Apr 032011
 

What is really going on In Fukushima? Nuclear Fission & Radiation 101

Radiation Stacks

Have you ever wondered what are those towers next to each reactors building in the Fukushima plant? These are the ‘Radiation Stacks’ looking like transmission tower they are there to vent radiation fumes for better dispersion in the event of an accident. Those stacks are designed to send radioactive emissions higher up into the atmosphere.

More images of Japan before and after the 11.3.11 Earthquake and Tsunami can be be seen here

The radiation stacks in Fukushima were not used this time, as they need electricity to push the emissions up the stacks. And electricity was gone once the tsunami hit. Another problem is that radiation stacks are designed to suck the air out of the containment buildings and as we could clearly see from pictures and footage there are not much of the building left to suck the air of.

Arnold Gundersen of fairewinds

When Nuclear power plant are designed, Risk of accidents are calculated and measures put in place to withstand and avoid catastrophic outcomes resulting from accidents. According to Arnold Gundersen of fairewinds, in the case of Fukushima those assumptions have been excided by at least 70% with up to 8 reactor cores involved. “They also assume a containment building would leak about 0.5% a day, but as of 23 of March, it is believed the containment has been breached, which means it is clearly leaking more then half a percent per day. And of course they assume that the leaking is pulled up those stacks and that is not happening either.”

Ground level release

As apparent from videos taken by helicopters circulating above the plant, emissions have not been going up they have been rolling down. This is called ‘building wake effect’ causing ground level radiation. According to Gundersen it is clear high ground level radiation exists in the area around the nuclear plant and in his view, this area will not be suitable for people to inhabit for a long long time.

Significant contamination levels 40 km around the plant are high. According to IAEA data published on 22nd of march, background radiation in this locations is 1600 times higher then normal background radiation. According to Gundersen this is coming from a cloud of gases hanging over this area. This clouds contain noble gases like Xenon (Xe) and Krypton (Kr) emitting gamma rays and causing exposure. Those tend to decay into other isotopes like Strontium, so even when they are gone, what they leave behind gets deposited on the ground and take a very long time to decay.

Surface contamination

IAEA reported to have has found 0.9 Mega Becquerels – per square meter, of ‘surface contamination’ of Beta and Gamma radioactive isotopes. This is 900,000 disintegrations every second, per square meter measured at 30 to 40 km away from the plant. For perspective take Chernobyl where the IAEA considered a ‘hot spot’ to be when Beta radiation excided 500,000 disintegrations per second per square meter. However in this case Fukushima may keep on leaking for a long long time unlike the Chernobyl event. Top government spokesman in Japan said today “The government expects that several months may be required before radioactive particles stop being released from the Fukushima Daiichi nuclear plant.”

Radiation levels how are they measured and what does it mean?

When Uranium splits, it makes daughter products, which will go on to split and decay too. In the process of disintegration they emit radiation in the form of Gamma ray, Beta particles and Alpha particles. When these particles decay, they give off or radiate energy, which can get absorbed by the body. That can cause cellular damage, like cancer, particularly in fast growing cells of children.

Gamma rays are the first radiation that is emitted by Nuclear power plant. Gamma rays radiation have very high energy, more powerful then X rays. When you hear in the news talk of radiation levels this is a measuring of Gamma Rays radiation emitted by say Uranium daughter products Xenon (Xe) and Krypton (Kr) present in the air.

Beta particles and Alpha particles can not be measured by Geiger counters but they can be absorbed by the body through soft tissue, breathing, eating, or cut in the skin. These particles will cause cellular damage only if they have been absorbed by the body and are inside it.

Beta particles: Iodine (I) gets absorbed by the thyroid and can problem to the thyroid but iodine outside the body cannot cause radiation damage. Caesium (Cs) another Beta particle is absorbed by the muscles known to effect the heart muscles in infants but can cause cancer tumours in muscle tissue. Strontium (Sr) is absorbed by the bones and is known to cause Leukaemia, Strontium can be absorbed through the skin and finds it’s way to the bone marrow.

Alpha Particles are the biggest and massive of them all. Usually comes from Depleted Uranium and, or Plutonium which is a very powerful particle. Breathing plutonium will produce lung cancer.

Measuring radiation: 1 Becquerel = 1 disintegrations of particles / per second / per square meter

Measuring Cellular damage: 1 millisievert (mSm) = 100 Millirem (mR)

Half life: Is the time it take for particles to disintegrate by half. As a rule of thumb, it takes 10 half lives for a substance to disintegrate.

So lets take Iodine as an example. Iodine takes 8 days to disintegrate by half, after 16 days only a quarter of it remains. Every 8 days whatever is there half of it disappears so in 80 days it is all gone.

Caesium and Strontium have 30 years half life, so it takes 300 years for it all to disintegrate.

The worst is Plutonium with half life of 24,000 years taking it a staggering 240,000 years for it to decay completely.

Plutonium is hard isotope to detect, as it does not emit Gamma rays. But it is now known that Plutonium has been found at Fukushima along with radioactive water and there are growing fears of a core meltdown.

