Research On US Nuclear Levels After Fukushima Could Aid İn 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 health risks 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 Fukushima 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 inert gas, 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 Nuclear Engineering Teaching Laboratory, said the average person in the U.S. receives about 16.4 microsieverts of radiation dose per day from various sources of naturally occurring radiation, such as radioactive materials in the soil, cosmic radiation 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.