Thursday, March 31, 2011

Over Here

Gamma ray spectra of particles in Seattle's air 
The spread of radiation continues with parts of Japan outside the evacuation zone recording radiation levels higher than the levels found around Chernobyl in regions Soviets deemed uninhabitable.  This situation may become clearer in the next few days.  Close to the Fukushima plant there is very little reliable information on radiation levels but farther away we have some very comprehensive coverage, including:

Live updates to radation levels from around Japan: http://japan.failedrobot.com/

(Here's a similar map: http://www.targetmap.com/viewer.aspx?reportId=4870 courtesy former SFSU student Joey F.   He survived the quake in northern Japan, and luckily lives on the west coast where the tsunami impact was minimal. )

NY times has a map of the radiation and several other maps regarding the quake:
http://www.nytimes.com/packages/flash/newsgraphics/2011/0311-japan-earthquake-map/index.html?view=daiichi


An article in New Scientist says that the amount of Cesium released now rivals that released by Chernobyl.    Which leads  to the question for us here in the US (especially here on the West Coast of the US): what are the long term health risks, Over Here?

The first step is to measure the radiation levels here as best we can.   This site has the IAEA's forecast for spread of Cs-137 (scroll down to see a global map):

http://blog.alexanderhiggins.com/net2/japan-nuclear-plume-radiation-map.aspx

Meanwhile testing of samples on the west coast is ongoing.   At my home institution, San Francisco State, Daniel C. is using a geiger counter to measure radiation levels at the air intake for Thornton Hall.    He's been able to record the number of decays per unit time and had noticed some variation depending on how much rain we get.  More information can be provided if one examines the gamma ray spectrum of the sources, because certain elements give off gamma rays of characteristic energies when they decay.
The figure above comes from an article discussed here in which UW researchers/students detected several isotopes, most noticably I-131 from the disaster in Japan. A similar project is underway at U.C. Berkeley:

http://www.mercurynews.com/science/ci_17719939?IADID=Search-www.mercurynews.com-www.mercurynews.com&nclick_check=1

I just learned from my friend Josh that radiation has now been detected in milk in Washington AND California.  The levels of I-131 are extremely low, so no need to panic yet.  But I am glad that I've been feeding my family and myself high levels of non-radioactive Iodine-rich healthy food (eg. yogurt, seaweed, plus bananas for Potassium).   One note of caution in interpreting news media stories:

 I just learned  from this interview with Dr. Helen Caldicott: that the descriptions of radiation given in the press as "equal to one chest X-ray" are meaningless and deceiving if we are talking about radioactive matter getting into the body.   Medical X-rays come from the outside and do not concentrate anywhere in the body.  But Iodine concentrates in the thyroid gland and I-131 was responsible for hundreds if not thousands of cancers at Chernobyl....in spite of its short half life!  Another example: the skin does a great job of stopping Alpha particles, however if an Alpha emitting source (with a short half life) is ingested the results can be fatal, as shown in the murder of a Russian Ex-KGB spy with Polonium 210, an Alpha emitter.

Wednesday, March 30, 2011

More Criticality

Gee, I must be prophetic or something: a day after my blog post on Criticality, the discussion of ongoing fission reactions has begun to surface major media sources.  First from a Bloomberg Article:


 ...melted fuel in the No. 1 reactor building may be causing isolated, uncontrolled nuclear chain reactions, Denis Flory, nuclear safety director for the UN’s International Atomic Energy Agency, said at a press conference in Vienna.  Nuclear experts call these reactions "localized criticality," which will increase radiation and hamper the ability to shut down the plant. The reactions consist of a burst of heat, radiation and sometimes an "ethereal blue flash," according to the U.S. Energy Department’s Los Alamos National Laboratory web site. Twenty-one workers have been killed by "criticality accidents" since 1945, the site said.  Radioactive chlorine found March 25 in the Unit 1 turbine building suggests chain reactions continued after the reactor shut down, physicist Ferenc Dalnoki-Veress of the James Martin Center for Nonproliferation Studies in Monterey, California, wrote in a March 28 paper
The paper cited above has a detailed analysis, and suggests that Chlorine from salt water has been irradiated with neutrons during a criticality incident to produce the radioactive isotope: Cl-38.  This isotope isn't a big threat; the point is that if criticality is going on continuously or sporadically workers are at a serious and unpredictable risk of extremely hazardous radiation.

Second,  the Guardian interviewed the US expert (on GE's BWR's) who installed the Fukushima reactors who who said:
radioactive core in a reactor at the crippled Fukushima nuclear power plant appears to have melted through the bottom of its containment vessel and on to a concrete floor, experts say, raising fears of a major release of radiation at the site.
In case you missed the movie, this is basically the China Syndrome, where the reactor fuel becomes a radioactive lava that melts a hole in the containment vessel and drips wherever gravity will take it.

While we still haven't seen any close up photos of the reactors or the spent fuel ponds, two videos of the plant, from the Ground  and  from the Air give us a pretty clear idea that the spent fuel pools at least (which have no containment vessels) are seriously thrashed.

