“ Mechanical Properties of Nuclear Grade Graphite at High Temperatures and Pressures ”

1. By: Matt Luedeman, Peter Wells, Chris Dyke Advisor: Jay McCormack Clients: Dr. Karl Rink Dr. Gabriel Potirniche Dr. Akira Tokuhiro “Mechanical Properties of Nuclear Grade Graphite at High Temperatures and Pressures”

2. Overview • Problem Overview • Testing Procedures • Vessel Design • Budget • Future Plans • Questions

3. 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

4. Problem Overview Cont. 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.

5. Testing Procedures Young’s Modulus

6. Testing Procedures Shear Modulus

7. Testing Procedures Coefficients of Friction • Kinetic • Static

8. Vessel Design Vessel Requirements • Dimensions • Heating Source • Viewing Window • Electrical Input • Safety • Access

9. Vessel Sizing Vessel needs to be large enough to conduct experiments for: • Our testing procedures • Graduate student experimentation • Future experiment or design implementations

10. Vessel Sizing Cont. Our proposed vessel will have: • ID = 12 inches • L = 12 inches • The thickness will depend on the temperature of the steel

11. Heating Sources Internal Heating • Heats Specimen Quickly • More Energy Efficient • Simplifies Overall Design External Heating • Takes Longer to Heat • Less Energy Efficient • Creates Challenges for Experimentation

12. Internal Heating • There is little excess energy used. • Requires a temperature control unit • Variable voltage controller • Two possible methods: • Flanged Immersion Heaters • Sending a current through a wire • NiCr wiring

13. Immersion Heaters • Application • Benefits • Disadvantages

14. NiCr Heating Fiber Insulated Heater from Zircar Ceramics: • Custom Size • Insulation included • Time to heat • Temperature Control

15. Vessel Thickness • Fiber insulated heater temperature graph from Zircar Ceramics • According to the ASME standards for pressure vessel design

16. Viewing Window We need a viewing window for: • Conducting Testing • Observing Equipment • Design Factors: • High Flexural Strength • Known energy deflection characteristics

17. Electrical Input • Required to allow for internal input of wiring • Power feed-through must be rated to withstand: • Pressure • Temperature of outside of insulation

18. Safety Vessel will need: • Pressure Relief Valves • Design Safety Factor • To Comply with ASME Regulations

19. Access Vessel needs to have access in order to: • Vary experiment setup • Perform Maintenance on Heating Unit

21. Budget

22. Future Plans • Finalize Vessel Design • Viewing Window • Vessel Thickness • Insulation Shape • Order Materials • Assemble Vessel • Test Apparatus • Perform Mechanical Testing in Vessel (Time Permitting)

25. CATIA Rendering of Vessel

26. Vessel Thickness

27. Power Input Calculation