Trump não prolonga prazo das tarifas para lá de 1 de agosto. Carta à UE enviada em dois dias

[MarcoAntonio]

marco, deixa lá discutir a questão do crescimento económico ou depressão. Esse tema está a ser amplamente discutido por ti noutro tópico já....

Marta, discute lá o que quiseres.

Eu estou a intervir a propósito do tema central do segundo artigo dos dois que o Ulisses colocou neste tópico...

[Pata-Hari]

marco, deixa lá discutir a questão do crescimento económico ou depressão. Esse tema está a ser amplamente discutido por ti noutro tópico já....

[MarcoAntonio]

O k deve ser minúsculo. Não há perigo de ninguém não ter entendido portanto "no harm done"...

Previsões alarmistas e não científicas sobre o que se passa nas centrais nucleares pode ser bem mais nocivo: para a economia, para a saúde das pessoas e para os investimentos pessoais!

[canguru]

num raio de 20Km

Km? Kelvin*metro como unidade de distância?

[MarcoAntonio]

Uma boa forma de medir o efeito até agora e o verdadeiro potencial do que ainda poderá ocorrer é olhar por exemplo para as medidas preventivas: em torno da daiichi foram evacuadas as pessoas num raio de 20Km e não está a ser ponderado o alargamento da área, não obstante estar a ser considerado que em algum ponto poderá ser necessário libertar vapor radioactivo para libertar a pressão dentro do reactor.

Infelizmente - e expectavelmente - os médias mais generalistas não transparecem a verdadeira gravidade da situação e estão pouco interessados/motivados para fazê-lo...

[Supermann]

Fukushima is a triumph for nuke power: Build more reactors now!
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Quake + tsunami = 1 minor radiation dose so far

By Lewis Page • Get more from this author

Posted in Physics, 14th March 2011 13:58 GMT

Analysis Japan's nuclear powerplants have performed magnificently in the face of a disaster hugely greater than they were designed to withstand, remaining entirely safe throughout and sustaining only minor damage. The unfolding Fukushima story has enormously strengthened the case for advanced nations – including Japan – to build more nuclear powerplants, in the knowledge that no imaginable disaster can result in serious problems.

Let's recap on what's happened so far. The earthquake which hit on Friday was terrifically powerful, shaking the entire planet on its axis and jolting the whole of Japan several feet sideways. At 8.9 on the Richter scale, it was some five times stronger than the older Fukushima plants had been designed to cope with.

If nuclear powerplants were merely as safe as they are advertised to be, there should have been a major failure right then. As the hot cores ceased to be cooled by the water which is used to extract power from them, control rods would have remained withdrawn and a runaway chain reaction could have ensued – probably resulting in the worst thing that can happen to a properly designed nuclear reactor: a core meltdown in which the superhot fuel rods actually melt and slag down the whole core into a blob of molten metal. In this case the only thing to do is seal up the containment and wait: no radiation disaster will take place1, but the reactor is a total writeoff and cooling the core off will be difficult and take a long time. Eventual cleanup will be protracted and expensive.

In fact, though the quake was far beyond design limits, all the reactors went into automatic shutdown perfectly: triumph number one. Control rods slammed into the cores, absorbing the neutrons spitting from the fuel rods and pinching off the uranium-fission chain reactions powering the plant.

However, the cores were still producing heat and radiation at this point: intermediate radioactive isotopes of caesium and iodine are created during normal running. They have short half-lives and decay to insignificant levels within days of a shutdown, but for that time the reactor will still produce a few per cent of the heat it puts out in normal running – and this is still a lot of heat. If it is not dealt with, it can eventually melt down parts of the core, though the resulting mess will not be nearly as bad as a runaway meltdown.

Thus, even with the control rods in, the core still needs to be cooled for some days until the "residual" heating dies away and so power and water need to be supplied for this purpose. Backup cooling driven by diesels came on at all the plants without trouble, despite the way-beyond-spec hit from the quake: triumph number two.

For a few hours all was well. Then the tsunami – again, bigger than the plant had been built to cope with – struck, knocking out the diesel backups and the backup diesel backups.

Needless to say, this being a nuclear powerplant, there was another backup and this one worked despite having been through a beyond-spec quake and the tsunami. Battery power cut in and the cores continued to be cooled, giving the plant operators some hours of leeway to bring in mobile generators: triumph number three.

Unfortunately it appears that the devastation from the quake and tsunami was sufficient that mobile power wasn't online at all the sites before the temperatures inside the cores began to climb seriously. At this stage the cores are sitting immersed in cooling water inside their terrifically thick and strong airtight containment vessels. As the water is not being circulated and cooled any more, it is getting hotter, turning to steam, and pressure is building inside the vessel. Left alone the vessel interior will presently become hot enough to start melting the tough alloy casings of the fuel rods, at which stage the interior will fill with long-half-life radioactive materials – and will thus have to be buttoned up tightly and abandoned for a long time, creating a mess.

