vast majority of the time, safely and without incident.

On screen: (The picture transitions back to the nuclear plant, with 2 balls orbiting it. Then 3 more balls join the orbit.)

Narrator: The next 3 levels are rarely activated, but are frequently exercised, evaluated, maintained and improved upon.

On screen: (A white ball, labelled Level 3, appears then disappears, revealing a scene of level 3 activities, including workers assessing a situation in front of a white board.)

Narrator: Level 3 refers to the plant’s robust safety systems, designed to stop the progression of an accident.

On screen: (A white ball, labelled Level 4, appears then disappears, revealing a scene of level 4 activities, including workers conducting repairs.)

Narrator: Level 4 works to contain radioactive material within a specially designed containment structure.

On screen: (A white ball, labelled Level 5, appears then disappears, revealing a scene of level 5 activities, including various professionals working together at a distance from the nuclear plant.)

Narrator: Level 5 enlists comprehensive off-site emergency response to minimize consequences to the public and the environment.

On screen: (The picture changes to a bubble, which gets smaller and swings into orbit with the 4 other bubbles. The bubbles disappear into the nuclear plant.)

Narrator: With this reactor design, each level of protection is tough. The multiple levels of defence are built in to reinforce, defend and maintain the protection of the public and the environment.

On screen: (The plant stands alone. Nature and civilization begin to flourish around the nuclear plant and in the distance. The CNSC wordmark appears, made up of the Canadian flag symbol and the words “Canadian Nuclear Safety Commission”. The Canada wordmark then appears.)

Music: The music fades out.

Life at the Canadian Nuclear Safety Commission

Learn more about what our employees do and why the CNSC is a great place to work.


We are Canada’s nuclear regulator. We are highly skilled professionals committed to safeguarding the health, safety and security of Canadians and the environment.

From uranium mining to nuclear reactors, to the decommissioning of nuclear sites and the management of nuclear waste, the CNSC ensures that all things nuclear in Canada are safe.

We implement Canada’s international commitments on the peaceful use of nuclear energy; disseminate scientific, technical and regulatory information to the public; and foster effective relations with local, national and international stakeholders.

We have our headquarters in the nation’s capital, along with offices across the country.

Why work with us?

Not only are we a world-class regulator, we are an employer of choice.

Our comprehensive compensation and benefits package includes a full house of total rewards with unique offerings that make it one of the most attractive packages on the block.

We pride ourselves on our positive work environment, where employees feel valued and supported.

Diversity and inclusion

Our employees say that having great colleagues is one of the best parts of working at the CNSC.

We work to create and maintain a discrimination-free and inclusive work environment that leverages everyone’s strengths to achieve our goals.

Career development

At the CNSC, continuous learning is encouraged and supported. We invest in our employees and believe that learning is a career-long process.

We offer a full range of activities – from job aids, webinars and online learning, to one-on-one mentoring and language training.


Our Recognition Program is designed to foster pride in the work of our employees and to encourage individual and team commitment to the organization’s goals and objectives.

Health and wellness

We are at our best when our bodies and minds are healthy, and when our workplace is respectful and supportive.

That’s why we participate in mental health campaigns and hold several health and wellness activities throughout the year.

Work-life balance

We know that there’s more to life than a career, no matter how satisfying that career might be.

CNSC employees do important, challenging work – but also have time to enjoy their personal lives.

We provide a variety of benefits and flexible work arrangements to support the lives of employees and their loved ones, outside of work.

Community involvement

We encourage employees to participate in worthwhile causes and charitable campaigns, including the Government of Canada Workplace Charitable Campaign.

Our employees give generously and see the value in giving back to the community to support those in need.

These things are important to our employees. We think that they may be important to you, too.

Join our team of professional, passionate individuals – make an impact doing the work you love, in an organization that you are proud to be a part of.

Trust in Motion at the CNSC

We asked our stakeholders to share their views on the importance of trust in Canada’s nuclear regulator. Here’s what they had to say.


The video transitions to a body of water. A pier and 4 large boats are static in the background.

In white text, the following words appear on the screen:

We asked our stakeholders to share their views on the importance of trust in Canada’s nuclear regulator.

The video transitions; the frame moves along the body of waters shore.

In white text, the word:


Appears on screen in the lower right corner.

It’s tremendously important to have a nuclear regulator for the simple fact that we all need to be accountable to someone. We have to have accountability.

The video transitions to Austin Paul sitting on the shoreline of the body of water.

In white text, the title:

Austin Paul, Wolastoqey First Nation

Appears on the lower right side.

The video transitions to a moving landscape of a downtown city.

In white text, the title:


Appears on screen in the lower right corner.

Citizen engagement is really key. Citizens are increasingly looking for a meaningful opportunity to be engaged in decisions that affect them. They don’t always trust the way that they used to.

They don’t always defer to the decisions of elites the way that they used to. So ensuring that regulatory agencies have open, transparent, meaningful decision-making processes with opportunities for engagement of the public is extremely fundamental.

The video transitions, and a shoulder shot of Monica Gattinger appears on screen.

In white text, the title:

Prof. Monica Gattinger, University of Ottawa

Appears on the lower left screen.

The video transitions to two CNSC employees walking on a shoreline.

In white text, the title:


Appears on the lower right screen

Through any time I have ever sat down and talked to them, they ask pointed, good questions.

But you know, more than anything, they’re very commonly concerned and they explain things to us in a very common-sense approach so everybody can understand.

The video transitions to a shoulder shot of Ron Mawhinney,

In white text, the title:

Ron Mawhinney, Community Relations Liaison Committee Member

Appears on the lower right screen

The video transitions to an open body of water with ducks swimming in the background.

