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Materials Science & Technology
The objectives of MSTD are: promote the advancement of materials science in Nuclear Science Technology; support the multidisciplines which constitute it; encourage research by providing a forum for the presentation, exchange, and documentation of relevant information; promote the interaction and communication among its members; and recognize and reward its members for significant contributions to the field of materials science in nuclear technology.
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Utility Working Conference and Vendor Technology Expo (UWC 2024)
August 4–7, 2024
Marco Island, FL|JW Marriott Marco Island
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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.”
Jan S. Muransky, John G. Shatford, Craig E. Peterson, Gregg B. Swindlehurst
Nuclear Technology | Volume 148 | Number 1 | October 2004 | Pages 48-55
Technical Paper | RETRAN | doi.org/10.13182/NT04-A3547
Articles are hosted by Taylor and Francis Online.
For certain steam line break (SLB) analyses, the RETRAN-3D Oconee model predicts water carryout through the break. The amount of liquid carried from the system is dependent on the assumed break size, feedwater boundary conditions, and initial conditions. Although liquid carryout is potentially realistic during this scenario, there are no plant or test facility data on which to validate the amount of water carryout.Because the steam generator tube stress evaluation is a safety related analysis, a conservative approach is required. Overcooling effects for an SLB transient are maximized by retaining as much steam generator liquid as possible to remove energy from the reactor coolant system. Because water carryout is nonconservative, and due to the lack of data, the analysis is performed assuming no liquid is carried from the break. This boundary condition is difficult to impose on a RETRAN-3D analysis since the amount of liquid entrained in the break flow is determined by internal code models, which the analyst cannot control directly.This paper presents the methodology used to eliminate water carryout for these types of calculations. The methodology consists of a combination of special RETRAN-3D code modifications and model input changes.In the second part of the paper, the results of an SLB analysis for the Oconee Nuclear Station employing the above methodology are presented. These analyses are done to compute the temperature differences between the steam generator tubes and the shell of the once-through steam generator. The temperature of the thin tubes decreases much faster than the temperature of the shell during an overcooling transient such as an SLB, resulting in tensile stresses that might lead to tube failures.A number of break sizes were analyzed starting with a double-ended main SLB down to a small break of 0.0372 m2 (0.4 ft2). The sensitivity of the tube tensile stress to the assumed break size is presented.