ARCHIVED - Pre-history

About 5 billion years ago, the temperature and pressure at the centre of our sun became sufficient to induce nuclear fission. Soon after the formation of the planets about 4.8 billion years ago, Earth melts due to radioactive heating, gravitational collapse and heavy meteorite bombardment. The dense particles sink and the densest of them, including uranium, thorium and any remaining plutonium, collect at the very centre of Earth.

More than 1.5 billion years ago, a nuclear fission reaction takes place in an underground uranium deposit in Oklo, Gabon, Africa. The fission reaction continues - off and on - for hundreds of thousands of years. Eventually, the reaction stops.

Scottish physicist Charles Thomson Rees Wilson invents the cloud chamber, also known as the Wilson Chamber, for viewing vapour trails left by ionizing radiation. The Nobel Prize in Physics 1927 would be divided equally between Arthur Holly Compton for his discovery of the effect named after him and Charles Thomson Rees Wilson for his method of making the paths of electrically charged particles visible by condensation of vapour.

Wilhelm Conrad Röntgen conducts the first "röntgenogram" procedure, which leads to the development of X-ray technology. (Source: Nobel Foundation)

Antoine Henri Becquerel discovers radioactivity of uranium, when wrapped photographic plates become exposed by an unknown ray emanating from uranium salts. He believes the salts had given off a type of X-ray due to exposure to sunlight, but later disc

At his summer home in Baddeck, Nova Scotia, Alexander Graham Bell makes many experiments with X-rays which are recorded in his journals. He experiments with the telephone transmission of X-ray signals; while this may not have been the birth of teleradiology, it was arguably the conception. Bell would also later be the first person to suggest the use of radium to treat cancer.

Wilhelm Conrad Röntgen wins the first Nobel Prize in Physics for earlier work in recognition of his discovery of the rays subsequently named after him. (Source: Nobel Foundation)

The 1903 Nobel Prize is divided, one half awarded to Antoine Henri Becquerel “in recognition of the extraordinary services he has rendered by his discovery of spontaneous radioactivity", the other half jointly to Pierre Curie and Marie Curie (née Sklodowska) “in recognition of the extraordinary services they have rendered by their joint researches on the radiation phenomena discovered by Professor Henri Becquerel".

At McGill University, Sir Ernest Rutherford demonstrates that alpha particles are helium atoms and determines their decay series. He coins the term "half-life" and prophetically states, in his book Radio-Activity : "There is reason to believe that an enormous store of latent energy is resident in the atoms of radioactive elements… If it were ever possible to control at will the rate of disintegration of the radioelements, an enormous amount of energy could be obtained from a small quantity of matter."

Explore 90 years of remarkable research at and memorable contributions by Canada's national science organization. (Source: National Research Council Canada)

The Radium Girls are a group of female factory workers who contract radiation poisoning from painting watch dials with glow-in-the-dark paint at the United States Radium factory in Orange, New Jersey around 1917. The women, who had been told the paint was harmless, ingest deadly amounts of radium by licking their paintbrushes to sharpen them; some also paint their fingernails with the glowing substance. Five of the women challenge their employer in a court case that consequently establishes the right of individual workers who contract occupational diseases to sue their employers.

The Nobel Prize in Chemistry 1921 is awarded to Frederick Soddy for his contributions to our knowledge of the chemistry of radioactive substances and for his investigations into the origin and nature of isotopes. (Source: Nobel Foundation)

The International Commission on Radiological Protection (ICRP) is established as an independent advisory body located in Ottawa, to advance the science of radiological protection by providing recommendations and guidance on all aspects of protection against ionizing radiation. (Source: International Commission on Radiological Protection)

Canada's first uranium- and radium-bearing ores are discovered at Port Radium on the shores of Great Bear Lake, Northwest Territories. The mine begins operating in 1932-1933. (Source: Prince of Wales Northern Heritage Centre, Yellowknife, Northwest Territories (PWNHC))

Eldorado Gold Mines Ltd. sets up a radium refinery in Port Hope, Ontario (about 100 kilometres east of Toronto) to extract radium from ore concentrate. Until 1944, processing residues are stored 300-400 metres west of the plant site in the Lakeshore Disposal Area. (Source: Port Hope Area Initiative)

Eldorado Gold Mines Ltd. begins mining radium in Port Radium, Northwest Territories. The mine operates until 1940. (Source: Eldorado , Robert Bothwell, pp.4, 75-76)

In Ottawa, George Laurence is one of the first people in the world to demonstrate a nuclear chain reaction.

