“ mechanical properties of nuclear grade graphite at high temperatures and pressures ”

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“Mechanical Properties of Nuclear Grade Graphite at High

Temperatures and Pressures”

By: Matt Luedeman, Peter Wells, Chris DykeAdvisor: Jay McCormackClients: Dr. Karl Rink Dr. Gabriel Potirniche Dr. Akira Tokuhiro

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Overview Problem Overview

Testing Procedures

Vessel Design

Budget

Future Plans

Questions

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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

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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.

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Testing Procedures

Young’s Modulus

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Testing Procedures

Shear Modulus

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Testing ProceduresCoefficients of Friction Kinetic Static

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Vessel Design

Vessel Requirements Dimensions Heating Source Viewing Window Electrical Input Safety Access

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Vessel Sizing

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

implementations

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Vessel Sizing Cont.Our proposed vessel will have:

ID = 12 inches L = 12 inches The thickness will depend on the

temperature of the steel

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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

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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

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Immersion Heaters

ApplicationBenefitsDisadvantages

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NiCr HeatingFiber Insulated Heater from Zircar Ceramics:

Custom Size Insulation included Time to heat Temperature Control

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According to the ASMEstandards for pressurevessel design

Fiber insulated heatertemperature graph fromZircar Ceramics

Vessel Thickness

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Viewing Window

We need a viewing window for: Conducting Testing Observing Equipment

Design Factors: High Flexural Strength Known energy deflection characteristics

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Electrical Input Required to allow for internal input of wiring Power feed-through must be rated to

withstand: Pressure Temperature of outside of insulation

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Safety

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

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Access

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

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Budget

Item Cost ($)Stainless Steel 800-3000Fiber Insulated Heater 1000Power Supply 700Feed-Throughs 500Labor 200-750Window 200Other 1000

Total (approximately) 4200 - 7000

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Future Plans

Finalize Vessel Design Viewing Window Vessel Thickness Insulation Shape

Order Materials Assemble Vessel Test Apparatus Perform Mechanical Testing in Vessel

(Time Permitting)

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CATIA Rendering of Vessel

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Vessel Thickness

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Power Input Calculation