Plutonium has been discovered in 5 location around the Fukushima plant, assumed to be from soil samples. And if there are 5 the likelihood there are a lot more. This is worrying not only because it will take quarter of a million years to decay, but also since a microgram of Plutonium is sufficient to cause a lethal cancer. (Divide 1 gram to a million parts you get 1 microgram)

Plutonium is present in all Nuclear reactors, not just in those using Mox fuel which is using a mix of spent Plutonium and Uranium.

Gundersen estimates that if Plutonium have been found on site it is likely to be found off site too and said: “The health consequence should not be downplayed by Tokyo Electric”

Highly radioactive water measured over 100 rem per hour, has been discovered in trenches outside the nuclear containment. This indicates a breach in the containment. Gundersen stated: “I think this water is leaking into the ocean. The quantity of radiation detected in the ocean is an indication of enormously large source of radioactive water hitting the ocean.” He doubts such high levels could be from air releases.

There are many reason to support the idea, that damage to the core and containment has occurred and that large amount of radiation is and will continue to escape Fukushima with catastrophic effects all over the world not just locally in Japan.

Nuclear chain reaction still going on in Unit 1

Today the possibility that Fukushima Unit 1 may be having a nuclear chain reaction is openly discussed. New data released by TEPCO the plant operator indicates that even though Fukushima Unit 1 was shut down during the March 11 earthquake, it appears to have “gone critical” again without human intervention. The detection by TEPCO of short-lived radioactive isotopes substantiates the existence of this inadvertent criticality.

What is a chain reaction

When Uranium atom splits, it also produces 2 Neutrons, those hit the next Uranium atom and causes it to split and on and on. That is called ‘chain reaction’. So when Neutrons are present, it indicates a chain reaction in a nuclear reactor.

Neutron Beam

On the 23 of March The Kyodo news published an item titled “Neutron Beam observed 13 times at crippled Fukushima nuke plant” It said: “The measured neutron beam may be evidence that uranium and plutonium leaked from the plant’s nuclear reactors and spent nuclear fuels have discharged a small amount of neutron beams through nuclear fission.”

Chlorine-38

This week a reputable scientific paper was published on Japanfocus.org titled “What Caused the high Cl-38 Radioactivity in Fukushima Daiichi Reactor #1?” Where it discuses the discovery of an isotope called Chlorine-38, which does not exist in nature.

Chlorine-38 is created from Chlorine-37 absorbing a Neutron. Chlorine-37 is present in sea water and sea water has been used inside the reactors in an attempt to cool it. The paper suggests that nuclear chain reaction with sea water was responsible for the Chlorine-38 isotope found.

Tellurium 129

On the 1st of April, TEPCO the plant operator published it’s own report where they presented that the isotope Tellurium 129 was found in Fukushima unit 1. Tellurium 129 has 70 minute half life and that according to Gundersen can only exist if Nuclear Fission is still going on. This isotope decays very quickly and should not have been found had the reactor has been shut down. The report also indicate 10 times higher levels of iodine 131 in Unit 1 compared with measurements in Unit 2 and 3.

Gundersen concludes: “ I think Unit 1 has a part of it’s reactor core still undergoing periodic Nuclear Fission.”

How safe are Nuclear power plant?

Since the Fukushima Crisis began we have seen many talking heads and captains of industries coming forward to reassure us that Fukushima is a one off, freak accident and we have nothing to worry about…

Steven Chu American Energy secretary said: “The American people should have full confidence that the the united states has rigorous safety regulations in place to ensure that our nuclear power is generated safely and responsibly”

Peter Bradford former Nuclear regulatory Commissioner, NFC said: “This is not the time to be talking about building new nuclear power plants too expensive anyway. The nuclear renaissance was a shambles even before this accident because of the high cost… It is very hard to imagine that the average American sitting in front of their television set since this accident began that the families are turning to each other saying I would like to put our savings into the building of the next round of Nuclear power plants right now dear”

Nuclear Power plant, fault lines and danger zones in the US

Despite the fact that most Nuclear Power plant are situated near fault lines and danger zones in the US the Nuclear Energy regulator stated the chance of earthquake damage is 1 in 74,000. That is 10 times more likely you will ever win $10,000 on the lottery in the US.

Dave Lochbaum spent 30 years as an expert in the Nuclear industry and is now campaigning for more harsher safety regulation. He is part of a the ‘Union of Concerned Scientist’ and claims the industry ignored his warning about the reactors safety design. He Published a book about it and now his fears come true in the form of the Fukushima meltdown.

Lochbaum who lives 10 miles away from an aging Nuclear plant said he would like to see a very aggressive regulator to make sure no shortcuts are going on, but said: “we don’t have that effective regulator”.

Obama said “Nuclear plant are designed to withstand earthquakes but having said that nothing is completely fail safe nothing is completely full proof.”

The future

Nuscale Power wants to place a small nuclear reactor in your back yard and it is modular they boast, meaning you could have few of them… Smaller is safer experts say. But no one likes to talk of the issue of toxic waste.

France is developing an Under water Reactors to be placed off shore at the bottom of the sea. ‘Flax blue unit made by an army contractor is said to be 2 years a way from reality.