ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Division Spotlight
Radiation Protection & Shielding
The Radiation Protection and Shielding Division is developing and promoting radiation protection and shielding aspects of nuclear science and technology — including interaction of nuclear radiation with materials and biological systems, instruments and techniques for the measurement of nuclear radiation fields, and radiation shield design and evaluation.
Meeting Spotlight
2024 ANS Winter Conference and Expo
November 17–21, 2024
Orlando, FL|Renaissance Orlando at SeaWorld
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!
Latest Magazine Issues
Aug 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
September 2024
Nuclear Technology
Fusion Science and Technology
August 2024
Latest News
Nuclear new build procurement considerations
It may seem counterintuitive, but the best time to enhance the ability to support operations and maintenance for a new plant is before construction starts. This is one of many lessons learned by the currently operating nuclear fleet. As construction and startup of many nuclear facilities was completed, it quickly became evident that the ability to efficiently support operations and maintenance was limited. Most of the information necessary to establish and manage procurement of spare and replacement items, maintenance, and configuration of the facilities was unavailable and had to be gathered on a case-by-case, “on-demand” basis. Absence of necessary information and the associated challenges resulted in the need for staff augmentation and multiyear-long projects to develop equipment bills of material and maintenance programs and to perform technical evaluations for the huge quantities of spare and replacement items being requested.
D. Cai, P. Titus, C. Rana, H. Zhang, S. Sheckman
Fusion Science and Technology | Volume 77 | Number 7 | November 2021 | Pages 617-628
Technical Paper | doi.org/10.1080/15361055.2021.1921362
Articles are hosted by Taylor and Francis Online.
The National Spherical Torus eXperiment (NSTX) has undergone a major upgrade to NSTX-U at the Princeton Plasma Physics Laboratory. NSTX-U will double the toroidal field, plasma current, and neutral beam injection heating power, as well as significantly increase the pulse duration. The plasma-facing components (PFCs) in the NSTX-U vacuum vessel are mainly graphite, which has a total surface area of about 41 m2. To achieve high vacuum and reduce impurity from PFCs during operation, it is important to bake the graphite parts and remove most of the moisture absorbed by graphite during installation. Typical bakeout for NSTX-U lasts about 3 to 4 weeks. The NSTX-U inner vacuum vessel, i.e., the center stack casing, will be heated to about 450°C by passing 8 KA direct current through it during bakeout. The design of the bakeout bus directly attached to the casing flanges at vessel top and bottom are covered in detail in this paper. At the vessel top, the water-cooled bus terminal is subject to high thermal growth (about 18 mm in the vertical direction and 3 mm in the radial direction). At the vessel bottom, the bakeout bus must withstand 120 KA of halo current during disruption, as well as dislocation from thermal growth. This paper covers the design to address all these challenges. A machined CuCrZr terminal with internal water-cooling channels was used to prevent any brazing work in high stress areas. Detailed analysis will also be covered to show that the proposed design can satisfy thermal, structural, and fatigue requirements during bakeout and operation.