Willem's Planet

In none of the reporting on television of the dangers of exposure to radiation from a nuclear power plant have I seen any explanation of how radiation is measured, and what levels of radiation would actually be dangerous.

So first things first.   Radiation dose equivalent exposure is measured in milliSivert (1 mSv = 10⁻³ Sv) or microSievert (1 μSv = 10⁻⁶ Sv).

Here are some examples of typical doses –

• Dental Radiography : 0.005 mSv
• Mammogram : 3 mSv
• Average dose to people living within 16km of Three Mile Island accident : 0.08 mSv; maximum dose: 1 mSv
• Approximated  radiation exposure at Fukushima Dai-Ichi Nuclear Power station within 20km: 0.023 mSv or 23μsv; 30km radius: 4μsv (on 03-16-2011 as per NHK World report – may change as this item is active)
• Immediately after the Chernobyl disaster, some 24,000 people living within 9 miles (15 km) of the plant – residents of nearby Pripyat – received an average dose of 450 mSv before they were evacuated.

In most countries the current maximum permissible dose to radiation workers is 20 mSv per year averaged over five years, with a maximum of 50 mSv in any one year.   A term that is used for nuclear workers is to aim for levels that are ‘As low as is reasonably achievable’, abbreviated as  ALARA.

This is not where the radiation story ends, though.    We are all bombarded with radiation from the environment, from food and from medical procedures (picture from World Nuclear Association’s website).    I get more of it when I fly (of course, airline pilots get even more), and I get radiated when I walk through the full-body scanner at airport security.    (The TSA admitted just today that a recent series of tests of these scanners produced levels 10 times higher than expected .. so they’re following up with more tests).

Update from World Nuclear News : Operations to relieve pressure in the containment of Fukushima Daiichi 3 have taken place after the failure of a core coolant system. Seawater is being injected to make certain of core cooling.   Malfunctions have hampered efforts but there are strong indications of stability.

I was supposed to travel out to China but postponed my trip to Wednesday.   So I get to catch up reading the magazines that pile up while I’m away.   An fascinating article about cloud computing in Bloomberg Businessweek gives a run-down of where we’re headed with amassing digital information on the planet.   Here it is, with a few lines I added of my own.

1,000 kilobytes (kB) is a megabyte (MB) .. 10⁶ bytes
>   a picture file taken by a cell phone is 2 MB big
1,000 megabytes is a gigabyte (GB) .. 10⁹ bytes
>   a high-end desktop computer has 10 GB of random access memory (RAM)
>   a corporate SAP system may have 200 GB of memory
1,000 gigabytes is a terabyte (TB) .. 10¹² bytes
>   a high-end desktop computer has 1 or 2 TB of disk drive space

1,000 terabytes is a petabyte (PB) .. 10¹⁵ bytes
>   1 TB equals 13 years of HDTV content
1,000 petabytes is an exabyte (EB) .. 10¹⁸ bytes
>   1 EB of mobile traffic data was generated in the USA last year
1,000 exabytes is a zettabyte (ZB) .. 10²¹ bytes
>   0.8 ZB equals the entire globe’s digital data in 2009, according to IDC
>   35 ZB is the forecast for the volume of all digital data in 2020,
and finally (for now!)
1,000 zettabytes is a yottabyte (YB) ..10²⁴ bytes

Background information from Wikipedia (already updated with the events of yesterday and today) :

The Fukushima I Nuclear Power Plant,, often referred to as Fukushima Dai-ichi, is a nuclear power plant located in the town of Okuma in the Futaba District of Fukushima Prefecture, Japan.  The plant consists of six boiling water reactors.   These light water reactors have a combined power of 4.7 GW, making Fukushima I one of the 25 largest nuclear power stations in the world.   Fukushima I was the first nuclear plant to be constructed and run entirely by the Tokyo Electric Power Company (TEPCO).

In March 2011, in the immediate wake of the Sendai earthquake and tsunami, the Japanese government declared an “atomic power emergency” and evacuated thousands of residents living close to Fukushima I.    Ryohei Shiomi of Japan’s nuclear safety commission said that officials were concerned about the possibility of a partial meltdown at Unit 1.   The following day, Chief Cabinet Secretary Yukio Edano said that a partial meltdown at Unit 3 is “highly possible.” [end of Wikipedia entry]

The World Nuclear Organization (WNA) publishes updates at http://www.world-nuclear.org/.   As of today 5 of the 6 units have been successfully shut down.   Three were running when the earthquake hit.    The earthquake tripped the start of an automatic shutdown sequence per the design of the reactor, but under these conditions a nuclear plant requires power from another source to run all the pumps, motors, fans and instruments used in the shutdown process.   If there is no off-site electricity from the grid available as was the case here, the plant gets this power from a large diesel generator/(s).    But the tsunami destroyed the diesel generators, leaving the units with no power.    There may have been other procedures, contingencies or redundancies for emergencies, but it appears the scale of the damage caused by the earthquake quake/tsunami combination was not in the plan.   Let it be said that at 8.9 on the scale this was a very big earthquake that would have sorely tested any nuclear power station’s contingencies.

