SEDE BOQER, Israel - Dec. 18, 2015 - Researchers at Ben-Gurion University of the Negev (BGU) have found that radioactive matter migrates more quickly in carbonate bedrock formations once it has leaked from a tank from near surface waste sites and geological repositories.
Corroded stored waste containers can lead to radionuclide (radioactive) leakage, which may reach groundwater.
The study, published in the online journal Environmental Science & Technology (ACS Publications), determined the impact of intrinsic colloid formation on increased migration of leaked radioactive materials in the environment. Colloids are microscopic inorganic or organic solids that remain suspended in water. Intrinsic colloids are formed when radioactive waste mixes with other dissolved components in the groundwater, such as bicarbonate.
"This study showed that intrinsic colloids formed by interactions between soluble Cerium (Ce) and carbonates significantly increase the mobility of Ce injected into a carbonate rock fracture," explains BGU Zuckerberg Institute for Water Research Director Prof. Noam Weisbrod, Ph.D. "The formation of intrinsic colloids, if not accounted for, could result in the under prediction of radionuclide migration through fractures in fine-grained carbonate bedrock, such as chalk."
In the study, Ce mobility as an intrinsic colloid was studied in an artificial rainwater (ARW) solution containing salt concentrations representative of those found in Negev Desert rainwater through a natural discrete chalk fracture.
In the United States at the Nevada test site, radioactive elements moved 1.3 kilometers from their source in just 30 years: significantly more than what was predicted from theoretical calculations. However, the extent to which intrinsic colloids contributed to this migration remains unclear.
"Determining the specific impact of intrinsic colloid formation by radioactive elements can aid in the development of migration models predicting radionuclide transport on a field-scale," says Prof. Weisbrod. "Thus, intrinsic colloids are expected to play an important role in actinide (radioactive elements) transport from nuclear repositories."
This study is part of the graduate work of Emily Tran, a student in Weisbrod's group at the Zuckerberg Institute for Water Research. The other researchers participating in this study were Ofra Klein-Ben David from the Nuclear Research Center of the Negev and Nadya Teutsch with the Geological Survey of Israel, Jerusalem.
Influence of Intrinsic Colloid Formation on Migration of Cerium through Fractured Carbonate Rock research funding was provided by The Pazi Fund (Grant 248) of the Israel Atomic Energy Commission (DOI) 10.1021/acs.est.5b03383.
About Zuckerberg Institute for Water Research
The Zuckerberg Institute for Water Research (Zuckerberg), Israel's largest and leading water institute, conducts interdisciplinary, cutting-edge research and graduate education in hydrology, water sciences and desert studies, aimed at improving human well being through technologies and policies for sustainable use of water resources. World-renowned researchers are focused on desalination technologies and water groundwater production, water quality and microbiology, as well as water resource economics and management. Zuckerberg graduate programs attract students from all corners of the world who are involved in research projects and collaborations in both developed and underdeveloped countries globally. Named for New York philanthropist Roy Zuckerberg, the Institute was founded in 2002 within the Jacob Blaustein Institutes for Desert Research at the Sede Boqer Campus of Ben-Gurion University of the Negev. For more information, visit http://www.aabgu.org/water.
About American Associates, Ben-Gurion University of the Negev
American Associates, Ben-Gurion University of the Negev (AABGU) plays a vital role in sustaining David Ben-Gurion's vision, creating a world-class institution of education and research in the Israeli desert, nurturing the Negev community and sharing the University's expertise locally and around the globe. With some 20,000 students on campuses in Beer-Sheva, Sede Boqer and Eilat in Israel's southern desert, BGU is a university with a conscience, where the highest academic standards are integrated with community involvement, committed to sustainable development of the Negev. AABGU is headquartered in Manhattan and has nine regional offices throughout the U.S. For more information, please visit http://www.aabgu.org.
Environmental Science & Technology