The video transitions to a shoulder shot of Ron Mawhinney,

In white text, the title:


Appears on the lower right screen

The video transitions, and a shoulder shot of Helen Ward-Wakelin appears on screen

To ensure that First Nations communities are part of the regulatory process with CNSC, we have the opportunity, as well as anybody in the public, to intervene in public hearings.

In white text, the title:

Helen Ward-Wakelin, Mi’kmaq First Nation

Appears on the lower left screen

The video transitions to an aerial view of a small community on a coastline.

In white text, the title:


Appears on the lower right screen

The video transitions, and a shoulder shot of Suzanne D’Eon appears on screen.

The CNSC’s role and its diligence in implementing its role over the last 40, 50 years has really built trust in communities like mine and the individuals that live in them.

In white text, the title:

Suzanne D’Eon, Mayor of Deep River, Ontario

Appears on the lower right screen

The video transitions to an aerial view of a community.

In white text, the title:

Open & Transparent

Appears on the lower right screen

The video transitions, and a shoulder shot of Adrian Foster appears on screen.

So transparency on the part of the regulator, both for myself as a mayor as well as for the public, we need to understand how the regulator is coming to decisions. We need to understand the process and be able to be part of that process, so transparency is paramount. We need to know that the regulator is unbiased and is going to take a science-based approach to all of the things that they do.

In white text, the title:

Adrian Foster, Mayor of Clarington, Ontario

Appears on the lower right screen

The video transitions to an aerial view of a community.

In white writing, the title


Appears on the lower right screen

The video transitions, and a shoulder shot of Adrian Foster appears on screen.

The video transitions; Austin Paul is on the shoreline of the body of water

As a member of the Wolastoqey nation, my ancestors have lived here for 13,000 years and we would all love to continue living here for 13,000 years into the future. I’m an avid land user. I’m a hunter, I’m a gatherer. It’s very comforting to know that people are actively employed to ensure that what we’re harvesting is safe.

The Canadian Nuclear Safety Commission wordmark is presented in both official languages.

What is Radioactive Waste?

Radioactive waste is any liquid, gas or solid that contains a radioactive nuclear substance and for which there is no foreseeable use. Watch the video to learn more about what radioactive waste looks like and where it comes from.


What is radioactive waste? Radioactive waste is any liquid gas or solid that contains a radioactive nuclear substance and for which there is no foreseeable use. There are four general classes of radioactive waste in Canada. Uranium mine and mill waste, low level radioactive waste, intermediate level radioactive waste and high-level radioactive waste. The first of the four general classes is uranium mine and mill waste. This includes tailings and waste rock generated by the mining and milling of uranium ore. Tailings have the consistency of fine sand, while waste rock is simply gravel and broken up rock. Next, we have low level radioactive waste, which is more radioactive than clearance levels and exemption quantities allow. It requires isolation and containment for up to several hundred years. Nuclear power plants, research reactors, test facilities, radio isotope manufacturers or users, uranium refining and conversion and nuclear fuel fabrication facilities produce low level waste. It can come in various forms, such as used equipment, paper, cable, clothing, decommissioned parts and even mops. Thirdly, we have intermediate level radioactive waste, which contains concentrations of long-lived radionuclides elements that emit radiation. It requires isolation and containment for longer than several hundred years. Nuclear power plants, prototype and research reactors, test facilities and radio isotope manufacturers and users produce intermediate level waste. It could come in the form of refurbishment waste such as old components, ion exchange resins and some radioactive sources used in radiation therapy. Lastly, we have high level radioactive waste, which is primarily used nuclear fuel along with small amounts of waste that generate significant heat and radioactivity. It requires long term isolation. Nuclear power plants prototype in research reactors and test facilities produce high level waste. It comes in the form of used nuclear fuel that is still significantly radioactive.

The Canadian Nuclear Safety Commission regulates all classes and forms of radioactive waste in Canada to protect the health and safety of people and the environment. You can find more info at

Near Surface Disposal Facility – Chalk River Laboratories

The Near Surface Disposal Facility (NSDF) is a proposed engineered disposal facility for low-level radioactive waste at the Chalk River Laboratories site.


The NSDF application to the CNSC

We’re the Canadian Nuclear Safety Commission, Canada’s nuclear regulator.

Our staff are reviewing the application from Canadian Nuclear Laboratories to build a Near Surface Disposal Facility (NSDF) in Chalk River, Ontario.

What does “near surface disposal” mean?

An NSDF is a type of waste facility where radioactive waste is stored at or below the ground’s surface.

In order to prevent contaminants from getting into the surrounding environment, the waste is placed in vaults or cells, with a special bottom liner.

This project would include 10 storage cells. When a cell is full, a cover will be placed on top to seal the waste and protect it from contact with people, animals and weather.

Protecting our water

We know there are concerns about the proposed Near Surface Disposal Facility affecting the Ottawa River.

That’s why over 50 specialized scientific and technical experts, like geoscientists and structural engineers, at the CNSC and across government are carefully reviewing every detail of CNL’s application, taking into account international best practices.

It’s their job to ensure the facility will meet Canada’s rigorous standards for protecting people and the environment:

They’re assessing protective materials planned for the facility, to ensure that the liner and cover systems contain and isolate the waste.

They’re studying water flows to ensure the impact on the Ottawa River would be negligible if small amounts of contaminants ever travelled to the river, both during operation and after the facility is shut down.

They’re also assessing whether the structure could withstand very severe earthquakes.

Like you, we want to protect the environment, so we all have clean water, air and soil — now and for future generations.

Learn more about how our experts are working to protect you and your community at

What is a small modular reactor?

It’s our role to ensure nuclear reactors – big or small – are safe for Canadians and the environment. Learn more about small modular reactors and how they’re changing how the world thinks about nuclear power.


What is a small modular reactor?

