SNAPSHOT PRELAUNCH SNAPSHOT LAUNCH SNAPSHOT LAUNCH SNAP OVERVIEW General Background By: Glen Schmidt February 7, 2011 References: 94ETEC-DRF-1476 DCN: SP-100-XT-0002 SNAP Reactors Overview • North American Aviation’s Atomic International Division (AI) was under contract with the Atomic Energy Commission (AEC) to perform R&D work on Systems for Nuclear Auxiliary Power (SNAP). • A total of eight different SNAP reactors were built and tested at AI. SNAP Nuclear Reactors • Designs were typical for space power systems and included: SER SNAP-2 Experimental Reactor (Ground tested) S2DR S10FS-1 S10FS-3 S10FS-4 S10FS-5 S8ER S8DR SNAP-2 Developmental Reactor (Ground tested) SNAP-10A Flight Reactor (Failed acceptance test) SNAP-10A Flight Reactor (Ground tested) SNAP-10A Flight Reactor (Launch tested) SNAP-10A Flight Reactor (Spare - Stored) SNAP-8 Experimental Reactor (Ground tested) SNAP-8 Developmental Reactor (Ground tested) SNAP 10A PROGRAM Mission Requirements • • • • • • • Power Life Weight Spacecraft Orbit Safety Other 500+ watts 1 year ~ 1000 lbs Agena B modified with Atlas booster 700 nm (north to south orbit) subcritical until launch startup subcritical during re-entry, water/sand immersion, & ground accidents. SNAP 10A PROGRAM System Design Evolution • Concepts Static thermoelectric-conduction heat transfer Static thermoelectric-liquid metal circulation heat transfer • Preliminary Design Solid core with radial fins for waste heat rejection • Prototype Designs Conical corrugated SST structure, 40 (10 mil) parallel tubes & manifolds, control drive motors located below reactor, TE pump located at base of structure • Final Flight Designs Corrugated titanium structure, 40 (20 mil) parallel D-tubes, control drives and thermoelectric NaK pump located above the radiation shield, and instrumentation & controls located in a compartment below the structure SNAP Nuclear Reactors I 5 Fairy! um ?y ha: Suspermon FL): 5. x. REINF- Helleciu' I?FLb"m?n rum? .l'.a1 :'Siealj ?Ki . I'Fvepl Lirw-Jr' i?wErH?? ??rnn Figure 2. First SNAP Reactor Concept SNAP 1O Reactor Shz?'c Be Conducucr Males Fuel Renee:ch 7V7 Convener I Radialcr 3'3" Figure 4. SNAP 10 Hol Junction) SNAP 10A Reactor SNAP 10 Package Nose-Co ne Separation Line?4"- Reactor Coolant Tube Thermoelectric Element Thermal Shield 8 I Support Cylinder 7? -- Jon: I {?u'lldvi --L - I Payload Hadwxx Area My, I . I, Expansion Compensator Core REE Shield Radiator Upper Manifold Pump Lower Manilold Base Struciure Figure 5. SNAP 10A Mark II (June 1960) SNAP 10A Reactor Conn?er Tube Themodoctric Element: Thermoeiecmc Pump Hadnlor 0.0. Pump Heckler ?anma Supper! Rm . 3 Rmtor Suppon I a .ci' Lithium Hydride I 5 Shield . l' Exp-mam Cmpenuto: Flame 6. SNAP 10A System (June 1981) TT 09H SNAP 10A Reactor TIE WTORS EXPANSDN CMENSATCR STRUCTURE 8 RING STIFFEPERS LOWER MANIFOLD CONTENT 7?56l-0033A SNAP System 10A Schematic Figure .3. SNAP 10A Reactors 3 Elm ctura! Finel Test PSME FSM 1 NenrNusiear Gust Test Them-lei Test FSMJ. Nun-Numear Dual Test FSEM-E Eleel Cement FSEM-E - Test-Agene Elect Bumps! Test-Vehlele F54 to Launch Site Flight System Assemth Fuel Loaan 3: Ame-pl F34 Fiight System Engineering Fiight System Assembly Fuel Leading a Accept Figure 9. SNAP 10A System Deuelepment Sequence SNAP 10A Development Schedule FEM-2 FEM-1 Faith: FEED-3 F5-1 Fad F5-4 F5-5 Fi?-1 1952 JASDND JFMAHJ Tit: {Sylan um Tu: EHUW mom Ila-urn min: Einqu _a?nf 43 any: JASOHD 1?36! 