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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
International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering (M&C 2025)
April 27–30, 2025
Denver, CO|The Westin Denver 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!
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Dragonfly, a Pu-fueled drone heading to Titan, gets key NASA approval
Curiosity landed on Mars sporting a radioisotope thermoelectric generator (RTG) in 2012, and a second NASA rover, Perseverance, landed in 2021. Both are still rolling across the red planet in the name of science. Another exploratory craft with a similar plutonium-238–fueled RTG but a very different mission—to fly between multiple test sites on Titan, Saturn’s largest moon—recently got one step closer to deployment.
On April 25, NASA and the Johns Hopkins University Applied Physics Laboratory (APL) announced that the Dragonfly mission to Saturn’s icy moon passed its critical design review. “Passing this mission milestone means that Dragonfly’s mission design, fabrication, integration, and test plans are all approved, and the mission can now turn its attention to the construction of the spacecraft itself,” according to NASA.
J. A. Mowrey, S. I. Abdel-Khalik, K. W. Ross
Nuclear Technology | Volume 111 | Number 2 | August 1995 | Pages 283-302
Technical Paper | Nuclear Criticality Safety Special / Reactor Operation | doi.org/10.13182/NT95-A35138
Articles are hosted by Taylor and Francis Online.
A RELAP5/MOD3.1 model of a boiling water reactor and an interface are developed as a real-time test platform for a physical feedwater control system and turbine governors. The reactor plant modeled is Browns Ferry unit 2. The model is used to test and tune the new digital reactor feedwater control system (RFWCS) for units 2 and 3. The set of modeled components, trips, and controls is determined based on the testing requirements for the RFWCS. The work is performed in two phases. In the first phase, the existing plant is modeled, including the previously existing analog feedwater control system and governor. The resulting RELAP5 model is benchmarked against existing plant data. Benchmarking results are presented along with data on initialization to steady state. Once the benchmarking effort is completed, the control systems in the model are altered to allow testing of the digital RFWCS in real time. An interface is developed to allow communications with the digital RFWCS and operator interaction, which allows the test platform to be used to determine control system response to various transients. Descriptions of the RELAP5 model and hardware and software for the interface are provided.