Small modular reactors, or SMRs, use fission to create heat that generates energy like traditional nuclear reactors.

They’re designed to be smaller than a traditional reactor.

They vary in size and the power they produce.

What about regulation?

The CNSC has been providing feedback to companies for several years through the pre-licensing vendor design review process.

Big or small and no matter the technology, the CNSC’s role is to regulate the nuclear industry and protect the health and safety of the public and the environment.

Canadian Nuclear Safety Commission

Government of Canada

How small are Small Modular Reactors?

Small modular reactor facilities come in many forms: from the size of a three-storey building to a full city block. Learn more about these new technologies and the work being done to protect Canadians and the environment.


How small are small modular reactors?

They can be as small as a three-storey building or as large as an entire city block.

That’s the equivalent of a mid-size shopping mall!

Regardless of their size, the major parts of SMRs will be housed within a larger facility.

This is where you will find systems that... support safe operation and maintenance, harness heat, which can do useful things like generate electricity.

We have been preparing to regulate SMR projects for many years.

Anyone who wants to build and operate an SMR facility needs to meet our requirements for... Safety, security, environmental protection, Canada’s commitments to nuclear non-proliferation.

Big or small and no matter the technology, it’s the CNSC’s role to regulate the nuclear industry and protect the health and safety of the public and the environment.

Canadian Nuclear Safety Commission

Government of Canada

Stay safe working with portable nuclear gauges

Portable nuclear gauges have sources that emit radiation. To work safely with these gauges, here’s what you need to know. Watch the video to learn more.


Portable Nuclear Gauges

(Blank screen showing the following disclaimer):
This video contains guidelines on working safely with portable gauges and is not intended to be a sole source of information for training purposes. Specific information and requirements are found in the manufacturer operating manuals for each gauge model, the Nuclear Safety and Control Act (NSCA) and applicable regulations, as well as the licence issued by the Canadian Nuclear Safety Commission (CNSC).

(Opening image CNSC logo TEXT ON SCREEN: Stay safe working with portable nuclear gauges)

Voice-Over: Stay safe working with portable nuclear gauges

Portable nuclear gauges have sources that emit radiation.

(Shot of worker on a roadway holding the portable gauge with construction sounds in the background.)

To work safely with these gauges, here’s what you need to know.

(Text on screen: Preparing and using Portable Nuclear Gauges)

Voice-Over: Preparing and using Portable Nuclear Gauges

Before you start anything, be sure to attach the dosimeter your employer provided somewhere between your neck and waist.

(Close up of worker clipping on the dosimeter to their chest)

Voice-Over: If you do not have a dosimeter, you must log every shot, even practice shots.

(Shot of worker logging shots in the log book)

Voice-Over: If you are approaching 650 shots in a year, bring it up with your radiation safety officer.

(Shot of worker bending down over the gauge with Prohibited symbol) Voice-Over: When using the gauge, don’t hover over it or point it at others while the source is exposed.

(Shot of worker carrying the gauge over to the hole. Person sets gauge over hole) Wait until the gauge is set over the hole before extending the source rod.

(Shot of worker stepping away from the gauge and waiting for the beep. Signals for a coworker to move back with him)

Voice-Over: Keep your co-workers and anyone else in the area at least two meters away from the gauge.

Once it’s set, move away from the gauge.

(Shot of worker stepping back into the shot of the gauge and takes the reading, safely retracts the gauge and moves it away)

Voice-Over: Once it’s done, retract the source rod from the ground, and then move the portable gauge.

(Cut to shot of worker securing the gauge on the jobsite. As a group of people walk away. Chained closed or locked in a truck.)

Gauges must always be under direct supervision, so if you’re going to lunch or taking a break the gauge has to be locked safely and securely.

(Text on screen: Transporting Portable Nuclear Gauges)

Voice-Over: Transporting Portable Nuclear Gauges

(Shot of worker placing documents into truck door before stepping into truck)

Voice-Over: First, make sure you have the right shipping documents with you before traveling with a gauge to or from the job site.

Voice-Over: Documents must always be within arm’s reach.

(Shot of worker closing the tailgate of the truck and checking to ensure that the lock is secure)

Voice-over: Second, when packing the gauge for transport, make sure the shutter is fully closed to protect yourself and the public.

(Shot of worker checking to ensure that shutter is closed with a radiation survey meter)

Voice-Over: The best practice to check a shutter is with a radiation survey meter.

(Shot or worker lifting gauge to show underside, and placing survey meter at the bottom of the gauge)

A mirror check is a secondary option for checking the shutter.

(Shot of worker inspecting the gauge and package)

Voice-Over: Also check that the gauge and transport case are not damaged.

(Shot indicating each of the labels and where they are placed on the packaging)

Voice-over: Once it is in its type A package make sure the following labels and markings are present and legible:

(Close shot identifying each label)

Voice-Over: Two properly completed category Yellow-II labels on opposite sides of the package

Voice-Over: The UN number and proper shipping name next to each category label, Consignor ID, Name of package manufacturer and VRI code

(Shot of workers placing gauge in a secure storage area, labelled with signs indicating that the gauge is in that location

Voice-Over: At the end of the day, make sure the gauge is safely and securely stored.

(Shot sequence of damaged gauges)

Voice-over: If the gauge is damaged, lost, stolen or involved in a transport accident follow your company’s emergency response procedures and inform the appropriate persons immediately.

(Text on screen: CNSC Duty Officer Phone number: 1-844-879-0805) Voice-Over: If you can’t reach your RSO call the CNSC duty officer immediately at 1-844-879-0805

(Shot of workers looking a gauge from a safe distance) Voice-Over: Following these simple steps will help keep you and others safe when using portable nuclear gauges

(Generic CNSC video close cut shot) Voice-Over: For more information on portable gauges or the CNSC visit our website:

What are Financial Guarantees?

