What is Radiation?
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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 nuclearsafety.gc.ca, 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.
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.
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