Monday, March 18, 2013

Radiation and Energy Deathprint;

Before I begin I wanted to say sorry for not posting in a while. I have been involved in a discussion thread on linked in regarding nuclear power green energy and the necessities or lack there of surrounding climate change.

There has also been some fun debate regarding a paper by Marcott et al attempting to demonstrate a strong increase in warming. The paper is drawing extensive criticism that will be making it into a blog post sooner rather than later here. However this post is a response to a comment and question from Cathy to my article on nuclear power.

" doesn't let you post a comment. but..?...1 death in japan, 31 in japan....have there not been or will there be more deaths as a result of the ...failure? and in russia we heard for years about children being born with birth defects because of chernobyl? so although it may not be a "high death rate" at the time of the failure...what if any is the number of deaths that occured down the road but as a result?"

In reality 31 people died from directly linked causes from Chernobyl. we can expand that number up to about 70 if we include a few workers who showed signs of radiation poisoning or 9 children who died of a thyroid tumor afterwards. Projecting cancer rates beyond that are iffy but the actual number of lives affected by Chernobyl. comes at somewhere between 4,000 and 27,000 from the WHO.

Many people cite three mile island but the best estimates for actual exposure is less than that of a chest xray showing essentially no increased risk of cancer. In that forum I linked, someone tried to point to "hundreds of cases", and that the actual estimates were off by a factor of 100. What's interesting is that if we take the cancer risk from the NRC estimates and multiply it by 100 you will get 1 more fatal cancer per population of about 18,000 people. Based on the highest estimates of 2 million people exposed, and noting that dispersion increases the farther you are the legitimacy of hundreds of cases drops fast. At most about 100 people were affected. There are far more attempting to file suit.

Fukushima is the most recent plant to have a problem. Even so there are currently no projected casualties, and thus far no one has died. While we should marvel at this people are still clamoring fear's surrounding nuclear energy. People haven't died from Fukushima because of a marked improvement in containment and response compared to Chernobyl. To be clear about how safe the fukushima disaster was, the tsunami that hit japan killed 20,000 people. The WHO has concluded that the people surrounding the plant were only subject to 10-50mSv of radiation. It requires a 1000 mSv exposure to produce measurable health effects. There's an excellent article on the subject in Forbes.

Radiation is an abstract concept and giving a measurement is essentially meaningless to most people. If you haven't read the webcomic XKCD I recommend doing so, but for now here is a chart that was put together to explain radiation and dosages.


So what is radiation? Well in short it's a magnetic wave. The same type of wave that we use to transmits radio or cellphone signals. This has led some people to fear any form of electromagnetic wave and is exactly why every 5 years or so someone starts reporting on how cellphones cause cancer. They don't, people are stupid, and we can prove it.

The electromagnetic spectrum is large, it contains all kinds of radiation from infrared, radio, ultraviolet to even the normal light which we use to see every day. Here is a really good graphic from NASA depicting the electromagnetic spectrum. 

So what makes some radiation dangerous? Well the answer lies in what we know as Ionizing radiation. This essentially has enough energy to whisk the electrons orbiting an atom away. It only occurs at the higher frequencies.  This is why cell phones, radio, and even your microwave wont give you cancer. The frequency, or distance between the peaks, is simply too far apart to disrupt the electron. At the upper end of the visible spectrum the radiation starts becoming ionizing radiation.

If your having trouble envisioning this think of a fisherman on an ocean in a little dinghy. Assuming calm seas, waves don't hit him too frequently, so he sits fishing. On a windy day the frequency and number of waves slowly push his little dinghy around. In the same way an electron is simply pushed off with an ionizing wave.

Once the electron has been removed the atom becomes ionized and the chemical bonds can begin to destabilize (assuming no electrons absorbed from water etc.). When this hits DNA, individual codons (the base pairs for DNA) can break apart interrupting the sequence and distorting the gene. In most cases the cells simply die. However under the right circumstances the altered cell can become cancerous, never dying and continuing to replicate.

So how dangerous is nuclear power and the inherent radiation? How do we compare this to other power sources? The easiest  way is to take the total number of deaths. So we have a maximum of 27,000 from Chernobyl and that's pretty much it. The WHO projects a negligible impact from fukushima, and TMI had at most, assuming the 100 factor increase, an extra 100 deaths. I even had someone want to talk about uranium mining deaths pre 1950 which comes to 1,595. So if we add it all up there's the 27,000 plus 1,695 external deaths. But just for a nice big margin of error lets increase the externality death count to 3,000. I'm adding 1,300 people to the death toll just because I like round numbers, let's say 30,000 people have died from nuclear energy.

That's kind of shitty, but so was the Banqiao dam disaster which killed, 170,000 people. Clearly a total death toll is not necessarily an accurate measure of a technologies efficacy or safety. So let's divide the deaths by the amount of energy produced. That way we can accurately compare lives lost per unit of production. When we do this using worst case scenario numbers we get a list that looks like this

Energy Source               Mortality Rate (deaths/trillionkWhr)
Coal – global average         170,000    (50% global electricity)
Coal – China                         280,000   (75% China’s electricity)
Coal – U.S.                               15,000    (44% U.S. electricity)
Oil                                               36,000    (36% of energy, 8% of electricity)
Natural Gas                                4,000    (20% global electricity)
Biofuel/Biomass                    24,000    (21% global energy)
Solar (rooftop)                              440    (< 1% global electricity)
Wind                                                 150    (~ 1% global electricity)
Hydro – global average          1,400    (15% global electricity)
Nuclear – global average            90    (17%  global electricity w/Chern&Fukush)
So from this nuclear looks like the safest possible source. But they didn't include those extra 3,000 people that I want to add just because I really want nuclear to lose this competition. if we take 30,000/27,000 we get a multiplying factor of 1.11. Nice so nuclear has killed... oh only 99.9 people compared to wind's 150 and solar's 450. Well damn and using the lower estimates without those externalities were looking at around 12 people per trillion kilowatt hours. 
This is including all the old data from plants that were built 60-70 years ago. What about those bigger more modern plants. Lets assume that chernobyl like disasters occur at a similar rate to nuclear core incidents. Now lets compare modern gen III plants to Gen II plants on a core failure basis. 
Heres the wikipedia article im using for the source material.
So Gen II's had 10,000 incidents per 1 billion years. Not too shabby, that means there is roughly 10 incidents per 1 million operating years or 1 incident per 100,000 operating years. Thats not too shabby, if we have 1,000 plants running for 100 years we should have one core damage event.
 Now that's the plants running without a tsunami or reactor operators simply screwing the pooch like Fukushima and Chernobyl respectively. But lets just say that the ratio is comparable with weather and human failures. 

Gen III reactors have only 60 core incidents per 1 billion years for a high end dangerous and terrifying European pressurized reactor (Im not sure the sarcasm is detectable). The economic simplified boiling water reactor only has 3 incidents per 1 billion years. The reduction of fatalities from these designs would fall from 27,000 to roughly 9-180 people.  And that assumes no containment. Our containment designs alone are the reason Fukushima will not have a noticeable casualty or cancer rate. This means that nuclear power is the only source that can produce almost zero casualties. 

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