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Division Spotlight
Materials Science & Technology
The objectives of MSTD are: promote the advancement of materials science in Nuclear Science Technology; support the multidisciplines which constitute it; encourage research by providing a forum for the presentation, exchange, and documentation of relevant information; promote the interaction and communication among its members; and recognize and reward its members for significant contributions to the field of materials science in nuclear technology.
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.
W. W. Graham, III, D. S. Harmer, C. E. Cohn
Nuclear Science and Engineering | Volume 38 | Number 1 | October 1969 | Pages 33-41
Technical Paper | doi.org/10.13182/NSE69-A19350
Articles are hosted by Taylor and Francis Online.
The familiar rod-drop method for determining delayed-neutron parameters has been refined with new techniques of data collection, analysis, and correction. Values for a highly enriched uranium, heavy-water reactor have been obtained which have a general applicability because they have been accurately corrected for reactor power history, post-shutdown sub-critical neutron multiplication, and finite rod-drop time. Neutron flux after shutdown by rod drop in the Georgia Tech Research Reactor was monitored for periods in excess of three days using two detectors operated in parallel. One detector used a thermal-neutron-sensitive scintillator, the other a fission chamber. Flux-decay data were fit by weighted least squares using the Variable Metric Minimization method. This method was able to fit all the data simultaneously without limit on the number of fitting parameters. The most statistically-significant fit was obtained with 13 delayed-neutron groups, one of which was attributed to background due to its negligibly small decay constant. A fitting expression was used which accurately described the data collection process in which each data point was taken as the time integral of the flux over a finite time interval. The results are compared with values which have been obtained by small irradiated uranium samples and with decay-constant values in the last reported heavy-water in-reactor determination. There are indications that delayed-neutron effectiveness is enhanced by ∼3% in this type of reactor and that the effectiveness of photoneutron groups is decreased by ∼28% because of attenuation of high-energy gamma rays.