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
Here is some real news for you, since this article has none
8/16/2011 7:40:38 PM
Sony is cutting the PS3 by $50:
"Nowadays, security guys break the Mac every single day. Every single day, they come out with a total exploit, your machine can be taken over totally. I dare anybody to do that once a month on the Windows machine." -- Bill Gates
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
U.S. Air Force F-35 Lightning II, F-22 Raptor Team Up for “Integration Training”
November 19, 2014, 9:15 AM
U.S. Marshals Using Fake, Airplane-based Cell Towers to Scan Cell Phones of Americans
November 14, 2014, 9:05 AM
Ford Enlists Wind Energy Corp. to Provide Wind, Solar Energy to Four U.S. Dealerships
November 10, 2014, 10:58 AM
Disney Reveals Star Wars Ep. VII Title -- "The Force Awakens"
November 6, 2014, 3:45 PM
U.S. Navy Lockheed F-35C Completes First Carrier Landing
November 4, 2014, 12:44 PM
Microsoft Co-founder Paul Allen Donates $100M to Fight Raging Ebola Epidemic
October 23, 2014, 6:05 PM
Most Popular Articles
Wal-Mart: Miss Thanksgiving, Get Xbox One + Master Chief Collection for $299
November 17, 2014, 9:40 PM
Sweden Mulls Labelling "Sexist" Video Games in the Wake of Gamergate
November 17, 2014, 2:00 PM
Nokia Lumia 635 LTE Windows Phone is Only $40 at Best Buy on Black Friday
November 18, 2014, 11:59 AM
It's Official: Twitter is Profitable "Junk"
November 16, 2014, 10:45 PM
Apple Releases OS X 10.10.1 Yosemite, iOS 8.1.1 Updates
November 17, 2014, 1:43 PM
Latest Blog Posts
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
Space Terrorism is a Looming Threat For the United States
Apr 23, 2014, 7:47 PM
More Blog Posts
Copyright 2014 DailyTech LLC. -
Terms, Conditions & Privacy Information