Letting off some steam

What the Japanese powerplant chiefs decided to do at this point is vent off some of the steam from the containment vessels in order to cool the interiors down. At this point the steam is not contaminated with any long-lived nasties, but it has been well soaked in neutrons and thus it contains quite a lot of very short-lived (half-life measured in seconds) radioactive materials such as Nitrogen-16. Within a minute of being released, such steam is just steam again, but it is radioactive when it comes out.

This is obviously emotive stuff – radioactive gas leaks – even if it is harmless to anyone beyond the plant fence (the workers inside are in protected control rooms or wearing protective gear).

So the situation is being managed and the cores are being kept cool by venting off steam. Power is restored by mobile generators to most of the reactors and soon their cooling systems are running again for a smooth shutdown.

But in two cases the normal cooling systems couldn't be made to run again even once mobile power arrived on scene. The normal systems use very pure de-mineralised water, and the plant operators couldn't get a supply of this running again at these reactors. Water adulterated with other things – such as sea salt – is less desirable, as its use means that other radionuclides are generated in small quantities: also it will cause a lot of expensive equipment corrosion and so forth.

But after some time, water levels inside the three cores sank low enough from the venting that hot bits of core started to stick up out of the liquid. These parts were then being kept cool much less effectively, and trace amounts of the caesium and iodine isotopes powering the residual heat reaction were detected in the air outside the plants. This first happened on Saturday.

The plant operators thus bit the bullet and fell back on yet another backup system: they injected seawater mixed with boric acid (liquid control-rod material) into the cores. This meant a fair bit of expensive damage to the two reactors, and also that the steam emitted when venting would be slightly more radioactive due to the salt and other trace chemicals in the sea water.

This is why the Japanese operators have chosen purposely to release the steam from these reactors, not into the atmosphere, but into the interiors of their reactor buildings. These too can be made gas-tight in order to contain leaks from the containment vessel, though they aren't terrifically strong and able to hold massive pressures.

The idea was to hold the steam in the buildings for the necessary short periods until it was no longer radioactive at all before letting it out of the building – and then venting off some more steam into the building, so cooling the cores. Holding the steam in the buildings wasn't really necessary – more of a gesture than anything else – but it was done nonetheless.

Unfortunately this decision has proved to be a PR blunder rather than a bonus. Steam which has been superheated as in a reactor core can break up into hydrogen and oxygen, which is naturally an explosive mixture. At Chernobyl, this actually happened inside the containment vessel and the resulting explosion ruptured the vessel, leading to a serious release of core radioactives – though this has had basically zero effect on the world in general nor even much impact on the area around Chernobyl.

Under control

But proper nuclear reactors are designed so that you can't get water breakup to hydrogen and oxygen inside the containment vessel, only outside it: triumph number four for the Japanese plants' designers. Thus the hydrogen explosions which subsequently took place, though visually spectacular, did nothing more than blow the roofs off the reactor buildings – the containment vessels and their systems remain unbreached and under command from the relevant control rooms. The risk of explosion was known and notified in advance: it was accepted by the plant operators and regulators in return for the very slight reduction in radiation exposure close to the reactor buildings.

All reactors' temperature is now under control and the residual heat reactions inside them continue to die away; soon, no further cooling will be required. The three worst affected will cost more to put right than the other ones, having been cooled with the backup-backup seawater system and lost their roofs, but the process of sorting them out will not be a lot more onerous than a normal periodic refuelling. All the other affected reactors have achieved quite normal shutdowns, though nuclear safety being nuclear safety it will be some time before they can be fired up again.

Radiation health effects have been pretty much zero. At times there have been heightened radiation levels inside the plants from short-life isotopes in the steam releases – sometimes enough that an unprotected person next to a reactor building might have sustained a year's normal dose from background radiation in an hour. This is not particularly terrifying, really – nobody is scared at the prospect of living another year on planet Earth – but it is being reported under scaremongering headlines. Another thing the weekend reporters have missed was the fact that all but tiny traces of the airborne radionuclides (from the salt in the seawater coolant) were disappearing before they could even cross the street; there is essentially no health hazard to people living nearby. Precautionary evacuations and tests were just that: precautionary.

