Of course, if you live in Japan right you are. We sympathize deeply with the unimaginable losses that have occurred there from earth quakes, tsunamis and serious nuclear reactor damage.
Nuclear energy will be questioned for many years as a viable answer to energy needs.
Some say nuclear energy is necessary to minimise global warming. If you want to be in this debate you need to know more.
The nuclear debate is growing in importance as governments everywhere are looking for ways to maintain economic growth AND reduce the effects of global warming. But it now looks like the disadvantages are just too great.
Radiation is really nothing more than the emission of energy waves through space, as well as through physical objects. Usually these energy waves are electromagnetic radiation which are classified into
Gamma rays and
In 1896 a French scientist, Henri Becquerel found that his photographic plates had become fogged, even though they had been protected from light. What this meant was that another source with properties of light, some rays, had penetrated the plates’ covering. He concluded that this effect came from compounds that he was working with containing uranium. Materials with such properties are called radioactive and include also thorium and potassium.
The three types of radiation with varying abilities to penetrate objects or bodies are
You can shield yourself from alpha radiation by something as flimsy as a sheet of paper. Beta rays need six millimetres of aluminium and gamma rays are stopped by dense material only, like lead.
Radiation is everywhere
Cosmic radiation is produced by nuclear fusion occurring in the sun and stars in the universe. Its rays are made up of high-energy electrons, neutrons and nuclei of very short wave lengths.
These travel easily through an inch of lead. And the higher you are in the Earth’s atmosphere the more exposed you are to these rays because the further they travel into our atmosphere the more they are slowed down. Astronauts are exposed to high levels of cosmic radiation.
Cosmic radiation can alter DNA in the cells in human and animal bodies.
Nuclear radiation damages cells
Radiation can damage cells and the DNA inside them through its ionizing effect. This effect happens when a high-energy carrying particle or photon removes an electron within an atom’s nucleus from its orbit, thereby changing the properties of the atom. If enough ionization occurs DNA, cell and tissue damage result.
A common example is sunburn, caused by its ultraviolet light. Mutations can result, such as melanoma and other cancers. Of course ionizing effects from nuclear radiation from radioactive materials can do the same thing.
X-rays, gamma rays and far ultraviolet light are always ionizing. Near ultraviolet light and visible light are only ionizing to some molecules. Radio waves and microwaves do not have any ionizing effect.
Beneficial effects of nuclear radiation
Nuclear radiation has a number of beneficial uses, including:
Medicinal, such as radio therapy for cancers and X-rays
Dating purposes (no, this not where you nuke a ‘toxic’ date)
Level indicators and thickness gauges
In smoke detectors and
In tracing locations of gas or liquid leaks or
Tracing locations of malfunctioning in the body such as a blocked kidney
Sterilisation of medical instruments or bacteria or moulds in foods
These, and other such applications,involve low levels of radioactive compounds. However repeated exposure to X-rays is hazardous to your health because of the ionising effects of nuclear radiation.
How long does nuclear radiation last?
All radioactive substances decay over time. Some take fractions of seconds, others many thousands of years.
In theory all radio active substances stay slightly radio active and are never completely inert. That’s why it is more appropriate to use the ‘half-life’ of a radio active substance to indicate its level of radio activity. Its half life is the time it takes for its radio activity to fall by half.
For example, if the radioactivity of a radioactive substance fell by half every two years, its half life would be two years. You notice that it takes much longer for its radio activity to fall to very low levels and that after six years it would have dropped to one-eight of its radio activity.
At every step of its decay the radio active substance transforms into another substance as the composition of the nuclei in its atoms changes.
The half-life of uranium 238 is 4.5 billion years. That means that within that time half of the remaining uranium 238 will have decayed.
Are there any remedies for nuclear radiation effects?
In nuclear bomb explosions or nuclear reactor accidents radio active iodine can be dispersed over wide geographic areas. In the case of the Chernobyl accident it was, as far as 500 km. We do not know what the extent of radiation in the Japanese nuclear disaster may be yet but effects may also be global. Thyroid cancer is one result of such radiation.
Here is a powerful video available on YouTube about Chernobyl's nuclear fallout effects. Beware, it's quite disturbing in parts!
There is a way to avoid this toxicity but it has to be done before exposure to the radioactive nuclear radiation product iodine. Taking
potassium iodide (KI) or potassium iodate (KIO3)
will saturate the thyroid gland with the safe and stable iodine, contained in these chemicals. This leaves no room for the radioactive iodine to be taken up in the thyroid. Therefore any ingested or inhaled iodine is rapidly eliminated via the kidneys.
Of course KI or KIO3 tablets offer no protection against other radio active elements nor from external radiation.
Nuclear radiation - a risk?
Given that there are some 440 nuclear reactors worldwide you’d expect the risk of radiation to be high. However, the only major nuclear accident that saw radiation escape over large areas has to date been Chernobyl.
We hope the 2011 Japanese nuclear situation will not be added.
A limited number of people died in the Chernobyl event and there are various estimates of how many people will be affected over the long term. It should be pointed out that the Chernobyl plant lacked a protective housing, unlike almost all other nuclear reactors and that the shut-down procedures followed were contra-indicated.
Then the Japanese reactors did have such housing but it was not enough to shield the plants from them blowing up, as a result of multiple factors going wrong, notably the tsunami that killed off energy supply to cooling the reactor core.
Distinguished scientist James Lovelock, author of and other books, holds that every person on Earth has radioactive elements in their bodies from past nuclear bomb tests.
However he also holds that cancer rates have not demonstrably risen as a result. According to him the risks of nuclear energy are minimal and outweigh the risks posed by global warming by the use of fossil fuels.
Of course others vehemently disagree. Obviously one serious accident is too many, like the March 2011 Japanese earthquake and its effects on nuclear reactors there show. As well, each nuclear bomb and depleted uranium-tipped missile is one too many.