So for the remaining reactor that is still running : it is being cooled by spraying seawater with boron onto it.    This is inside the containment shell.  The water brings the temperature and pressure down and the boron helps to absorb radiation.   The explosion shown by the media was the refueling floor which is still outside the primary and secondary containment area.   But it should be clear by Monday if all of this worked and the core can be stabilized and cooled.   Presumably all of the control rods have been dropped into place (the WMA does not mention that they are not).

The plant personnel are certainly in danger and the evacuation around the reactor is justified.    This emergency at the Fukushima power station has brought comparisons to the 1979 disaster at Three Mile Island near Harrisburg PA, which resulted in a partial meltdown of the reactor core – but in the TMI incident the reactor was brought under control quickly (in a day) and no one was injured.   Of course, then there is Chernobyl 1986, the only Level 7 (‘Major Accident’) event on the International Nuclear Event Scale recorded so far, which exposed large numbers of people to substantial amounts of radiation.

This cutaway diagram shows the central reactor vessel and thick concrete containment in a typical boiling water reactor of the same era as Fukushima Daiichi 1

http://www.theatlantic.com/infocus/2011/03/earthquake-in-japan/100022/

I followed the news reports of the earthquake for the better part of the evening.   The link above shows pictures with shocking detail of the widespread damage.  Some damage was reported in Hawaii and in marinas along the California coast and a 25 year-old daredevil photographer was swept into the sea (he was standing on the beach) and drowned.

There is also concern for damage to Japan’s nuclear reactors.   Japan’s nuclear safety agency said the situation was most dire at Fukushima Daiichi’s Unit 1, where pressure had risen to twice what is consider the normal level.   The International Atomic Energy Agency said in a statement that diesel generators that normally would have kept cooling systems running at Fukushima Daiichi had been disabled by the tsunami’s flooding.

I was sorry to learn of the tsunami and earthquakes in Japan of Thursday, so closely following the one in New Zealand.   It prompted me to look for this famous picture that I didn’t even know the full name of.    In its most simple form its title is The Wave but it is really The Great Wave off Kanagawa (神奈川沖浪裏, Kanagawa Oki Nami Ura, lit. “Under a Wave off Kanagawa”).

From Wikipedia : It is a woodblock print by the Japanese artist Katsushika Hokusai.   An example of ukiyo-e art, it was published sometime between 1830 and 1833 (during the Edo Period) as the first in Hokusai’s series Thirty-six Views of Mount Fuji (Fugaku sanjūrokkei (富嶽三十六景?)), and is his most famous work – probably one of the most recognized works of Japanese art in the world.

Click the picture to enlarge it and then check out Mount Fuji in the distance and the boatsmen in the foreground.      We are so small against these forces of nature.

This truck is in the back alley by my house since the neighbors there is adding a new room to their house (from the looks of it).  So is the colorful tree frog found in nature? I wondered.  Sure enough – it’s a Red-eyed Tree Frog (Agalychnis callidryas) and this picture was taken in Costa Rica in 2007 by Jan Sevcik, a zoologist from the University of Prague.    Look at those sticky fingers!  They eat insects, are 2 to 3 inches long and can live up to 5 years.

I’m finally downloading a few more applications for my iPhone .. this one is Google’s Goggles : a very ambitious little program that tries to ‘recognize’ an object that you snap with the phone’s camera.    I got some impressive results but also some disappointments.     The program recognized the m from from m&m candy canister; the zhong character* from my Chinese Without Tears book; the Logitech logo on my mouse, and a picture of the Eiffel Tower on the computer screen.   I could not get it to recognize my little space shuttle model (aww) even after a dozen attempts at different angles; or my own little Eiffel Tower replica.    Maybe the lighting or the background should have been different.

*zhong 中 means ‘center’ or ‘middle’ and is used in the characters for China, literally ‘middle kingdom’  中 国

It’s the birthday of the famous Chinese poet Li Bai (he lived from 701 to 762) ‘The Sage of Intoxication’.  So it’s the 1310th anniversary (picture from Google’s China home page).  The poet is regarded with the same reverence in the East as Shakespeare is in the West.   His hometown is Jiangyou in Sichuan province.   I actually looked up one of his poems called ‘Difficulties in Traveling’ and ran it through Google Translator, but the results were uninspring.  It takes a poet to translate poetry!

Here is the foggy view from where we were waiting for the bus this morning.   The stone elephant and blue hue is from the Pattaya Hotel next to my apartment.  Two more work days then I get to go home!

Finally, the Kingkey Finance Center Plaza that I mentioned yesterday was hiding in plain sight on a photo of the Panasonic building.   I will post better pictures of it now that I know it’s there!  but here’s a glimpse.   It’s going to reach 440m (1440ft) and have 97 floors.