NSTD Research Projects: TRP
TRP 07. Development of Dose Coefficients for Radionuclides Produced in Spallation Targets
August 2001 - April 2006
Research Objectives & Methods
Results from this study will be used to produce Annual Limits on Intake (ALIs) and Derived Air Concentrations (DACs) for rare radionuclides created by spallation target systems that are not included in Federal Guidance Report (FGR) No. 11. Additionally, Dose Coefficients (DCs) developed will augment the radiological data in Publications 68 and 72 of the International Commission on Radiological Protection (ICRP), contributing to the safe operation of accelerator-driven nuclear systems.
A Dose Coefficient Working Group was established in 2001 to direct and oversee consortium activities. Representatives from the Dose Coefficient Working Group developed and verified a methodology to determine internal and external dose for select radionuclides. Data collected included decay modes, decay energy levels, and radiation energies and intensities.
The DC working group prioritized a list of radionuclides projected to be released via air emissions or in the inventory of a mercury target following a lengthy irradiation period. Only radionuclides with a half-life greater than one minute were considered. These 81 radionuclides were then categorized into three distinct categories, based on half-life, available information, and other technical factors.
All Category 2 radionuclides were investigated to determine which database was most current. Dose coefficients were then generated for the Category 2 radionuclides using both ENSDF and NUBASE. The results were compared and showed good agreement. In accordance with FGR No. 11, dose coefficients were evaluated for an adult male with the target tissues of gonads, breast, lung, red marrow, bone surface (endosteum), thyroid, remainder, and total committed effective dose equivalent (this considers total dose incurred to specific organs or tissues with respect to radiation type over a period of 50 years). Following determination of these variables, values of ALIs and DACs were then calculated for each radionuclide.
- Phillip Patton, Health Physics
- Mark Rudin, Health Physics
- Keith Echerman, Oak Ridge National Laboratory
- Tony Andrade, Los Alamos National Laboratory
- Brent Boyack, Los Alamos National Laboratory
- Rich Brey, Associate Professor, Idaho State University
- Faculty & Graduate Students from:
- Francis Marion University
- Georgia Institute of Technology
- Texas A&M University
- I. Javakhishvili Tiblisi State University, Georgia
- University of Florida
- University of Tennessee
- Tserenpagma Chaoui, Masters, Health Physics
- Ashley Gann, Masters, Health Physics
- Sung Yop Kim, Masters, Health Physics
John Shanahan, Masters, Health Physics
Yayun Song, Masters, Health Physics
- Deanna Tuttle, Masters, Health Physics
- Jeffrey Wyler, Masters, Health Physics
- Laura Mercer, Undergraduate, Health Physics
- Adam Arndt, Visiting Graduate, Idaho State University
- Chandra Gold, Visiting Graduate, Idaho State University