Also this moving first hand account from one of the workers on the scene contains the following interesting quote.
Most of the Fukushima complex is still too irradiated to stay in for any length of time, the workers said. In their two hours off – and whenever radiation spikes – they retreat to a “safe haven”, a two-storey earthquake-resistant building at the centre of the complex constructed in July last year.
Its crazy that the safe bunker was just constructed last year!  If this quake had happened 8 months earlier, its likely that the entire plant would have been abandoned and left to meltdown after only a week or so!   (NOTE: this may yet happen, and is Prof. Michio Kaku's 'worst case scenario').  (NOTE2: The story above contains an apparently untrue claim that 6 workers were killed when #3 exploded.  No fatalities so far, just injuries, and radiation sickness)

Monday, March 28, 2011

Thinking Criticality

If you are involved in education, you probably read the title as "Thinking Critically".  But the word I want to discuss here in Criticality.   In the nuclear context, the critical mass is the minimum amount of a fissile material needed to create a chain reaction.   All nuclear reactors sustain a chain reaction while they are working.  (They can stop the chain reaction at any time using control rods, whereas a nuclear bomb, using highly enriched Uranium/Plutonium, creates a chain reaction which is out of control.)  Criticality accidents, where the chain reaction is triggered by mistake, can be fatal, and took place during the Manhattan Project (as dramatized in "Fat Man and Little Boy") and more recently at a Japanese nuclear facility in 1999.

So lets think Critically about Criticality.

When the quake struck, control rods deployed and the three active reactors #1,2,3 all stopped their nuclear chain reactions, we are told.  We wouldn't then expect any more chain reactions.  However, nuclear fuel has the inherent potential to create a chain reaction, because of the high energy of every uranium or plutonium nucleus.  So my question is: to what extent have the reactors re-started fission chain reactions?  I find the following evidence for this happening:

--The buildings housing Reactors 1&3 exploded.  The hydrogen that caused these explosions was from the outer layers of the fuel rods reaching such high temps. that they extracted the Oxygen from the water, leaving Hydrogen behind which exploded.   This was reported as a "partial meltdown"

--Early on, the US stressed the importance of the spent fuel pool at reactor #4....I now realize why.  This spent fuel pool contained not just spent fuel but active fuel removed from the reactor core for an inspection.  This is extremely dangerous because the spent fuel pools have no containment structures around them.  Building #4 is also in ruins, destroyed by a fire in the pool.  How does a pool of water catch on fire?  The answer must be that there was no water in the pool.  The 1000+ rods there produced so much heat that they boiled the water away, then without coolant, they heated up more caught fire and probably melted down also.  TEPCO said of this "we cannot rule out the possibility of re-criticality".  Any incident of additional fission has serious health implications since the fission products (eg. I-131, Cs-137, Sr-90)  are carcinogenic and because this will cause increased radiation locally which is hazardous to worker on the scene.  So TEPCO must be carefully trying to determine if any when any of these reactor go critical again.  They just haven't shared that information.

--The presence of short-lived isotopes suggests that fission reactions are ongoing.   An earlier claimed detection of I-134 (with a half life of 1 hr. ) has been  debunked.  But it has now been over two half-lives of I-131 (2x8 days) so 80% of the original I-131 is gone.   Further detections of this isotope in large quantities would indicate ongoing fission.    TEPCO and/or the Japanese govt. yesterday admitted that reactor #2's fuel rods underwent "partial temporary meltdown" last week.  I'm guessing this is in addition to the initial meltdown.  "Temporary", I take it, is their code word for saying "we think criticality has stopped here."

Part of critical thinking is to analyze what is being discussed and see if it is consistent with the facts or if it is not supported.  But another  part of critical thinking is to ask the question "what is not even being discussed?"  In this age of media distraction, I would argue that this aspect is more important.  So here is a list of my critical questions.  If any of you have seen them answered please let me know (you can post a comment below).  I'd love to see the Japanese press raise some of these questions.

1. Why are there no detailed photos of the 3 reactor cores which melted down?  This is the first thing TEPCO should/would have done even before the radiation levels got to high to prevent anyone from getting close.   I'm guessing these photos exist and are not being released.

2. Why are there no detailed photos of the state of the spent fuel pools, esp. in reactor 4?

3. Why has TEPCO not published a detailed list of when and where "re-criticality" is likely to have taken place, and where it has not?   For each reactor TEPCO, must be able to say either:
  • fission did or probably did restart at these times  OR
  • fission did not restart and is not currently ongoing   OR
  • we have no idea: fission could be going on in there and we wouldn't even know.
If the answer is the third of those, I'd be worried.

Good news/Bad News

There's bad news and good news from this past weekend:

Radiation levels in Reactor #2 are 100,000 times above the normal level.

Unfortunately, this is the good news.


"Good" because a previous report suggested that radiation levels were 10 million times normal level.  This extreme reading has now been dismissed as erroneous, "due to operator fatigue".

