1 / 36

Nuclear Reactors for The Moon and Mars

This document presents a comprehensive overview of the Martian Surface Reactor (MSR) concept, aimed at providing reliable nuclear power for human habitats on Mars and the Moon. Key highlights include the design characteristics, safety features, and environmental considerations for the reactor's components—such as the core design, power conversion unit, radiator, and shielding. The reactor is designed to be light, compact, and accident-resistant while achieving high efficiency and power output. Future work will focus on safety analysis, materials performance, and scalability for larger missions.

gilon
Télécharger la présentation

Nuclear Reactors for The Moon and Mars

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Nuclear Reactors for The Moon and Mars Tyler Ellis Michael Short Martian Surface Reactor Group November 14, 2004

  2. MSR Motivation

  3. Nuclear Physics/Engineering 101

  4. Nuclear Physics/Engineering 101

  5. Habitat Reactor Proposed Mission Architecture

  6. MSR Mission • Nuclear Power for the Martian Surface • Test on Lunar Surface • Design characteristics of MSR • Safe and Reliable • Light and Compact • Launchable and Accident Resistant • Environmentally Friendly

  7. MSR Components • Core • Nuclear Components, Heat • Power Conversion Unit • Electricity, Heat Exchange • Radiator • Waste Heat Rejection • Shielding • Radiation Protection

  8. CORE

  9. 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

  10. Core - Design Choices • Fast Spectrum • Ceramic Fuel – Uranium Nitride, 35 w/o enriched • Tantalum Burnable Poison • Liquid Lithium Heatpipe Coolant • Fuel Pin Elements in tricusp configuration • External control using drums • Zr3Si2 Reflector material • TaB2 Control material

  11. Core - Design Specifications • UN fuel and Ta poison were chosen for heat transfer, neutronics performance, and limited corrosion • Heatpipes 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, 1800K

  12. Fuel Pin Heatpipe Tricusp Material Core - Design Specifications (2) • Fuel pins are the same size as heatpipes and arranged in tricusp design

  13. 99cm Reflector and Core Top-Down View Reflector Control Drum Reflector 37 cm Core Fuel Fuel Pin Zr3Si2 Reflector Total Mass: 1892kg 10cm Radial Reflector 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

  14. Core - Future Work • Perform U235 enrichment versus system mass analysis • Investigate further the feasibility of plate fuel element design • Develop comprehensive safety analysis for launch accidents

  15. PCU

  16. PCU – Design Concept Goals: • Remove thermal energy from the core • Produce at least 100kWe • Deliver remaining thermal energy to the radiator Components: • Heat Removal from Core • Power Conversion System • Power Transmission System • Heat Exchanger/Interface with Radiator

  17. PCU – Design Choices • Heat Transfer from Core • Heat Pipes • Power Conversion System • Cesium Thermionics • Power Transmission • DC-to-AC conversion • OOOO gauge Cu wire transmission • Heat Exchanger to Radiator • Annular Heat Pipes

  18. PCU – Design Specifications • Heat Pipes from Core: • 1 meter long • 1 cm diameter • 100 heat pipes • Molybdenum Pipes • Lithium Fluid • Boiling point @ STP: 1615K • Pressurized to boil @ 1800K CORE

  19. PCU - Design Specifications (2) • Thermionic Power Conversion Unit • Mass: 250 kg • Efficiency: 10%+ • 1MWt -> 100kWe • Power density: 10W/cm2 • Surface area per heat pipe: 100 cm2

  20. Reactor PCU - Design Specifications (3) • Power Transmission • D-to-A converter: • 20 x 5000VA units • 300kg total • Small • Transmission Lines: • AC transmission • OOOO gauge Cu wire • 1kg/m

  21. PCU - Decision Specifications (4) • Heat Pipe Heat Exchanger

  22. PCU – Future Work • Improving Thermionic Efficiency • Material behavior in high radiation environment • Heat pipe failure analysis • Scalability to 200kWe • Using ISRU as thermal heat sink

  23. Radiator

  24. Radiator – Design Concept • Need a radiator to dissipate excess heat from a nuclear power plant located on the surface of the Moon or Mars.

  25. Radiator – Design Choices • Evolved from previous designs for space fission systems: • SNAP-2/10A • SAFE-400 • SP-100 • Transfers heat from PCU to heat pipes • Radiates thermal energy into space via large panels

  26. Radiator – Design Choices (2) • Heat pipes send heat to large radiator panels through vaporization of fluid • Heat conducted to panels at the condensing end of the heat pipes • High-emissivity panels use radiation to reject heat to space

  27. Radiator – Design Specifications • Nb-Zr heat pipes with carbon radiator panels • Panels folded vertically next to reactor during transit • For operation panels lay parallel to surface Core PCU Unfolds on surface Panels radiate to environment Radiator Packed for launch

  28. Radiator - Future Work • Mechanical design of radiator panels • Mathematical modeling

  29. Shielding

  30. Shielding - Design Concept • Dose rate on Moon & Mars is ~14 times higher than on Earth • Goal: • Reduce dose rate to between 0.6 - 5.7 mrem/hr • Neutrons and gamma rays emitted, requiring two different modes of attenuation

  31. Shielding - Design Choices Neutron shielding Gamma shielding B4C shell Tungsten shadow shield • Separate reactor from habitat • Dose rate decreases as 1/r2 for r >> 50cm • Use lunar or Martian surface material for further radiation attenuation

  32. Shielding - Constraints • Weight limited by landing module (~3 MT) • Temperature limited by material properties (1800K) Courtesy of Jet Propulsion Laboratory

  33. Shielding - Geometry • Cylindrical shell to attenuate neutrons to target dose within < 50 m • Shadow shield may be more appropriate depending on mission parameters • B4C will be stable up to 2100K • Hydrogenous materials are not viable

  34. Shielding - Future Work • Shielding using extraterrestrial surface material: • On moon, select craters that are navigable and of appropriate size • Incorporate precision landing capability • On Mars, specify a burial technique as craters are less prevalent • Specify geometry dependent upon mission parameters • Shielding modularity, adaptability, etc.

  35. Reactor Mass Breakdown Core: 2.7 MT PCU: 2.05 MT Radiator: 1.5MT Shield: 2 MT ___________________ Total Mass of Reactor – 8.25 Metric Tons Well Below Lander Limit of 15 MT

  36. MSR GroupExpanding Frontiers with Nuclear TechnologyTyler Ellis tyler9@mit.eduMichael Short hereiam@mit.edu

More Related