Saturday, March 26, 2011

Nuclear Radiation: What you need to know

source: gmanews
The Japan earthquake and tsunami damaged many structures, including the Tokyo Electric Power Company’s nuclear power facility in Fukushima Prefecture on the coast of northeastern Japan.

In particular, the cooling facilities of Fukushima Daiichi nuclear reactors 1-4 have been damaged, making it difficult to close down the facilities entirely.

Rumors quickly spread that the nuclear radiation leaking from these reactors would reach the Philippines, where a spurious text message on Monday, March 14, sowed panic and confusion on the matter.

GMA News Online has created this document to answer some frequently asked questions and quell unfounded fears about the events currently unfolding in Fukushima, Japan.


What is radiation?

Radiation is energy given off by matter in the form of rays or high-speed particles. There are many kinds of radiation and not all of them are dangerous.

Heat and light are actually types of radiation that humans can see and feel. However, there are other types that we can’t detect. One of these is particle or “nuclear" radiation, which is used in nuclear power plants.


What is ionizing radiation?

Nuclear radiation is a type of ionizing radiation, which is invisible and passes through matter. We use ionizing radiation like x-rays and gamma rays all the time for medical purposes. However, large doses of ionizing radiation passing through living tissue can affect natural biological processes. Exposure to large doses can be harmful to one’s health.

The effect of radiation exposure is dependent on three factors:

strength of the radiation
size of the body
length of exposure.

What is a nuclear meltdown?

When a nuclear power plant malfunctions, unchecked nuclear reactions can cause the radioactive material and its container to heat up and melt. The material may escape into the surrounding environment if the containment structure has been damaged.

The process is similar to an overheating engine: if its radiator or cooling system malfunctions, a motor will heat up and its parts will bind and eventually fail.

The resulting danger from a nuclear meltdown is exposure to the environment of radioactive material, but not a nuclear explosion.


Is the Philippines safe from nuclear radiation from the damaged plants in Japan?

Yes. The Philippines is too far away to be directly affected by any radiation that may come from the Fukushima power plant, even in the event of a meltdown.

Presently, there are concerns that radioactive material (made of particles that are capable of producing radiation) may escape from the plant and be carried by wind to neighboring countries. These concerns have increased recently amid fears that a meltdown may cause the radioactive material to be exposed to the environment.

However, the Philippines’ Department of Science and Technology (DOST) has carefully studied wind patterns and assessed that radioactive particles are highly unlikely to reach the country.

“There is virtually no chance the radiation will reach us, especially with wind patterns over Japan, which are moving away from the Philippines. The chances of radiation reaching the Philippines are almost nil," stressed DOST chief Mario Montejo.

Furthermore, the World Health Organization (WHO) has announced that there is no evidence of any significant international spread of radiation from Japan's crippled nuclear site.


Can the Fukushima Daiichi plant explode like a nuclear bomb?

No. A nuclear bomb explodes because it is specifically designed to explode, by concentrating all the radioactive material in a small space and causing it to release all its energy right away.

In contrast, a nuclear power plant is designed to release energy in a steady manner. As such, there is no danger of a nuclear-bomb-like disaster.

The explosions reported recently at the Fukushima Daiichi plant were from damage to adjacent structures, but not to the containment unit where the radioactive material is stored.

And even if the containment structure collapses, it will not result in a nuclear explosion. People in surrounding areas would only be at risk of being exposed to the radioactive material.



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source: gmanews

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