The number which appears after the name of a substance helps to indicate its place in the list of decay products. When the numbers go down by four, an alpha particle has been emitted. When the numbers stay the same, a beta particle has been emitted. Most of the time, but not always, there is a gamma ray emitted to accompany the alpha or beta emission.

Thus uranium-238 changes into thorium-230 (in three stages), which then changes into radium-226, and thence into radon-222. The numbers keep getting smaller because the atoms are losing a part of themselves.

. . . back to [ TABLE OF CONTENTS ]

B. URANIUM AND ITS USES

B.1. Where is uranium found?

Tiny amounts of uranium are found almost everywhere. However, concentrated deposits of uranium (called ores) are found in just a few places, usually in hard rock or sandstone. These deposits are normally covered over with earth and vegetation.

In Canada (see the map below) uranium mining has taken place in the Northwest Territories (Great Bear Lake and Rayrock), in northern Saskatchewan (Cluff Lake, Key Lake, Rabbit Lake, Wollaston Lake and Uranium City), in Ontario (Elliot Lake and Bancroft), and in a few other places.

Uranium has also been mined in the southwest United States, Australia, parts of Europe, the Soviet Union, Namibia, South Africa, Niger and elsewhere.

In the 1970s, uranium deposits were discovered in British Columbia, Nova Scotia, and Labrador, but due to citizen opposition, the uranium mining companies have not been allowed to mine the ores in these areas.

In the past fifteen years, Saskatchewan has become the uranium capital of the world. The richest uranium ores ever discovered have been found in Saskatchewn.

. . . back to [ TABLE OF CONTENTS ]

B.2. How did Canada get into the uranium business?

Before 1939, there was no significant use for uranium. German potters used it to make a reddish glaze, and it was studied by scientists for its radioactive properties. Then, during World War II, scientists realized that extremely powerful bombs could be made by "splitting" uranium atoms using nuclear fission, which is described in section C.

When the U.S. needed uranium to build the world's first atomic bombs, Canada paid to have a deserted, privately-owned radium mine in the Northwest Territories re-opened as a uranium mine. Canada secretly bought up shares in the company, Eldorado Mining and Refining, and turned it into a crown corporation: Eldorado Nuclear Ltd.

At the Eldorado refinery in Port Hope, Ontario, uranium from the NWT and the Congo was processed for the U.S. army who used it to produce the world's first atomic bombs. These bombs completely destroyed two Japanese cities at the end of the war in 1945.

. . . back to [ TABLE OF CONTENTS ]

B.3. How is uranium used in atomic bombs?

The explosive in the Hiroshima bomb was a rare kind of uranium, found in very low concentrations in every sample of uranium. The Nagasaki bomb was made from a different nuclear explosive material called plutonium. But plutonium -- the most commonly used nuclear explosive today -- has to be made from uranium. In fact, without uranium, none of the current nuclear weapons could have been built.

For twenty years after the first atomic explosions, Canada's uranium was sold to make many more atomic bombs as well as hydrogen bombs, which are even more powerful (but which still require uranium or plutonium as a "trigger"). In 1959, uranium was Canada's fourth most important export, after newsprint, lumber and wheat. At that time, it was all sold for military explosive purposes.

. . . back to [ TABLE OF CONTENTS ]

B.4. How is uranium used in nuclear reactors to produce electricity?

In the 1960s, the nuclear fission process began to be used to produce electricity in special machines called nuclear reactors. These machines use uranium as a kind of fuel to boil water. The steam that is produced spins a turbine to make electricity. There are now twenty nuclear power plants in Canada, and hundreds worldwide. Eighteen nuclear plants are operating in Ontario. There is also one in Québec and another in New Brunswick.

Since the Three Mile Island accident in 1979, and especially since the Chernobyl accident in 1986, almost no new nuclear reactors have been sold. However, in 1990 Ontario Hydro announced that it wants to build about a dozen more.

. . . back to [ TABLE OF CONTENTS ]

B.5. Are there other uses for nuclear reactors?

Nuclear reactors fuelled with uranium can be used to produce artificial radioactive substances called "radioisotopes" for use in industry, scientific research and medicine. Alternatively, many of these radioisotopes can be produced in special machines called accelerators, which do not require the use of uranium.

