Monday, March 14, 2011

The truth about Japan's damaged nuclear reactors


Courtesy of Warren Meyer, writing at Coyote Blog, we are pointed to an excellent article at Brave New Climate that provides solid, factual information about the danger (or lack thereof) posed by the damaged nuclear reactors in Japan. Here's an excerpt.

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.

. . .

  • 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.


There's more at the link. Excellent, rational information to calm irrational fears.

Peter

13 comments:

Anonymous said...

The article is well presented. I am glad to see the clear statement regarding the loss of the generators due to flooding. This seems like a "for want of a nail" type of event.

I am not so certain about the evaluation there is a low level of risk. Now reactors 1, 2, *and* 3 (of 4 at Fukushima) have had explosions. Upon core exposure the Zircaloy fuel cladding reacts with steam to produce the hydrogen which has exploded.

The concern is not only the cooling to the reactors and integrity of the containment vessels, but with the spent fuel pools - most of which are located on top of the reactor buildings in this case. If the fuel in a pond starts to burn due to lost cooling, it can release a huge amount of radioactive material to the atmosphere. There seems to be some risk that a critical state will occur due to fuel melting and pooling. The boron added to the seawater is to reduce this risk.

To me this sounds very bad and as if there is not any adequate control of the situation.

Some links. The last one regarding weather patterns to the U.S.:

http://www.theoildrum.com/node/7638#more

http://www.theoildrum.com/node/7646

http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=1763

Old NFO said...

Good link and these folks got it right... The plant was scheduled to close this year anyway, as it was at end of life, so the dismantling was already in the plan.

Anonymous said...

While I agree with the "don't panic" thrust of Warren's discussion, this statement is misleading:
The intermediate radioactive materials (Cesium and Iodine) are also almost gone at this stage, because the Uranium decay was stopped a long time ago.
The half-life of Cesium-137 is 30 years or so, and that of the longest-life Iodine-129 is millions of years. Assuming the I-129 is only at trace levels, the next Isotope, I-125 has a halflife of about 60 days. So to say "it's almost gone" may simply mean it's diluted. or wind-borne to distant places. But it assuredly is not "gone."

Leatherneck

Anonymous said...

Leatherneck, in the comments at the blog the author clarifies: when the cesium contacts seawater, as is happening in Japan, there is a chemical reaction that neutralizes the radioactivity, making the half-life moot. He needs to bump that into the article for clarity, I agree.
LittleRed1

Betty said...

I hope it's all right, Peter. I feel so terribly bad for all those lives lost and survivors permanently traumatized and disrupted; they certainly don't need radiation to top it off. I just had to stop following the news on it because I can't stand the misery any more.

Anonymous said...

Peter, for some up-to-date info from the brilliant minds at MIT, check out their Nuclear Science & Engineering dept's biog at MITNSE.com.

Anonymous said...

Over at the Rott(nicediggie.net) there is an explanation of what is happening by a guy with years in the nuc-plant bidness. He does a really good job of expaining the situation.

dave said...

Red, would you mind clarifying your comment about "a chemical reaction that neutralizes the radioactivity?" I've never heard of a chemical reaction that changed the nuclear structure of an atom to induce stability in an isotope that is otherwise prone to decay.

raven said...

All the enviro wackos will use this as a excuse to continue the attack on nuke plants. No wonder there are problems, we have not been able to design and build a new one for 40 years.
Those bastards will not be happy until we are living in mud huts. I used to consider myself a conservationist- but the movement has been taken over by commies, driven by the desire to control peoples actions, using the purported "eco-benefit" as a smokescreen to enact a totalitarian state.

Crucis said...

I'm disgusted with all the fear mongering. One idiot was claiming the "fallout" would reach the west coast "any day now."

'Course the state media is trying their best to demonize it all. One (ABC?) even said there had been a nuclear explosion. They back-stepped some time later but the damage had been done.

There are plenty of articles going around that explains the issue and the danger is essentially nil except for the workers who have to go inside the containment vessel.

Unfortunately, the Japanese government is being so confusing and contradictory about every thing and that just makes everything worse.

Anonymous said...

Dave, according to what I've read, the radioactive cesium (Cs) settles. When it contacts seawater, it forms cesium hydroxide (CsOH) which then dissipates rapidly. Cesium hydroxide is a strong base but is not radioactive and has industrial uses, including color photography.

Sources: BraveNewClimate blog, "Cesium Hydroxide" in the industrial chemical section of www.chemicalland21.com and, yeah, Wikipedia for the stoichiometry.

LittleRed1

dave said...

Red, I think there's been some confusion. While combining Cs with water will make CsOH + H2, it doesn't transmute the unstable 137Cs into stable 133Cs. What it can do is turn the less-soluble metal into a highly-soluble hydroxide salt, enabling it to "dissipate rapidly;" that is, not making it stable, just spreading it around until it's not strong enough to be worth worrying about.

Only a nuclear reaction can transmute elements. Further, the decay product of 137Cs isn't 133Cs--137Cs emits a single beta particle, maintaining its mass but increasing its atomic number by 1 (from 55 to 56), becoming 137Ba. About 95% of the 137Ba is a high-energy state, which decays with a gamma ray to the ground state (but with no elemental transmutation). All of this happens without regard to whether or not the Caesium atom is chemically bound to anything else. The only advantage of the -OH ion would be to spread it around so that no one location got too much radiation.

Nuclear physics is fun!

Anonymous said...

OK, still no reason to panic, but there is no water left in the spent fuel pool of reactor 4 at Japan's Fukushima nuclear plant, resulting in "extremely high" radiation levels, the chair of the U.S. Nuclear Regulatory Commission warned Wednesday.

It's getting seriouser by the day.

Leatherneck