A financial guarantee is a tangible commitment by a licensee that there will be sufficient resources to safely terminate licensed activities.


In order to ensure that people in the environment are protected, the CNSC ensures that licensees make sufficient provisions for not only the safe operation of activities, but also the termination of those activities.

That means that licensees must have something called a financial guarantee. Having a financial guarantee is the measure to properly account that funding is available for the decommissioning and disposal of all licensed material and equipment so that this liability doesn't fall on taxpayers.

Following the end of their nuclear activities, licensees must ensure that all locations associated with the license are cleaned up and that waste is disposed of appropriately.

Having a financial guarantee in place ensures there are funds available to complete all decommissioning activities. Failure to fulfill this requirement is considered non-compliance and could result in regulatory action.

The CNSC would only access a financial guarantee in the event that a licensee no longer exists or that they are unavailable to decommission the facility.

An example would be in the case that they go bankrupt. This financial guarantee may involve various types of financial security such as funds, surety bonds, letters of credits, and so on. And to ensure the financial guarantees remain valid, in effect, and sufficient for decommissioning, there are periodic renewals and revisions when deemed necessary.

So I hope this clarifies things a bit when we say that the CNSC regulates all nuclear activities, from cradle to grave. Rest assured, you are in safe hands.

If you have more questions about financial guarantees, drop us a line at

Pressure tubes: The heart of the reactor

Pressure tubes contain the fuel bundles and primary coolant (water) in a nuclear reactor. Their safe operation is ensured through extensive research, testing and modelling development by the licensee to understand the impact of expected operational wear and tear. In its comprehensive and rigorous oversight, the CNSC analyzes and evaluates the data provided by the licensee to confirm that pressure tubes remain safe for operation.


Inside all CANDU nuclear power reactors in Canada are several hundred fuel channels. Each one has four spacers, end fittings, a calandria tube and pressure tubes.

Pressure tubes form the heart of the reactor. They are used to contain the fuel bundles and coolant.

During regular nuclear power plant operation, pressure tubes are exposed to high temperatures, high pressure and intense radiation, which can cause them to deteriorate. Much like any machine, with time, parts need to be tested, serviced and replaced.

The CNSC licenses nuclear power plant operators, who are required to regularly monitor the condition of the pressure tubes, which must meet operational fitness standards.

Some of the key areas to watch for in a pressure tube are subtle changes in shape, general flaws, and resistance to cracks. This is monitored through periodic testing.

Engineers deliberately designed CANDU pressure tubes to withstand this operational wear and tear.

Through extensive research and predictive modelling, licensees must understand the pressure tube’s ability to withstand any deterioration, and provide the CNSC with periodic inspection plans. Licensees must perform inspections and demonstrate that each pressure tube is able to continue to safely operate into the future.

CNSC staff review and evaluate the data provided by the licensee to confirm that the pressure tubes meet operational standards.

The CNSC, Canada’s nuclear regulator, ensures comprehensive and rigorous oversight. We will only issue a licence when we are confident that a nuclear power plant is and will remain safe to operate.

How the CNSC Regulates

This video explains how the CNSC regulates Canada’s nuclear industry.

How the CNSC regulates - Transcript

The Canadian Nuclear Safety Commission
or the CNSC, regulates the nuclear sector
to protect the public, workers, and the environment.
So... how does it do this?
First, the CNSC sets requirements
for all nuclear activities. Legislation,
regulations, regulatory documents, and licences,
outline the rules for activities
like uranium mining, power generation,
nuclear medicine, and industrial applications.
And whether requirements are being developed
or reviewed, consulting with Aboriginal groups,
industry and the public is an important
part of the process.
Anyone wanting to undertake activities
in the nuclear sector, needs to apply
for a licence from the CNSC.
When the CNSC receives an application,
its engineers, geologists, radiation protection specialists,
and other experts assess it carefully.
Information on design, safety, health,
and environmental impacts is considered
when reviewing the licence application.
For large nuclear facilities like uranim mines
or nuclear power plants,
a public hearing is usually held.
An independent commission hears
from the licence applicant and people
who support, oppose,
or have questions about the project or who have
information that will help in the review.
The commission considers all information
presented at the hearing before making a decision,
which includes licence conditions
and an expiry date.
For smaller facilities, like cancer clinics,
and for certain activities
like the transportation of nuclear substances,
CNSC staff are authorized to make licensing decisions.
The CNSC certifies people who occupy key positions
such as control room operators
at nuclear power plants or those who work
with highly radioactive sources.
It also certifies the design of radiation devices
used to treat cancer, sterilize medical equipment,
and measure soil density,
as well as the design of packages
for transporting certain nuclear substances
such as bulk shipments of medical isotopes.
But the CNSC’s role doesn’t stop there.
Once a licence is granted,
the CNSC verifies that activities are conducted safely
and that licensing conditions are met.
Each year, it carries out
scheduled and unplanned inspections
for more than 2,500 licences.
If licence conditions are not being met,
the CNSC takes immediate action.
It can issue orders or monetary penalties,
and suspend or revoke a licence.
The CNSC also ensures public safety
through its own environmental monitoring
of water, soil, and produce surrounding nuclear facilities.
Transparency and openness are important to the CNSC.
For instance, every year, inspection results
are published and discussed
at Commission meetings
where the public can get involved,
comment, and ask questions.
It also discloses incidents on its website
to keep the public informed and publishes
extensive reports on Canada’s international
commitments to nuclear safety and waste management.
And this is how the CNSC upholds its mandate
to protect the health, safety, and security
of Canadians and the environment.
For more information, visit the CNSC website.

