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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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Deep Space: The new frontier of radiation controls
In commercial nuclear power, there has always been a deliberate tension between the regulator and the utility owner. The regulator fundamentally exists to protect the worker, and the utility, to make a profit. It is a win-win balance.
From the U.S. nuclear industry has emerged a brilliantly successful occupational nuclear safety record—largely the result of an ALARA (as low as reasonably achievable) process that has driven exposure rates down to what only a decade ago would have been considered unthinkable. In the U.S. nuclear industry, the system has accomplished an excellent, nearly seamless process that succeeds to the benefit of both employee and utility owner.
M. Guyot, P. Gubernatis, C. Suteau
Nuclear Science and Engineering | Volume 178 | Number 2 | October 2014 | Pages 202-224
Technical Paper | doi.org/10.13182/NSE13-80
Articles are hosted by Taylor and Francis Online.
Numerical simulations of the primary phase of a hypothetical core disruptive accident are currently based on a multiple-channel approach, which requires that subassemblies or groups of subassemblies be represented together as independent channels. Generally, a single-pin treatment is used to model the channel fuel pins. The limitation of this simplified approach should be assessed because it can affect voiding and melting patterns that in turn may influence reactivity insertions and power history. In the same manner, the single-pin hypothesis may introduce important biases in the prediction of can-wall thermal ablation. Radial propagation of the degradation and subsequent accident consequences may thus be affected. To improve the safety assessment of sodium fast reactors, two-dimensional effects are investigated using a multiple-pin model. Numerical results for a severe accident transient show that the current methodology is nonconservative and predicts the onset of sodium boiling with a delay. A two-node radial meshing of the subassembly is preferred for treating the peripheral ring of fuel pins separately from the rest of the pins. This treatment would allow overcoming the previous issue and give more accurate initiating phase simulations.