Nuclear reactors also serve to drive the propulsion units of nuclear submarines. In addition, special military reactors are used to produce most of the nuclear explosive materials used in nuclear weapons.

. . . back to [ TABLE OF CONTENTS ]

B.6. Are the peaceful and military uses of uranium incompatible?

Nuclear reactors fuelled with uranium automatically produce plutonium as a byproduct. If that plutonium is chemically separated from the rest of the radioactive garbage in the spent reactor fuel, it can be used as a nuclear explosive. So, the spread of nuclear power around the world gives more and more countries the option of producing nuclear weapons at some future time.

In 1974, India exploded a bomb that was made from plutonium produced in a reactor given to the Indian government as a gift by the Canadian government. It was not an electricity-producing reactor, but a smaller machine called a "research reactor".

Canada has also given or sold reactors to Taiwan, Pakistan, South Korea, Argentina and Romania. Several regimes in these client countries have displayed an interest in either developing nuclear weapons themselves, or in sharing their nuclear technology with other countries having such military ambitions (e.g. Iraq and Libya).

. . . back to [ TABLE OF CONTENTS ]

B.7. Has Canada ever produced plutonium for use in bombs?

During World War II, European scientists worked in a top-secret laboratory in Montreal, paid for by Canada, to find the most efficient method for producing plutonium for atomic bombs. This involved the use of a special material called "heavy water".

In 1944, a military decision was taken in Washington D.C. to build one or more "heavy water reactors" at Chalk River, Ontario, to test the Montreal laboratory's findings. When these Canadian reactors began operating after the war was over, they proved to be among the very best plutonium-producing reactors in the world. The reactor that was given to the Indian government was a copy of one of these.

To help defray the cost of its nuclear research program, the Canadian government sold plutonium produced in Chalk River reactors to the U.S. military for use in bombs for over twenty years. Plutonium from Chalk River was akso sent to the U.K. to assist the British in the development of their first atomic bombs. The British learned how to separate plutonium for military use by building and operating a plutonium separation plant at Chalk River, in cooperation with Canadian scientists. French scientists working at the Montreal laboratory likewise learned valuable lessons which assisted in the development of France's first nuclear weapons.

. . . back to [ TABLE OF CONTENTS ]

B.8. Does Canada still sell uranium and plutonium for bombs?

Since 1965, Canada has had a policy of selling uranium for peaceful purposes only -- that is, as fuel for nuclear reactors. Any country purchasing Canadian uranium or a Canadian nuclear reactor must promise not to use it or the byproduct plutonium for bombs. This policy is complemented by an international nuclear Non-Proliferation Treaty (NPT). However, as the Indian experience shows, the policy cannot be enforced; if a country chooses to make atomic bombs, Canada cannot prevent it.

. . . back to [ TABLE OF CONTENTS ]

B.9. Does Canadian uranium still find its way into nuclear bombs?

Over 85 percent of Canadian uranium is exported. In most cases, before being sent on to foreign customers, it first goes to a uranium enrichment plant. For every seven pounds of uranium that enters the enrichment plant, less than one pound ends up in the finished product: reactor fuel. The other six pounds of uranium are discarded as a waste material having no significant civilian use.

Some of this cast-off uranium, called "depleted uranium", was regularly used by the U.S. military in the construction of nuclear weapons. In fact, it was the raw material from which weapons-grade plutonium was created in special military reactors.

     containers of depleted uranium                      "target rods" made from depleted uranium
left over from uranium enrichment                    used to produce plutonium for bombs

photos by Robert Del Tredici

---

Depleted uranium is also used in the manufacture of metal components for the bomb itself, thereby more than doubling the explosive power of each warhead. The U.S. military makes no distinction between depleted uranium of Canadian origin and depleted uranium of any other origin.

When Canadian uranium was enriched in the Soviet Union, Canada did not allow the USSR to keep the depleted uranium within its borders because of its military potential.

B.10. Are there any other uses for uranium?

There are other uses for uranium, but they are less important. Some bullets are coated with uranium so that they can pierce through heavy armour. Some tanks are reinforced with uranium to make them stronger. Uranium is used as a weight in some airplanes and in the Cruise missiles tested in the Canadian north.