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Division Spotlight
Young Members Group
The Young Members Group works to encourage and enable all young professional members to be actively involved in the efforts and endeavors of the Society at all levels (Professional Divisions, ANS Governance, Local Sections, etc.) as they transition from the role of a student to the role of a professional. It sponsors non-technical workshops and meetings that provide professional development and networking opportunities for young professionals, collaborates with other Divisions and Groups in developing technical and non-technical content for topical and national meetings, encourages its members to participate in the activities of the Groups and Divisions that are closely related to their professional interests as well as in their local sections, introduces young members to the rules and governance structure of the Society, and nominates young professionals for awards and leadership opportunities available to members.
Meeting Spotlight
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
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Latest News
First astatine-labeled compound shipped in the U.S.
The Department of Energy’s National Isotope Development Center (NIDC) on March 31 announced the successful long-distance shipment in the United States of a biologically active compound labeled with the medical radioisotope astatine-211 (At-211). Because previous shipments have included only the “bare” isotope, the NIDC has described the development as “unleashing medical innovation.”
Larry G. Blackwood, Yale D. Harker
Nuclear Technology | Volume 132 | Number 3 | December 2000 | Pages 366-374
Technical Paper | Reactor Safety | doi.org/10.13182/NT00-A3150
Articles are hosted by Taylor and Francis Online.
Current nuclear criticality safety limit requirements for transporting TRUPACT-II waste containers to the U.S. Department of Energy's Waste Isolation Pilot Plant (WIPP) specify that the 239Pu fissile gram equivalent (FGE) plus two times its measurement error must be 325 g for a payload of fourteen 55-gal drums. The authorized method for calculating a TRUPACT-II FGE measurement error value is to take the square root of the sum of the squared error values for the individual containers (often called root-sum-squares or simply RSS). However, to the extent that the individual drum measurements contain common bias effects (e.g., due to common calibration or other adjustment factors), the corresponding measurement errors are correlated, and simple RSS calculations will underestimate the true error in the TRUPACT-II FGE value.The RSS calculations assume independence, while common bias effects can induce strong correlations between the errors in measurements. Significant bias effects can occur when the matrix characteristics for a particular waste type are not fully accounted for in the measurement process. Depending on the relative size of the bias error compared to precision error, the true measurement error can be greater than twice that calculated by RSS. In such cases, the FGE shipping requirement may not be met. To avoid underestimating the error, bias components should be estimated and propagated separately (combined only at the final step in the TRUPACT-II FGE calculation), or the effect of bias on covariance between measurements must be calculated. These covariance terms then need to be included in the final uncertainty calculations.