IONISING RADIATION is just one type of radiation. In physics, radiation describes any process in which energy travels through a medium or through, space, ultimately to be absorbed by another body.
In discussing the nuclear industry, we are not talking about other forms of radiation, which are mainly non-ionising – e.g: acoustic radiation (sound, ultrasound, infrasound) non-ionising forms of electromagnetic radiation (i.e., radio waves.)
While there is debate about whether or not electrmagnetic radiation is harmful to life, there is conclusive proof that ionising radiation is harmful.
RADIOACTIVE ISOTOPES: How they spread from the nuclear industry
at left – the many stages of the nuclear cycle – at each stage, radiation is emitted. Transport of nuclear materials goes on between each stage.
What is IONISING RADIATION?
Uranium atoms are unstable, breaking up into other atoms – radioisotopes, and giving off energy in the form of gamma rays
The 3 types of radiation (alpha, beta and gamma) are different in the way that they can travel through substances . (Alpha rays do not penetrate the body, but can be breathed in, or swallowed, and remain in tge body.) The radioactive isotopes also last for different lengths of time (see table below left)
Radioactive isotopes vary in the time they take to break down.This length of time is measured in “half-lives” – counting the time it takes for an isotope to lose half of its radioactivity.
Some of the many toxic isotopes that are regularly released from nuclear reactors into water and air are Radioactive iodine 131, (half-life of 8 days), & Strontium 90 (half-life 28 days), Cesium 137 (half-life 30 years) is gradually released from ageing reactors.
Plutonium 239, created in nuclear reactors, is an alpha particle with a half-life of 24.400 years
What are “high level” and “low level” wastes?
Where exactly do these radioactive elements come from?
High-level waste consists mostly of milling tailings, spent nuclear reactor fuel from both commerical power plants and military facilities, as well as reprocessed materials .
Low-level waste includes the remainder of radioactive wastes and materials generated in power plants, such as contaminated reactor water, plus those wastes created in medical laboratories, hospitals, and industry. Such wastes come in many ways, including – ” protective clothing of people in contact with radioactive materials, old medical radiation equipment from hospitals and clinics.
All can emit radiation for hundreds of thousands of years. It spreads through the environment mainly through water. Buried wastes leak into groundwater.
The property called radioactivity means that the individual atom decays at a certain rate, emitting energy in the process, each decay, in the event results in the breakdown of the original atom into an atom of a different element and accompanied by the release of energy.Beginning with the change to Thorium 234 each atom of uranium is transformed in steps through 13 elements before becoming a stable element of lead
One element in this decay series of Uranium is a gas called Radon 222 . Being a gas, Radon can seep into the mine air from rock surfaces and cracks exposed by mine openings. Normal radio active decay of Radon then continues in the mine atmosphere.
The first four daughters of Radon are believed to pose the principle threat to the health of the miners because they result in a relatively record release of Alpha energy. When a mixture of Radon and its daughters is inhaled, most of the Radon atoms are exhaled before they have time to decay. But many Radon daughters are retained in the lungs where the decay and release alpha particles which can damage living tissues…
Slow intake of this Radon gas can cause cancer of the lungs, breast cancer, and Uranium can cause deformity in the human body besides causing Kidney cancer while Radium causes bone cancer. ….
The half life of Thorium which is a gamma emitter is 80,000 years, and that of Radium, an alpha emitter is 1600 years. So the present radioactive elements will go on increasing and one can just imagine what an epidemic it would be with all the waste from tailing ponds that will multiply for thousands of years ….
Cancer cases among Aboriginal people living near Australia’s biggest uranium mines is doubling, a study by the Federal Governments leading Indigenous Research body shows, according to the Sydney Morning Herald, of the 23rd November 2006. There have also been many Uranium Tailing disasters, in Australia, Canada and the United States, even though these countries are armed with the most “State of the Art” tailing dams. …………