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Division Spotlight
Fuel Cycle & Waste Management
Devoted to all aspects of the nuclear fuel cycle including waste management, worldwide. Division specific areas of interest and involvement include uranium conversion and enrichment; fuel fabrication, management (in-core and ex-core) and recycle; transportation; safeguards; high-level, low-level and mixed waste management and disposal; public policy and program management; decontamination and decommissioning environmental restoration; and excess weapons materials disposition.
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.”
Paul E. Mariner (SNL)
Proceedings | 16th International High-Level Radioactive Waste Management Conference (IHLRWM 2017) | Charlotte, NC, April 9-13, 2017 | Pages 286-293
Humic complexation has the potential to increase actinide mobility and hamper waste isolation in geologic nuclear waste repositories. This study shows that humic complexation of tetravalent actinides (Th(IV), U(IV), Np(IV), and Pu(IV)) has been overestimated in past performance assessments of the Waste Isolation Pilot Plant (WIPP). Major reductions are needed for PHUMSIM and PHUMCIM, the equilibrium concentration ratios of humic-bound aqueous actinide to non-colloidal aqueous actinide. These coefficients are currently set at a value of 6.3 based on Th(IV) measurements in particle size fractions of seawater. Actual humic partitioning is expected to be significantly lower in WIPP brines primarily because pH is higher (~9) and concentrations of competing cations (e.g., Mg2+) are higher. In this work, data from recent studies of Th(IV)-humic, U(IV)-humic, and Ca2+-humic complexation are used to simulate competitive humic complexation under WIPP repository conditions and to estimate new An(IV) PHUMSIM and PHUMCIM values. The new lower coefficients reduce the humic-bound An(IV) concentrations by more than 99%, causing a reduction in total mobile An(IV) concentrations by 85% to 86%, assuming no other type of An(IV) colloid (i.e., intrinsic, microbial, and mineral fragment colloids) is present in significant concentrations.