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Division Spotlight
Decommissioning & Environmental Sciences
The mission of the Decommissioning and Environmental Sciences (DES) Division is to promote the development and use of those skills and technologies associated with the use of nuclear energy and the optimal management and stewardship of the environment, sustainable development, decommissioning, remediation, reutilization, and long-term surveillance and maintenance of nuclear-related installations, and sites. The target audience for this effort is the membership of the Division, the Society, and the public at large.
Meeting Spotlight
International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering (M&C 2025)
April 27–30, 2025
Denver, CO|The Westin Denver Downtown
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
Argonne’s METL gears up to test more sodium fast reactor components
Argonne National Laboratory has successfully swapped out an aging cold trap in the sodium test loop called METL (Mechanisms Engineering Test Loop), the Department of Energy announced April 23. The upgrade is the first of its kind in the United States in more than 30 years, according to the DOE, and will help test components and operations for the sodium-cooled fast reactors being developed now.
J. T. Mihalczo, V. K. Paré, G. L. Ragan, M. V. Mathis, G. C. Tillett
Nuclear Science and Engineering | Volume 66 | Number 1 | April 1978 | Pages 29-59
Technical Paper | doi.org/10.13182/NSE78-A15186
Articles are hosted by Taylor and Francis Online.
The theory of a method of determination of reactivity from power spectral density measurements with 252Cf and the results of experiments with a critical assembly mockup of a liquid-metal fast breeder reactor (LMFBR) and with uranium (93.2 wt% 235U) metal cylinders and a sphere are presented. This method of reactivity determination has an advantage over existing methods in that it determines the reactivity only from properties of the reactor at the subcritical state of interest and thus does not require a calibration near delayed criticality. In these experiments, the reactivity was varied by changing the fissile loading or the amount of neutron absorber inserted; for the LMFBR mockup, the reactivity varied to ∼75 dollars subcritical, and for the uranium metal assemblies to ∼30 dollars subcritical. These experiments verified for the first time the predictions of theory that could be tested in the measurements. This method has potential use in the fuel loading of reactors to determine the reactivity far subcritical before initial criticality is achieved. It has the advantage of not requiring a calibration at known reactivity by another method; furthermore, the interpretation of the measured data to obtain the reactivity does not depend on relative or absolute values of the source intensity or detection efficiency. It can also be used to determine the reactivity of assemblies where loading to criticality is undesirable or where sufficient material to achieve criticality is not available.