195-4 1DI-5 FHAMJJASOHD FHAHJJAEOHDJ FMAHJJASOND FMAMJJAEGHD Fir ?nuntlc Anus-Ii: 5mm: Tut Flt; a umlv?l'mll G.Li?ihll' GHT?IF-Ilihi?Duh-wad In La mm Guam in Support FEEM-E Ind FEM-3 Til-? ?(Fl-rd I Shackl?. Mr Fu: im- Thin'rulTI-lt Till-F Carlin-EH?, mm FEM-2 Fauna-I Prociduro NF I'll Etltu Tin chickautlt?u Fab DHim-u-dtulammh GuMIfur?u?thaiHIvT?gl-?ng Mural-114nm 90?day Fab Than-HT?! 3N Jun! Till Tilt Tum maul-Murme Mun-tum:- Fah 5N Tint UWFIILH ?pl-(Fug; Dry Tram-? Fuh- Banu?_ Tut Autumn-1:5 Llunch. Au .. Emil-"til Placidln Fab I I Tut I IE?:ng I I FHAMJJASDHD FHAHJJAEDNDJ FMAMJJ AEDHD FMAHJJASDND JFM-AHJ Figuru 1D. SNAP 10A Symams Fabrlcatlun and Tasting Schadula GL5 5225155 SNAP 10A Facility Schedule 1959 1966 1961 1962 1953 1964 1965 Fa Nu?t?; 55?:qu FHA AEDNDIJ FMAMJJ Asonali FHAHJJ ASDHDIJ Fain MJJ A 50MB 4 FMAMJ AEOND -I arm: :91. Pm I I 313 immrEaszvm-?u 5 micnmum cons." tin-mm Int Dawn-allot! EJEH mar Tea Fs-a 4 Cm; F1 1 T031 ?24 "m . . . .?it?ws?a 3.0 013 023 Consultant?s-n a an: Imimlmun F5514 5 5 SEW-1101(If! Cmuwh-nn J. M. 92? 5 4 ?55tiara-z .. com-?mm? .: Chum: im1lum-l mum uni Can-mm arid Dunkirqu :Lnd Lrin I - ML A4 mc?m,?x 4L Ir 1' rm); (.3) a Ch?wl? 1a}. shield Fania-1.30. Manama-I and Final-TMmm: Hanan, Equipman Ingram?. and {trauma FS-1 Acmicon-urwuna. Chodmui Curmrumuna. Chou-m: D25 m. Futurt?. Hannah .4106 Shun-mi Damian!"an and [10eran mm? a - arm-w Clo-11.1er a mud-tom? El 5? Canislructnon and Activate-n - Ft r11 Mf?llml SPTF FHA JFMAMJJESONDIJFHAHJJASDND GU {Li I Edd Figure 42. SNAP Facility Construction, Activation, and Utilization Schedule SNAP Facilities-SSFL BUILDING NAMES EXPERIMENTAL REACTOR TEST BUILDING SNAP GENERALIZED CRITICAL BUILDING NON-NUCLEAR COMPONENT ASSEMBLY AND PERFORMANCE TEST BLDG. FLIGHT SYSTEMS NUCLEAR QUALIFICATION TEST BUILDING DEVELOPMENTAL POWER AND FLIGHT SYSTEMS NUCLEAR TEST BLDG. REMOTE HANDLING MOCK-UP BUILDING NON-NUCLEAR MECHANICAL VIBRATION AND SHOCK TESTING BUILDINH THERMAL AND VACUUM ENVIRONMENTAL TEST BUILDING SNAP OFFICE BUILDING NO.1 SNAP OFFICE BUILDING N0. '2 SNAP OFFICE BUILDING NO. 3 LAUNCH HANDLING AND MOBILE EQUIPMENT DEVELOPMENT SNAP 3 GROUND PROTOTYPE SYSTEM NUCLEAR TEST BUILDING OFFICE BUILDING EAECI NON-NUCLEAR REACTOR QUALIFICATION TEST BUILDING POWER CONV EFISIDN SUB-SYSTEM TEST BUILDING SNAP ELECTRICAL COMPONENT TEST BUILDING LIQUID METALS TEST BUILDING NON-NUCLEAR THERMAL STRUCTURAL TEST BUILDING SNAP STORAGE AREA SNAP SHIELD TEST FACILITY SNAP 2 Experimental Reactor • General Description: Number of fuel elements Date went critical: First power operation: Thermal power: Thermal energy: Time at power & temp Final shutdown: 61 September 19, 1959 November 5, 1959 50 kWt 225,000 kWt-h 1900 h at 1200 F 3300 h above 900 F November 19, 1960 SNAP 2 Developmental Reactor • General Description: Number of fuel elements Date went critical: First power operation: Thermal power: Thermal energy: Time at power & temp Final shutdown: 37 April 1961 November 5, 1959 65 kWt 273,000 kWt-h 2800 h at 1200 F 7700 h above 900 F December 1962 SNAP 10A Non-Nuclear Systems • Designs were prototypical mockups of space power systems and included: PSM-1 PSM-1A PSM-1B PSM-3 FSM-1 FSEM-2 FSEM-2A FSEM-3 FSM-4 Prototype system for structural testing Prototype system modified for structural testing Prototype system for heat shield/launch vehicle compatibility Prototype system for NaK fill & thermal-vacuum tests Flight system for shock/vibration & thermal vacuum tests Flight system for electrical testing & Agena compatibility tests Flight system rebuilt for flight status & launch procedure tests Flight system for Launch Contractor compatibility testing Flight system for non-nuclear qualification testing SNAP 10A Reactor Assembly 1, . 