UC Researchers Produce First Quantitative Estimate of Fukushima Radiation Leak
August 16, 2011 11:47 AM
comment(s) - last by
UC San Diego researchers concluded that 400 billion neutrons were released per square meter surface of the cooling pools at Fukushima Daiichi
that shook Japan and crippled the reactor at Fukushima Daiichi nuclear plant back in March caused quite a bit of havoc with the release of
contamination of crops
and of course, the thousands of lives lost. At the same time, news networks like
sensationalized reports, causing unnecessary nuclear-related fear. U.S. senators even demanded the Nuclear Regulatory Commission to
repeat an expensive inspection
of U.S. nuclear plants.
In an attempt to clear some confusion and understand exactly how much radiation actually leaked from the damaged nuclear reactor at the Fukushima Daiichi nuclear plant in Japan on March 11, atmospheric chemists at the University of California, San Diego, have produced the first quantitative estimate of how much radiation actually leaked from the reactor.
Mark Thiemens, study leader and Dean of the Division of Physical Sciences at UC San Diego, along with post-doctoral researcher Antra Priyadarshi, and a team of researchers, observed the amount of radioactive sulfur in the air soon after the earthquake in Japan and was able to report a quantitative measurement of the amount of radiation leaked.
When fuel rods melt, products like neutrons leak from the fuel rods. Seawater is used to cool the hot reactors, and absorbs the leaked neutrons. These neutrons "collide" with chloride ions in the seawater, which results in the loss of a proton out of the nucleus of a chloride atom and turns the atom into a radioactive form of sulfur. Most of this vaporizes into steam when the saltwater comes into contact with the hot reactors, and to avoid explosions due to the collection of hydrogen, operators vent the steam into the atmosphere. Once in the air, the sulfur reacts with oxygen to create sulfur dioxide gas and eventually sulfate particles.
On the other side of the Pacific Ocean in La Jolla, California on March 28, 2011, Thiemens and his team noticed an "unprecedented spike" in radioactive sulfur in the air. They used a model, which was based on the NOAA's observations of atmospheric conditions, to determine the path the air took to get to California over the previous 10 days, and found that it had come from Fukushima Daiichi.
The next step was to calculate
how much radiation had leaked
from the reactor based on the path over the Pacific Ocean. They took into account that some sulfate particles had fallen into the ocean or decayed along the way, and concluded that 400 billion neutrons were released per square meter surface of the cooling pools. They predicted that this occurred between March 13, 2011 and March 20, 2011. March 13 was when operators began flooding the reactor with seawater.
"You know how much seawater they used, how far neutrons will penetrate into the seawater and the size of the chloride ion," said Priyadarshi. "From that, you can calculate how many neutrons must have reacted with chlorine to make radioactive sulfur."
To achieve the levels observed in California, the team said the concentrations a kilometer above the ocean close to Fukushima must have been 365 times above normal levels. Over the four days that the team took measurements, which ended March 28, Thiemens measured 1501 atoms of radioactive sulfur in sulfate particles per cubic meter of air. They mentioned that this was the highest they had seen in two years of observations and recordings.
According to the researchers, the radioactive sulfur observed was produced by partially melted nuclear fuel in the storage ponds or reactors. While cosmic rays can produce radioactive sulfur, the team noted that these rays rarely mix into the layer of air right above the ocean.
Despite the high levels of radioactive sulfur recorded in California, Thiemens and his team said these levels were
not dangerous to human health
"Although the spike that we measured was very high compared to background levels of radioactive sulfur, the absolute amount of radiation that reached California was small," said Thiemens. "The levels we recorded aren't a concern for human health. In fact, it took sensitive instruments, measuring radioactive decay for hours after lengthy collection of the particles, to precisely measure the amount of radiation."
was published in
Proceedings of the National Academy of Sciences
This article is over a month old, voting and posting comments is disabled
RE: If radiation is harmless, LETS ALL EAT SOME PLUTONIUM!
8/17/2011 8:43:45 PM
Some radiation is not just healthy, it's damn near necessary.
Our skin uses UV radiation to manufacture Vitamin D. There's actually a bunch of recent studies claiming that kids aren't getting ENOUGH radiation as nobody goes outside anymore.
Granted in a higher dose it can and will kill you. However this is true for pretty much everything from water to a 57 Studebaker.
Interesting side note for those not in the know - did you know the human body is naturally radioactive itself? Most of this comes from Potassium-40 (if I recall correctly). Apparently Potassium sometimes breaks down into this radioactive isotope.
Fun science experiment - fill your suitcase with bananas (or better yet, Brazil nuts) the next time you fly. The amount of Potassium-40 contained in a whole suitcase full should be enough to set off the airport's radiation detectors... :D
"I modded down, down, down, and the flames went higher." -- Sven Olsen
Fifteen Metric Tons of Radioactive Water Leaks from Fukushima Daiichi Plant
June 28, 2011, 1:17 PM
Study: Nuclear Radiation May Affect Gender of Babies
May 29, 2011, 12:17 PM
Locally-Grown Crops Near Fukushima Daiichi Plant Banned Due to Radiation Fears
March 21, 2011, 11:27 AM
EDITORIAL: U.S. NRC Confirms MSNBC.com Reporter Mislead, Sensationalized Nuclear Story
March 18, 2011, 11:59 PM
U.S. Senators Demand NRC Repeat Costly Inspection of Nuclear Power
March 17, 2011, 4:15 PM
SpaceX Falcon 9's Seventh Supply Mission to ISS Ends w/ Fiery Stage 1 Explosion
June 28, 2015, 1:10 PM
Cool Science Video: Glowing Millipede Prowls the Nevada Desert
May 18, 2015, 12:00 PM
Newly Discovered Costa Rican Glass Frog is Kermit's Doppelgänger
April 22, 2015, 11:26 AM
Researchers Hope to Find "Exotic" Lifeforms Inside Crater of Dinosaur Killing Meteor
April 14, 2015, 8:47 PM
Mathematician's Sociological Formulation May Explain the "Hipster Paradox"
April 14, 2015, 1:13 PM
Cool Science Video: This is What a McDonald's Burger Looks Like in Your Stomach
April 7, 2015, 1:43 PM
Most Popular Articles
As iPad Sales Wane and Watch Flops, iPhone Saves Apple's Profit With Its Heroics
July 22, 2015, 6:13 PM
Editorial: Reddit Allows Itself to be Hijacked as a Hate Platform For Racist Bigots
July 21, 2015, 6:32 PM
Microsoft July 29 Windows 10 Launch: Freebies, Rollout, and What's Next
July 21, 2015, 2:40 PM
Quick Note: Apple Watch to Get Brick and Mortar Boost From Best Buy
July 27, 2015, 3:00 PM
Mozilla and Facebook to Adobe: It's Time to Kill Flash
July 20, 2015, 6:30 PM
Latest Blog Posts
Sceptre Airs 27", 120 Hz. 1080p Monitor/HDTV w/ 5 ms Response Time for $220
Dec 3, 2014, 10:32 PM
Costco Gives Employees Thanksgiving Off; Wal-Mart Leads "Black Thursday" Charge
Oct 29, 2014, 9:57 PM
"Bear Selfies" Fad Could Turn Deadly, Warn Nevada Wildlife Officials
Oct 28, 2014, 12:00 PM
The Surface Mini That Was Never Released Gets "Hands On" Treatment
Sep 26, 2014, 8:22 AM
ISIS Imposes Ban on Teaching Evolution in Iraq
Sep 17, 2014, 5:22 PM
More Blog Posts
Copyright 2015 DailyTech LLC. -
Terms, Conditions & Privacy Information