In fact only one person so far has sustained any measurable extra radiation dose above normal: a plant worker, according to the IAEA, sustained about 10 per cent of a normal year's background radiation dose. Other workers have been injured by the hydrogen explosions and the quake/tsunami, and one killed in a crane accident, but quite frankly being a nuclear powerplant worker at Fukushima has been pretty safe compared to just being an ordinary citizen in quake-hit Japan.

So to sum up: all plants are now well on their way to a cold shutdown. At no time have their operators come even close to running out of options. No core has melted down and come up against the final defensive barriers: the safety systems did not come even close to failing, despite being tested far beyond what they had been designed to take. One person has sustained a small dose of radiation which need cause him no concern.

The whole sequence of events is a ringing endorsement for nuclear power safety. If this – basically nothing – is what happens when decades-old systems are pushed five times and then some beyond their design limits, new plants much safer yet would be able to resist an asteroid strike without problems.

But you wouldn't know that from looking at the mainstream media. Ignorant fools are suggesting on every hand that Japan's problems actually mean fresh obstacles in the way of new nuclear plants here in the UK, Europe and the US.

That can only be true if an unbelievable level of public ignorance of the real facts, born of truly dreadful news reporting over the weekend, is allowed to persist.

Spread the word. And if you doubt us on any of this, please read this excellent early description of the events, or follow the reports from the IAEA and World Nuclear News. Very few other channels of information are much use at the moment. ®

1There is an enduring popular myth suggesting that such a core would become so hot that nothing could resist it: being heavy, it would thus melt its way through the foundations of the reactor, through the planetary crust and notionally to the other side of the planet – the so-called "China syndrome". The idea that the core could burn through the base of its containment is about as credible as the idea that it would remain together in the planet's molten interior and then – having somehow done so and thus reached the centre of the Earth – then ascend back to the surface again at the antipodes.

[Supermann]

**original post below**

I know this is a fairly full on statement from someone posting his very first blog. It will also be far and away the most well written, intelligent post I ever make (I hope!) It also means I am not responsible for its content.

This post is by Dr Josef Oehmen, a research scientist at MIT, in Boston.

He is a PhD Scientist, whose father has extensive experience in Germany’s nuclear industry. I asked him to write this information to my family in Australia, who were being made sick with worry by the media reports coming from Japan. I am republishing it with his permission.

It is a few hours old, so if any information is out of date, blame me for the delay in getting it published.

This is his text in full and unedited. It is very long, so get comfy.

I am writing this text (Mar 12) to give you some peace of mind regarding some of the troubles in Japan, that is the safety of Japan’s nuclear reactors. Up front, the situation is serious, but under control. And this text is long! But you will know more about nuclear power plants after reading it than all journalists on this planet put together.

There was and will *not* be any significant release of radioactivity.

By “significant” I mean a level of radiation of more than what you would receive on – say – a long distance flight, or drinking a glass of beer that comes from certain areas with high levels of natural background radiation.

I have been reading every news release on the incident since the earthquake. There has not been one single (!) report that was accurate and free of errors (and part of that problem is also a weakness in the Japanese crisis communication). By “not free of errors” I do not refer to tendentious anti-nuclear journalism – that is quite normal these days. By “not free of errors” I mean blatant errors regarding physics and natural law, as well as gross misinterpretation of facts, due to an obvious lack of fundamental and basic understanding of the way nuclear reactors are build and operated. I have read a 3 page report on CNN where every single paragraph contained an error.

We will have to cover some fundamentals, before we get into what is going on.

Construction of the Fukushima nuclear power plants

The plants at Fukushima are so called Boiling Water Reactors, or BWR for short. Boiling Water Reactors are similar to a pressure cooker. The nuclear fuel heats water, the water boils and creates steam, the steam then drives turbines that create the electricity, and the steam is then cooled and condensed back to water, and the water send back to be heated by the nuclear fuel. The pressure cooker operates at about 250 °C.

The nuclear fuel is uranium oxide. Uranium oxide is a ceramic with a very high melting point of about 3000 °C. The fuel is manufactured in pellets (think little cylinders the size of Lego bricks). Those pieces are then put into a long tube made of Zircaloy with a melting point of 2200 °C, and sealed tight. The assembly is called a fuel rod. These fuel rods are then put together to form larger packages, and a number of these packages are then put into the reactor. All these packages together are referred to as “the core”.

The Zircaloy casing is the first containment. It separates the radioactive fuel from the rest of the world.

The core is then placed in the “pressure vessels”. That is the pressure cooker we talked about before. The pressure vessels is the second containment. This is one sturdy piece of a pot, designed to safely contain the core for temperatures several hundred °C. That covers the scenarios where cooling can be restored at some point.