Positive Void Coefficient of Reactivity and CANDUs

The void coefficient of reactivity ─ not exactly your dinner table discussion topic, and chances are you’ve never heard of it. What’s important to know is that it is a well-known characteristic that is understood by the Canadian Nuclear Safety Commission. A CNSC expert explains.


Positive void reactivity, very simply, is that if...

In the unlikely event of a loss of coolant accident,

or a big pipe break if you like, and that there is gas introduced

or water removed from the pipes, in a CANDU design,

the power will increase.

In other designs, the power will decrease.

However, this is a very known feature,

it's been known from the very beginning-and there's

engineering controls for that.

In particular, the CANDU system has two very,

very fast independent shut-down systems which will shut down the

reactor within two seconds and completely eliminate

any of those-- that problem, if you like.

So we are very confident that it's a controlled item.

Should it not function as designed,

there still would not be a serious consequence,

in the sense of public danger, because the reactor geometry

is very, very precise for this phenomena to occur.

So as soon as any kind of damage starts happening

to the reactor itself, the reactor will shut itself

down even without the control systems.

So, that aspect, if you like, as I mentioned,

is very well understood,

you have lots of engineering controls around it,

and we do not see that as a safety concern.

The CNSC’s Hearing Process

Want to know more about the CNSC’s hearing process? This video explains how Commission hearing’s work, how members of the public can get involved and more.


Hi, my name is Aurèle

and I work at the Canadian Nuclear Safety Commission

or the CNSC for short.

If a company wants to build, change,

operate or decommission a nuclear facility in Canada,

it must Officially submit a licence application to the CNSC.

Applications are then reviewed by CNSC staff

who make recommendations to the Commission -

an independent tribunal that makes informed, transparent

decisions on the licensing of major nuclear facilities

and nuclear-related activities.

Many factors, such as the project's safety and design

as well as any potential environmental or health impacts,

are taken into consideration.

For major nuclear facilities, a public hearing is usually held.

When you imagine a hearing, think of a court-like setting

with evidence being presented and questions being asked.

To inform the public that a hearing will take place,

the CNSC posts a Notice about it on its website.

The notice contains details about the hearing

and information on how the public can participate.

The CNSC also places ads in local newspapers

to inform the public of the upcoming hearing.

To participate, you can fill out an online form,

send us an email or contact us by phone.

Submit your comments in writing by the advertised deadline,

explaining how you are affected by the activity or project

and what information or expertise you have

that will help the Commission in making its decision.

You may also have the possibility of making an oral

presentation during the hearing,

based on the key points of your written comments.

The information you submit is available to the public.

Public hearings are also webcast live as they happen,

and are later posted to our website.

Financial assistance may be available for intervenors

through the CNSC's Participant Funding Program.

Once the public hearing has adjourned,

the Commission reviews all information presented to it

before making a decision whether to issue or amend a license.

If the Commission grants a license,

CNSC staff conducts inspections, audits

and uses other tools to make sure all conditions

contained in the license are met.

For more information,

please visit us online.

Participant Funding Program

Interested in finding out more about the CNSC’s Participant Funding Program (PFP)? The CNSC just launched a video that explains how we provide financial assistance through our PFP program to help get the public involved in our regulatory activities. Find out how the PFP works, who can apply, what are eligible expenses, and more.


Hi my name is Adam

and I work at the Canadian Nuclear Safety Commission

or CNSC for short.

Today, I want to talk to you about how the CNSC provides

financial assistance through its Participant Funding Program

to get the public involved in its regulatory activities.

For major nuclear facilities and projects,

our regulatory decision-making process often includes a hearing

with presentations by the public and the nuclear industry.

Through the hearing process,

the Commission seeks valuable information to help it gain

a better understanding of the potential impacts of the

nuclear facility or activity being proposed.

It's important that we hear from individuals,

Aboriginal groups and not-for profit organizations that have

information or expertise

to help the Commission make its decision.

We recognize that participating in a hearing or other regulatory

process, such as an environmental assessment,

takes time, effort and sometimes money.

To encourage the public's involvement,

we offer financial assistance through our

Participant Funding Program.

Eligible expenses include professional fees,

travel and administrative costs.

To apply, complete the application form on our website.

When a funding opportunity becomes available.

Be sure to describe your interest in the project,

how much funding you are requesting and how this funding

will help you participate and bring valuable information

to the Commission.

An independent committee reviews all applications and makes

funding recommendations to CNSC management.

If you are awarded funding, you will need to sign an agreement.

Be aware that only expenses incurred after signing the

contribution agreement will be paid,

so get your application in as soon as a funding opportunity

is advertised.

For more information and to receive e-mail notifications

regarding CNSC activities and funding opportunities

please visit us online.

Nuclear in your neighbourhood

Discover how the CNSC makes sure that nuclear activities, and the facilities where they take place, are safe for Canadians and the environment.


Hi, I’m Adam.

What do you think of when I say "nuclear" or "radiation"?

Not these?

What if I told you that radiation is all around us?

Don’t believe me?

Well, let’s have a look around.

Have you ever heard of cosmic radiation?

It comes from the sun and from space but the Earth’s

atmosphere provides us with a lot of protection

from cosmic radiation.

It makes up about one-fifth of the naturally occurring

radiation we are all exposed to everyday on Earth.

Of course, the higher up you go, the less protection

from the atmosphere there is.

That’s why your exposure to natural radiation

increases when you work in space, take a flight,

or even go mountain climbing.

But don’t worry, the extra radiation exposure

you’d get from taking a cross-Canada flight is only

a tiny fraction of the total radiation dose you can be

safely exposed to in one year.

The Earth itself is also naturally radioactive.

Radioactive elements like carbon and hydrogen occur in

plants, water, and air.

Rocks and soil also contain small amounts of uranium.

Sixty percent of all the radiation you are

exposed to comes from naturally occurring sources

like the sun and the Earth.

