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RED ALERT: Japan’s Nuclear Disaster Is

 Still In Its InfancyFOTO DIVULGAÇÃO


 

By The International Perspective

Firstly I’d like to thank Chris Martenson and Arnie Gundersen of Fairwinds Associates for producing the first assessments of the situation in, what I would call, a logical and easy-to-understand fashion. Martenson interviewed Gundersen a couple of days ago and you can catch it here, on Martenson’s free blog site.

I’ll admit, since coincidentally writing about Japan’s structural challenges on the day of the Tsunami, I have stayed away from the subject. Up until now that is, because, to be honest, the market is forcing my hand and I’m compelled to do at least some basic analysis on the situation. Here are my thoughts – again, sincere apologies if this comes across as “too simplistic”, but remember, I’m no scientist, nor am I particularly clever!

To quickly update you on today’s news flow in this respect. The government has engaged what can only be described as a political shake-down of the utility industry. A sorrowful industry which, already battered and bruised, will now have to cough up massive compensation bills and raise billions of dollars at a time when the market is hardly embracing risk. Today this caused massive distortion in the markets with rumors that Tokyo Electric Power (TEPCO) itself may go under (see graphs below). TEPCO shares lost over a quarter of their value today. So far the company has lost 90% of it’s value since the accident and the company posted a Y 1.2 Trillion loss in May. S&P downgraded its debt to junk and prominent analysts are saying the whole thing will fold unless the government steps in. It ain’t pretty.

Boiling Water Reactor Nuclear Systems

Let’s start with the theory and a simple picture:

Boiling Water Reactor

Fukushima is what we call a Boiling Water Reactor (BWR) system. Put (very) simply, in terms of electricity generation process, it’s a bit like we just substitute nuclear fuel for any other heat-producing material like coal or diesel. It heats water which drives a steam turbine to produce electricity.

Now, see the nuclear fuel elements? They are located in what we call the “core” and are the key here because those are the little puppies that produce all the energy – a serious amount of energy. So much so that they need to be constantly restrained from their natural urge to overheat the core to thousands of degrees centigrade and simply vaporize the entire structure – typically referred to (at times incorrectly) in the media as a “meltdown”.

Now first let’s rule out a common misconception. Nuclear power station meltdowns can never cause a nuclear explosion like a nuclear bomb. But that’s as much comfort as you going to get I’m afraid. Instead, what can happen, in a “criticality” meltdown, for instance, is, effectively, pure and simple overheating – which then can cause other types of explosions to occur. A criticality is a situation where too much fuel is in one place, or in too close a proximity with another fuel source. Such is the sheer ferociousness of these substances that, even at low enrichment levels, proximity alone can cause a chain reaction between the fuel sources, which can then literally meltdown the fuel metal and anything in the vicinity, which then allows the radioactive material to flow and accumulate, creating yet more criticality in a sort of vicious virtuous cycle.

This is why, on the diagram above, you see that the fuel is set in fuel elements or “fuel rods”, because they are just metal rods. Note how there are also control rods which rise to disassociate the fuel rods from each other in the event of a failure.

The most important element of this design, though, is water. Water is constantly pumped around the rods to ensure that they do not overheat and vast quantities of water are allowed to flow between the rods because this extra surface area allows the heat to be transferred to the water (and away from the rods) much more efficiently. Simplistically, think of it like a radiator, which has fins or ripples to increase the surface area in order to dissipate heat much more efficiently (around the room of a house, for example). I labor the point here because it is critical to the nature of a criticality like Fukushima’s – which we will discuss in more detail in the next piece!

Fukushima Boiling Water Reactor System

Now let’s introduce another diagram:

Fukushima Reactor

This is the Fukushima reactor type, specifically, and we can see the steel containment vessel and, more importantly, we see a couple of other things which the first diagram did not illustrate. Firstly, notice that there is a spent fuel pool – a sort of swimming pool bank where spent fuel cells are kept. This will come in important when we discuss the detail of each reactor in depth in my next piece too. Obviously. they can’t just throw these spent cells away because even after they’ve served their purpose they are still hot, highly radioactive and very dangerous – and will remain so for a very long time! Secondly, and this is important, notice that there is a second chamber that completely encapsulates the reactor vessel. This chamber is solid concrete and very thick.

Both the steel containment vessel and the concrete shell or “drywell” were designed and engineered with only one thing in mind: to contain a nuclear meltdown or criticality. Notice also there is a donut-shaped tube around the bottom: this is the “wetwell”. The theory is this: in the event of a temperature explosion or meltdown, highly pressurized and radioactive steam is discharged into the drywell and it is then quenched and contained in the wetwell donut, which can apparently hold a million gallons of water and is designed specifically to receive highly pressurized steam of this nature.

Chernobyl vs Fukushima

Gundersen is clearly a leading expert on this matter and I’d say easily the most vocal. While the INES think that the Fukushima accident ranks Level 7 (the highest level) only ever achieved once before by Chernobyl, Gundersen thinks that the situation is even worse than the devastating Urkraian disaster 25 years ago. And he’s not the only one voicing this possibility, a piece on the business insider website the writer, DK Matai, quotes:

The Japanese nuclear crisis has the potential to be larger than Chernobyl because there are several tons of nuclear waste stored in the reactor cores that could be lofted into the environment in the event of explosion. Cracks are already there in the containment vessels of reactors one, two and three. If those cracks grow, or if there is an explosion, this could be something beyond Chernobyl, because of the various fission products being released into the environment.

