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By: Matt Luedeman, Peter Wells, Chris Dyke Advisor: Jay McCormack Clients: Dr. Karl Rink Dr. Akira Tokuhiro. “ Mechanical Properties of Nuclear Grade Graphite at High Temperatures and Pressures ”. Overview. Problem Overview Testing Procedures Vessel Requirements
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By: Matt Luedeman, Peter Wells, Chris Dyke Advisor: Jay McCormack Clients: Dr. Karl Rink Dr. Akira Tokuhiro “Mechanical Properties of Nuclear Grade Graphite at High Temperatures and Pressures”
Overview • Problem Overview • Testing Procedures • Vessel Requirements • Heating Components • Vessel Sizing • Future Plans • Questions
Problem Overview Purpose: The Next Generation Nuclear Power Plant (NGNP) uses a graphite pebble bed as a neutron moderator. • Dust creation • PEBBLES Code • Unknown properties of nuclear grade graphite
Project Goals Two main parts: • Create testing procedures for finding Young’s/Shear Modulus, Poisson’s Ratio Static/Kinetic Coefficients of Friction. • Create a heated pressure vessel that can simulate the environment in a nuclear reactor.
Testing Procedures Young’s Modulus Coefficients of Friction Shear Modulus
Vessel Requirements Vessel Requirements • Temperature: 700 C • Pressure: 7 MPa • Testing Space: 12” Diameter, 12” Length • Room for Heater • Viewing Window
Heater Fiber Insulated Resistance Wire Heater from Zircar Ceramics: • Custom Size: 16” Length, 16” OD • Insulation included • Time to heat • Temperature Control
Temperature Control Variable transformer: • Varies power to heater • Controls heater temperature • Thermocouples used to take temperature readings
Electrical Input • Provide power to heater while still keeping seal • Power feed-through must be rated to withstand: • Pressure • Temperature of outside of insulation • Insulated standoff used
Vessel Sizing Cylinder Requirements: • 18” L, 16” ID • Thickness dependent on temperature and pressure Flanges • Standard Size to fit on Cylinder
Cylinder Thickness • Fiber insulated heater temperature graph from Zircar Ceramics • According to the ASME standards for pressure • vessel design a 5/8” cylinder thickness was required
Flanges Slip-On Flanges • Size based on standard flange size to fit around pipe Blind Flanges • A thickness of 3.25” was chosen based on the temperature and pressure they will see
Bolts/Gaskets • 20 Bolts are used on each side of the vessel • Special high temperature gaskets are used to seal the vessel
FEA In order to analyze the stresses seen by each component of the vessel, a computer simulation was performed using finite element analysis software.
Viewing Window/Burst Disk We need a viewing window for: • Conducting Testing • Observing Equipment • A burst disk will be added for safety purposes
Future Plans • Fabricate burst disk and window • Perform Hydrostatic assessment • Complete temperature analysis to determine requirements for insulation