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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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EPA administrator Lee Zeldin talks the future of nuclear
In a recent interview on New York radio station 77 WABC, administrator of the Environmental Protection Agency Lee Zeldin talked with host John Catsimatidis about the near-term future of the domestic nuclear industry and the role the EPA will play in the sector.
Catsimatidis kicked off the interview by asking if the U.S. will be able to reach total energy independence. Zeldin responded by saying that decreasing energy dependence on other countries, especially adversaries, was a top priority for him and the Trump administration.
Glenn E. Sjoden
Nuclear Science and Engineering | Volume 155 | Number 2 | February 2007 | Pages 179-189
Technical Paper | Mathematics and Computation, Supercomputing, Reactor Physics and Nuclear and Biological Applications | doi.org/10.13182/NSE07-A2655
Articles are hosted by Taylor and Francis Online.
A new exponential spatial differencing scheme based on zeroth spatial transport moments, the exponential directional iterative (EDI) Sn scheme for three-dimensional (3-D) Cartesian geometry, is presented. The EDI scheme is a logical extension of the positive, efficient exponential directional weighted (EDW) method used in the PENTRAN parallel Sn solver in an adaptive differencing strategy. The EDI scheme uses EDW-rendered exponential coefficients as initial values to begin a fixed-point iteration to refine exponential coefficients. Iterative refinement of these coefficients typically converged in fewer than four fixed-point iterations per ordinate, and yielded more accurate angular fluxes compared to other schemes tested. Overall, the EDI scheme is an order of magnitude more accurate than EDW, and two orders of magnitude more accurate than the legacy diamond zero (DZ) scheme for a given mesh. EDI is therefore a good candidate for a fourth-level scheme in the PENTRAN adaptive sequence. The 3-D Cartesian computational cost of EDI was ~20% more than EDW, and only ~40% more than DZ. Thus, EDI renders increased accuracy using zeroth spatial transport moments in a straightforward manner for any 3-D Cartesian code. More evaluation is ongoing to determine suitability in an upgraded adaptive differencing sequence algorithm in PENTRAN.