The bad news is:

--That levels inside reactor 2 are over 1000 mSv/hour.  We don't know how much over this level because apparently the dosimeters used to measure radiation levels don't go that high.   This is a little hard to believe given that the range from 1000mSv to 6000mSv is the range where severe radiation sickness and death occur....that's just the range I'd want to be sensitive to in a case like this.  (workers at a different Japanese nuclear facility received doses in this range and above at an earlier criticality accident ; two of them died)  The Japanese gov't. is extremely upset with TEPCO for releasing the erroneous data.  However I can easily understand that it could have occurred when, a day after two co-workers were sent to the hospital with radiation burns, one worker  got a high reading and got the hell out.

-- Iodine-134 was detected.   This is the most troubling observation to me.  We've all been talking about radioactive I-131, which has a half life of 8 days.  But I-134 has a half life of just under an hour.   It is also a fission product.   To me this implies only one thing:  that fission was still going on inside somewhere (probably in the core) within a few hours of when that reading was taken (Saturday, I think).  If fission is ongoing it means that one  or more of these reactors have "turned themselves back on".

--To control the situation (and cool the fuel), they need to continuously circulate water, which means fixing the pumps.   To fix the pumps, they need safe (ie non-lethal) conditions for the workers.  To make it safe for the workers, they need to remove the highly radioactive water that's pooled there now, which they are trying to do.  But CNN is reporting that


But Nishiyama noted that there is no place to put water pooled in the No. 2 building's basement.  The plan is to extract the water using what he called a condenser. But that apparatus is "almost full," as are several storage tanks nearby. A similar challenge is holding up the removal of collected water in the No. 3 unit's turbine building basement.
In other words, with each passing day, we are getting farther and farther away from solving the problem, rather than closer.

--There is growing but indirect evidence that a leakage of Uranium or Plutonium has occurred.  This has not been stated directly in the media, but I am inferring it based on articles like this one from Kyodo news, which states that a measurable flux of neutrons is coming from somewhere outside the reactors. The neutrons could be from spontaneous fission of Pu-240 or perhaps U-238.    I'm going to go out on a limb here an make my first prediction in this blog, based on rather sketchy evidence:  in the next few days, we'll get a report that the reactors have released Plutonium or Uranium into the environment.   TEPCO may already suspect this is happening, but since Plutonium is such a frightening nuclear buzzword, they are likely hesitant to make any such announcement until they have both confirmation and a plan of action for how to deal with it.

That's all I've got time for now, I'm working on research paper, a proposal and repainting the bathroom at home.

UPDATE:  About an hour after making this post,  TEPCO admitted a Plutonium leak.   In fact they said that the soil samples were collected about a week ago, so Plutonium was on the ground there for a week without anybody knowing (unless you assume that TEPCO has been sitting on this information...which I am not claiming).

Sunday, March 27, 2011

Sources

I've been asked where to get good information regarding Fukushima Daiichi nuclear crisis.  While I understand the principles of fission and some of the different reactor types, I'm not an expert in nuclear reactors (or nucular reactors!).  Here are the sources of information I've been using, roughly in the order that I check them:

1. NYTimes status updates on the six reactors:
http://www.nytimes.com/interactive/2011/03/16/world/asia/reactors-status.html
as well as NYTimes coverage in general.

2. Wikipedia's article on the disaster, in particular the daily update part:

http://en.wikipedia.org/wiki/Fukushima_I_nuclear_accidents#Third_week

3. The Union of Concerned Scientists, of which I am a member, has a lot of good background information as well as a daily press conference with journalists which they make available here:

http://www.ucsusa.org/nuclear_power/nuclear_power_risk/safety/japan-nuclear-crisis-briefings.html

4. Brad Friedman's Blog   (and Twitter Page).  Friedman appears to be a progressive journalist of national prominence, focusing on election issues.  But he seems to have  access to some good sources in Japan.

5. Just discovered this one:  MIT's Nuclear Science & Engineering Dept.  has quite a bit of useful information.  See, for example their take on  worst case scenarios.

6. Dr. Michio Kaku's blog  Dr. Kaku is a theoretical physicist who has long been skeptical of fission power.  Some of my physicist colleagues criticize his somewhat theatrical presentation.   On the other hand I appreciate his directness.   (But then I'm biased: Kaku interviewed me for his book "Parallel Worlds".)  Also Kaku is currently on a tour promoting a new book so his postings on the crisis are interspersed with updates relating to the book.

Saturday, March 26, 2011

Nuclear Demon is Thirsty

This photo wins the sad irony prize.  On the day after the largest city on Earth sold out of bottled water,  it shows a barge full of fresh water being towed by a tug.   "Oh good", I thought.  "Fresh water for Tokyo's infants, so they don't have to drink radioactive tap water."   But reading the caption more closely, I discovered that the barge is actually heading north to Fukushima Dai-ichi and the fresh water will be dumped onto the nuclear reactors.   At that point it will become irradiated, and either evaporate into the open air or  flow into the ocean.   After a week of feeding the reactors  sea water, the salt that was left behind has begun to clog up the works....the nuclear demon inside them now wants fresh water...and he'll get it.

