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Division Spotlight
Radiation Protection & Shielding
The Radiation Protection and Shielding Division is developing and promoting radiation protection and shielding aspects of nuclear science and technology — including interaction of nuclear radiation with materials and biological systems, instruments and techniques for the measurement of nuclear radiation fields, and radiation shield design and evaluation.
Meeting Spotlight
Utility Working Conference and Vendor Technology Expo (UWC 2024)
August 4–7, 2024
Marco Island, FL|JW Marriott Marco Island
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
Vogtle-3 shuts down for valve issue
One of the new Vogtle units in Georgia was shut down unexpectedly on Monday last week for a valve issue that has been investigated and repaired. According to multiple local news outlets, Georgia Power reported on July 17 that unit 3 was back in service.
Southern Company spokesperson Jacob Hawkins confirmed that Vogtle-3 went off line at 9:25 p.m. on July 8 “due to lowering water levels in the steam generators caused by a valve issue on one of the three main feedwater pumps.”
Sang-Moon Lee, Kwang-Yong Kim
Nuclear Technology | Volume 175 | Number 2 | August 2011 | Pages 361-370
Technical Paper | Fission Reactors | doi.org/10.13182/NT11-A12309
Articles are hosted by Taylor and Francis Online.
The shape optimization of the upper plenum of a pebble bed modular reactor (PBMR)-type gas-cooled nuclear reactor has been performed by using three-dimensional Reynolds-averaged Navier-Stokes (RANS) analysis and a multiobjective optimization procedure. A multiobjective genetic algorithm is used for multiobjective optimization. Two objective functions related to the uniformity of the flow distribution at the core inlet and pressure drop through the upper plenum are employed. Three geometric design variables, namely, the ratio of the thickness of the slot to the diameter of the rising channels, the ratio of the height of the upper plenum to the diameter of the rising channels, and the ratio of the height of the slot at the inlet to that at the outlet, are used for the optimization. Latin hypercube sampling is used to determine the experimental points. The response surface approximation model is used to approximate the Pareto-optimal front with three-dimensional RANS analysis using the shear stress transport turbulence model. Seven optimal shapes have been obtained using k-means clustering. From an analysis of two typical optimal designs, it is found that both of the objective functions have been improved remarkably in comparison with the reference design.