Research on US nuclear levels after Fukushima could aid in future nuclear detection

The amount of radiation released during the Fukushima nuclear disaster was so great that the level of atmospheric radioactive aerosols in Washington state was 10,000 to 100,000 times greater than normal levels in the week following the March 11 earthquake and tsunami that triggered the disaster.

Despite the increase, the levels were still well below the amount considered harmful to humans and they posed no to residents at the time, according to researchers at The University of Texas at Austin.

The findings, published by a mechanical engineering professor at the Cockrell School of Engineering and researchers at Pacific Northwest National Laboratory (PNNL), provide important insight into the magnitude of the disaster. They also demonstrate huge advancements in the technology that's used for monitoring nuclear material and detecting covert nuclear operations around the world.

"I think the conclusion was that this was a really major event here," Cockrell School of Engineering Associate Professor Steven Biegalski said of the disaster.

Biegalski was on a faculty research assignment at PNNL in Richland, Washington. Its here that, using technology that Biegalski helped improve, he and a team of researchers were the first to detect radioactive materials from Fukushima in the U.S.

The material detected, Xenon 133, is of the same chemical family as helium and argon and is an , meaning it does not react with other chemicals. The gas is not harmful in small doses and is used medically to study the flow of blood through the brain and the flow of air through the lungs.

Tracy Tipping, a health physicist and laboratory manager at The University of Texas at Austin's Teaching Laboratory, said the average person in the U.S. receives about 16.4 microsieverts of per day from various sources of naturally occurring radiation, such as radioactive materials in the soil, from outer space and naturally occurring radioactive materials within the body. In Washington, the increased levels from Fukushima meant the daily dose during that time could have been about 16.4017. A harmful amount that would cause obvious symptoms of exposure is anywhere from two to three million microsieverts at one time, he said.

"So, you can detect the increase but being detectable does not mean it's harmful," Tipping said.

Xenon 133 is a nuclear fission product that is closely monitored at nuclear stations around the world because it can be used to determine whether a country has conducted an illegal or covert nuclear test explosion. Such tests are banned under the Comprehensive Nuclear-Test-Ban Treaty (CTBT), which was adopted by the United Nations in 1996 and created a worldwide network of nuclear monitoring stations.

Similarly to how 911 emergency centers can pinpoint the location of a cell phone call by triangulating the signal between many different cell towers, nuclear stations within the network share information on Xenon 133 and other to determine where they originated. The network, established as part of CTBT, is crucial to detecting clandestine nuclear tests.

The detection of the radioactive gas in Washington is significant because it demonstrates technology advancements made by Biegalski, PNNL and others, to create a more sensitive monitoring system – one that's capable of detecting extremely small amounts of the gas.

"The culmination of international research collaborations resulted in this very sensitive monitoring technology. These advancements will not only be beneficial for nuclear monitoring, they are also very beneficial to the emergency response teams called to disasters like Fukushima," said Biegalski, an expert in nuclear forensics, nuclear modeling, and nuclear monitoring, who is currently developing complex algorithms that will be used to improve the capabilities even more.

As soon as he and PNNL researchers began detecting radioactive gases in Washington, they shared the data with federal officials in the U.S. and Japan so that it could be relayed to emergency responders on the ground at Fukushima.

"As the measurements came in sooner and at higher concentrations than we initially expected, we quickly came to the conclusion that there were some major core melts at those facilities," Biegalski said. "I remember being in the lab thinking, 'Wow, if this is all true we have a far more bigger accident than what we're hearing right now."

The thought was confirmed by data collected by he and PNNL researchers. Their study reports that more radioxenon was released from the Fukushima facilities than in the 1979 meltdown at the Three Mile Island Nuclear Generating Station in Pennsylvania and in the 1986 Chernobyl in the Ukraine.

Biegalski said the reason for the large release in Fukushima, when compared to the others, is that there were three nuclear reactors at the Japan facilities rather than just one.

The study was published in the Journal of Environmental Radioactivity.

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Citation: Research on US nuclear levels after Fukushima could aid in future nuclear detection (2011, September 9) retrieved 27 May 2019 from
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User comments

Sep 09, 2011
Yes, nuclear energy is dangerous.

Nuclear energy is stored in the nucleus, as rest mass (E = mc2)

Nuclear energy can be safely used, if we can find a way to end the alliance of politicians with leaders of science, major industries, unions, the news media, and government agencies.

Otherwise we face the real possibility of a totalitarian one-world government that controls people instead of governments that people control.

With kind regards,
Oliver K. Manuel
Former NASA Principal
Investigator for Apollo
Emeritus Professor of
Nuclear & Space Science

Sep 09, 2011
Here is an abstract that I was invited to submit to "Thorium Energy Conference ThEC-11" at Columbia University on 10-12 October 2011:


Hopefully the organizers will not object to the last blunt sentence -

"The TFMSR (Thorium-Fuelled Molten Salt Reactors) may be the safest way for Western nations to meet future energy needs, if political leaders have the courage to insist that the waste products not be left for other countries or future generations to dispose [7]."

7. China announces thorium energy project (1 Feb 2011):

The abstract has not yet been accepted for oral presentation, but I will happily make travel arrangements and pay my own way to present the paper, if accepted for oral presentation.

Sep 11, 2011
As an ordinary citizen, without the benefit of an education in nuclear science, I would appreciate a clearer explanation of the cumulative effects of the overall radioactive aerosols detected.

The half-life of Iodine at aprox. 8 days is easy enough to disregard, but the lasting effects of strontium, cesium are another matter. Is it safe to eat the tomatoes in my garden here in Seattle?

Sep 11, 2011
Yes, almost certainly so.

Strontium behaves like Calcium and accumulates in bones and teeth

Sr-89 and Sr-90, as I recall from many years ago, both accumulated in baby's teeth and were used to demonstrate the danger of atmospheric tests of nuclear weapons.

False, fear-based propaganda is today destroying confidence in governments and in science.

I welcome questions and ask you to join me in ending misuse of government science.

With kind regards,
Oliver K. Manuel
Former NASA Principal
Investigator for Apollo

Sep 11, 2011
Misinformation on energy that powers the Sun, Earth's climate, and sustains our lives [1-3] is a grave danger to National Security.

NAS was "established by an Act of Congress . . . on March 3, 1863 . . . calls upon the NAS to "investigate, examine, experiment, and report upon any subject of science or art" whenever called upon to do so by any department of the government" [1].

Please join me in asking Congress to request a FULL and CANDID evaluation from NAS of conflicting information in [1-3], BEFORE approving more funds for government research.

1. UN's IPCC reports (1990-2007)

2. Super-fluidity in the solar interior: Implications for solar eruptions and climate", JFE 21, 193-198 (2002)

3. "Neutron repulsion", in press

With your help, integrity can be restored to science and government!

Oliver K. Manuel

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