Friday, March 25, 2011

The China Syndrome

Last night my wife Rachel and I watched the 70's movie "The China Syndrome".  The movie's producer & actor, Michael Douglas, described it as a "classic monster movie" with the role of the monster being replaced by a dangerously malfunctioning nuclear power plant.  The movie is famous for bringing awareness about the dangers of nuclear power to the US audience.   Critics claiming the movie was overblown were silenced when, 12 days after its release, the US experienced its worst civilian nuclear disaster.  The partial meltdown at Three Mile Island, unfolded almost exactly as portrayed in the movie: faulty gauges led reactor workers to believe the reactor had too much coolant, when in fact it had not enough, causing the radioactive fuel rods to heat up and melt down.

Seeing the movie for the first time,  I was surprised how much of it was about the media, and how the societal role of journalists is being diminished by TV execs clamoring to boost ratings to please their corporate advertisers.   (I was also stunned at how new, clean, uncrowded  LA's freeways looked in the 70s!) The movie is full of cinematic drama, but none of that can compare to a story I just read about workers inside the Fukushima Daiichi power plant in Japan.

As this NYT article describes, workers inside the plant survived the largest quake in Japanese history, only to be choked by smoke in the darkness.  With a deadly tsunami approaching at over 100 mph, they were actually trapped behind automatically locking doors by their TEPCO supervisors!!

"I felt things shaking, and then it went crazy," Nishi recalled in an interview. "I was shouting, Stop! Stop!" Then the lights went out, leaving about 200 workers inside the reactor in near-darkness since the structure has no windows.
A small red emergency light started blinking. "Then some kind of white smoke or steam appeared and everyone started choking," Nishi said. "We all covered our mouths and ran for the door." But the door leading outside was locked, shut down automatically during the temblor to contain any leakage... "Everyone was screaming." ... with workers shouting and pleading to be allowed out, supervisory TEPCO employees appealed for calm, saying that each worker must be tested for radiation exposure...
 Nishi recalled angry shouts from among the workers including expletives from a couple of Canadians. "We were shouting that the reactor structure was going to collapse or that a tsunami might come,"...Eventually, TEPCO workers tested about 20 people before giving up and throwing open the doors.

Today's developments:

  • In a situation eerily similar to one scene in the movie, a puddle of highly radioactive water accumulated on the floor of Reactor #3, and three workers stepped into it.  They received radiation burns on their legs, and were hospitalized.  They got a dose of 2-6 Seiverts...not milliSeiverts.  I sure hope only their ankles were exposed, because this dose in general can cause "hemorrhaging, diarrhea, peeling skin, sterility and death if  left untreated", according to the NIH.   There are sketchy reports they have internal effects as well.
  • We now have likely breaches the containment vessels for units #1, #2, and #3, which are leaking radioactive water.    One of the reasons "this is nothing like Chernobyl" is that Chernobyl didn't have a containment vessel.  Now, effectively, neither does Fukushima #1,2,3.  The seawater that was sprayed in has evaporated and left thousands of pounds of salt behind.   This may clog things up but isn't inherently dangerous.  
  • The amount of Cesium-137 released by Fukushima Daiichi is now HALF that released by Chernobyl...and things are not getting any better.  People should stop saying "this is nothing like Chernobyl" and start saying: "this is the worst nuclear accident in history except Chernobyl." This report has comprehensive details.  
  • The toxicity in Tokyo & Chiba's drinking water has moved to Hitachi and Tokaimura and has been found in 6 prefectures.  If levels stay down in Tokyo, at least means that fewer infants will be exposed to radioactive tap water above the safe levels.
While most media sources are willing to say "workers struggle to bring reactors under control", they don't seem to be willing to say what is clearly implied by this statement: These reactors are out of control.    The longer this goes on, the more likely it seems to me that they will not be able to be brought under control unless and until an unknown number of people sacrifice their lives.

Thursday, March 24, 2011

Megacity Bugout?


I have a son who is 1 year old and will be 2  in May.   When I was around his age, one place I got to visit was Tokyo.   My parents took me there on a trip from Manila, where they were living (and where I was born).   I can't say I remember being an infant in Tokyo, but I can say I've been there.

Tokyo is the #1 Largest "Megacity" in the world with a population (34.2 million people) equal to California's in one huge metropolitan area that includes Yokohama.    Officially there are 8.6 million within the city limits (the green oval you see in the LANDSAT image above is the Emperor's Palace)  Yesterday, the Japanese health ministry announced that Tokyo's drinking water was too radioactive for infants to drink.
Ei Yoshida, head of water purification for the Tokyo water department, said at a televised news conference that Iodine 131 had been detected in water samples at a level of 210 becquerels per liter, about a quart. The recommended limit for infants is 100 becquerels per liter. For adults, the recommended limit is 300 becquerels. 
With about 9 million people affected, (including those in a few nearby "towns" of 100,000+ people each) stores sold out of bottled water in an hour of panic buying.  This news left me to ponder:

-- While infants were cautioned not to drink tap water eg. in formula, pregnant mothers were not so restricted, even though experts cited in the NYTimes article above said that pregnant mother are at high risk, that they absorb Iodine and pass it through the placenta to their fetuses.

-- At first I was hopeful that this announcement might encourage somewhat more reliance on breastfeeding over using formula.   However, it dawned on me that there are mixed messages to these mothers as to whether they can consume the tap water or not.   We know that our fellow mammals, cows, when making milk, do concentrate and pass along radioactive Iodine they've taken in from the environment (this was a big problem at Chernobyl when humans drank that milk).  So I see no reason to assume that human brestmilk is not similar.    I find it discouraging that the NYTimes article about nutritional needs of infants doesn't even contain the word "breast" !!

