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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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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ANS joins others in seeking to discuss SNF/HLW impasse
The American Nuclear Society joined seven other organizations to send a letter to Energy Secretary Christopher Wright on July 8, asking to meet with him to discuss “the restoration of a highly functioning program to meet DOE’s legal responsibility to manage and dispose of the nation’s commercial and legacy defense spent nuclear fuel (SNF) and high-level radioactive waste (HLW).”
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.