1. 22.033 Final Design Presentation

2. Vasek Dostal Knut Gezelius Jack Horng John Koser Joe Palaia Eugene Shwageraus And Pete Yarsky With the Help of Kalina Galabova Nilchiani Roshanak Dr. Kadak

3. May 15 th, 200322.033, Mission to Mars Our Vision Use nuclear technology to get people from Earth to Mars and back

4. May 15 th, 200322.033, Mission to Mars Outline Mission plan Decision methodology Space power system Surface power system Conclusions

5. May 15 th, 200322.033, Mission to Mars Mission Plan Summary Precursor 1 –Telecommunication nuclear powered satellite in Mars orbit Precursor 2 –ISRU and surface nuclear reactor demonstration / Sample Return Manned Missions –Establish the infrastructure –Send the people –Bring them back

6. May 15 th, 200322.033, Mission to Mars Mars Nuclear Telecom Satellite Primary Objectives Validate space reactor system Validate nuclear electric propulsion system Provide high data rate communications. Increases science yield. In space, power is knowledge. Secondary Objectives Orbital video and hi-res pictures. High power Mars orbit experiments (active radar, etc.)

7. May 15 th, 200322.033, Mission to Mars ISRU & Surface Reactor Demo / Sample Return Primary Objectives: Validate Mars surface reactor technology Validate Mars surface ISRU Secondary Objectives Produce fuel for sample return Return Martian rocks to Earth

8. May 15 th, 200322.033, Mission to Mars Mars Infrastructure Launch Window 1 Launch 2 Nuclear Powered Transfer Systems Launch first Earth Return Vehicle Launch first set of surface Infrastructure ERV waits in Mars Orbit Reactor deployed, ascent stage fueling begins Transfer Systems return to Earth for reuse

9. May 15 th, 200322.033, Mission to Mars Manned Exploration Launch Window 2 Refuel all 3 Transfer Systems (sitting in LEO) Launch 2 nd ERV & Surface Infrastructure Launch Transit/Surface Hab Crew1 meet Hab in HEO Crew Lands near existing infrastructure Transfer Systems return to Earth for reuse

10. May 15 th, 200322.033, Mission to Mars Manned Exploration Launch Window 3 Crew Meets ERV in Mars Orbit, return. More infrastructure sent to Mars. Second Crew Deployed. This Plan is similar to NASA ’ s Design Reference Mission, but modified to take advantage of Nuclear Electric Propulsion.

11. May 15 th, 200322.033, Mission to Mars Electric Propulsion Options Precursor cargo missions Array of advanced Ion / Hall thrusters Power 10 – 80 kW I sp 3000 – 10000 sec Thrust 1 – 3 N

12. May 15 th, 200322.033, Mission to Mars Electric Propulsion (Manned) Variable Specific Impulse Magnetoplasma Rocket – VASIMR - 10 MW of power

13. May 15 th, 200322.033, Mission to Mars Space Power Goals Low mass –<3 kg/kW e Scalable –200-4000 kW e Simple and reliable –No moving parts Multiple round trips

14. May 15 th, 200322.033, Mission to Mars Space Power Unit High temperature heat rejection –Reduces the radiator size Thermo Photo Voltaic cells –High efficiency power conversion (up to 40%) –No moving parts Molten salt coolant –High temperature, low pressure coolant –Good heat transport medium Ultra-compact high power density reactor

15. May 15 th, 200322.033, Mission to Mars ANDIE 1.Molten salt transfers the heat from the core to the radiator 2.All power is radiated towards TPV collector 3.TEM self powered pumps circulate the molten salt coolant 4.TPV collectors generate DC from thermal radiation 5.Residual heat is dissipated into outer space Advanced Nuclear Design for Interplanetary Engine