-- A 50% increase in the I-131  levels in the water would cause the safe limit to (300 Bq/liter) to be exceeded for all adults.  (NOTE: Late breaking stories are now reporting a decline in radiation in the drinking water--let's hope this is permanent and real, not just a response to there now being no alternative since bottled water is sold out!).  Even at the current level (200 Bq/liter) is it really  OK for 9 million people to be getting 2/3 of the unsafe dose?  Suppose, at this level, that an adult can be 99.9% sure they won't get thyroid cancer.  Well 99.9% safe means 0.1% unsafe.   So in Tokyo's population, that would mean 9,000 cancer cases.   I just made those numbers up, so don't use them.  But the point is that for a population that big you need a much higher margin of safety.  Tokyo is big enough to beat 1 in a million odds.

"What's the worst case scenario?"  This question is often asked.   To me the worst case would be if the a big new radioactive release, (eg of Plutonium in the MOX fuel at reactor 3) coincided with a wind shift that puts Tokyo/Yokohama in the line of fire.  Winds have supposedly carried the fallout over the ocean up till now  (though this doesn't explain how it got into Tokyo's water?).  But weather forecasts are now calling for a change in wind direction, within days turning  Tokyo's millions into potential downwinders.   Imagine what would ensue if 1.) all people with children or 2.) everybody decided they should get out of "Dodge".    Japan has extensive earthquake/emergency plans, but how do you evacuate a population the size of California's ???   Has anyone  considered this (worst case) possibility?  Here's google.com's answer:




ps.  This post is dedicated to my parents: my father who lived in Yokohama, and my mother who decided to marry my father after visiting Tokyo.  I am grateful to them for their decisions  which have affected my life and for their continued  inspiration and support. 

Tuesday, March 22, 2011

Elemental

Here is a periodic table.  I like them because they always amaze me with the bewildering array of elements that stars have been able to produce in 13.7 billion years.  As you remember, each element comes in different "flavors" or isotopes, each of which has  different number of neutrons.  Usually only one isotope is stable: the rest decay radioactively.   Check out U (Uranium) and Pu (Plutonium) down at bottom row.  These are in nuclear reactors and bombs.  When they decay (fission) they have  a huge number of options for how to do it.  Many of the resulting elements, the "daughter products", are themselves radioactive and quickly decay.   This process leaves us mainly with three radioactive elements:

Iodine-131 (Half life: 8 days)
Strontium-90  (Halflife 29 years)
Ceasium-137   (Half life 30 years)

In coping with radioactive "fallout" from a fission reactor, one option is to load up on stable Iodine before the I-131 arrives.   Similarly, Cesium behaves much like Potassium (K) since they are in the same column on the periodic table and Strontium (Sr) behaves like Calcium.  This suggests we also can increase our intake Calcium (eg dairy products) & Potassium (eg bananas), to diminish uptake of Sr & K


My friend Monique, (whose mother is a survivor of the Hiroshima bombing) posted the first official comments on this blog, and pointed out that the radioactive samples being detected here in the US are mainly Iodine.   That is good because the half life of Iodine 131 is shorter, meaning that whatever effects are present will only be with us for a relatively short time.

Conversely, in Japan, we can expect the effects to last a long time.   Already the US has banned food from four Prefectures near Fukushima

http://edition.cnn.com/2011/HEALTH/03/22/japan.food.safety/index.html?hpt=T2

While the ocean waters are measured at  dozens of times the usual levels, calling into question the safety of fish stocks (which supposedly aren't much affected if they fish come from the deep).  It seems likely that many tons of food will need to be destroyed, even as survivors struggle to get adequately fed in shelters.

Responses

I'd like to share some comments and responses some of you have made.

From Erica, who was hospitalized for a while, when she had serious symptoms of Chron's colitis.:
 I like this  article: http://technorati.com/lifestyle/article/what-does-being-safe-really-mean1/ 

From what I've found, each  abdominal x-ray was about 8 mSv, each abdominal CT was between 10 and  30 mSv. The World Nuclear Association says that 100 mSv per year is the lowest dose at which there is an increased risk of cancer.  At the  time it seemed like all the x-rays were necessary because I was in a  
critical situation, but I still wish that they had been up front about  the possible long-term effects of such exposure. I probably would have  declined some of the x-rays as I suspected they were going overboard.

My thoughts:  it seems like the 100 miliSeivert (mSv) reading is the one to focus on.  Above that and you can start getting radiation sickness  like nausea.   Increase to 1000 mSv and you get even worse symptoms, like bleeding and at 5000-10,000 mSv the person will die, depending on how much medical care they get.   The Japanese govt./TEPCO upped the radiation dosage it will allow its workers to take to 200 mSv.   They now have brought in some 6000 people according to one report.   This is way up from the 100 person shifts that were being swapped out after they overdosed on radiation.  This suggests that Japan is employing a strategy similar to that used in dealing with Chernobyl, where the USSR Govt. conscripted 600,000 men to be "liquidators",  each taking a high, but survivable dose to help clean up the plant.   (This was after the initial accident which killed dozens due to radiation overdoses).   Radiation levels at the plant are sometimes over 100 mSv per hour, so in a matter of minutes the workers are getting the maximum safe amount for one YEAR.    For reference, levels like normal "background" levels are 2-3 mSv per year!   So a single CT scan gives you, in a few minutes 10x what you would get per year normally, but this is about 5x less than a dangerous level.

