Although I try to avoid verbatim repeats of people’s comment postings, this one is so clear and coherent that it really has to be preserved from the daily disappearing and endlessly scrolling comment threads appearing now daily at theOilDrum.

This is precisely the type of understanding the nuclear industry as a whole does not want people to have, and they try to keep these daily realities out of the media and public eye as much as possible in order to maintain the fiction of safe, clean power.

ransu on March 19, 2011 – 9:00am, TheOilDrum.com Drumbeat discussion

Disclaimer: I am not an expert in this field. I work with metrology of physics standards.

If you ever walk into a nuclear power plant, you will see danger signs with either or both of these written on them:

DOSE RATE

CONTAMINATION

Basically there are two kinds of exposure to radioactivity: the direct exposure to radiation where an external source emits EM energy in the form of particles or energy which hit your body – let us call it external. For example walking alongside the waste pool now exposed and without its blanket of water between you and the rods, would mostly likely give you a lethal dose.

In a nuclear power plant areas marker with DANGER! DOSE RATE are areas where you are close enough or unshielded from the reactor core, waste pool or primary circuit. You need to wear a dosimeter and the time you spend there is monitored and limited. This part of radioactivity is what we can directly measure in units called Sievert with portable counters and indicators and the one currently quoted all over the media.

However it is contamination which is in many ways is a far greater danger. In order to have radiation you need something that radiates – a decaying radioisotope. Normally all these isotopes remain safely in the reactor core – and the extremely pure circulating primary water holds almost no radioactive isotopes (except for some very short lived temporarily created by the intense core radiation). However over time, and if you have abnormalities, especially accidents, core radiation can change the surrounding materials into radioactive isotopes – which is why you choose all materials and fluids very carefully and control their purity – and keep everything absolutely clean around there!

Areas of a nuclear power plant with DANGER CONTAMINATION include areas for fission material handling and areas indirectly exposed to intense radiation – where there is a possibility that some radioactive particles have either escaped or formed around surfaces where you might touch them, carry them with you, even inhale them. In these areas you need to wear a protective suit, and everything you carry with you outside, including yourself, needs to go through decontamination – meaning lots of scrubbing. You don’t want to get stuck with even one of these nasty particles because they can enter your body and literally give you “the dose of your life”.

So, if you mess up the core or waste containment, have explosions, fire – you are basically releasing much more then just ‘radiation’ – you are releasing contamination into the environment (Chernobyl radiation map 1996). Radioisotopes escaping outside the plant and blown along the winds as smoke and dust and eventually being deposited by rains. And you cannot really measure that danger until you collect soil samples and take them to a lab for a proper analysis.

For a nuclear emergency crew then, dealing with fallout, sampling a wide area for these particles begins to give a good idea of what kind of safety measures should be implemented: what areas to evacuate, what advice about outdoor activities to give, how foods derived from plants and animals from the area should be treated etc.

So far we have heard a lot of this advice being given – but the actual contamination figures they might have sampled – have been kept off the media – perhaps to avert further panic. It could also be that due to the extensive damage to the infrastructure of the whole area, and the priority of saving lives, there has been little chance to collect enough data.

Now we are starting to see the authorities take samples for iodine in milk for example. But to get a better picture of the isotopes released – and the long term ‘destiny’ of the surrounding area – even the whole country – will take some time. At a minimum there is a need establish a rough relative distribution of the different isotopes released – and to sample a fairly large area – then compare that to wind and precipitation patters over that area during the whole fallout period – to get a estimate of the total amount of contamination (measured in Curie) and its distribution. Further analysis with spectrometry will tell the types of isotopes so the biological effects can be factored into any response plan and eventual decontamination of the area.

The nuclear tragedy will depend on that: short term contamination of the food chain – and long term contamination of the soil.

Lots of such studies done since Chernobyl can be found from Google.

I love Japan and will always remember the cherry blossoms falling everywhere while attending my friends wedding in Miyajima island near Hiroshima. Visiting the museum of the bomb was a very moving experience and afterwards praying at the monastery overlooking the town gave me time to contemplate how truly strong spirited these people were for having rebuilt their city and moved on with their lives.

Dealing with the effects of the tsunami is one thing. But reawakening the horrors of the atomic age would be very upsetting for the Japanese I can imagine. And it is traditional to take off your shoes while going inside buildings, especially the home, which is considered holy ground: cleanliness is sacred. Upsetting the purity of the environment – with invisible and possibly deadly contamination – will have a very spiritual interpretation for the Japanese. A fallout contaminating their country, perhaps for years to come, rather than causing just fear, would cause deep sadness indeed.

Many thanks to this poster for such a clear and explicit explanation of the realities of being inside a running live nuclear power plant.

The more of this type of information is released and can enter the public’s collective understanding, the better.

This entry was posted on Saturday, March 19th, 2011 at 15:24 and is filed under Our World. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.