So, where, then, does the other forty percent come from?

From man-made nuclear activities.

And that’s where we come in.

I work at the Canadian Nuclear Safety Commission,

or CNSC for short.

We regulate the use of all nuclear substances in Canada,

whether they’re being used to power a reactor, to detect

cracks in a jet engine, or to detect and treat cancer,

just to name a few.

Most of the exposure you’ll receive from man-made nuclear

activities will actually come from medical procedures.

Nuclear medicine is used to diagnose and

treat many different illnesses.

Cancer clinics use nuclear substances or machines like

linear accelerators to treat cancers by targeting the cancer

cells with high-energy beams.

They can also use tiny radioactive implants to

kill the cancer cells.

The CNSC inspects hospitals and clinics to make sure that the

nuclear substances and equipment are being used safely.

We also make sure the nuclear substances

are disposed of properly.

The CNSC also licenses many other uses

for nuclear substances.

They can be found in just about every neighbourhood.

Let’s start with your home.

Say you were going through your daily morning routine,

and you burn your toast, what would happen?

[smoke detector beeping]

This right?

This smoke detector would go off.

Most household smoke detectors contain a radioactive material

called Americium-241 to detect smoke in the air.

They are safe and do not pose any health

risk to you or your family.

The CNSC licenses the Canadian companies that design

and produce smoke detectors.

Did you know that your computer, your alarm clock

and all other electric appliances in your home

could be powered by nuclear technology?

Fifteen percent of Canada’s electricity is generated

by nuclear power plants.

Which brings us here...

There are a total of nineteen nuclear reactors in Canada.

The CNSC licenses these facilities to ensure

that they operate safely.

One of their license conditions is to regularly test the ground

and surface water around the facility to make sure people

and the environment are safe.

Now let’s move on to your school.

Wondering where you can find the nuclear material?

It’s right here... in the exit sign.

Tritium, a radioactive form of hydrogen, is sealed inside

glass tubes that are treated with phosphor.

The tritium makes the phosphor glow, even during a power outage

as it doesn’t need electricity or batteries to work.

Supermarkets, hospitals, and many other public

places use tritium exit signs.

And yes, as you probably guessed, we regulate

facilities that process tritium.

So what does your supermarket have to do

with nuclear technology?

In Canada, a number of foods such as onions,

potatoes, wheat, flour, spices and some seasonings

are approved for irradiation.

Irradiation is the process of exposing food to ionizing

radiation in order to kill microorganisms.

This is done to prevent food poisoning from harmful bacteria,

like E. coli and salmonella, and to keep food fresh longer.

And no, irradiating food does not make the food radioactive.

Now we all know that summer in Canada is construction season.

Portable gauges are radiation devices often

used on constructions sites.

They can measure road thickness and detect moisture

in soil without having to dig.

The CNSC licenses all handheld radiation devices and ensures

that anyone using them has been properly trained.

Now for the really cool stuff - space exploration also relies

on nuclear technology to study and explore our

solar system, including Earth, the Moon and Mars.

Although the United States led the charge in the

latest Mars space missions, Canada contributed in small

but significant ways.

In one of the missions to Mars, Canadians contributed the Alpha

Particle X-Ray Spectrometer, or APXS for short.

It’s a sensor that uses alpha particles and

X-rays to determine the chemical composition

of the rocks on Mars.

So as you can see, radiation and nuclear technology

are all around us...

near and far.

The CNSC ensures that all nuclear facilities, activities

and man-made substances are safe in Canada and that you and I,

and the environment are protected.

Nuclear power plant refurbishment

This video presents an overview of CNSC’s role in regulating the refurbishment of nuclear power plants in Canada.


Hi! My name is Jeff Stevenson and I work as an inspector with the Canadian Nuclear Safety Commission.

In Canada we have several nuclear power plants located in Ontario and New Brunswick.

After about 30 years of operation, refurbishment can extend the life of a nuclear reactor for another 25 to 30 years.

We ask that the operator consider all possible safety improvements, including new technologies.

Think of refurbishment like rebuilding a car or renovating your entire house, but on a much larger scale.

During the refurbishment of a nuclear reactor, some typical components that are replaced include feeder pipes and pressure tubes.

Other components like turbines and fuel handling equipment can be restored and reused.

As Canada's nuclear regulator, we at the Canadian Nuclear Safety Commission, oversee all aspects of refurbishment projects: from the initial planning to when the reactor starts producing electricity again – to make sure that it is all done safely.

One thing I should specify is that if an important safety improvement is identified before a refurbishment is planned, we'll ask the operator to do it as soon as possible or to implement acceptable mitigation measures.

As part of the licensing process, we require that several technical assessments be performed before giving the green light to a project like this.

Two key technical assessments are the integrated safety review and the environmental assessment.

In a nutshell, the integrated safety review identifies possible improvements to safety systems.

This is a rigorous and systematic process that looks at the reactor's current state and compares it against modern standards to identify what needs to be improved.

The environmental assessment looks at the possible environmental impacts of both the refurbishment work itself and of the facility's long term operation for several more decades.

The environmental assessment is very comprehensive.

It includes studying potential impacts on water, animals, plants, air quality and the public.

Before the CNSC will allow a refurbishment to proceed, the plant operator must show through this thorough environmental assessment that the environment, and ultimately the public, is protected.

During refurbishment, the CNSC verifies that the changes and safety improvements made to the reactor are completed according to plan.

Once all refurbishment activities are finished and our inspections are completed, we closely monitor the return to service of the reactors.

Some of the main steps that require our approval before the plant can be restarted to produce electricity again include; loading fresh fuel in the reactor core, restarting the reactor and increasing power level above 30 or 50 percent, depending on the design of the reactor.

