Tracking A Legacy Of Waste In The West Siberian Basin

Fifty years ago, Russian scientists began discharging this liquid radioactive waste into nearby rivers and open reservoirs. Abouta decade later, they also began injecting radioactive waste into what they believed were very slow moving fields of groundwaterin the West Siberian Basin, located in central Russia.

The practice of discharging into open reservoirs continued until the early 1990s. Over time, Russian scientists discovered wastehad migrated in the aquifer underlying one reprocessing site to a nearby stream and could threaten the drinking water ofresidents.

In 1990, Russia's Ministry of Atomic Energy, MINATOM, signed a Memorandum of Cooperation with the U.S. Departmentof Energy in the areas of environmental restoration and waste management and agreed to jointly study how radioactive wastetravels in groundwater. Scientists from DOE's Pacific Northwest National Laboratory were chosen to lead the U.S. portion ofthe contaminant transport modeling project as part of the agreement.

Pacific Northwest scientists are investigating the West Siberian Basin's hydrogeology - how water moves under the ground'ssurface - to better track and predict the future path of radioactive waste. Research is focused on waste storage and disposal atthree former plutonium production sites in the basin - Mayak, Tomsk and Krasnoyarsk. The laboratory's scientists are using thesame computer model they apply at DOE's Hanford site in Washington state to simulate flow of radionuclides in groundwater.

"This research is the best chance to learn how large concentrations of man-made radionuclides travel in a natural setting, overlong distances and over a long period of time," said Mike Foley, principal investigator for Pacific Northwest. "To date, existinggroundwater models have been based on small-scale lab tests and observations of low-concentration, naturally occurringradionuclides."

After the models are developed, Pacific Northwest scientists will estimate how the contaminants have moved over time andestimate their future path. The models will help improve understanding of how radioactive wastes react with the rocks as theyare transported by groundwater.

The findings are expected to influence remediation strategies at the three Russian sites.

Since 1992, Pacific Northwest scientists have modeled the hydrogeology of the West Siberian Basin and of Mayak using datafrom groundwater studies provided by Russia. West Siberia is the largest basin and region of low relief on earth. Next, it isproposed that the scientists will model the Tomsk site and, possibly, Krasnoyarsk.

"We need to know the chemistry of how radioactive plumes move below the surface," Foley said. "That knowledge could beapplied to landfills, tank spills and future waste storage issues in the United States. We have to be able to predict the risk ofcontaminant migration in order to properly clean it up."

Pacific Northwest and Russian scientists have worked together closely. They bring complementary site characterization,contaminant sampling and modeling expertise to bear on the common problem of better understanding the migration ofradioactive wastes in groundwater systems.

"We're both trying to take advantage of each other's knowledge and resources," said Charlie Cole, Pacific Northwest scientist.

DOE's Office of Environmental Management has funded this project at Pacific Northwest with about $3.3 million since 1992.

Pacific Northwest is one of DOE's nine multiprogram national laboratories and conducts research in areas of environment,energy, health sciences and national security. Battelle, based in Columbus, Ohio, has operated Pacific Northwest since 1965.