Nuclear waste consists of unwanted cast-off radioactive materials, all of them potentially harmful..
Radioactive materials are substances containing a considerable quantitiy of unstable atoms.
Unstable atoms are atoms that sooner or later undergo a sudden violent disintegration.
Disintegratins atoms give off damaging subatomic projectiles referred to as “atomic radiation”.
Atomic radiation is hazardous to living cells, often causing cancers and damaging eggs & sperm.
Atomic radiation cannot be shut off by any method known to science, so it is a perpetual problem.
Accordingly, nuclear waste must be kept out of the environment of living things as far as possible.
When released, radioactive materials can contaminate air, food, soil, property and living things.
Radioactive exposures to living organisms are measured in “sieverts” (Sv) and “millisieverts” (mSv).
One sievert of exposure causes radiation sickness; a millisievert is one one-thousandth of a sievert.
Prompt radiation effects can only be observed if the exposure is large, over a short period of time.
Low dose exposure can cause delayed effects such as cancer, seen many years after the exposure.
Damage to eggs and sperm can result in genetic illnesses in children and in later descendents.
Each radioactive element has a half-life – the time required for half of its atoms to disintegrate.
If its half-life is a year or less, a radioactive element will disappear in a matter of decades.
If its half-life is many 1000s of years, a radioactive element can be dangerous for a million years.
Each radioactive element has its own pathways through the environment and the human body.
Some radioactive elements lodge in the body, causing internal irradiation of bodily organs.
Radiation damaged tissue that becomes cancerous must be surgically removed or destroyed.
Uranium is a naturally-occurring radioactive heavy metal with a half-life of 4.5 billion years.
Through a chain of atomic disintegrations, uranium creates two dozen radioactive byproducts.
These byproducts, called “decay products” or “progeny”, are far more hazardous than uranium.
Uranium progeny include extremely dangerous elements: radium, radon, polonium, & others.
Radium, radon and polonium are among the most potent cancer-causing agents known to science.
The sand-like uranium “mill tailings” are radioactive wastes containing all the progeny of uranium.
Over 70 % of radioactive material in the uranium ore is left in the tailings.for thousands of years.
Uranium progeny are naturally-occurring poisons but mining has made them much more available.
Canada has accumulated over 220 million tonnes of uranium tailings, stored on the surface.
Uranium is used as a fuel for nuclear reactors, in which uranium atoms are fissioned or “split”.
Hundreds of new radioactive elements are created as the broken pieces of uranium atoms.
These “fission products” are millions of times more radioactive than uranium and its progeny.
A single used nuclear fuel element, newly produced, can give a fatal dose of radiation in seconds.
Fission products are so radioactive that they generate heat for centuries after they are produced.
A nuclear reactor accident is an event that allows these fission products to escape outside the plant.
Some fission products concentrate in specific organs: iodine in the thyroid, strontium in the bones
A few of the fission products have half-lives measured n the thousands or even millions of years
Countries with nuclear reactors have no way to destroy fission products or render them harmless.
They plan to bury the used nuclear fuel in a “safe” underground repository for millions of years.
No mone can be sure that nature won’t find a way to bring the fission products back to the surface.