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Division Spotlight
Fuel Cycle & Waste Management
Devoted to all aspects of the nuclear fuel cycle including waste management, worldwide. Division specific areas of interest and involvement include uranium conversion and enrichment; fuel fabrication, management (in-core and ex-core) and recycle; transportation; safeguards; high-level, low-level and mixed waste management and disposal; public policy and program management; decontamination and decommissioning environmental restoration; and excess weapons materials disposition.
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 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.”
Apoorva Rudra, Masahiro Kawaji (City College of New York), Aleksandr V. Obabko Saumil Patel (ANL)
Proceedings | Advances in Thermal Hydraulics 2018 | Orlando, FL, November 11-15, 2018 | Pages 694-700
Very High Temperature Reactors (VHTRs) have passive safety systems in comparison to the traditional current generation nuclear reactors that have active safety systems. In addition, they have gaseous coolants like helium proposed for them that allow them to operate at a temperature over 1000 oC along with other applications. However, several substantial engineering challenges are expected in VHTRs and can lead to localized hot spots in the reactor core as a result of degraded heat transfer in coolant channels. Our work addresses one such scenario called flow relaminarization. The following work incorporates 3D simulations in a very long pipe wherein turbulence is sustained throughout for the largest aspect ratio (L/D ratio) known in literature (~235). This work is the first step of a two-step process towards the final objective of studying heat driven turbulent gas relaminarization. Simulations are performed using a high order, spectral element and massively parallel CFD code called NEK5000 that combines the geometric flexibility of finite elements with the high accuracy of spectral methods. A replication method along with recycled periodicity is incorporated to successfully sustain turbulence throughout the pipe. The maximum Reynolds number incorporated for these simulations is 5190 which is chosen keeping in mind the flow relaminarization (forced convection) experiments that were performed by the group in the past. A sensitivity study on the polynomial order was performed as well and based on that the polynomial order chosen for the simulations was 6.