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Division Spotlight
Mathematics & Computation
Division members promote the advancement of mathematical and computational methods for solving problems arising in all disciplines encompassed by the Society. They place particular emphasis on numerical techniques for efficient computer applications to aid in the dissemination, integration, and proper use of computer codes, including preparation of computational benchmark and development of standards for computing practices, and to encourage the development on new computer codes and broaden their use.
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.”
Z. D. Whetstone, K. J. Kearfott
Nuclear Technology | Volume 176 | Number 3 | December 2011 | Pages 395-413
Technical Paper | Radiation Transport and Protection | doi.org/10.13182/NT10-118
Articles are hosted by Taylor and Francis Online.
This research was conducted to determine the optimal way to shield a compact, isotropic neutron source into a beam for active interrogation neutron systems. To define the restricted emission angle and to protect nearby personnel when stand-off distances are limited, shielding materials were added around the source. Because of limited space in many locations where active neutron interrogation is employed, a compact yet effective design was desired. Using the Monte Carlo N-Particle Transport Code, several shielding geometries were modeled. Materials investigated were polyethylene, polyethylene enriched with 10B, water, bismuth, steel, nickel, INCONEL® alloy 600, tungsten, lead, and depleted uranium. Various simulations were run testing the individual materials and combinations of them. It was found that at a stand-off distance of 1.5 m from the source, the most effective shielding configuration is a combination of several layers of polyethylene and steel. Without any shielding, the dose is 3.71 × 10-15 Sv/source particle. With a shielding consisting of multiple layers of steel totaling 30 cm thickness interspersed with several layers of polyethylene totaling 20 cm thickness, the dose drops to 3.68 × 10-17 Sv/emitted neutron at radians opposite the shield opening. The layered shielding approach is more effective at reducing dose equivalent and neutron fluence than shields made out of single continuous layers of the same material and thicknesses. Adding boron to the polyethylene and substituting tungsten for steel would make the shielding more effective but would add mass and cost.