The entire “hardware” of the nuclear reactor – the pressure vessel and all pipes, pumps, coolant (water) reserves, are then encased in the third containment. The third containment is a hermetically (air tight) sealed, very thick bubble of the strongest steel. The third containment is designed, built and tested for one single purpose: To contain, indefinitely, a complete core meltdown. For that purpose, a large and thick concrete basin is cast under the pressure vessel (the second containment), which is filled with graphite, all inside the third containment. This is the so-called “core catcher”. If the core melts and the pressure vessel bursts (and eventually melts), it will catch the molten fuel and everything else. It is built in such a way that the nuclear fuel will be spread out, so it can cool down.

This third containment is then surrounded by the reactor building. The reactor building is an outer shell that is supposed to keep the weather out, but nothing in. (this is the part that was damaged in the explosion, but more to that later).

Fundamentals of nuclear reactions

The uranium fuel generates heat by nuclear fission. Big uranium atoms are split into smaller atoms. That generates heat plus neutrons (one of the particles that forms an atom). When the neutron hits another uranium atom, that splits, generating more neutrons and so on. That is called the nuclear chain reaction.

Now, just packing a lot of fuel rods next to each other would quickly lead to overheating and after about 45 minutes to a melting of the fuel rods. It is worth mentioning at this point that the nuclear fuel in a reactor can *never* cause a nuclear explosion the type of a nuclear bomb. Building a nuclear bomb is actually quite difficult (ask Iran). In Chernobyl, the explosion was caused by excessive pressure buildup, hydrogen explosion and rupture of all containments, propelling molten core material into the environment (a “dirty bomb”). Why that did not and will not happen in Japan, further below.

In order to control the nuclear chain reaction, the reactor operators use so-called “moderator rods”. The moderator rods absorb the neutrons and kill the chain reaction instantaneously. A nuclear reactor is built in such a way, that when operating normally, you take out all the moderator rods. The coolant water then takes away the heat (and converts it into steam and electricity) at the same rate as the core produces it. And you have a lot of leeway around the standard operating point of 250°C.

The challenge is that after inserting the rods and stopping the chain reaction, the core still keeps producing heat. The uranium “stopped” the chain reaction. But a number of intermediate radioactive elements are created by the uranium during its fission process, most notably Cesium and Iodine isotopes, i.e. radioactive versions of these elements that will eventually split up into smaller atoms and not be radioactive anymore. Those elements keep decaying and producing heat. Because they are not regenerated any longer from the uranium (the uranium stopped decaying after the moderator rods were put in), they get less and less, and so the core cools down over a matter of days, until those intermediate radioactive elements are used up.

This residual heat is causing the headaches right now.

So the first “type” of radioactive material is the uranium in the fuel rods, plus the intermediate radioactive elements that the uranium splits into, also inside the fuel rod (Cesium and Iodine).

There is a second type of radioactive material created, outside the fuel rods. The big main difference up front: Those radioactive materials have a very short half-life, that means that they decay very fast and split into non-radioactive materials. By fast I mean seconds. So if these radioactive materials are released into the environment, yes, radioactivity was released, but no, it is not dangerous, at all. Why? By the time you spelled “R-A-D-I-O-N-U-C-L-I-D-E”, they will be harmless, because they will have split up into non radioactive elements. Those radioactive elements are N-16, the radioactive isotope (or version) of nitrogen (air). The others are noble gases such as Xenon. But where do they come from? When the uranium splits, it generates a neutron (see above). Most of these neutrons will hit other uranium atoms and keep the nuclear chain reaction going. But some will leave the fuel rod and hit the water molecules, or the air that is in the water. Then, a non-radioactive element can “capture” the neutron. It becomes radioactive. As described above, it will quickly (seconds) get rid again of the neutron to return to its former beautiful self.

This second “type” of radiation is very important when we talk about the radioactivity being released into the environment later on.

What happened at Fukushima

I will try to summarize the main facts. The earthquake that hit Japan was 7 times more powerful than the worst earthquake the nuclear power plant was built for (the Richter scale works logarithmically; the difference between the 8.2 that the plants were built for and the 8.9 that happened is 7 times, not 0.7). So the first hooray for Japanese engineering, everything held up.

When the earthquake hit with 8.9, the nuclear reactors all went into automatic shutdown. Within seconds after the earthquake started, the moderator rods had been inserted into the core and nuclear chain reaction of the uranium stopped. Now, the cooling system has to carry away the residual heat. The residual heat load is about 3% of the heat load under normal operating conditions.

The earthquake destroyed the external power supply of the nuclear reactor. That is one of the most serious accidents for a nuclear power plant, and accordingly, a “plant black out” receives a lot of attention when designing backup systems. The power is needed to keep the coolant pumps working. Since the power plant had been shut down, it cannot produce any electricity by itself any more.