Eldorado's Port Radium mine in the Northwest Territories is reopened as a uranium producer to meet increasing demand from the UK and the U.S. It operates until 1960. (Source: Eldorado , Robert Bothwell, pp. 101-104, 429)

In 1966, AECB President G. C. Laurence described the origins of the Montreal Lab: “Early in 1942 the British decided that their research effort on atomic energy would be more effective if it were moved to the United States where the supply of equipment and materials was easier and where they could collaborate closely in the American programme. The Americans rejected this proposal. They felt that it was too great a security risk because the senior members of the group that would be sent from Britain were refugees from countries in Europe that were under Nazi domination. The British then suggested that their team be moved to Canada where they would be closer to the American effort. The Americans could scarcely refuse to accept this arrangement…. The Montreal Laboratory and the research and development that has since grown from it have brought Canada recognition as one of the pioneer nations in atomic energy, have given greater authority to Canadian opinion in international relations, and have opened greater opportunities for us in industry and commerce."

Canada, the U.S. and the UK institute a ban on private exploration and development of mines to extract radioactive materials. (Source: Eldorado , Robert Bothwell, pp.148-149, 246)

Consolidated Mining and Smelting Company, Ltd. (CM&S) produces Canada's first heavy water (D2O) in Trail, British Columbia. (Source: An Early History of Heavy Water , Chris Waltham)

The Government of Canada nationalizes Eldorado Gold Mines and establishes Eldorado Mining and Refining as a federal Crown Corporation with a monopoly on uranium prospecting and development. (Source: World Nuclear Organization)

Canada's nuclear age begins at a Combined Policy Committee meeting in Washington, DC, where representatives from Canada, the UK and the U.S. agree that Canada should build a heavy water reactor to produce plutonium from uranium. (Source: Department of Foreign Affairs and International Trade )

Chalk River, Ontario is selected as the site of the new Canadian nuclear laboratory and research complex. (Source: Legion Magazine )

Dr. Don Dewar, who eventually becomes Scientific Advisor to the AECB, is present as an observer at the Trinity Site, in New Mexico, where the first atomic device is exploded. (Source: Trinity Atomic Web Site)

The United States drops atomic bombs on Hiroshima and Nagasaki, Japan.

Canada's first experimental research reactor, ZEEP (a zero energy experimental pile), begins operating at the Chalk River Laboratories; it is used for physics research and to provide information for the start-up of the National Research Experimental (NRX) reactor. Canada also becomes the second country in the world to use a reactor to control nuclear fission. (Source: Canadian Nuclear Society)

U.S. President Harry Truman, British Prime Minister Clement Attlee and Canadian Prime Minister Mackenzie King board the USCGC Sequoia for discussions about the atomic bomb and atomic energy. (Source: Nuclear Age Peace Foundation)

The Controller of Radioactive Substances, established under the War Measures Regulations and acting pursuant to order-in-council PC 5225, orders that: the sale, purchase, delivery and acquisition of uranium require permits issued by the Controller; statements of amounts must be filed regularly; and all persons involved in the mining, refining, purchasing and selling of uranium are to report as the Controller requires.

Under Roy Errington, Eldorado starts a radium sales department. (Source: Eldorado , Robert Bothwell, p. 224)

The Honourable Clarence Decatur Howe, Minister responsible for nuclear matters, 1946-1956

The General Assembly of the United Nations creates the Atomic Energy Commission (UNAEC), whose task is to prepare proposals for promoting the peaceful use of nuclear energy and to develop safeguards against the proliferation of nuclear weapons. The Co

The Atomic Energy Control Act is passed in Canada. Under the Act, the Government of Canada establishes the Atomic Energy Control Board as a regulatory agency to provide for “control and supervision of the development, application and use of atomic energy and to enable Canada to participate effectively in measures of international control of atomic energy." (Source: A History of the Atomic Energy Control Board, Gordon H.E. Sims, pp. 22-25)