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Optimization of screening for radioactivity in urine by liquid scintillation

Reese, Robert P.; Shanks, Sonoya T.

Numerous events have or could have resulted in the inadvertent uptake of radionuclides by fairly large populations. Should a population receive an uptake, valuable information could be obtained by using liquid scintillation counting (LSC) techniques to quickly screen urine from a sample of the affected population. This study investigates such LSC parameters as discrimination, quench, volume, and count time to yield guidelines for analyzing urine in an emergency situation. Through analyzing variations of the volume and their relationships to the minimum detectable activity (MDA), the optimum ratio of sample size to scintillating chemical cocktail was found to be 1:3. Using this optimum volume size, the alpha MDA varied from 2100 pCi/L for a 30-second count time to 35 pCi/L for a 1000-minute count time. The typical count time used by the Sandia National Laboratories Radiation Protection Sample Diagnostics program is 30 minutes, which yields an alpha MDA of 200 pCi/L. Because MDA is inversely proportional to the square root of the count time, count time can be reduced in an emergency situation to achieve the desired MDA or response time. Note that approximately 25% of the response time is used to prepare the samples and complete the associated paperwork. It was also found that if the nuclide of interest is an unknown, pregenerated discriminator settings and efficiency calibrations can be used to produce an activity value within a factor of two, which is acceptable for a screening method.

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The Navruz Project: Transboundary Monitoring for Radionuclides and Metals in Central Asia Rivers. Data Report

Passell, Howard D.; Barber, David S.; Betsill, J.D.; Littlefield, Adriane L.; Matthews, Robert F.; Mohagheghi, Amir H.; Shanks, Sonoya T.

The Navruz Project is a cooperative, transboundary, river monitoring project involving rivers and institutions in Kazakhstan, Kyrgyzstan, Tajikistan, and Uzbekistan, and facilitated by Sandia National Laboratories in the U.S. The Navruz Project focuses on waterborne radionuclides and metals because of their importance to public health and nuclear materials proliferation concerns in the region. The Project also collects data on basic water quality parameters. Data obtained in this project are shared among all participating countries and the public through a world-wide web site (http://www.cmc.sandia.org/Central/centralasia.html), and are available for use in further studies and in regional transboundary water resource management efforts. This report includes graphs showing selected data from the Fall 2000 and Spring 2001 sampling seasons. These data include all parameters grouped into six regions, including main rivers and some tributaries in the Amu Darya and Syr Darya river systems. This report also assembles all data (in tabular form) generated by the project from Fall 2000 through Fall 2001. This report comes as the second part of a planned three-part reporting process. The first report is the Sampling and Analysis Plan and Operational Manual, SAND 2002-0484. This is the second report.

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The Navruz Project: Transboundary Monitoring for Radionuclides and Metals in Central Asia Rivers. Sampling and Analysis Plan and Operational Manual

Passell, Howard D.; Barber, David S.; Betsill, J.D.; Littlefield, Adriane L.; Mohagheghi, Amir H.; Shanks, Sonoya T.

The transboundary nature of water resources demands a transboundary approach to their monitoring and management. However, transboundary water projects raise a challenging set of problems related to communication issues, and standardization of sampling, analysis and data management methods. This manual addresses those challenges and provides the information and guidance needed to perform the Navruz Project, a cooperative, transboundary, river monitoring project involving rivers and institutions in Kazakhstan, Kyrgyzstan, Tajikistan, and Uzbekistan facilitated by Sandia National Laboratories in the U.S. The Navruz Project focuses on waterborne radionuclides and metals because of their importance to public health and nuclear materials proliferation concerns in the region. This manual provides guidelines for participants on sample and data collection, field equipment operations and procedures, sample handling, laboratory analysis, and data management. Also included are descriptions of rivers, sampling sites and parameters on which data are collected. Data obtained in this project are shared among all participating countries and the public through an internet web site, and are available for use in further studies and in regional transboundary water resource management efforts. Overall, the project addresses three main goals: to help increase capabilities in Central Asian nations for sustainable water resources management; to provide a scientific basis for supporting nuclear transparency and non-proliferation in the region; and to help reduce the threat of conflict in Central Asia over water resources, proliferation concerns, or other factors.

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Results 26–30 of 30
Results 26–30 of 30