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Division Spotlight
Fusion Energy
This division promotes the development and timely introduction of fusion energy as a sustainable energy source with favorable economic, environmental, and safety attributes. The division cooperates with other organizations on common issues of multidisciplinary fusion science and technology, conducts professional meetings, and disseminates technical information in support of these goals. Members focus on the assessment and resolution of critical developmental issues for practical fusion energy applications.
Meeting Spotlight
Conference on Nuclear Training and Education: A Biennial International Forum (CONTE 2025)
February 3–6, 2025
Amelia Island, FL|Omni Amelia Island Resort
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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How to talk about nuclear
In your career as a professional in the nuclear community, chances are you will, at some point, be asked (or volunteer) to talk to at least one layperson about the technology you know and love. You might even be asked to present to a whole group of nonnuclear folks, perhaps as a pitch to some company tangential to your company’s business. So, without further ado, let me give you some pointers on the best way to approach this important and surprisingly complicated task.
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.
