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Division Spotlight
Nuclear Criticality Safety
NCSD provides communication among nuclear criticality safety professionals through the development of standards, the evolution of training methods and materials, the presentation of technical data and procedures, and the creation of specialty publications. In these ways, the division furthers the exchange of technical information on nuclear criticality safety with the ultimate goal of promoting the safe handling of fissionable materials outside reactors.
Meeting Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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
NRC cuts fees by 50 percent for advanced reactor applicants
The Nuclear Regulatory Commission has announced it has amended regulations for the licensing, inspection, special projects, and annual fees it will charge applicants and licensees for fiscal year 2025.
Jose March-Leuba, Dan G. Cacuci, Rafael B. Perez
Nuclear Science and Engineering | Volume 93 | Number 2 | June 1986 | Pages 124-136
Technical Paper | doi.org/10.13182/NSE86-A17664
Articles are hosted by Taylor and Francis Online.
A physical model of nonlinear boiling water reactor (BWR) dynamics has been developed and employed to calculate the amplitude of limit cycle oscillations and their effects on fuel integrity over a wide range of operating conditions in the Vermont Yankee reactor. These calculations have confirmed that, beyond the threshold for linear stability, the reactor's state variables undergo limit cycle oscillations. This work shows that the amplitudes of these oscillations are very sensitive to changes in operating conditions and are not restricted to small magnitudes as observed in previous stability tests. Consequently, large-amplitude limit cycle oscillations become a possible scenario for BWR operation at low-flow conditions. The effects on fuel integrity of such large-amplitude oscillations have been studied in detail. In particular, it has been shown that limit cycles that oscillate with frequencies higher than 0.25 Hz and that reach the high-power safety scram level of 120% are not likely to compromise fuel integrity.