Experience with Chernobyl disaster guides research on radio-isotopes

Image: Wikipedia Commons

The Russian nuclear engineers were conducting an experiment.  As it began, they determined the test would not work properly unless they disconnected the emergency safety systems.  Inside the reactor there was a sudden and unexpected power surge, and when an emergency shutdown was attempted, a larger spike occurred, which led to a rupture in a reactor vessel and a series of explosions that blew off the heavy steel and concrete lid of the reactor.

In the explosion and subsequent fire, more than 50 tons of radioactive material were released, where it was carried into the atmosphere by air and then by water currents thousands of miles across the earth.  The Soviets hoped no one would find out, but Swiss and other radiation monitoring stations more than 1,000 miles away reported increases in radiation levels.

At 1:23 on Saturday morning, April 26, 1986 the nuclear disaster at Chernobyl began.  Naturally, the news media centered all their attention for weeks to the developing disaster story reporting speculative predictions that tens of thousands would die and hundreds of thousands would have cases of cancer.

At that moment, Peter H. Santschi, who today is Regents Professor of Marine Sciences at Texas A&M University at Galveston and Oceanography at Texas A&M University at College Station, was head of the Isotope Geochemistry and Radiology Section of the Swiss Institute for Water Resources and Water Pollution Control in Dübendorf, Switzerland, and lecturer at ETH.  He was notified on the same day of the incident in Chernobyl.  He immediately halted his research, and put all efforts in helping to monitor the air and water throughout Switzerland.

“I knew we had to act straightaway,” said Santschi.  “I knew that this was a serious situation, but it was also an opportunity to conduct a natural experiment that had never occurred before.”

During the large-scale testing of nuclear weapons in the 50s and 60s, the technology did not exist that would collect the data that technology of the 1980s provided.  “With Chernobyl, we had a cloud that was produced a thousand kilometers away coming to us, raining out and the concentrations were high enough to be measured by scientists so we could follow the pulse through the rain, surface and ground waters, as well as grass and cow milk.”

The media reaction was rapid and strong.  The fear spread.  People stopped going outside in Western Europe, while schools and universities in Eastern Europe were closed, workers stayed home and much of the food and crops in the contaminated area were destroyed.

However, Santschi’s team found the reality was that concentrations were very small and posed no threat to public health in Switzerland and Western Europe.

“The amount of radiation from the Chernobyl accident increased the annual dose to the Swiss population by somewhere between 5 or 10 percent, but you have to go a hundred times over the annual dose limit (to the general population) to go over the radiation dose of high natural background areas in Iran, Brazil, and India, in order to get statistically sound predictions of an increased risk of illness, and a thousand times for the risk of death,” said Santschi. “Environmental scientists are not activists as some people think.  They are really detectives trying to get at the truth.”

Despite the research data, the nuclear industry in the United States as well as worldwide suffered and never recovered.  “It basically shutdown the implementation of new reactors and all the old reactors of the 70s are now aging and do not have the failsafe design that we could have today.”

Santschi’s experience and research of the Chernobyl accident has brought him to investigate the modifying effects of organic matter in soils and wetlands to potentially toxic radioactive iodine-129 and plutonium at U.S. waste sites and in soils from Fukushima in Japan.  He is determining how radio-isotopes interact with organic substances, both underground and on the surface.  This research could ultimately help shield humans from health risks related to the transportation, storage and disposal of radioactive materials.

Elements, chemical compounds and other forms of matter are passed from one organism to another and migrate from one part of the ecosystem to another through biological and chemical cycles.  Radioisotopes in soils reach rivers through soil erosion, from where they are then transported the ocean.

Santschi is researching ways to slow down or stop the migration of the radioactive contaminants through surface and groundwater.  “There are processes that make the elements more sticky thereby preventing them from migrating and ultimately cause radioactive materials to stay put,” Santschi says.

Funded by the U.S. Department of Energy, the research provides a testing ground to solve problems affecting worldwide human health and the environment and provides training for Texas A&M Galveston students to learn state-of-the-art experimental approaches in marine and environmental sciences.