Matai, then goes on to cite other sources with the same opinion:

Longer Term Exposure

Experts say this accident may turn out to be much bigger and more destructive than the Chernobyl meltdown in 1986, labeled as history’s worst nuclear accident. The Japanese government has sought to calm the markets by downplaying what has really gone on at the Fukushima nuclear reactors.  Today the Japanese prime minister said the situation is improving, even after the announcement that the threat level had been raised to 7.  But it’s clear a nuclear power plant housing six separate reactors — with four of them in trouble — including several large pools holding huge quantities of spent fuel rods which are undergoing repeated explosions and sporadic episodes of nuclear fission could certainly dwarf the Chernobyl accident in size, complexity, danger and potential for long-term damage.

The Russian View

Fukushima is much bigger than Chernobyl according to some Russian nuclear experts such as Natalia Mironova, a thermodynamic engineer, interviewed by Agence France Presse (AFP).  The nuclear disaster at Japan’s Fukushima power plant is “much bigger than Chernobyl” and could rewrite the international scale used to measure the severity of atomic accidents. Chernobyl was level seven and it had only one reactor and lasted only two weeks. We have now [four] weeks (at Fukushima) and we have four reactors which we know are in very dangerous situations,” she warned.  “Chernobyl was a dirty bomb explosion. The next dirty bomb is Fukushima and it will cost much more” in economic and human terms, she added, because of the urban population centres in its proximity.

Is a large fire in a small building more destructive than a small fire in a large building? It’s hard to say. Now, I know it’s not always good to compare two completely different situations but I suppose if it helps us in any way to gauge risk then we must look at every way we can to calibrate the scale of Japan’s nuclear disaster.

Here is how the two incidents differ at a glimpse (and the BBC also has a good table on this).

Firstly the cause: Chernobyl was caused by a power surge which effectively caused a massive meltdown and blew the whole reactor vessel up into the air. Importantly, it was not a pure Boiling Water Reactor system but rather a “Graphite Moderated BWR”. This is much more combustible system as the graphite can effectively ignite. Also, crucially, there was no massive outer containment or drywell/concrete containment bulb. So the vessel went up like a volcano during a series of explosions (some of them hydrogen explosions) sending debris high up into the air and dumping it across the land. Crucially, though, it was only one reactor which blew up.

At Fukushima, the problem was not a surge of power, but, rather, a lack of power after the massive Tsunami and Earthquake crippled the cooling systems and all infrastructure around the plant. This lack of power highlights the ongoing nature of the disaster – it is not just a discrete event. The battery backup lasted only 8 hours after which the nuclear reactors were on their own and chain reaction of events started. The diesel generators are supposed to come on line to supply electricity for cooling pumps automatically but (as Gundersen points out) the tsunami had actually swamped the pumps which cooled the diesel engines. So even if the diesel engines had independently performed their task they would have soon become useless!

It is no wonder the market is reacting – there is clearly a failing of a bigger order at play here.

The Fallout

It could be said that Chernobyl was an uncontained explosion on a single reactor while Fukushima is a series of contained implosion on four reactors but, nearly three months later, this internalized instability leaves the four reactors in a menacingly perilous state. Indeed, even from an environmental perspective, it is still not completely clear which event is actually worse and the reason is simply because of the word “is” in the last sentence. I deliberately use present tense when talking about the Fukushima reactor implosion because the process is still being played out before our very eyes and it appears that most people think that the threat is now over. Not so. Not so at all, in fact – as we will find out.

Also, just because the explosion was housed in vessels specifically designed to contain a criticality, does not mean that over time the eventual fallout will not be just as destructive as Chernobyl. Because Chernobyl did not have a concrete containment drywell shell, observationally, it was a far more sensational criticality event, yet, incidentally, relatively little has been made of the sheer magnitude and force of the Japanese criticality events, given that they blew the foresaid containment vessels apart. As a separate calibration, Gundersen notes that ten times more radioactivity was found in the ocean from Fukushima than was found in the Black Sea from Chernobyl. So at the very least, we are dealing with new scientific and environmental challenges we have never dealt with before, we stepping out into the unknown here. The reality is, only time will tell which event was worse and only one thing remains certain – it’s still far too early to come to any conclusion about the potential fallout from Fukushima.

Fukushima did not happen. Fukusima IS HAPPENING… still.

Unfortunately, the economic containment by Japanese corporations and policy officials could not have been much worse – exacerbated by their deafening silence and sheer communication vacuum of information. Despite this being initiated by a natural disaster of epic proportions, it does not provide cover for the blatant failings of the officials, management and system as a whole. Japanese utilities, and this TEPCO’s Fukushima power plant in particular, were repeatedly warned that they did not have enough tsunami protection. The tsunami did not just tip the scale for breaching defenses, it completely overwhelmed and destroyed them – it was not a marginal miscalculation. Given the pump design-flaws I highlighted earlier, this bodes for more than just an engineering glitch. It is a structural issue within the industry as a whole. This has not been a moment of shining glory for the Japanese utility companies.

Furthermore, there are not one but four reactors in play in Fukushima and each one of them is in a critical state, each one of them is significantly prone to its own unique set of risks. It’s an incredibly complex set of circumstances – much more so than anything we’ve ever seen before, I think.

In my next briefing, I will go through each of the four Fukushima reactors one by one and summarize the risks involved. For now, though, it’s late and time for me to go to bed. I leave you with a few relevant graphs of market activity related to the event.

Anúncios

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