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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!
Latest Magazine Issues
Jul 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
August 2024
Nuclear Technology
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 since 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. local time 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.”
Brandon Wilson, Kelly McCary, Christian Petrie (ORNL), Thomas Blue (Ohio State)
Proceedings | Nuclear Plant Instrumentation, Control, and Human-Machine Interface Technolgies (NPIC&HMIT 2019) | Orlando, FL, February 9-14, 2019 | Pages 478-487
Sapphire optical fiber, with an internal cladding and an array of type-II Bragg gratings inscribed in it, was tested in-situ in the Ohio State Research Reactor (OSURR) to determine the viability of using sapphire as a sensor in an ionizing radiation environment. The sapphire fiber was attached to an optical frequency domain reflectometer (OFDR), which recorded the temperature of the fiber, at the locations of the gratings along the fiber, during the irradiations in the OSURR. The sapphire Bragg gratings survived the irradiations in the OSURR and produced reasonable temperature measurements for ~2.1 Equivalent Full Power Hours (EFPHs) of irradiation, corresponding to a neutron fluence of ~1.7 x 1017 n/cm2. The lead-in silica fiber, and perhaps the sapphire fiber itself, exhibited darkening, which affected sensing during the third day of irradiation; but adjusting the sensitivity of the OFDR corrected for this. During the reactor irradiations on the following day, the fiber produced reasonable temperature measurements to a four day total irradiation of ~8.8 EFPH, corresponding to a neutron fluence of ~7.3 x 1017 n/cm2. In summary, the sapphire sensors survived to fluences that are larger than those that they must withstand for testing in TREAT (~1 x 1017 n/cm2). The accuracy and precision of these sensors still needs to be determined. Also, it is must be acknowledge that fiber darkening in silica and sapphire may be flux dependent.