Through each of these steps, we ensure that all required testing has been done properly.

At the CNSC, we have extensive experience in regulating refurbishment projects.

Five reactors have been refurbished in Canada, so far.

We are also committed to continuous improvement.

We exchange information with international organizations such as the International Atomic Energy Agency, to learn from others experiences.

We also work with other national nuclear regulators to identify best practices and bring them back here in Canada

to enhance the safety of our own facilities.

Radiation and Health

The CNSC continues to explain radiation in simpler terms. The Radiation and Health video takes you beyond the tiny world of the atom to explore sources of radiation, the concept of dose, and how radiation affects the body and health.

Industrial uses of nuclear technologies

The CNSC has developed a new educational video explaining how nuclear technology is used safely in industrial applications. The video is part of the suite of CNSC educational resources designed for Canadian students.

Post-Fukushima Improvements to Nuclear Power Plants

Ask an Expert video series — This video explains some of the improvements made to nuclear power plants in Canada in response to the lessons learned from the Fukushima accident.

Impact of Fukushima on Canada’s Nuclear Regulation

Ask an Expert video series — This video explains some of the enhancements made to Canada’s nuclear regulatory framework in order to integrate the lessons learned from the Fukushima accident.

Medical uses of nuclear technologies

The CNSC has developed a new educational video explaining how nuclear technology is used safely in medical applications. The video is part of the suite of CNSC educational resources designed for Canadian students.

What is Radiation?

The CNSC has produced a new video designed to demystify radiation – we answer the question What Is Radiation? The video features CNSC experts explaining the basics of radiation in simple terms – what it is, the different types, radioisotopes, and radioactive decay.


Title: What is Radiation?

(The CNSC logo forms directly on the screen. After a moment, the title card fades in below the logo, followed by text on screen beneath it.)

Text on screen: What is radiation?

Text on screen: Understanding radiation with the Canadian Nuclear Safety Commission

What do smoke detectors, emergency lights and nuclear power all have in common? Radiation! But what exactly is radiation?

(The SFX and text-on-screen both fade out. Our host, Julie Burtt fades in, above her graphics of a smoke detector, exit sign and nuclear power appear one at a time. The camera slowly zooms from a long shot to a medium long shot. Throughout the entire video, Julie addresses the camera directly.)

Thanks to high-school science class, most of us have heard about radiation. But many of us may not know exactly what it is.

(Graphics disappear, and cut to a medium long shot of Julie.)

I’m Julie, and I work for the Canadian Nuclear Safety Commission.

(Cut to a medium close up of Julie, a vertical line appears in the centre of the screen beneath Julie, then simultaneously expands outwards to both the left and right, like an atom splitting, to spell out her name and title.)

Text on screen: Julie Burtt
Radiation and Health Sciences Officer
Canadian Nuclear Safety Commission

Simply put, radiation is the release of energy in the form of moving waves or streams of particles. This energy can be low-level, like microwaves and cell phones; or high-level, like X-rays or cosmic rays from outer space. These are known as non-ionizing and ionizing radiation.

(Julie’s name/title super disappears. Cut to a medium long shot as Julie gives examples of non-ionizing and ionizing radiation applications, visuals illustrating each of the examples she gives "appear" on the screen above her: a microwave, cell phone, x-rays, and cosmic rays. As well, the words "non-ionizing" and "ionizing" appear to the left and right of her as text-on-screen).

Text on screen: non-ionizing

But if we really want to understand radiation, we need to go inside the tiny world of the atom.

(Cut to a medium close-up, Julie glances at an animated atom spinning above her hand. Julie playfully "tosses" the atom towards the camera.)

Remember that high-school science class? Atoms are the microscopic building blocks of all matter in the universe.

(As the atom "hits" the camera, filling the frame, we cut to a full animation of an atom, with animated electrons spinning around it.)

Everything around us is made up of atoms, from the largest galaxies to our own bodies.

(Shot of galaxies, which fades to an image of sunlit silhouettes.)

The centre of the atom is called the "nucleus." That’s where the word "nuclear" comes from – there is a tremendous amount of energy inside!

(Cut to a medium close-up of Julie pulls one super from the left that says, "nucleus" and another from the right of the screen that says, "nuclear".)

Text on screen: Nucleus

The nucleus of an atom is made up of two particles: protons, which carry a positive charge, and neutrons, which have no charge.

(Animation of an atom, text on screen highlights where the neutrons and protons are. The neutrons are illustrated as blue balls that have a negative sign on them, and the protons are seen as red balls with a positive sign.)

Text on screen: Nucleus

Outside the nucleus are electrons, which carry a negative charge. The attraction of these negative electrons to the positive nucleus is what keeps the atom together.

(Animation of electrons spinning around an atom on the left side of the frame, with text appearing on the right side of the frame that says, "electrons are negatively charged".)

Text on screen: Electrons are negatively charged

Now, every element in the periodic table has a specific number of protons and neutrons.

(Fade to an image of the periodic table.)

But sometimes an atom will have too many or too few neutrons.

(Cut to animation of one atom containing protons & neutrons, which then transitions to 3 atoms.)

Text on screen: 8 protons 8 protons 8 protons
6 neutrons 8 neutrons 9 neutrons

When this happens, it becomes unstable, or "radioactive."

(Cut to a medium close-up of Julie, who then pulls down a "radioactive" super.)

Text on screen: radioactive

An unstable atom is called a radioisotope. For example, two extra neutrons in a hydrogen atom creates the radioisotope tritium.

(Cut back to animation of 3 atoms containing protons & neutrons. Then cut to animation of atom with two extra neutrons demonstrating that radioisotope of hydrogen is tritium.)

Text on screen: Radioisotope of Hydrogen

That’s the stuff that helps make exit lights glow in the dark!