Things were going well for an hour. One set of multiple sets of emergency Diesel power generators kicked in and provided the electricity that was needed. Then the Tsunami came, much bigger than people had expected when building the power plant (see above, factor 7). The tsunami took out all multiple sets of backup Diesel generators.

When designing a nuclear power plant, engineers follow a philosophy called “Defense of Depth”. That means that you first build everything to withstand the worst catastrophe you can imagine, and then design the plant in such a way that it can still handle one system failure (that you thought could never happen) after the other. A tsunami taking out all backup power in one swift strike is such a scenario. The last line of defense is putting everything into the third containment (see above), that will keep everything, whatever the mess, moderator rods in our out, core molten or not, inside the reactor.

When the diesel generators were gone, the reactor operators switched to emergency battery power. The batteries were designed as one of the backups to the backups, to provide power for cooling the core for 8 hours. And they did.

Within the 8 hours, another power source had to be found and connected to the power plant. The power grid was down due to the earthquake. The diesel generators were destroyed by the tsunami. So mobile diesel generators were trucked in.

This is where things started to go seriously wrong. The external power generators could not be connected to the power plant (the plugs did not fit). So after the batteries ran out, the residual heat could not be carried away any more.

At this point the plant operators begin to follow emergency procedures that are in place for a “loss of cooling event”. It is again a step along the “Depth of Defense” lines. The power to the cooling systems should never have failed completely, but it did, so they “retreat” to the next line of defense. All of this, however shocking it seems to us, is part of the day-to-day training you go through as an operator, right through to managing a core meltdown.

It was at this stage that people started to talk about core meltdown. Because at the end of the day, if cooling cannot be restored, the core will eventually melt (after hours or days), and the last line of defense, the core catcher and third containment, would come into play.

But the goal at this stage was to manage the core while it was heating up, and ensure that the first containment (the Zircaloy tubes that contains the nuclear fuel), as well as the second containment (our pressure cooker) remain intact and operational for as long as possible, to give the engineers time to fix the cooling systems.

Because cooling the core is such a big deal, the reactor has a number of cooling systems, each in multiple versions (the reactor water cleanup system, the decay heat removal, the reactor core isolating cooling, the standby liquid cooling system, and the emergency core cooling system). Which one failed when or did not fail is not clear at this point in time.

So imagine our pressure cooker on the stove, heat on low, but on. The operators use whatever cooling system capacity they have to get rid of as much heat as possible, but the pressure starts building up. The priority now is to maintain integrity of the first containment (keep temperature of the fuel rods below 2200°C), as well as the second containment, the pressure cooker. In order to maintain integrity of the pressure cooker (the second containment), the pressure has to be released from time to time. Because the ability to do that in an emergency is so important, the reactor has 11 pressure release valves. The operators now started venting steam from time to time to control the pressure. The temperature at this stage was about 550°C.

This is when the reports about “radiation leakage” starting coming in. I believe I explained above why venting the steam is theoretically the same as releasing radiation into the environment, but why it was and is not dangerous. The radioactive nitrogen as well as the noble gases do not pose a threat to human health.

At some stage during this venting, the explosion occurred. The explosion took place outside of the third containment (our “last line of defense”), and the reactor building. Remember that the reactor building has no function in keeping the radioactivity contained. It is not entirely clear yet what has happened, but this is the likely scenario: The operators decided to vent the steam from the pressure vessel not directly into the environment, but into the space between the third containment and the reactor building (to give the radioactivity in the steam more time to subside). The problem is that at the high temperatures that the core had reached at this stage, water molecules can “disassociate” into oxygen and hydrogen – an explosive mixture. And it did explode, outside the third containment, damaging the reactor building around. It was that sort of explosion, but inside the pressure vessel (because it was badly designed and not managed properly by the operators) that lead to the explosion of Chernobyl. This was never a risk at Fukushima. The problem of hydrogen-oxygen formation is one of the biggies when you design a power plant (if you are not Soviet, that is), so the reactor is build and operated in a way it cannot happen inside the containment. It happened outside, which was not intended but a possible scenario and OK, because it did not pose a risk for the containment.

So the pressure was under control, as steam was vented. Now, if you keep boiling your pot, the problem is that the water level will keep falling and falling. The core is covered by several meters of water in order to allow for some time to pass (hours, days) before it gets exposed. Once the rods start to be exposed at the top, the exposed parts will reach the critical temperature of 2200 °C after about 45 minutes. This is when the first containment, the Zircaloy tube, would fail.

