Mike Kowalkowski Week 6: February 22 nd 2007

1. Mike KowalkowskiWeek 6: February 22nd 2007 Project Aquarius Power Engineering Group MRCF, LP, NPS Vehicle Focal HAB, MLV, MR Power Contact

2. EP / NPS Brayton Reactor Sizing Main Rad. • Conceptual Design • Common 2 MWe, 10 year reactor for NPS & EP • Surface reactor buried • Boron-aluminum bay & LiH / W cap provide “safe” radiation dose at 6 m 4 • Closed Brayton Cycle (24%) conversion efficiency • P / M / V – EP System • Power: 2 MWe capacity • Mass: 27.6 mta • Radiation Area: 2270 m^2b • Volume: 12600 m^3 (Rogge) • a includes a 20% budget1 • b includes a 10% budget1 Power Conditioner Comp. Turb.. T.A. Shield Mars Ground Reactor

3. MRCF (Mars Rocket Construction Facility): Oversizedmobiletent Mass: 0.38 mt Stowed Volume: 21.5 m^3 Power: 0.0 kWe Aluminum poles & nylon mass included Mobile system so rocket can be constructed on the launch pad. LP (Launch Pad): Launch gantry only MLV Mass Lifted: 500 mt Power: 85 kWe 5 minute lift time Highly dependent on finalized mass of MLV 1.0 km from HAB requires significant cabling mass at higher (1.0 MWe) power 6 On the order of 1 mt Ryan Scott developing code MRCF Over LP 25 m 50 m MRCF / LP Sizing

4. Backup Slides Week 4 Readiness Level

5. Reactor mass Scaled from nuclear power fuel number with 3x shield provision 65 MWd/kg Courtesy: Courtney Rogge 8 24% CBC cycle efficiency 9 Additional masses baselined against documentation 1,2,3,9 Surface reactors have higher power conditioning requirements, accounting for higher overall masses, but the fundamental reactor is the same Thermal radiator concept Radiators are also aluminum skin of the EP system and are deployable on the surface. Surface power conditioning and distribution Masses and volumes not entered into the reactor bed. Shield analysis With a safety zone of 6 meters, the HAB will be placed 100 meters to 400 meters from the nuclear power source without significant risk EP / NPS Reactor Sizing Logic (1)

6. Reactor Mass 21.8% Total System Shield Mass 20.5% Total System Turbo alternators 16.6% Total System Thermal Radiators 15.6% Total System Power Conditioning (Surface) 13.5% Total System Heat Exchanger / Controller 11.97% Total System EP / NPS Reactor Sizing Logic (2)

7. EP / NPS Reactor Sizing Logic (2) • As has been previously recognized, shielding mass and reactor mass have been difficult to size, primarily because of security classifications of referenced codes. After ~10 hours / day for four days of autonomous research and consultation with the nuclear engineering department, these numbers are shown to be embraced and accepted by current research. • A purer, mathematically based code is being developed from the Sandia National Laboratory RSMASS-D reactor and shield sizing study 5, Auburn University’s Lunar electricity wiring study 6, and NASA’s Lunar power management and distribution guidelines 7. Although these mathematical models will add further integrity to the final mass and volume numbers, the overall system masses should not reduce or increase significantly from the numbers presented today. This mathematical model will serve as a check to the NPS literature sizing model presented today and should be complete by next week.

8. System Mass Trends

9. Specific System Power

10. Calculations Sheet EP/NPS • Reference full spreadsheet online under references.1,2,3,8 • Kowalkowski.xls … 8 pages

11. Calculations Sheet MRCF/LP • Reference full spreadsheet online under references. • Kowalkowski.xls … 8 pages

12. Power Systems Trade Study • Thermoelectric vs. Sterling vs. Brayton 10 • Assume high temperature (2000K) Brayton Cycle 1 • Most efficient power cycle above 100kWe, blade and coating technology available • Current power requirements on the surface • 1MWe ISPP / LP • 150 kWe HAB • With a 90% conditioning and distribution coefficient, 1.25 MWe • This could allow for a reduction of size in reactor, but I have been told that ISPP fuel requirements may increase, increasing the total amount of fuel needed to near 1.5 MWe levels (Kassab) • This is dependent on MLV mass

13. Cited References • 1 Mason, Lee. A Comparison of Fission Power Systems Options for Lunar & Mars Surface Applications. AIP - Space Technology and Applications International Forum, 2006.Available online. • 2 Juhasz, Albert, et. al. Lunar Surface Gas Turbine Power Systems with Fission Reactor Heat Source. 3rdInternational Energy Conversion Engineering Conference, 2005. Available online. • 3 Juhasz, Albert, et. al. Multimegawatt Gas Turbine Power Systems for Lunar Colonies. 4th International Energy Conversion Engineering Conference, 2006. Available online. • 4 Wright, Steven A and David Poston. Low Mass Radiation Shielding for Martian Surface Power Reactors. AIP - Space Technology and Applications International Forum, 2002.Available online. • 5 Marshall, Albert C. RSMASS-D: An Improved Method for Estimating Reactor Mass and Shield Mass for Space Reactor Applications. Sandia National Laboratories, 1997. Available Online. • 6 Gordon, Lloyd B. Electrical Transmission on Lunar Surface: Part 1 – DC Transmission. Auburn University, Auburn, Alabama. March 2001. Available Online. • 7 Metclaff, Kenneth J. Lunar PMAD Technology Assessment. NASA Lewis Research Center. Feb 1992. Available Online. • 8Courtney Rogge. Conversations with a Nuclear Engineer. 19 February 2007. Basic Reactor Fuel Mass and Volume Sizing. • 9 Baggenstoss, W.G. and T.L. Ashe. “Mission Design Drivers for Closed Brayton Cycle Space Power Conversion Configuration.” Journal of Engineering for Gas Turbines and Power. October 1992, Vol. 114, pgs. 721-726. • 10 Mason, Lee. A Comparison of Brayton and Sterling Space Nuclear Power Systems for Power Levels from 1 Kilowatt to 10 Megawatts. AIP - Space Technology and Applications International Forum, 2001.Available online.