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Division Spotlight
Nuclear Installations Safety
Devoted specifically to the safety of nuclear installations and the health and safety of the public, this division seeks a better understanding of the role of safety in the design, construction and operation of nuclear installation facilities. The division also promotes engineering and scientific technology advancement associated with the safety of such facilities.
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ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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
Norway’s Halden reactor takes first step toward decommissioning
The government of Norway has granted the transfer of the Halden research reactor from the Institute for Energy Technology (IFE) to the state agency Norwegian Nuclear Decommissioning (NND). The 25-MWt Halden boiling water reactor operated from 1958 to 2018 and was used in the research of nuclear fuel, reactor internals, plant procedures and monitoring, and human factors.
Shawn D. Pautz, Tara M. Pandya, Marvin L. Adams
Nuclear Science and Engineering | Volume 169 | Number 3 | November 2011 | Pages 245-261
Technical Paper | doi.org/10.13182/NSE10-30
Articles are hosted by Taylor and Francis Online.
The well-known “sweep” algorithm for inverting the streaming-plus-collision term in first-order deterministic radiation transport calculations suffers from parallel scaling issues caused by a lack of concurrency in the spatial dimension along the direction of particle travel. We investigate a new class of parallel algorithms that involves recasting the streaming-plus-collision problem in prefix form and solving via cyclic reduction. This method, although computationally more expensive at low levels of parallelism than the sweep algorithm, offers better theoretical scalability properties. Previous work has demonstrated this approach for one-dimensional calculations; we show how to extend it to multidimensional calculations. Notably, for multiple dimensions it appears that this approach is limited to long-characteristics discretizations; other discretizations cannot be cast in practical prefix form. Computational results on two different massively parallel computer systems demonstrate that both our “forward” and “symmetric” algorithms behave similarly, scaling well to larger degrees of parallelism than sweep-based solvers. We do observe some issues at the highest levels of parallelism (relative to the computer system size) and discuss possible causes. We conclude that this approach shows good potential for future parallel systems but that parallel scalability will depend on the architecture of the communication networks of these systems.