And this started to happen. The cooling could not be restored before there was some (very limited, but still) damage to the casing of some of the fuel. The nuclear material itself was still intact, but the surrounding Zircaloy shell had started melting. What happened now is that some of the byproducts of the uranium decay – radioactive Cesium and Iodine – started to mix with the steam. The big problem, uranium, was still under control, because the uranium oxide rods were good until 3000 °C. It is confirmed that a very small amount of Cesium and Iodine was measured in the steam that was released into the atmosphere.

It seems this was the “go signal” for a major plan B. The small amounts of Cesium that were measured told the operators that the first containment on one of the rods somewhere was about to give. The Plan A had been to restore one of the regular cooling systems to the core. Why that failed is unclear. One plausible explanation is that the tsunami also took away / polluted all the clean water needed for the regular cooling systems.

The water used in the cooling system is very clean, demineralized (like distilled) water. The reason to use pure water is the above mentioned activation by the neutrons from the Uranium: Pure water does not get activated much, so stays practically radioactive-free. Dirt or salt in the water will absorb the neutrons quicker, becoming more radioactive. This has no effect whatsoever on the core – it does not care what it is cooled by. But it makes life more difficult for the operators and mechanics when they have to deal with activated (i.e. slightly radioactive) water.

But Plan A had failed – cooling systems down or additional clean water unavailable – so Plan B came into effect. This is what it looks like happened:

In order to prevent a core meltdown, the operators started to use sea water to cool the core. I am not quite sure if they flooded our pressure cooker with it (the second containment), or if they flooded the third containment, immersing the pressure cooker. But that is not relevant for us.

The point is that the nuclear fuel has now been cooled down. Because the chain reaction has been stopped a long time ago, there is only very little residual heat being produced now. The large amount of cooling water that has been used is sufficient to take up that heat. Because it is a lot of water, the core does not produce sufficient heat any more to produce any significant pressure. Also, boric acid has been added to the seawater. Boric acid is “liquid control rod”. Whatever decay is still going on, the Boron will capture the neutrons and further speed up the cooling down of the core.

The plant came close to a core meltdown. Here is the worst-case scenario that was avoided: If the seawater could not have been used for treatment, the operators would have continued to vent the water steam to avoid pressure buildup. The third containment would then have been completely sealed to allow the core meltdown to happen without releasing radioactive material. After the meltdown, there would have been a waiting period for the intermediate radioactive materials to decay inside the reactor, and all radioactive particles to settle on a surface inside the containment. The cooling system would have been restored eventually, and the molten core cooled to a manageable temperature. The containment would have been cleaned up on the inside. Then a messy job of removing the molten core from the containment would have begun, packing the (now solid again) fuel bit by bit into transportation containers to be shipped to processing plants. Depending on the damage, the block of the plant would then either be repaired or dismantled.

Now, where does that leave us?
The plant is safe now and will stay safe.
Japan is looking at an INES Level 4 Accident: Nuclear accident with local consequences. That is bad for the company that owns the plant, but not for anyone else.
Some radiation was released when the pressure vessel was vented. All radioactive isotopes from the activated steam have gone (decayed). A very small amount of Cesium was released, as well as Iodine. If you were sitting on top of the plants’ chimney when they were venting, you should probably give up smoking to return to your former life expectancy. The Cesium and Iodine isotopes were carried out to the sea and will never be seen again.
There was some limited damage to the first containment. That means that some amounts of radioactive Cesium and Iodine will also be released into the cooling water, but no Uranium or other nasty stuff (the Uranium oxide does not “dissolve” in the water). There are facilities for treating the cooling water inside the third containment. The radioactive Cesium and Iodine will be removed there and eventually stored as radioactive waste in terminal storage.
The seawater used as cooling water will be activated to some degree. Because the control rods are fully inserted, the Uranium chain reaction is not happening. That means the “main” nuclear reaction is not happening, thus not contributing to the activation. The intermediate radioactive materials (Cesium and Iodine) are also almost gone at this stage, because the Uranium decay was stopped a long time ago. This further reduces the activation. The bottom line is that there will be some low level of activation of the seawater, which will also be removed by the treatment facilities.
The seawater will then be replaced over time with the “normal” cooling water
The reactor core will then be dismantled and transported to a processing facility, just like during a regular fuel change.
Fuel rods and the entire plant will be checked for potential damage. This will take about 4-5 years.
The safety systems on all Japanese plants will be upgraded to withstand a 9.0 earthquake and tsunami (or worse)
I believe the most significant problem will be a prolonged power shortage. About half of Japan’s nuclear reactors will probably have to be inspected, reducing the nation’s power generating capacity by 15%. This will probably be covered by running gas power plants that are usually only used for peak loads to cover some of the base load as well. That will increase your electricity bill, as well as lead to potential power shortages during peak demand, in Japan.

