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Division Spotlight
Thermal Hydraulics
The division provides a forum for focused technical dialogue on thermal hydraulic technology in the nuclear industry. Specifically, this will include heat transfer and fluid mechanics involved in the utilization of nuclear energy. It is intended to attract the highest quality of theoretical and experimental work to ANS, including research on basic phenomena and application to nuclear system design.
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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Fusion Science and Technology
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.”
H. Huang, S. A. Eddinger, M. Schoff
Fusion Science and Technology | Volume 55 | Number 4 | May 2009 | Pages 373-379
Technical Paper | Eighteenth Target Fabrication Specialists' Meeting | doi.org/10.13182/FST55-373
Articles are hosted by Taylor and Francis Online.
National Ignition Facility (NIF) specifications have stringent dimensional accuracy requirements on target components. For example, the laser-hole diameter on an ablator capsule must be characterized to ±0.5 m to ensure proper fill tube insertion and to minimize the glue joint mass to <2.5 ng. A charge-coupled-device-based X-ray radiography and tomography instrument (commercially obtained from Xradia, Inc.) is used in target metrology where sample opacity precludes the use of optical techniques; however, the built-in caliper for dimensional measurement cannot provide the required accuracy. The instrument has three main error sources: (a) point projection magnification, (b) imaging lens distortion, and (c) phase contrast shift. The sample feature size dictates the calibration strategy. For large features such as the shell diameter, (a) and (b) dominate the error budget. The built-in caliper is accurate to ~2 to 3%, corresponding to a ±50-m error for a 2000-m NIF capsule. In this work, we developed an X-ray transmission dimension standard and developed (by measuring the standard) a software algorithm to "un-distort" the acquired images without resorting to the standard each time. The latter approach reduces the processing time by 50% and still offers a tenfold accuracy improvement and makes the Xradia instrument useful in screening components. For small features such as laser-drilled holes, (c) is dominant. It shifts the apparent wall boundary to cause a typical ~2-m error for the 5- to 10-m hole diameter. We developed an empirical correction technique with 0.5-m accuracy, in which the dimensions measured by radiography were benchmarked against those by a focused ion beam and scanning electron microscope after sample cleavage. The improved accuracy allows the glue mass to be estimated to 1 ng as required by the NIF specifications.