16. May 15 th, 200322.033, Mission to Mars ANDIE Core Physics Power 11 MW th Dimensions 20  20  20cm Total mass 185 kg Reflector thickness 6 cm (Zr 3 Si 2 ) Coolant, molten salt (50:50 NaF-ZrF 4 ) Fuel, RG Pu carbide, honeycomb plates k eff BOL = 1.1 Core lifetime 570 FPD

17. Honeycomb Fuel

18. ANDIE Core Layout

19. May 15 th, 200322.033, Mission to Mars ANDIE Thermal Hydraulics Fuel centerline temperature1767K Core inlet temperature 1550K Core outlet temperature 1600K Core mass flow rate 249.81 kg/s Plate spacing 5.5 mm Plate thickness 2.05 mm Pressure drop 123 kPa Pumping power 11.89 kW (40 kWe)

20. May 15 th, 200322.033, Mission to Mars Internal Radiator Radiates 10MW towards TPV collectors TPV collectors generate 4 MW e (η=40%) Operates at 1575K temperature Annular U-tube design 39/35mm outer/inner diameter Made of titanium (w/ high emissivity coating) U-tube height 15 m Radiator weight 2967 kg Molten salt weight 1975 kg

21. May 15 th, 200322.033, Mission to Mars Pumps TEM pumps from SP-100 program –Thermoelectric Electromagnetic Pump –Self powered –Self starting –Self regulating –No moving parts –10 year operating life –Designed to operate at 1310-1350K –Available operating experience

22. May 15 th, 200322.033, Mission to Mars Shielding ANDIE Radiation Detector mR/hr W LiH W Ĵ o = 8.752 x 10 13 n/cm 2 s Neutron Moderation and Absorption: LiH Gamma Attenuation: W RadiatorRadiator

23. May 15 th, 200322.033, Mission to Mars How much does ANDIE weigh?

24. May 15 th, 200322.033, Mission to Mars Surface Power Goals Sufficient power for all surface applications (i.e. ISRU, habitat etc.) –~200 kW e ObjectivesWeight 25 Years of Operation29.4% Low Mass17.6% Slow Transients20.6% Low Reactivity Swing8.8% Chemically Inert in CO 2 23.5%

25. May 15 th, 200322.033, Mission to Mars Surface Reactor Decision Problem 192 Possible Combinations –Neutron Spectrum: Thermal, Epithermal, Fast –Coolant: CO 2, LBE –Reactor Fuel: UO 2, UC, US, UN –Matrix Material: BeO, SiC, ZrO 2, MgO –Fuel Geometry: Pin, Block 4 Decision Options Formulated –Option 1: Epithermal, CO 2, UO 2, BeO, Block –Option 2: Fast, CO 2, US, SiC, Block –Option 3: Fast, LBE, UC, Pin –Option 4: Thermal, CO 2, UO 2, BeO, Block

26. May 15 th, 200322.033, Mission to Mars Multi-Attribute Utility Theory

27. Option 1: Epithermal, CO 2, UO 2, BeO, Block Option 2: Fast, CO 2, US, SiC, Block Option 3: Fast, LBE, UC, Pin Option 4: Thermal, CO 2, UO 2, BeO, Block

28. May 15 th, 200322.033, Mission to Mars Surface Power System Cooled by Martian atmosphere (CO 2 ) –Insensitive to leaks Shielded by Martian soil and rocks –Low mass Hexagonal block type core –Slow thermal transient (large thermal inertia) Epithermal spectrum –Slow reactivity transient –Low reactivity swing

29. May 15 th, 200322.033, Mission to Mars CADEC Pressurized CO 2 from atmosphere cools the core Direct, closed, recuperated Brayton cycle for electricity production (η net ~20%) CO 2 cooled Advanced Design for Epithermal Converter

30. May 15 th, 200322.033, Mission to Mars CADEC Core Physics Power 1 MW th Dimensions L=160 cm, D=40 cm –37 hexagonal blocks Total mass 3800 kg Reflector thickness 30 cm (BeO) Coolant Martian atmosphere (CO 2 ) Fuel 20% enriched UO 2 dispersed in BeO k eff BOL = 1.14 Core lifetime >25 EFPY

