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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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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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Powering the future: How the DOE is fueling nuclear fuel cycle research and development
As global interest in nuclear energy surges, the United States must remain at the forefront of research and development to ensure national energy security, advance nuclear technologies, and promote international cooperation on safety and nonproliferation. A crucial step in achieving this is analyzing how funding and resources are allocated to better understand how to direct future research and development. The Department of Energy has spearheaded this effort by funding hundreds of research projects across the country through the Nuclear Energy University Program (NEUP). This initiative has empowered dozens of universities to collaborate toward a nuclear-friendly future.
R. Venkataraman, R. F. Fleming, E. D. McGarry
Nuclear Science and Engineering | Volume 126 | Number 3 | July 1997 | Pages 314-323
Technical Paper | doi.org/10.13182/NSE97-A24483
Articles are hosted by Taylor and Francis Online.
A new measurement-based method has been developed to determine the photofission contribution to measured responses of fission reactions in a mixed radiation field of neutrons and photons. Using this method, reliable upper and lower bounds can be established for the photofission contributions. Knowledge of the photon energy spectrum and the photofission cross sections is not required. The method involves the measurement and calculation of spectral indices of a fission reaction relative to a reaction whose response does not include any photon contribution. The differential changes in the spectral indices are measured as well as calculated with and without a gamma-ray attenuator. The measurements include responses from both neutrons and photons, whereas the calculations include contributions from neutrons only. An equation is derived for the ratio of photofission rate to neutron-induced fission rate using the definitions of the spectral indices. From this equation, algebraic upper and lower bounds can be determined for the photofission contribution using a minimum and a maximum value for the mass attenuation coefficient of the gamma-attenuating material at all photon energies. The method was tested in the radiation field inside the Materials Dosimetry Reference Facility (MDRF), which is a National Institute of Standards and Technology reference neutron field operating at the Ford Nuclear Reactor at the University of Michigan. Established algebraic upper bounds for the photofission contributions to the 237Np and 238U fission reactions in the MDRF were found to overlap zero. Conservative statistical upper bounds were established at the la level of confidence, and these are 0.87% for the 237Np fission reaction and 0.55 % for the 238U fission reaction.
