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
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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Fusion Science and Technology
Latest News
Taking shape: Fusion energy ecosystems built with public-private partnerships
It’s possible to describe fusion in simple terms: heat and squeeze small atoms to get abundant clean energy. But there’s nothing simple about getting fusion ready for the grid.
Private developers, national lab and university researchers, suppliers, and end users working toward that goal are developing a range of complex technologies to reach fusion temperatures and pressures, confounded by science and technology gaps linked to plasma behavior; materials, diagnostics, and electronics for extreme environments; fuel cycle sustainability; and economics.
Benjamin Rouben, Eleodor Nichita
Nuclear Technology | Volume 207 | Number 10 | October 2021 | Pages 1633-1638
Technical Note | doi.org/10.1080/00295450.2020.1827884
Articles are hosted by Taylor and Francis Online.
Throughout the years, various reports and training manuals on CANada Deuterium Uranium (CANDU) reactors have mentioned that the CANDU lattice is overmoderated. Overmoderation is not always defined in such documents but often appears associated with the positive void reactivity of the CANDU lattice. Some documents refer, logically, to overmoderation as meaning that the lattice pitch is larger than the pitch that maximizes the infinite-lattice multiplication constant but do not demonstrate this is the case for CANDU. We demonstrate that in fact, the CANDU lattice is undermoderated; that is, the current 28.575-cm lattice pitch is smaller than the pitch for which the infinite-lattice multiplication constant reaches its maximum. We hypothesize that the misconception of CANDU overmoderation may have originated from attributing the CANDU positive void reactivity to too much moderator by incorrectly equating the effect of losing heavy water coolant with the effect of losing heavy water moderator.