31. What does CADEC look like?

32. May 15 th, 200322.033, Mission to Mars CADEC Thermal Hydraulics System pressure 480 kPa Core inlet temperature 486  C Core outlet temperature 600  C Core mass flow rate 7.47 kg/s Channel diameter 30 mm Block flat-to-flat 63 mm Film temperature difference 2.5  C Pressure drop 25 kPa

33. May 15 th, 200322.033, Mission to Mars Shielding CADEC Martian soil Core Place for shutters Thickness (cm) 170180190200210 Corresponding dose rate, shield surface (mrem/hr) 75.531.713.35.62.4 Dose rate (GCR), Martian surface (mrem/hr) > 1.1

34. May 15 th, 200322.033, Mission to Mars Conclusions Mission plan –Technology demonstration Reliability assurance before people are committed –Long term, reusability strategy Reduces recurring costs to future missions

35. May 15 th, 200322.033, Mission to Mars Conclusions ANDIE : Innovations –Molten salt coolant Very high temperature, low pressure –Pre-rejection of heat at high temperature Small radiator mass –TPV collector High efficiency conversion –Ultra compact core Fast spectrum, RG PuC fueled Potentially reduced shield mass

36. May 15 th, 200322.033, Mission to Mars Conclusions CADEC Innovative features –Epithermal spectrum Slow kinetics (maintains large β eff ) Enhanced conversion Compromise between advantages of fast and thermal systems –CO 2 coolant Local resource Resistant to leaks or ingress –Martian soil shield

37. May 15 th, 200322.033, Mission to Mars Conclusions CADEC Brayton cycle –Acceptable efficiency (25%) –Open cycle - operation is challenging –Closed cycle - heat rejection is the weakest point of the design Massive pre-cooler required OR Required fan power is too high (reduces the efficiency to 20%) –The design requires further optimization

39. May 15 th, 200322.033, Mission to Mars Space Reactor Nuclear Design Thermal spectrum: Am242m Small fuel mass Requires moderator Challenging to control Goals Minimize reactor core mass and volume Provide 11 MW of thermal power for 3  180 days round trips Flat reactivity throughout lifetime Controlled by out-of-core mechanisms Fast spectrum: LWR Grade Pu Ultra-compact and light Controlled by direct leakage Potential for positive reactivity feedback Options explored

40. Space Reactor: Thermal Core Moderator Mass

41. Space Reactor: Thermal Core k inf BOL

42. May 15 th, 200322.033, Mission to Mars CECR Description DimensionsL: 160 cmD core: 40 cmD tot: 100 cm Hexagonal Pitch: 12.6 cm 7 Blocks in Core3800 kg Total Mass Volume Fraction (core) 65 v/o Fuel/Matrix 5 v/o Structure30 v/o Coolant Control25 v/o U238 Blanket 30 cm BeO Reflector 1 cm TaB2 Shutter Fuel Form30 v/o UO2 70 v/o BeO 20 % enriched U BOL 10 % Pu239 EOL

43. May 15 th, 200322.033, Mission to Mars Core Physics: Unit Cell Axial Leakage (unreflected) 6.5 %Neutron streaming Prompt Fission Time (  ) 6 usMirror BCs Delayed Neutron Fraction (  ) 0.0068 BOL0.0054 after 40 MWD/kgHM Reactivity Limited Burnup Keff = 1.05 at 40 MWD/kgHM Reactivity Swing: 0.13

46. May 15 th, 200322.033, Mission to Mars Core Physics: Whole Core (HOM.) TaB2 Control Drum Worth Total: -0.409 Per Drum: -0.0681 (-$10 BOL) Prompt Fission Lifetime (  ) 700 us  = 5.1 us (BOL) [SAFE 400: 0.0035 us (BOL)] H2O Immersion+0.124+$2 Designed to have negative feedback with CO2 on Mars