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Division Spotlight
Education, Training & Workforce Development
The Education, Training & Workforce Development Division provides communication among the academic, industrial, and governmental communities through the exchange of views and information on matters related to education, training and workforce development in nuclear and radiological science, engineering, and technology. Industry leaders, education and training professionals, and interested students work together through Society-sponsored meetings and publications, to enrich their professional development, to educate the general public, and to advance nuclear and radiological science and engineering.
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.”
Tohru Nakatsuka, Yoshiaki Oka, Seiichi Koshizuka
Nuclear Technology | Volume 121 | Number 1 | January 1998 | Pages 81-92
Technical Paper | Reactor Operations and Control | doi.org/10.13182/NT98-A2821
Articles are hosted by Taylor and Francis Online.
The plant system of a supercritical-water-cooled reactor is the once-through direct-cycle type, where steam-water separators and coolant recirculation systems are not necessary. It is different from those of a boiling water reactor (BWR) and a pressurized water reactor. The supercritical-water-cooled reactor is sensitive to perturbations of the feedwater flow rate because all of the core coolant, driven by the feedwater pumps, flows to the turbines without recirculating core flow. The axial coolant density change is three times larger than that of a BWR. It is necessary to analyze the controllability of the reactor against coolant flow and pressure perturbations to assess the technical feasibility of the reactor. The behaviors of a fast reactor cooled by supercritical water are analyzed for three principal perturbations: change of the control rod position, the feedwater flow rate, and the turbine control valve opening. Based on the step responses to the perturbations, the reactor control system is designed such that the pressure is controlled by the turbine control valves, the main steam temperature is controlled by the feedwater flow rate, and the core power is controlled by the control rods. It is not appropriate to control the pressure by the feedwater flow rate like in a supercritical fossil-fired power plant because of the nuclear thermal-hydraulic coupling. Parameters of the control system are selected by the test calculations to satisfy both fast convergence and stability criteria. Reactor behaviors with the designed control system are stable against the perturbations, although because the plant is the once-through direct-cycle type, the coolant inventory is small. Reactors cooled by supercritical light water are controllable with the described control system.