Also:  I wish people would be up front when it comes to all things radiation related!  There's an assumption, with which I strongly disagree, that the general public is "not well educated" enough to understand such things and are better off being uninformed and trusting professionals.

From Josh:

I have a batch of carrots growing in my backyard, and there have been rains in the past few days with this radiation cloud supposedly overhead. Should I ditch the carrots & soil? ?Or no need to be concerned about that?
My response:  I don't really know how much radioactivity could be accumulated in carrots, and I'm sure US authorities would say "don't worry."  But my response is:  if you don't eat garden grown food, where is the food you are eating coming from anyway?  Nearly all of my food comes from California, which also feeds the nation with its extensive farms.    So whatever the radiation level in your carrots,  you are unlikely to be able to find food with an obviously different radiation level, since the radiation is now all spread out here in Calif.  Things would be quite different if we were in Japan where it is very likely that some growing areas will be much more affected than others.

As before, I think the best thing we can do is eat a healthy diet and fortify our bodies and our childeren's bodies against the small doses of radiation that we are now getting.     In the next post, I'll discuss the radioactive isotopes  involved and what we can do to preemptively counter their effects.

Monday, March 21, 2011

One Day in A Nuclear Age, They May Understand our Rage

One group of people whose rage I can understand is Japanese farmers.   Recently, spinach and milk samples have turned up with radioactivity levels above the legal maximum in districts near Fukushima Dai-Ichi nuclear plant.  In this story/video:


http://edition.cnn.com/2011/WORLD/asiapcf/03/20/japan.nuclear.food/index.html?hpt=T2

We see an 80 year old Japanese woman, who is dismayed when a news crew with Geiger counters finds her spinach radioactive.     I sympathize with such farmers and hope they are adequately compensated by TEPCO.    A few points regarding this story:

--Why spinach?  Does it soak up Iodine or other isotopes more readily?   Its only been days since the first releases of radation...that seems a little quick to me.

--The story assumes that the radiation in food  was caused by the recent releases.  But were they even checking before?  Its seems possible that the Fukushima plant (which has one of the worst safety records in Japan) could have been releasing low level radiation for some time and that the radioactivity has been in the food all along.   A scientific response to hearing any measurement is:  "in comparison to what?"

--Press is saying that although some food exceeds rad. limits, there's still "no immediate health risk" from eating it.   Here's one way to translate that statement:

"no immediate health risk" = " get lethal thyroid cancer in 10 years"

One thing I've learned recently about radiation is that it is much more dangerous when ingested.  Surprisingly, our skin is a useful barrier to radiation just as it keeps out other foreign substances.  And many types of radiation can only penetrate a few milimeters.   (This is especially true for "Alpha" particles).  This implies however that eating radioactive food is much worse than simply holding it nearby.

Regarding the power plants, we have some good news to report.  The good news is that we now appear to be facing a quadruple catastrophe.   Doesn't sound good?  It is good because two days ago it was looking like a sextuple catastrophe, with all 6 reactors at risk, with rising temps.   The two mostly undamaged reactorss (#5, #6) now have power restored and are cooling.

However reactors 1,2,3,4 are still problematic.   #1 & #2 seem to have decreasing pressure levels in the cores which is a good sign.   A couple of days ago, physicist Michio Kaku described the aerial water drops as "trying to put out a forest fire with a squirt gun."  I thought that was an accurate, if harsh analogy.  However the next day workers set up an automatically firing hose that sprayed some hundreds or thousands of tons of water into a reactor over a period of 7 hours.  This sounded more powerful to me.  But then I  read   that this effort resulted in the water temperature going below 100C !!!!  Hello? 100C is the boiling point of (unpressurized) water, so all water is  below 100C!   These are not high-pressure water reactors, so I'm at a loss to see that this is any form of success.    In contrast, core temps. in reactors 5&6  are at meaningfully low "safe" levels: only (95F = 35 C):


http://www.nytimes.com/interactive/2011/03/16/world/asia/reactors-status.html

The above page is a good resource for current status of the reactors.  The fact that there ARE NO TEMP. READING for reactors 1,2,3,4 is worrying.  It probably means that the  thermometers there were all destroyed in the explosions and fires those reactors experienced.

One final item:  workers had to back off of reactor 3 due to high radiation levels.  This is a bad sign.  Unless people can get close to the reactors, its going to be hard to fix anything.   Japan is now rotating workers in in groups of 100 people, letting them get irradiated to somewhat above normal permissible maximum, then bringing in a fresh 100 people.   This is probably (but not definitely) the best strategy, since we don't know how people will ultimately be irradiated this way....possibly thousands, or whether they can do much good without getting close in.  Is it better to allow 50,000 people to get unhealthy levels of radiation or to allow 5, 10 or 20 people to get lethal dose of radiation?  I'm glad I don't have to make that decision.

