Frequently Asked Questions:
Q How does nuclear energy produce electricity?
A Atoms have 2 main parts, a dense nucleus at the centre surrounded by a number of outer electrons orbiting the nucleus much like the planets circle the sun. In a nuclear reactor, the nucleus of Uranium atoms is split into two or fissioned, and in the process a great deal of energy is released in the form of heat. This heat is used to boil water into steam; the steam is used to turn a turbine which in turn spins an electrical generator, producing electricity for the users.
Q What’s the advantage of using Uranium for fuel,
instead of Diesel fuel?
A Splitting a Uranium atom releases about 90 million times as much energy as burning an atom of Diesel or any other hydrocarbon fuel. This is why a nuclear reactor can run for years on a single load of fuel. Additionally, unlike diesel exhaust which emits CO2 and other noxious pollutants into the air, all of the waste products of nuclear fission are retained, in solid form, within the fuel pellets. Nuclear reactors produce zero emissions during operation.
Q What is Uranium anyhow?
A Uranium is a naturally occurring metal that is mined from the earth like any other metal. It is denser than lead and is about as common as Tin.
Q Where do we get Uranium fuel from?
A Canada is one of the largest Uranium producers in the world. The richest deposits have so far been found in northern Saskatchewan, but commercial grade deposits have also been found in Labrador, Nova Scotia, Quebec, Nunavut, Northwest Territories, Ontario, Alberta and British Columbia. Many other countries also mine Uranium.
The Uranium ore is crushed and milled and sent to fuel fabrication plants in Canada and around the world where it is manufactured into cylindrical fuel pellets about the size of a sugar cube. The pellets are then placed in a metal structure to form a fuel bundle, which is placed in the reactor.
Q Do we have enough Uranium?
Won’t we start running out just like oil?
A There is enough proven reserves of Uranium to fuel the world’s reactors for many decades to come and new discoveries are being made all the time.. Furthermore, after Uranium has been used in the reactor, it can be re-cycled into new fuel that is burned in a different type of nuclear reactor that can extract up to 99 times more energy out of the fuel. This fuel cycle will ensure that we will have enough nuclear fuel for many centuries to come.
Q What about radiation; aren't nuclear reactors radioactive?
A When the atoms of nuclear fuel are split, the resulting fragments (called fission products) typically have more internal energy in their nucleus than normal. This energy is released in the form of radiation and we call this process of spontaneous energy release, radioactive decay. The core of a nuclear reactor is very radioactive so a lot of radiation is produced there. For this reason nuclear reactors have many layers of protective radiation shielding materials incorporated into their design to protect workers and the public. Federal regulations require that nuclear power plants give off extremely low levels of radiation and in fact some public buildings are more radioactive than nuclear power plants simply because of the natural radioactivity in the building materials they are made of.
Q What are those huge curved towers at nuclear plants for?
A Those huge curved towers are actually cooling towers. Large quantities of water are used to cool the steam condenser in large commercial power plants, and in order to protect the environment this cooling water must itself be cooled prior to return to the river or lake where it came from. The huge towers create a natural draft that cools the water prior to its return to its source. Although these towers are often associated with nuclear power plants, they are more commonly used at coal fired power plants.
Q Can a nuclear plant explode like a nuclear bomb?
A Absolutely No. It is a physical impossibility for a nuclear power plant to explode like a nuclear bomb. The concentration and structure of the nuclear fuel in a reactor is quite different from bomb material and it simply will not sustain an explosive chain reaction.
Q What does it mean when a nuclear reactor goes critical?
A A reactor that is “critical” simply means that it is in a steady state of heat production. The energy that is released by the sustained chain reaction of atom splitting in the fuel is neither increasing nor decreasing. When the reactor is sub-critical, heat production is decreasing and when the reactor is super-critical, heat production is increasing.
Q Does a nuclear reactor emit air pollution or greenhouse gasses?
A No. A nuclear power plant produces virtually none of the emissions that cause smog, acid rain, black carbon or greenhouse gasses. All reaction products remain within the nuclear fuel. The Canadian Energy Research Institute has determined that nuclear energy, over its full life cycle, produces just 1.8 grams of CO2 per kilowatt hour (g/kWh), which is comparable with wind generated electricity. This compares with 670 g/kWh for diesel generation, 540 g/kWh for natural gas fired generation and 1,050 g/kWh for coal fired generation. (Source: Comparative Life-Cycle Assessment of Electricity Generation in Ontario, CERI 2008). According to The National Renewable Energy Laboratory http://www.nrel.gov/analysis/sustain_lca_nuclear.html
“nuclear power is similar to other renewables and much lower than fossil fuel in total life-cycle GHG emissions."
Q What about the nuclear waste?
A Before all the nuclear fuel is consumed, the build-up of fission products in the Uranium fuel pellets makes them inefficient at producing heat. At this point the fuel is said to be “spent”, and is removed from the reactor. Commonly, though inaccurately, referred to as nuclear waste the “waste” is actually only partially used fuel that still contains much of the nuclear energy. This spent fuel can be sent to a processing facility where it can be recycled back into fresh nuclear fuel. Recycling the spent fuel greatly reduces the volume of the waste. Some countries have begun to dispose of high level nuclear waste in deep geological repositories while other countries are presently storing the waste in shielded containers in a secure storage facility.
For a more in-depth discussion on subject visit the Nuclear Waste Management Organization
