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2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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Latest News
NNSA awards BWXT $1.5B defense fuels contract
The Department of Energy’s National Nuclear Security Administration has awarded BWX Technologies a contract valued at $1.5 billion to build a Domestic Uranium Enrichment Centrifuge Experiment (DUECE) pilot plant in Tennessee in support of the administration’s efforts to build out a domestic supply of unobligated enriched uranium for defense-related nuclear fuel.
Joshua Wheeler, Ted Worosz, Seungjin Kim
Nuclear Technology | Volume 190 | Number 3 | June 2015 | Pages 215-224
Technical Paper | Thermal Hydraulics | doi.org/10.13182/NT14-69
Articles are hosted by Taylor and Francis Online.
Understanding the effects of spacer grids on the coolant flow through a nuclear reactor core is required for best-estimate design and analysis of the plant. The impact of a spacer grid on two-phase flows is of particular importance because the geometric effects of the grid can alter the two-phase flow structure and, consequently, the mass, momentum, and energy transfer characteristics. Therefore, a scaled separate-effects test facility is constructed to investigate the effects of a spacer grid on the hydrodynamics of air-water two-phase flow through a rod bundle. The test facility is scaled to maintain hydrodynamic and geometric similarity to single- and two-phase flows in a conventional pressurized water reactor and to facilitate detailed local measurements of two-phase flow parameters around the simulant fuel rods with a four-sensor conductivity probe. This paper presents measurements of local time-averaged two-phase flow parameters acquired upstream and downstream of the spacer grid with the conductivity probe in a representative subchannel of a 1×3 rod bundle for eight flow conditions. Characteristic features of the development of the two-phase flow parameters along the test section are discussed.