[Pata-Hari]

Marco, o tema é o crescimento ou não de vários sectores da economia por causa da destruição do terramoto. Regredir, não regredirá. Ou se avança no nuclear, ou na área médica ou nas renovaveis, no que for, será avanço e crescimento, além de reconstrução.

[MarcoAntonio]

Bem, mas imaginemos que a parte nuclear se torna importante. Não deverá ser um impulso a investimentos médicos e a mais investigação quer na área médica quer na tecnologia nuclear?

A discussão em torno do Nuclear vai aquecer concerteza (aliás, já começou) mas a longo-prazo qual vai ser o efeito, não sabemos ao certo...

O efeito até poderá vir a ser positivo quando a ocorrência for analisada a frio.

Afinal, para já (e não se prevê que passe disso) as centrais nucleares aguentaram uma tremenda prova de fogo com consequências mínimas...

[Pata-Hari]

Bem, mas imaginemos que a parte nuclear se torna importante. Não deverá ser um impulso a investimentos médicos e a mais investigação quer na área médica quer na tecnologia nuclear?

[MarcoAntonio]

I remain very worried about the inability of the Japanese government to gain control of the problems at the second plant, because the longer the crisis goes on, the more steam builds, and they have to release that steam, which has radiation in it. That would be the Chernobyl situation. The market is not down enough right now to handle a Chernobyl situation.

Isto não é verdade, não será nada como Chernobyl, a reacção e as condições em que ocorreu não são as mesmas de todo...

[Ulisses Pereira]

Marta, a esse respeito deixo um artigo de hoje do Cramer que fala disso e outro artigo em que ele está preocupado ainda com o que aí vem em termos da questão nuclear.

Why I'm a Buyer

By Jim Cramer
RealMoney Columnist
3/14/2011 10:01 AM EDT

"First, a caveat before you read this: We should not have to discuss anything but how to help the Japanese. That's the first priority. It cannot be overstated, and you could argue that all commentary about what could happen financially is an affront to the victims. Ethically it does seem wrong. Ethically it is sacrilege.

So why do it?

Because my experience is that people more than just information about the tragedy and sympathy for the victims. They also want help on their own financial situation. They want to do the right thing. They do not want abdication from me or people like me. They look to us because of our experience and our ability to give context to events.

For me, there is ample evidence that there are many misinformed judgments being made about what will happen now. For example, the perception is that the economy must slow because of the events in Japan. I do not necessarily think that is the case. Historically, rebuildings -- after Katrina, or the storms in Australia, or the terrible hurricane in South Florida not that long ago -- spur a large amount of economic growth. They unleash reserves from insurance companies that is new money. They force governments to make emergency loans as fast as possible. Rebuildings lead to TREMENDOUS economic activity.

That activity then leads to orders for equipment to rebuild and for materials to rebuild. Right now, for example, Japan has a massive power shortage. So much of their power has been taken offline. To rebuild power, you need gigantic amounts of materials and earth-moving equipment and cranes. In the interim, you need diesel generators to provide power for emergency situations.

In short, you need Caterpillar (CAT - commentary - Trade Now). Go to their website. Look at the breadth of product they have. Almost every single element of their production line, including the one picked up from Bucyrus, will be boosted by this earthquake and tsunami. I would predict a gigantic amount of hiring by CAT to meet this demand.

You need contractors to rebuild Japan. There are many contractors worldwide. I have been highlighting Fluor (FLR - commentary - Trade Now) because it has a big office in Tokyo and is one of the companies with the rare breadth of knowledge to build power plants of all kinds -- although it is not a nuke builder like Shaw (SHAW - commentary - Trade Now) -- and because it can build the liquefied natural gas terminals needed to have Japan switch to all nat gas for new plants. I think the nuke situation is dire enough that new nukes are unlikely, while coal will be discouraged because the Japanese are realistic that there is no such thing as clean coal.

Then there will be the huge amount of copper and aluminum that will be needed to rebuild electric power liners and to provide the materials for the turbines for the nat gas engines. If you go to Alcoa's (AA - commentary - Trade Now) website, you can see that turbines are a huge business for Alcoa, and they have been a bad business. I think that won't be the case going forward.

All of these are just microcosms of what happens when a country basically goes offline and has to start over again.

In the meantime, the Japanese will have less economic activity that requires oil burning. They just can't bring the stuff in, because there is a dearth of places to refine it. That's going to cause a short-term glut like we have in this country. It is also going to trigger a huge amount of futures selling by producers anxious to lock in prices before they go down, which is going to put more pressure on crude.

