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Division Spotlight
Accelerator Applications
The division was organized to promote the advancement of knowledge of the use of particle accelerator technologies for nuclear and other applications. It focuses on production of neutrons and other particles, utilization of these particles for scientific or industrial purposes, such as the production or destruction of radionuclides significant to energy, medicine, defense or other endeavors, as well as imaging and diagnostics.
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.
Keiichi Saito
Nuclear Science and Engineering | Volume 37 | Number 3 | September 1969 | Pages 380-396
Technical Paper | doi.org/10.13182/NSE69-A19114
Articles are hosted by Taylor and Francis Online.
Input-noise sources in at-power reactors are formulated under the basic assumption that a set of macrostochastic variables characterizing the state of the reactors has Markoffian properties. An input-noise source is defined as the ratio between the power-spectral density of fluctuations in the reactor-power level and the square modulus of the source-transfer function. Random birth and death processes of neutrons give rise to a “white” contribution to the input source. Additional contributions are found which have the break (roll-off) angular frequencies determined by the relaxation time constants of the feedback effects on reactivity. These “non-white” terms come from fluctuations in neutron-reaction cross sections caused by temperature variations. The ratio of the non-white to the white terms increases as the reactor power increases. It also depends on the magnitude of the reactivity coefficients of feedback. Before one evaluates the magnitude of the non-white noise term, however, there should be knowledge of some statistical parameters relating the noise to random emission of energy by nuclear fissions, random exchange between the fuel and the coolant in heat transfer reactions and random removal through the coolant flow. The formula for analyzing the power-spectral density of the temperature fluctuations is also derived where the same unknown statistical parameters appear. Measurements of both the power and the temperature fluctuations will serve to determine these parameters whereby one will be able to obtain better information on the time constant and the reactivity coefficient of each feedback effect.
