Martian Surface Reactor Group December 3 2004 Massachusetts Institute of Nuclear Engineering Technology Department Martian Surface Reactor Group OVERVIEW Need for Nuclear Power Fission 101 Project Description Description and Analysis of the MSR Systems Core Power Conversion Unit PCU Radiator Shielding Conclusion Massachusetts Institute of Nuclear Engineering Technology Department MSR Group 12 3 2004 Slide 2 Motivation for MSR NASA Concept Exploration and Refinement Study Surface Power Electric Power Level kWe Lunar Surface Power Options Fission Reactor Fission Reactor Solar Chemical Solar Radioisotope Solar Martian Surface Power Options Solar power becomes much less feasible Mars further from Sun 45 less power Day night cycle Dust storms Too short Lifetime for Martian missions Nuclear Power dominates curve for Martian missions Duration of use 10 15 2004 Slide 1 Bill Nadir Massachusetts Institute of bnadir mit edu Competition Sensitive Do not distribute outside of NASA Draper MIT team Nuclear Engineering Technology Department MSR Group 12 3 2004 Slide 3 Need for Nuclear Power Massachusetts Institute of Nuclear Engineering Technology Department MSR Group 12 3 2004 Slide 4 Fission 101 Massachusetts Institute of Nuclear Engineering Technology Department MSR Group 12 3 2004 Slide 5 MSR Mission Nuclear Power for the Martian Surface Test on Lunar Surface Design Criteria 100kWe 5 EFPY Works on the Moon and Mars Massachusetts Institute of Nuclear Engineering Technology Department MSR Group 12 3 2004 Slide 6 Decision Goals Litmus Test Works on Moon and Mars 100 kWe 5 EFPY Obeys Environmental Regulations Extent To Which Test Small Mass and Size Controllable Launchable Accident Safe High Reliability and Limited Maintenance Scalability Massachusetts Institute of Nuclear Engineering Technology Department MSR Group 12 3 2004 Slide 7 MSR System Overview Core 54 Nuclear Components Heat Power Conversion Unit 17 Electricity Heat Exchange Radiator 4 Waste Heat Rejection Shielding 25 Radiation Protection Total Mass 8MT Massachusetts Institute of Nuclear Engineering Technology Department MSR Group 12 3 2004 Slide 8 CORE Massachusetts Institute of Nuclear Engineering Technology Department MSR Group 12 3 2004 Slide 9 Core Goals and Components Goals 1 2 MWth 1800K Components Spectrum Reactivity Control Mechanism Reflector Coolant System Encapsulating Vessel Fuel Type Enrichment Massachusetts Institute of Nuclear Engineering Technology Department MSR Group 12 3 2004 Slide 10 Core Design Choices Overview Design Choice Reason Fast Spectrum High Temp High Power Density UN Fuel 33 w o enriched High Temperature Breeding Lithium Coolant Power Conversion Re Cladding Internal Structure Physical Properties Zr3Si2 Reflector material Neutron Mirror Rotating Drums Autonomous Control Hafnium Core Vessel Accident Scenario Tricusp Fuel Configuration Superior Heat Transfer Massachusetts Institute of Nuclear Engineering Technology Department MSR Group 12 3 2004 Slide 11 Core Pin Geometry Fuel pins are the same size as the heat pipes and arranged in tricusp design Temperature variation 1800 1890K Heatpipe Fuel Pin Tricusp Material Massachusetts Institute of Nuclear Engineering Technology Department MSR Group 12 3 2004 Slide 12 Core Design Advantages UN fuel Ta absorber Re Clad Structure high melting point heat transfer neutronics performance and limited corrosion Heat pipes pumps not required excellent heat transfer small system mass Li working fluid operates at high temperatures necessary for power conversion unit 1800K Massachusetts Institute of Nuclear Engineering Technology Department MSR Group 12 3 2004 Slide 13 Core Dimensions and Control Reflector controls neutron leakage Small core total mass 4 3 MT 89 cm Reflector Fuel Pin 10 cm Reflector 42 cm Fuel Core 10 cm Massachusetts Institute of Nuclear Engineering Technology Department Reflector MSR Group 12 3 2004 Slide 14 Core Composition Material 7 Li 15 N Nat Nb 181 Ta Nat Re 235 U 238 U Purpose Coolant Fuel Compound Heatpipe Poison Cladding Structure Fissile Fuel Fertile Fuel Massachusetts Institute of Nuclear Engineering Technology Department Volume Fraction 0 073 0 353 0 076 0 038 0 110 0 117 0 233 MSR Group 12 3 2004 Slide 15 Core Power Peaking Peaking Factor F r 1 4 1 2 F r 1 0 8 0 6 0 4 0 2 0 22 20 18 16 14 12 10 8 6 4 2 0 2 4 6 8 10 12 14 16 18 20 22 Core Radius cm RPPRDrums In 1 31 Massachusetts Institute of Nuclear Engineering Technology Department RPPFDrums Out 1 24 MSR Group 12 3 2004 Slide 16 Operation over Lifetime Reactivity over Lifetime BOL keff 0 975 1 027 EOL keff 0 989 1 044 Dkeff 1 06 1 04 0 052 Keff Dkeff 1 08 0 055 1 02 1 00 0 98 0 96 0 94 0 1 2 3 4 5 Years of Operation Massachusetts Institute of Nuclear Engineering Technology Department MSR Group 12 3 2004 Slide 17 6 Launch Accident Analysis Worst Case Scenario Oceanic splashdown assuming Non deformed core All heat pipes breached and flooded Massachusetts Institute of Nuclear Engineering Technology Department MSR Group 12 3 2004 Slide 18 Launch Accident Results Inadvertent criticality will not occur in any conceivable splashdown scenario Reflectors Stowed Reflectors Detached Water Keff 0 970 Keff 0 953 Wet Sand Keff 0 974 Keff 0 965 Massachusetts Institute of Nuclear Engineering Technology Department MSR Group 12 3 2004 Slide 19 Core Summary UN fuel Re clad structure Hf vessel Zr3Si2 reflector Relatively flat fuel pin temperature profile 1800 1890K 5 EFPY of 1 2 MWth 100 kWe at 1800K Autonomous control by rotating drums over entire lifetime Subcritical for worst case accident scenario Mass 4MT Massachusetts Institute of Nuclear Engineering Technology Department MSR Group 12 3 2004 Slide 20 PCU Massachusetts Institute of Nuclear Engineering Technology Department MSR Group 12 3 2004 Slide 21 PCU Mission Statement Goals Remove thermal energy from the core Produce at least 100kWe Deliver remaining thermal energy to the radiator Convert electricity to a transmittable form Components Heat Removal from Core Power Conversion Transmission System Heat Exchanger Interface with Radiator Massachusetts Institute of Nuclear Engineering Technology Department MSR Group 12 3 2004 Slide 22 PCU Design Choices Heat Transfer from Core Heat Pipes Power Conversion System Reactor Cesium Thermionics Power Transmission DC to AC conversion 22 AWG Cu wire transmission bus Heat Exchanger to Radiator Annular Heat Pipes Massachusetts Institute of Nuclear Engineering Technology Department MSR Group 12 3 2004 Slide 23 PCU Heat