Saturday, March 19, 2011

The Needs of the Many...

Hi Everybody,

As the first radioactive Iodine and Cesium have been picked up today (Friday) in California (at extremely low levels), here's the latest from Japan:

TEPCO is allowing the workers a Fukushima to take higher doses (up to 200 miliSieverts) of radiation while while conscripting a growing army of workers to arrest the quadruple meltdown scenario:


http://edition.cnn.com/2011/WORLD/asiapcf/03/18/japan.nuclear.reactors/index.html?iref=NS1

This is probably because the radiation levels are so high, that if they
stick to the usual safety guidelines, workers wouldn't be able to get
anything done.  This Harvard physician computes that the workers at
Fukushima are being exposed to the maximum allowable ANNUAL dose (per the US NRC) in just 7.5 minutes:


http://www.health.harvard.edu/blog/radiation-risk-in-japan-an-update-201103182003

CNN reports "Abnormally high levels of radiation" are appearing in food in Japan.  A very candid analysis by Dr. Michio Kaku strongly recommends the Chernobyl Sarcophagus option (that link is now dead)

The first link above contains a quote from the ICRP:
"the benefit to others clearly outweighs the rescuer's risk."

That, with my mindset, inevitably suggests Spock's last words, before sacrificing his life to a radiation poisoning to ensure the survival of everybody else:  "The Needs of the Many outweigh the needs of the few, or the one"


http://www.youtube.com/watch?v=eVIt0DYKssI

It just now occurred to me that Spock's death scene may well have been inspired by the "biorobots" of Chernobyl.  "Biorobot" is a sardonic Russian term for humans who were asked to do what only robots should do.



-Chris

Reactor Summary & Iodine Precautions



Happy St. Patrick's Day.

Here's the latest from my research on the nuclear situation in Japan.

Workers at the Fukushima power plant are facing a quadruple  meltdown, with 4 out of 6 reactors suffering fire or explosion, and with active reactors #1,2,3 all having partial core meltdown.  Reactor #4 was offline for the quake, which surpisingly is worse: its active (not spent) fuel rods caught fire after boiling off their protective layer of water.  This means that if these rods so much as tipped over (eg due to 30 magnitude 6 aftershocks), they could "Turn On" and restart nuclear fission.  In the words of the Japanese power company "re-criticallity is possible".

If you didn't see it already I made a presentation to my class today on
nuclear reactions and this event:

http://www.physics.sfsu.edu/~chris/astro115/lectures/lec23.pdf

Another concern is that reactor #3 was using reprocessed nuclear fuel containing Plutonium (called "MOX").  Plutonium is not only hightly radioactive, it is also chemically lethal in small quantities.  The brave workers trying to put out the fires and cool the reactors are probably taking huge radiation levels.  They are now running in for 15 minutes, then swapping out.  If the situation deteriorates further, it  may be necessary to send in suicide volunteers, or as they called them at Chernobyl (after the real robots failed) "biorobots".

http://news.nationalgeographic.com/news/2011/03/110317-japan-reactor-fukushima-nuclear-power-plant-radiation-exposure/

By the way the Wikipedia page on the event is surpisingly comprehensive, including listing how much uranium/plutonium fuel is being stored vs. in the reactor cores.

http://en.wikipedia.org/wiki/Fukushima_I_nuclear_accidents

Meanwhile the UN is monitoring the radioactive plume as it moves downwind. What appears certain is that it will hit the western US tomorrow:

http://www.nytimes.com/interactive/2011/03/16/science/plume-graphic.html?ref=science

What's uncertain is how dangerous it is.  Given the potential for dilution over such a large area, its unlikely to be concentrated right now. However the US NRC officials have already said that it will be WEEKS not days before this is over.  So think of this as the beginning of a long exposure.   (comparison: walking behind a plume of car exhaust for 10 seconds vs. begin stuck in traffic for hours while in a convertable)

As you've heard, potassium iodine (KI) tablets are begin given to local people and US Troops in Japan, and there's been some panic buying here in the US, in spite of the fact that most health officials here are not recommending buying/taking the tablets here.  I think this is a good recommendation for them to make because frantic panicky people are likely to do something dumb like overdose on KI.    But none of us are frantic panicky people, so what action can we take?

Regarding Iodine: this is the most serious preventable risk.  The I-131 isotope concentrates in the thyroid where it decays and causes cancer. Children are the most vulnerable since thyroid cancer takes years to develop.   (Many of the Chernobyl victims were children who died of Thyroid Cancer)

If the body already has all the iodine it needs, then it won't take in any radioactive I-131 that comes by in the air.  For normal people (those who are not alergic to Iodine), the biggest risk in taking iodine appears to be rashes or nausea if excessive doses of Iodine are taken.    Remember that Iodine is a nutrient, we need to consume a small about, roughly 100 micrograms (not miligrams) per day, according to World Health Organization, who suggest increased intake of 280 micrograms for lactating mothers.  (It is required to produce something called T3 and T4 which I think are hormones)




http://www.uned.es/pea-nutricion-y-dietetica-I/guia/PDF/DRI%20-%20Recommended%20Intakes%20for%20Individuals%20-%20General%20-%20USDA%202004.pdf


http://www.who.int/nutrition/publications/WHOStatement__IDD_pregnancy.pdf

If you want to "fill your quota" of Iodine, how best do so if you don't want to buy and take KI tablets, which contain high levels of Iodine (miligrams)?   Here's some thoughts (remember 100 micrograms per day is normal...if you get a little above that they you probably won't retain any environmental iodine)

1.) Iodized Salt:  Several sources I've seen say this does not provide
enough iodine  to prevent I-131 uptake.  Bummer!

