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
Nuclear Criticality Safety
NCSD provides communication among nuclear criticality safety professionals through the development of standards, the evolution of training methods and materials, the presentation of technical data and procedures, and the creation of specialty publications. In these ways, the division furthers the exchange of technical information on nuclear criticality safety with the ultimate goal of promoting the safe handling of fissionable materials outside reactors.
Meeting Spotlight
2025 ANS Annual Conference
June 15–18, 2025
Chicago, IL|Chicago Marriott Downtown
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
May 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
July 2025
Nuclear Technology
June 2025
Fusion Science and Technology
Latest News
High-temperature plumbing and advanced reactors
The use of nuclear fission power and its role in impacting climate change is hotly debated. Fission advocates argue that short-term solutions would involve the rapid deployment of Gen III+ nuclear reactors, like Vogtle-3 and -4, while long-term climate change impact would rely on the creation and implementation of Gen IV reactors, “inherently safe” reactors that use passive laws of physics and chemistry rather than active controls such as valves and pumps to operate safely. While Gen IV reactors vary in many ways, one thing unites nearly all of them: the use of exotic, high-temperature coolants. These fluids, like molten salts and liquid metals, can enable reactor engineers to design much safer nuclear reactors—ultimately because the boiling point of each fluid is extremely high. Fluids that remain liquid over large temperature ranges can provide good heat transfer through many demanding conditions, all with minimal pressurization. Although the most apparent use for these fluids is advanced fission power, they have the potential to be applied to other power generation sources such as fusion, thermal storage, solar, or high-temperature process heat.1–3
Stefan Renger, Sören Alt, Ulrike Gocht, Wolfgang Kästner, André Seeliger, Holger Kryk, Ulrich Harm
Nuclear Technology | Volume 205 | Number 1 | January-February 2019 | Pages 248-261
Technical Paper | doi.org/10.1080/00295450.2018.1499324
Articles are hosted by Taylor and Francis Online.
In a joint research project of the Zittau/Goerlitz University of Applied Sciences, the Technische Universität Dresden, and the Helmholtz-Zentrum Dresden-Rossendorf, the main emphasis is the time-related assignment of simultaneous and interacting mechanisms at zinc sources and zinc sinks at boundary conditions of a loss-of-coolant accident (LOCA) in German pressurized water reactors (PWRs). The required experiments are carried out at semitechnical and laboratory scales.
Zinc is used as a protective coating, e.g., for gratings in the containment, showing high corrosion resistance due to a gradual formation of passivating layers. In contrast, its long-term behavior during LOCA changes significantly under the influence of the coolant chemistry of German PWRs. As a consequence, installations in the containment act as zinc sources. Released zinc ions change the chemical properties of the coolant and could, e.g., lead to layer-forming depositions of zinc borates in the core, which increases the possibility of a hindered heat dissipation. For experimental and methodical investigations of these phenomena, the test rig Zittau flow tray, a scaled sump model of a German PWR, was equipped with a full-length 3 × 3 fuel assembly dummy acting as core model, a preheater, and a cooler component. Nine 4.4-m-long fuel rod dummies simulate the decay heat by internal heating cartridges. This rig design enables experimental investigation of physicochemical mechanisms considering coolant containing boric acid and zinc and their influence on the thermohydraulic processes in the reactor core at post-LOCA boundary conditions. Additional zinc corrosion and zinc borate precipitation studies to elucidate chemical zinc corrosion mechanisms and dependencies of those processes on typical LOCA parameters were carried out using lab-scale corrosion/precipitation test facilities.
The time-dependent zinc release at hot-dip galvanized gratings (HGGs) was investigated regarding their position (e.g., inside or near the leaking jet, freely suspended, or submerged in the coolant) and their surface area as well as the temperature and flow rate of the coolant. The experimental database allows the approximation of corrosion rates in dependence of HGG position and the accident-specific coolant leakage rate as well as first mathematical approaches for the modeling of zinc sources.
