Documents in the NTIS Technical Reports collection are the results of federally funded research. They are directly submitted to or collected by NTIS from Federal agencies for permanent accessibility to industry, academia and the public.  Before purchasing from NTIS, you may want to check for free access from (1) the issuing organization's website; (2) the U.S. Government Printing Office's Federal Digital System website http://www.gpo.gov/fdsys; (3) the federal government Internet portal USA.gov; or (4) a web search conducted using a commercial search engine such as http://www.google.com.
Accession Number DE2012-1046070
Title Experimental and Analytic Study on the Core Bypass Flow in a Very High Temperature Reactor.
Publication Date Apr 2012
Media Count 135p
Personal Author C. G. Park M. H. Kim R. Vilim R. R. Schultz Y. Hassan
Abstract Core bypass flow has been one of key issues in the very high temperature reactor (VHTR) design for securing core thermal margins and achieving target temperatures at the core exit. The bypass flow in a prismatic VHTR core occurs through the control element holes and the radial and axial gaps between the graphite blocks for manufacturing and refueling tolerances. These gaps vary with the core life cycles because of the irradiation swelling/shrinkage characteristic of the graphite blocks such as fuel and reflector blocks, which are main components of a core's structure. Thus, the core bypass flow occurs in a complicated multidimensional way. The accurate prediction of this bypass flow and counter-measures to minimize it are thus of major importance in assuring core thermal margins and securing higher core efficiency. Even with this importance, there has not been much effort in quantifying and accurately modeling the effect of the core bypass flow. The main objectives of this project were to generate experimental data for validating the software to be used to calculate the bypass flow in a prismatic VHTR core, validate thermofluid analysis tools and their model improvements, and identify and assess measures for reducing the bypass flow. To achieve these objectives, tasks were defined to (1) design and construct experiments to generate validation data for software analysis tools, (2) determine the experimental conditions and define the measurement requirements and techniques, (3) generate and analyze the experimental data, (4) validate and improve the thermofluid analysis tools, and (5) identify measures to control the bypass flow and assess its performance in the experiment.
Keywords Control elements
Design
Efficiency
Forecasting
Irradiation
Life cycle
Manufacturing
Performance
Reactor cores
Simulation
Targets
Validation
VHTR reactor


 
Source Agency Technical Information Center Oak Ridge Tennessee
NTIS Subject Category 77H - Reactor Engineering & Nuclear Power Plants
Corporate Author Idaho National Laboratory, Idaho Falls, ID. Next Generation Nuclear Plant Project.
Document Type Technical report
Title Note N/A
NTIS Issue Number 1303
Contract Number DE-AC07-05ID14517

Science and Technology Highlights

See a sampling of the latest scientific, technical and engineering information from NTIS in the NTIS Technical Reports Newsletter

Acrobat Reader Mobile    Acrobat Reader