Ontario Power Generation
Nuclear Isotopes
Millions of Ontarians benefit from electricity generated by Ontario Power Generation. Few people are aware that the company also brings benefits to people in many countries around the world as a supplier of isotopes such as, heavy water, cobalt-60 and tritium. These stable and radioactive isotopes are key components in applications in medicine, food preservation, luminescent lighting, and fusion research.
Isotopes - What are they?
You'll recall from your high school chemistry studies that every atom of every element is made up of protons, neutrons and electrons. Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons in their nuclei, and therefore, different atomic weights.
If, by peering into an imaginary microscope, we could see a cluster of hydrogen atoms, we'd notice that almost all hydrogen atoms consist of an electron orbiting a proton.
Of every million hydrogen atoms, 150 have a nucleus that contains a neutron as well as a proton. This isotope of hydrogen is called deuterium.
Isotopes of a particular element have the same chemical properties because they have the same number of electrons. Deuterium bonds with oxygen to form heavy water (D2O). Heavy water, or deuterium oxide, is 10 per cent heavier than regular water because of an extra neutron. OPG uses heavy water to cool the fuel in CANDU and nuclear research/isotope reactors.
A third isotope of hydrogen is called tritium (T). Tritium is made in nuclear reactors and is radioactive.
Isotopes can be naturally occurring or produced, stable or unstable. Deuterium is a stable isotope. Unstable isotopes such as cobalt-60 and tritium undergo radioactive decay. During radioactive decay, energy is emitted and the element turns into a more stable form.
By harnessing the energy released by these isotopes, the medical and industrial worlds are able to provide essential services such as cancer treatment, sterilization and self-powered luminescent emergency lighting.
Radioactive Isotopes
Radioactive isotopes have too many or too few neutrons in their nucleus, which creates excess energy. Release of this excess energy is known as radiation, or radioactive decay, and persists until the radioactive isotope becomes non-radioactive. Tritium, for example, releases beta radiation until it becomes helium, which is stable and non-radioactive.
Improving Our Health with Cobalt-60
Cobalt-60 is one of the radioisotopes whose energy adds to the well being of millions of people. Ontario Power Generation supplies more than 80 per cent of the world's demand for this isotope. Cobalt-60 is produced in OPG's CANDU reactors by using adjuster rods that contain cobalt-59 inserts. Over time, some of the cobalt-59 inserts absorb a neutron and change at the atomic level to become cobalt-60. About every 24 months, the cobalt-60 adjuster rods are removed, processed and safely stored. Licensed end users include, scientists, technicians, and academic researchers - for irradiation technology applications.
Cobalt-60 emits gamma radiation, making it an ideal isotope for use in a variety of medical and industrial applications. One such application is sterilization with cobalt-60 irradiation - a Canadian technology used around the world to enhance the safety of perishable food, medical and consumer products. From syringes, gloves and surgical instruments to cotton balls and contact lens solution, cobalt-60 irradiation ensures the safety of hundred of products. Food irradiation using cobalt-60 is increasingly viewed as the safest and most effective way to eliminate harmful insects and bacteria from our food supply.
Lighting a New Way with Tritium
Tritium is a radioactive hydrogen isotope that has been a part of our environment for millions of years. It is also a by-product of the daily operations of a CANDU nuclear reactor. When the deuterium in heavy water captures an additional neutron from the immense number of particles passing among the fuel elements, it changes to become tritium. Ontario Power Generation makes tritium commercially available for use in the production of self-powered lights, tritium labeled chemicals for medical research, and research into future power sources.
Minute amounts of tritium combined with phosphor create luminescence. This energy efficient light source does not require electricity, and provides essential emergency lighting particularly for areas where electrical sparks can be dangerous and where minimal or no electrical wiring exists.
Heavy Water
Ontario Power Generation supplies the majority of the world's non-nuclear heavy water demand to chemical companies, research facilities and industrial laser manufacturers, among others.
Solvents created with heavy water are used in Nuclear Magnetic Resonance (NMR) analysis to help researchers determine the structure of complex organic chemicals. Through NMR analysis, we can further our understanding of life science. NMR techniques are used in pharmacology to screen potential drug candidates. In addition, heavy water is used in medical research to gain a better understanding of human metabolism.
Heavy water is electrolyzed to create deuterium gas which, like tritium, can be used for fusion research. Another emerging application for deuterium gas is the production of computer chips - in experimental settings, deuterium gas can extend the life of a computer chip to eight times that of a chip created with hydrogen gas.
Fusion - Power for the Future
Nuclear fusion has been hailed as the energy source of the future, the successor to coal, oil, and gas as underground reserves of these fuels are depleted. Today Ontario Power Generation is the principal supplier of tritium to fusion research projects around the world.
In fusion, the nuclei of lightweight atoms, such as hydrogen, fuse to make heavier atoms. That fusion gives off tremendous amounts of energy. It takes extremely high temperatures and pressure to force the nuclei to fuse.