2.) KI tablets: as I mentioned these have such high doses that they are
not recommended yet in the US

3.) Iodine crystals:  Used for purifying water worldwide.   A solution of I crystals in water yields 1 gram for every 3 liters of solution at room temperature. (wikipedia & other sources)  So if you had a 1 full liter of iodine solution, it would contain 1/3 gram of iodine.  But usually we just use one capful, which is 5 mililiters.   So each capful contains 1.6 miligrams of iodine = 1,600 micrograms.  This is about 10 days worth of your daily iodine intake.    No wonder the bactria don't like it at this level.     So if you take a capful of iodine and put it in a 1 liter bottle then slowly drink that bottle over the course of 1 week, you'll get a dose of a little over 100 micrograms per day, which will be enough to saturate your thyroid with sufficient iodine, especially if you are getting some dietary iodine, which you SHOULD be, esp. if you are akid or a lactating mom.

(Note for my PCT friends.  This means that on the PCT I took: 8 liters of water per day * 1 capful per liter (min!) * 1,600 micrograms I per capful= 12,000 micrograms per day for 186 days!!!!  With no ill health effects...except occasional excess gas ;)  By the way that's 2.3 whole grams over the course of 1/2 year.

4.) Dietary Iodine.

You can get Iodine through food with out having to drink that smelly iodinated water.  Best food to go for is seaweed, and apparently the Kombu is the best type  see the chart at the bottom of this article:

http://davidgrotto.wordpress.com/2011/03/16/natural-food-sources-of-iodine/

Good luck and please let me know if you have any additional information or have found anything wrong with the information I've presented.

Best wishes,

-Chris

First Mssg to Tom & Lifang regarding Iodine reactors

My friends Tom & Lifang started my interest in this topic by raising the issue Iodine.  Here's our initial exchanges:


Here's the dosage levels recommended by the World Health Organization for
Kids, Pregnant and lactating women and adults.  Basically everybody needs
about 1/10 of a microgram a day.

http://www.who.int/nutrition/publications/WHOStatement__IDD_pregnancy.pdf

Presumably if you get a bit more than that your thyroid will be hapilly
saturated w/ I2 and won't need any extra from Fukushima.




Thanks, and cograts to Tom for being so active and informed on this issue.

I too have been parsing the micgrograms (ug) vs miligrams (mg) text...and
in fact I just this morning edited Wikipedia's article on Iodine to
highlight the problem you mentioned.

Here's what I think based on that article.  Let me know if this makes
sense or not.  KI tablets apperently come in "130 mg" doses.  I think this
means that the total mass of the tablet is 130 mg.  But some of that
tablet may be filler. The active ingredient may be smaller.

By the way I think the authorities are acting responsibly in discouraging
any sort of Iodine related panic in the US.  Epidemiologically there's
more likelihood of some parent panicking and giving their kid an
dangerous overdose  (eg 2-3 GRAMS) than thier is of radiation poisoning
RIGHT NOW.

However the situation at Fukushima continues to deteriorate with even the
US NRC calling radiation levels "extremely high" and new revelations
getting worse including:

- previously harmless reactor #4 is now listed (by US NRC) as the biggest
threat even though it wasn't in use at the time.  That's  because it has a huge amount
of now exposed spent fuel which is burning

- Reactor 3 and possibly others also stored spent  in their roofs, so when
they exploded that stuff probably went all over the place.

- The 50 people working a the plant were removed...but may now be back.
If radiation levels get to high the plant will have to be abandoned to
melt down.   The only alternative is what they did in Chernobyl:
"biorobots"  Humans assigned to do something that only a robot should do.

We may be looking a months of radiation leaks....so there might be a
cumulatively significant signal even this far away.

Another thought:  our kids are probably getting a decent dose of iodine
from their food.  This can be boosted by adding a little kelp and some
kinds of seafood.  Anyone up for  sushi?

-Chris

Welcome to This Blog

For the first time, I've found it useful to start a blog.   The purpose of this blog is to provide information on the effects of the Magnitude  9.0 Tohoku Earthquake, especially focusing on the nuclear crisis at the Fukushima Dai-Ichi reactors and the radiological impact on San Francisco Bay Area where I live.   I've been sending updates to my friends, and decided it would be easier to store these in  a blog.

About me:  I'm an astronomy lecturer/adjunct professor at SF State.   I've included some of the information on the nuclear reactions in my class discussion, since we study nuclear reactions in the Sun and other stars.