Sunday, April 24, 2011

Japan, Radiation & Destiny 3

Is radiation all the same?  Are all reactors of the same type?  Are there are some radioactive elements more dangerous than others?

It is only recently that Japan has raised the danger level of the Fukushima nuclear accident to a level 7.  This means, that this accident has global implications.

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Nuclear Power Plants
abandoned control room
Gamma particles are essentially electromagnetic radiation of the photons/electrons. The energy of the gamma particles determines the depth of penetration of the tissues. The expulsive emission from the nucleus if approximated with another unstable radioactive element that can capture the emission can lead to a contained fissile reaction with release of energy. This process when controlled, produces heat in a nuclear reactor which drives steam turbines to produce electricity.  When this process is uncontrolled, it produces a nuclear explosion.  Wikipedia provides a clear definition of nuclear fission:
nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts (lighter nuclei), often producing free neutrons and photons (in the form of gamma rays).
Here is a short video which explains the process of nuclear fission.  If you cannot see the embedded video, here is the link:

Therein lies the mystery of the Nuclear Power Plant. The Nuclear Energy containment is nothing more than a sustained and contained nuclear reaction. Since the U-238 is inelastic and does not afford itself to a “chain-reaction” this very containment results in a sustained energy release and a contained fissile reaction.  Here is a video demonstrating how a typical nuclear reactor works.  If you cannot see the embedded video here is the link:

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The radiation levels at Chernobyl at the time of accident were 200 times that found at Hiroshima and Nagasaki and based on atmospheric radioactivity monitoring in Scotland for a brief period following the accident the radioactivity level rose to 10,000 times normal values.  Business Insider provided an interesting graphic on the different ratings used by international nuclear community as to what kinds of nuclear accidents can occur.  It is also an excellent article comparing Chernobyl to Fukushima.

What is of the most concern, is the MOX that we know the Japanese reactors in Fukushima use.  What is MOX?  It stands for Mixed Oxide Fuel.  This is a combined mixture of natural uranium, reprocessed uranium and depleted uranium.  The reason why MOX is an attractive alternative to some, is because it can recycle spent uranium from the standard nuclear reactor technology (light water reactors) which are the majority of nuclear reactors today.  MOX can also utilize what is called "weapons-grade" plutonium (Pu-239).  This plutonium is produced artificially in nuclear reactors.  MOX is considered much more dangerous simply because it has a half-life of 24,000 years.  But luckily for the world, reactor #3 in Fukushima is the only one to be contain any MOX and that, at only 5% levels.  Indeed, it was a concerted effort by Japanese environmentalists that prevented the reactor from containing she scheduled 33% of MOX.  All of the MOX in the reactor #3 remains in the core and none of it had yet been transferred to the now unprotected fuel pool.  Here is a short video explainin how a MOX reactor is made by illustrating the present construction of a MOX reactor in Savannah, Georgia.  If you cannot see the embedded video, here is the link:

victim of Hiroshima
We call these meltdowns and nuclear accidents disasters because of the effects on humans, animals and plants. Biological life forms live in a radioactive world. Radioactivity is in the atmosphere (cosmic radiation/solar radiation), in the soil and in the plants. Animals and humans who consume the plants and animals contain a minute fraction of these radioactive elements within their tissues. We are therefore constantly bombarded with radioactivity in our daily lives. 

Radiation and the Human DNA
Our genetic makeup is designed to withstand this onslaught through a mechanism of DNA Mismatch repair mechanism. Overwhelming that mechanism leads to either cell death (apoptosis) or disease. For instance it is believed that the human DNA takes about 10,000 hits daily. In human cells, both normal metabolic activities and environmental factors such as Ultra Violet (UV) light and radiation can cause DNA damage, resulting in as many as 1 million individual molecular disruptions per cell per day. DNA damages in frequently dividing cells, because they give rise to mutations, are a prominent cause of cancer. Here is a video that visualizes this repair mechanism in a simplified form.  If you cannot see the embedded video, here is the link:

DNA Repair Ligase
In contrast, DNA damages in infrequently dividing cells are likely a prominent cause of aging due to the slow reactive damage inflicted upon these cells. (These hits are random based on radioactive decays from the soil and inherently assimilated natural radioactive substances incorporated in various tissues of our body and via solar radiation). It is true that the incorporated radioactive materials in the body have a long half-life i.e. their propensity to decay is extremely slow and therefore emissions of alpha, beta or gamma particles is rare. But it is there, maybe not constant but forever the bell that has the potential to toll. In the event of such disasters where there is a dramatic increase in the radioactivity in the environment the body can be overwhelmed with the onslaught and that can lead to human cellular framework disintegration and chaos.

The cancer cell is wayward cell that has lost all constraints and restraints programmed into it. This loss of restraint and constraint from normal function and form leads to unrestricted growth.  Here is a brief video showing a 3D animation of the cancer process.  If you cannot see the embedded video, here is the link:

Lets dig a little deeper into the cellular DNA both in the nucleus and the mitochondria to understand what radiation does to living cells. Imagine the DNA with its double helix held together by the phosphate sugars and linked together by extremely loose water-soluble hydroxyl (OH) bonds. Now imagine a stray bullet (in this case an escaped electron) dislodging one of those (OH) bonds and in so doing ricochets and hits the corresponding Nucleic acid. This attack leads to a compromised connection between the Nucleic acids Adenine with Thymine and Guanine with Cytosine and also disrupts the Nucleic Acid.

In part 4 of this series we will continue with effects of radiation poisoning and how Japan's nuclear disaster might affect them and the rest of the world.

Co-Written by PlusUltraTech and Parvez Dara, MD FACP

1 comment:

Patrick said...

Very well done explanation for us atomically challenged tweeple thanks for the visual aids & important information that effects every creature on this planet.  The world will understand when its to late how bad this event was.  To much covering up will only make it worse. Governments do not understand that we are intelligent individuals not sheeple.  We make the difference.