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Division Spotlight
Isotopes & Radiation
Members are devoted to applying nuclear science and engineering technologies involving isotopes, radiation applications, and associated equipment in scientific research, development, and industrial processes. Their interests lie primarily in education, industrial uses, biology, medicine, and health physics. Division committees include Analytical Applications of Isotopes and Radiation, Biology and Medicine, Radiation Applications, Radiation Sources and Detection, and Thermal Power Sources.
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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July 2024
Fusion Science and Technology
Latest News
NRC engineers share their expertise at the University of Puerto Rico
Robert Roche-Rivera and Marcos Rolón-Acevedo are licensed professional engineers who work at the U.S. Nuclear Regulatory Commission. They are also alumni of the University of Puerto Rico–Mayagüez (UPRM) and have been sharing their knowledge and experience with students at their alma mater since last year, serving as adjunct professors in the university’s Department of Mechanical Engineering. During the 2023–2024 school year, they each taught two courses: Fundamentals of Nuclear Science and Engineering, and Nuclear Power Plant Engineering.
Gregg A. Morgan
Fusion Science and Technology | Volume 71 | Number 4 | May 2017 | Pages 478-484
Technical Paper | doi.org/10.1080/15361055.2017.1293454
Articles are hosted by Taylor and Francis Online.
Normetex® Model 15 scroll pump backed by metal bellows (MB) pump made by Senior Aerospace Inc. has been the preferred technology for use in tritium facilities world-wide. Normetex pumps are no longer available and identification of alternate pumps is required for performance and compatibility with tritium gas. Many of the pumps that could be used to meet the functional performance requirements (e.g. pressure and flow conditions) of the Normetex pump have features that include the use of polymers or oils and greases that are not directly compatible with tritium service. Though they are less desirable, alternative pumps may be used in tritium service with appropriate engineered controls to mitigate the impact of degraded organic compounds. These alternative pumps require characterization for potential application in tritium service.
One pump that has been identified as a potential replacement for the Normetex pump in some tritium service applications is the Edwards nXDS15iC. A series of pump tests were completed using this pump as a candidate replacement pump. The purpose of the pump testing is two-fold: (1) obtain baseline vacuum pump characteristics for the replacement pump intended for use in tritium service; and (2) verify that low pressure hydrogen gas can be transported over various distances up to 92 meters (300 feet) by the candidate pump. A series of pump tests were performed at various configurations using hydrogen gas (no tritium) and nitrogen to ensure that this pump can meet the performance requirements.
The Edwards pump meets the desired functional performance requirements, though there are other tradeoffs that must be considered. As for cost considerations, the Edwards scroll pump costs about ten (10) times less than a Normetex-equivalent scroll pump, which would significantly reduce initial start-up costs in a facility. However, the lifetime of the Edwards pump in a nearly pure tritium process stream is speculated to be only 3–6 months due to the polymer tip seals, whereas the all-metal Normetex pump can last for 5 years. Each application must determine whether the alternative pump considerations outweigh the cost differential. This paper summarizes the results of the tests that have been performed using various pump configurations.