That's why, despite the Bahrain protests -- which seem much more serious than the Saudi "Day of Rage" protests but seem more blatantly inspired by our Iranian Cold War enemies (it is that, isn't it?) -- the price of oil is not being affected in a positive way. The more it becomes clear that Iran is trying to bring down Bahrain, the more likely it is that the U.S. Navy is going to implore Obama to back Bahrain because it is the home of our most important fleet.

All of this amounts to a resurgence of economic activity that could not come at a better time, because I think it has become obvious that the Chinese downshift from 10%-11% growth to 8%-9% was causing a glut to develop in all materials and material-handling companies. Japan can siphon off product meant for China and take up that supply.

That's why I am a buyer here, not a seller. Too much good happening economically in the wake of the terrible, horrible loss of life in a great country and a great ally.

I know that when the proceeds of my charitable trust are freed, I will try to devote as much as I can to the Japanese. Again, a microcosm of how profits from stocks can help those in need. So the regret of having the discussion is mitigated by the good deeds that capital gains can do for those who most need it.

Random musings: I would be shorting all solar and wind stocks. They are stocks of hope, not of rigor. Thanks to Matt Horween, my accounting and chartist friend, for pointing that out.

At the time of publication, Cramer was long Caterpillar, Fluor and Alcoa. "

(in www.realmoney.com)


E aqui está o outro.


Crisis and Uncertainty

By Jim Cramer
RealMoney Columnist
3/14/2011 3:56 PM EDT
"Why go home long? That's what so many are thinking. We have Bahrain in what looks to be chaos, or at least in martial law, which could make it possible for the Iranians to work huge mischief. No one thinks that the nuke situation in Japan is stable, and it could continue to worsen. A breach of containment would produce a great deal of radiation.

At the same time, though, if we get any relief from the nuclear issue and if the Bahrain issue dissipates, then you can understand that tomorrow will be a day when the reconstruction plays will not be denied.

I remain very worried about the inability of the Japanese government to gain control of the problems at the second plant, because the longer the crisis goes on, the more steam builds, and they have to release that steam, which has radiation in it. That would be the Chernobyl situation. The market is not down enough right now to handle a Chernobyl situation.

The information is too sketchy. I cannot blame anyone for not wanting to own stocks because of this nuke situation. But otherwise, it would be clear sailing on the rebuild, and I do believe that Bahrain is under control, despite the footage, because the footage never seems to encapsulate the full story.

I am skeptical about what's happening in reactor No. 2. That's my principal worry. Hoping for the best. Fearing the worst as I prepare for my sixth anniversary show. "

(in www.realmoney.com)

[AC Investor Blog]

É engraçado porque a história nos diz que o esforço de reconstrução costuma trazer crescimento económico. E os Japoneses têm o problema crónico de consumirem pouco (deveríamos promover programas de troca com os tugas...), porque trabalham muito (estão a ver o porquê do programa de troca...?)

Estamos assistir ao efeito catástrofe, e só depois anteciparemos o efeito crescimento.

[Pata-Hari]

É engraçado porque a história nos diz que o esforço de reconstrução costuma trazer crescimento económico. E os Japoneses têm o problema crónico de consumirem pouco (deveríamos promover programas de troca com os tugas...), porque trabalham muito (estão a ver o porquê do programa de troca...?)

[Bull Bull]

Os principais mercados accionistas do outro lado do Atlântico abriram em baixa, com os investidores a tentarem avaliar de que forma é que o terramoto no Japão irá afectar a economia daquele país.

O índice industrial Dow Jones segue a perder 0,27% fixando-se nos 12.011,3 pontos. O S&P 500 cai 0,35% para se estabelecer nos 1.299,68 pontos.

Por seu lado, o Nasdaq desvaloriza 0,04%, a negociar nos 2.714,56 pontos.

A Exxon Mobil cai mais de 0,5%, pressionada pela descida dos preços do petróleo devido à convicção de que o terramoto no Japão irá penalizar o crescimento e reduzir a procura de combustível.

A Qualcomm, maior fabricante de chips para telemóveis, recua mais de 1%, depois de a Oppenheimer ter dito que o sismo terá um impacto negativo nesta indústria.

fonte: jornal negócios.

Abri este tópico porque este assunto faz-me alguma confusão.
Por exemplo, o sismo do japão ao meu ver poderá levar a uma maior procura de equipamentos e de bens devido à perda dos mesmos. Imagino a quantidade de pessoas que terão que comprar um novo telemovel e outros equipamentos. As construtoras deverão fazer um bom dinheiro. A escasses dos alimentos poderá levar a uma maior procura. Por isso é que me faz confusão esta noticia