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Devoted to all aspects of the nuclear fuel cycle including waste management, worldwide. Division specific areas of interest and involvement include uranium conversion and enrichment; fuel fabrication, management (in-core and ex-core) and recycle; transportation; safeguards; high-level, low-level and mixed waste management and disposal; public policy and program management; decontamination and decommissioning environmental restoration; and excess weapons materials disposition.
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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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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.
Haluk Utku, John M. Christenson
Nuclear Science and Engineering | Volume 116 | Number 1 | January 1994 | Pages 55-66
Technical Note | doi.org/10.13182/NSE94-A21481
Articles are hosted by Taylor and Francis Online.
The temporal subdomain method (TSM), based on a spatial finite element formulation, is investigated as a method for the solution of the space-time-dependent multigroup neutron dynamics equations. The spatial aspect of the problem was formulated as an array of finite elements by using a two-dimensional rectangular coordinate system subdivided into contiguous triangular elements. Within each element and within each neutron group, the flux was represented by a linear polynomial. Numerical experiments using a computer program developed during the course of the investigation demonstrated that the method is straightforward to implement and that it produces stable calculations for a wide range of time steps. The stability of the method has been tested for sinusoidal, ramp, and step-change reactivity insertions. The results show that the TSM outperforms most alternating direction implicit methods in the sense that a similar degree of accuracy can be achieved with larger time steps using the same number of nodes. System condition number calculations as a function of node number were also carried out for a series of static eigenvalue calculations to determine the likelihood of error propagation and the difficulty of inverting the global system matrices during the time-dependent calculations.