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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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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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Latest News
Nano Nuclear wins Air Force contract for Kronos MMR
New York City–based advanced nuclear technology developer Nano Nuclear Energy has been awarded a Direct-to-Phase II Small Business Innovation Research contract for its Kronos micro modular reactor (MMR) by AFWERX, the innovation and venture arm of the U.S. Air Force. The contract calls for AFWERX, with the 11th Civil Engineering Squadron, to explore the feasibility of deploying the Kronos MMR Energy System at Joint Base Anacostia-Bolling (JBAB) in Washington, D.C.
M. P. Sharma, A. K. Nayak
Nuclear Science and Engineering | Volume 188 | Number 2 | November 2017 | Pages 175-186
Technical Paper | doi.org/10.1080/00295639.2017.1339539
Articles are hosted by Taylor and Francis Online.
The Advanced Heavy Water Reactor (AHWR) is a vertical pressure tube–type, heavy water–moderated, and boiling light water–cooled natural-circulation–based reactor. The fuel bundle of AHWR contains 54 fuel rods arranged in three concentric rings of 12, 18, and 24 fuel rods. This fuel bundle is divided into a number of imaginary interacting flow passages called subchannels. Transition from a single-phase to a two-phase flow condition occurs in the reactor rod bundle with an increase in power. Predicting the thermal margin of the reactor has necessitated determining the diversion cross flow of coolant among these subchannels under two-phase flow. Thus, it is vital to evaluate cross flow between subchannels of the AHWR rod bundle. In this paper, experiments were carried out to investigate the diversion cross-flow phenomena for single- and two-phase flow in the simulated subchannels of the reactor. The size of the rod and the pitch in the test were the same as that of the actual rod bundle in the prototype. The cross-flow tests were carried out at atmospheric condition without adding heat. In addition, the capability of the existing correlation is also checked to predict the cross-flow resistance coefficient, and it is found that none of these models accurately predict the measured cross-flow resistance coefficient for the AHWR rod bundle. In view of this, a new model applicable to AHWR has been presented that predicts the cross-flow resistance coefficient quite accurately.