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The unseen wonders of nuclear power

Millions of Ontarians benefit from electricity generated at Ontario Power Generation’s nuclear stations.

But did you know 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?

Discover how these stable and radioactive isotopes are key components in applications in medicine, sterilization, food preservation, luminescent lighting and fusion research.

Breaking down isotopes

You may 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.

Isotopes can be naturally occurring or produced, stable or unstable. Deuterium, which bonds with oxygen to form heavy water, is a stable isotope. Heavy water is used to cool the fuel in CANDU and nuclear research reactors. 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.

Learn more about nuclear products below.


Keeping Ontarians healthy and safe.

Cobalt-60 is harvested at Pickering Nuclear Generating Station.

OPG solutions with Cobalt-60

About 40% of the world’s single-use medical devices, such as syringes, gloves, implants and surgical instruments, are irradiated and sterilized with Cobalt-60. The isotope emits gamma radiation, which makes it ideal to enhance the safety of medical products and perishable foods such as fruits, meats and spices.

Currently, Cobalt-60 is extracted from reactors at Pickering Nuclear and Bruce Power's Bruce B plant every 24 to 30 months. Plans are underway to expand Cobalt-60 production to Darlington Nuclear to ensure a steady supply as operations at Pickering wind down in 2024. Ontario’s CANDU reactors produce 50% of the world’s supply of the isotope.


Life-saving isotope soon to be harvested at Darlington.

Cobalt-60 produced at OPG's Pickering Nuclear Generating Station is used to sterilize medical equipment.

Nuclear next and new

OPG will soon expand the production of life-saving medical isotopes to its Darlington Nuclear station.

An innovative collaboration between OPG’s wholly-owned subsidiary, Laurentis Energy Partners, and BWX Technologies (BWXT) will see Molybdenum-99 harvested from reactors at Darlington.

Under this important supply agreement, the station will provide irradiation services to produce the isotope, which is used in over 30 million diagnostic and medical imaging treatments around the world each year, helping to detect illnesses like cancer and heart disease.

Darlington Nuclear will be the only source of Molybdenum-99 in North America, ensuring a stable domestic supply of this critical product.

Because of the unique design of Darlington’s CANDU reactors, medical isotopes can be removed while the reactor is still online, and without interrupting the station’s generation of clean energy. Once harvested, BWXT will utilize its newly designed, proprietary generators, called NeuCap1, to process the Molybdenum-99 into Technetium-99m, the final product that will be used in diagnostic imaging.