(Cut to a medium close-up of Julie in left side of frame. Exit sign appears to her right, then disappears on screen.)

Radioactive atoms want to become stable again. So they release energy until they get back to a balanced state. This process is known as "radioactive decay" and there are three main types:

(Cut to a long shot of Julie, and then to a medium close up of Julie as she pulls up a super that says, "radioactive decay".)

Text on screen: radioactive decay

Alpha, beta and gamma. Alpha particles are heavy and travel small distances; beta particles are lighter and travel further, and gamma radiation is actually a wave and it travels the farthest of all.

(Cut to animation of alpha, beta and gamma particle. A short line appears below the alpha particle, a longer line appears the beta particle, and a long wavy line appears below the gamma ray.)

Text on screen: Alpha

The time it takes for half of the radioactive atoms of a radioisotope to decay is called a "half-life". Half-lives can range from a fraction of a second, to billions of years.

(Cut to a medium close up of Julie as she pulls up a super from the right with the words, "half-life".)

Text on screen: half-life

Let me give you an example of how half-lives come into play in nuclear medicine.

(Cut to a medium long shot of Julie.)

Doctors inject patients with the radioisotope Technetium-99m which emits gamma radiation. A gamma camera can then take pictures of the patient’s insides to help with the diagnosis. The relatively short half-life of 6 hours for this radioisotope makes it ideal for these types of tests.

(Cut to visuals that illustrate Doctor injecting patient, and then to a shot of a Doctor using a gamma camera on a patient, and then back to a medium close-up of Julie addressing the camera.)

Let’s pretend these jellybeans are the nuclei of Tc-99m. After one half-life, half the atoms still in the body remain unstable, or "radioactive".

(Cut to a medium shot of Julie standing in front of a table covered in jellybeans. A long, old-fashioned ruler is in Julie’s hands. Julie places the ruler down on the table in the middle of the pile of jellybeans, and wipes half the jellybeans off the table.)

After two half-lives, one quarter of the atoms remain radioactive.

(Cut to a medium close-up of Julie as she speaks, and then to a medium shot as Julie places the ruler down again and wipes half the remaining jellybeans off the table.)

After three half-lives… well, you get the idea.

(From a medium shot, Julie continues to wipe off the remaining jellybeans in fast motion, until there is one left.)

After 24 hours, almost all the radioactivity is gone, thanks to radioactive decay and the body’s natural… shall we say…"processing."

(Cut to close-up of Julie’s hand holding remaining jelly bean, and then cut to medium close-up of Julie speaking directly to the camera. Julie pops the jelly bean in her mouth. SFX of a toilet flushing, Julie reacts, amused then smiles back at the camera.)

And that ends our science class on radiation. Congratulations – you passed!

(Cut back to a medium long shot of Julie facing camera.)

Now for the bonus question: can you tell me who keeps an eye on the nuclear sector in Canada? That would be us, the Canadian Nuclear Safety Commission!

(Cut to a medium close-up of Julie who reaches up out of frame and "pulls down" a super with the CNSC logo and title.)

We regulate the use of nuclear substances and materials, and ensure that all nuclear materials are used for peaceful purposes. We also work to protect your health and safety, as well as that of the environment.

(Cut to montage of images of the CNSC at work and those it helps, shots of work environments that use nuclear substances, and shots of a woman working in the environment with technical equipment.)

The Canadian Nuclear Safety Commission: the answers you need, from a source you can trust! Visit us at, on Youtube or Facebook.

(Cut back to a medium long shot of Julie, and then to a medium close-up of Julie as she reaches down out of frame and "pulls up" a super with the CNSC url. Fade out Julie and CROSSFADE IN full-screen of the CNSC name, logo, url, Canada Wordmark, Youtube/Facebook icons.)

Text on screen: We will never compromise safety.

Nuclear in Canada

The CNSC has created a new educational video explaining how nuclear energy and materials are used safely in Canada, and the role of the CNSC as regulator. The video is part of the suite of CNSC educational resources designed for Canadian students.


Title: Nuclear in Canada

(Introduction with music, the CNSC logo appears with the phrase "Canada’s Nuclear Regulator" and the video title "Nuclear in Canada". Cut to a CNSC employee who appears on screen)

In Canada, the regulation of nuclear energy and materials is done by the Canadian Nuclear Safety Commission.

We work to protect your health and safety as well as the environment....And we also ensure that nuclear substances are used peacefully.

Nuclear technology plays a big role in the lives of Canadians.

Did you know that power reactors provide millions of homes with electricity every year?

But let’s back up and see the whole picture.

Nuclear power comes from uranium. And to get it, you need to dig.

Uranium is taken from the mines and processed into fuel pellets.

Those pellets are used to power nuclear reactors and make electricity.

It takes 8 pellets, each no bigger than the tip of your finger, to power your home for an entire year.

You might think nuclear is limited to energy and reactors, but there’s more to it.

Nuclear substances are used in medicine to diagnose and treat diseases, saving millions of lives.

They help people with illnesses like cancer and thyroid problems.

The industrial sector also depends on nuclear technology.

For example, this technology is used by oil and gas companies when checking for damaged pipes.

Once the nuclear materials are used up, the goal is to reduce, reuse or recycle them.

When the three R’s aren’t possible, nuclear materials go into safe storage.

So, who keeps an eye on the nuclear sector?

That’s where the Canadian Nuclear Safety Commission comes in.

We ask the tough questions to ensure the safety of Canadians, and protect the environment.

(Cut to three questions that appear on screen: Will employees be protected at work? Would water sources be polluted? Will the health of Canadians be at risk?)

We license, monitor and inspect all nuclear activities and facilities. It’s our job to make sure the rules are followed and that everything runs safely.

To find out more, visit

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