MSR Group, 11/14/2004

1
CORE
2
Core - Design Concept

• Develop a 100 kWe reactor with a 5
  full-power-year lifetime
• Evaluation of options were based on design
  criteria
• Low mass
• Launchability
• Safety
• High Reliability

3
Core - Design Choices

• Fast Spectrum
• Ceramic Fuel Uranium Nitride, 33.1 w/o enriched
• Tantalum Burnable Poison
• Lithium Heatpipe Coolant
• Fuel Pin Elements in tricusp configuration
• External Control By Drums
• Zr3Si2 Reflector material
• TaB2 Control material

4
Core - Design Specifications

• UN fuel and Ta poison were chosen for heat
  transfer, neutronics performance, and limited
  corrosion
• Heat pipes eliminate the need for pumps, have
  excellent heat transfer, and reduce system mass.
• Li working fluid operates at high temperatures
  necessary for power conversion unit 1800 K

5
Core - Design Specifications (2)

• Fuel pins are the same size as the heat pipes and
  arranged in tricusp design.

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Core - Design Specifications (3)

• Reflector controls neutron leakage
• Control drums add little mass to the system and
  offer high reliability due to few moving parts

7
Integration

• Insert picture of reactor design from Joe

8
Launch Accident Analysis

• Many accidents were considered however, only
  accidents upon launch could not be prevented by
  extra safeguards.
• Worst Case Scenarios
• Uniform dispersion of all U235 in atmosphere
• Undeformed core with all heat pipes ruptured
  lands in water or wet sand

9
Launch Accident Results

• Total Dispersion of the 157 kg of U235 will
  increase the natural background radiation by
  0.0025
• Water and Wet Sand Landing will not result in
  criticality

Reflectors Stowed Reflectors Detached
Water Keff0.970810.00092 Keff0.953430.00109
Wet Sand Keff0.973870.00095 Keff0.964580.00099
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Future Work

• Investigate further the feasibility of plate fuel
  element design
• Optimize core configuration
• Examine long-term effects of high radiation
  environment on chosen materials
• Develop comprehensive safety analysis for launch
  accidents