4 . it: . TEESNAP 10A PSM-1 System SNAP 10A PSM-S System \lig?lr?l?fall! Figure 32. SNAP 10A Thermal-Hydraulic Performance Test Mockup (PSM-S) SNAP 10A FSM-1 System Figure 33. SNAP 10A Flighl System Hookup (F5H-1) SNAP 10A FSM-1 TEST SNAP 10A Luading System {Simplified} EM Pump lama Filter I Filter A. a I: (1 3 Core SNAP Being 3 No.1 3H: 1? I :34Drain Tank t_ Loading System SNAP 10A FSM-1 ORBIT TEST Page 85 - Hev Prestartup Simulation Solar Simulation DATE AND TIME I I200 Thermal Reference Test Sequence Figure 48. SNAP 10A Orbital Stanup Simulation Systems and Thermal Reference Test Sequence MEAN TEMPERATURE FIEI H5 CHECKLIST I. TE {m er I mean Dew [3"an RDTITIEW 3-20-64 I I200 TS-EBE CLOSED CONVERTER TE 8? a. I200 CONVERTER Dpuu ROTATEU 40 'qum 15-3 meets: [mute-Tn IMPEDANCE 3, i new are? a mm'm IHPF 3 -- meme? 15-: a 75-21 VOLT HEASURED IS TEMPERATURE HIT ICIICI conrnm [mums HDTAIED ens-55 8-22-en MOO I CONVERTER u?r rs ?3 ?1.6 I CONVERTER 3-23-94 eve-a $4 I I200 3-25-61- I IEOO SNAP 10A FSM-1 TEST mZ>_u -4 System SNAP 10A FSM SNAP 10A Nuclear Systems • Designs were nuclear space power flight systems and included: FS-1 FS-2 FS-3 FS-4 FS-5 Ground qualification system (failed in acceptance test) Reassigned to non-nuclear mock-up testing Ground thermal-vacuum qualification system Space flight system for launch & orbital demonstration Space flight system spare SNAP 10A FS-1 Reactor • General Description: Number of fuel elements Date went critical: First power operation: Thermal power: Thermal energy: Time at temperature Accept test terminated: Post-test Disassembly 37 ~May 1964 Failed acceptance 0 kWt 0 kWt-h ~ 50 h above 900 F June 1964 June 1964 SNAP 10A FS-3 Reactor • General Description: Number of fuel elements Date went critical: First power operation: Thermal power: Thermal energy: Electrical power Electrical energy Time at power & temp Final shutdown: 37 January 1965 January 1965 41 to 37 kWt 382,944 kWt-h 402 Watts 4028 kW-h 10005 h above 900 F March 16, 1966 SNAP 10A Reactor SNAP 1O Reactor SNAP 10A FS-4 Reactor • General Description: Number of fuel elements Date launched: First power operation: Thermal power: Thermal energy: Electrical power Electrical energy Time at power & temp Final shutdown: 37 April 3, 1965 (13:24PST) April 4, 1965 (01:45PST) 42+ to 39.4 kWt 41,349 kWt-h 600 to 530+ Watts 573.6 kW-h 1000 h above 1013 F May 16, 1965 SNAP 10A FS-4 Reactor Figure 51. SNAP 10A FS-4 Accepiance Teal Facility SNAP 10A Reactor SNAP-10A FLIGHT SYSTEM ACTIVITIES 1/1? 1? - ., I. 1.. "?iwm I it . I a: 4'3- I 5? 65 nu, SNAPSHOT LAUNCH SNAP 10A FS-5 Reactor • General Description: Number of fuel elements First thermal operation: Date went critical: Thermal power: Thermal energy: Time at temperature: Accept test complete: Placed in storage: 37 ~ February 1966 ~ March 1996 0 kWt 0 kWt-h ~40 h above 900 F ~May 1966 May 1966 SNAP 10A Reactor SNAP 10A Reactor SNAP 10A Components General Background By: Glen Schmidt February 7, 2011 References: 94ETEC-DRF-1476 DCN: SP-100-XT-0002 SNAP 10A Reflector Reactor Vessel Reflector Actuator Positioning Bracket Gear . Re?ector Segment I . Assembly Stop I ,r I. x. . Drum Retainer Band Lock 1 He'l?cmr Spring Housing Bracket Retainer Band Re?ecmr Assembly Sine COMFOI Main BIocks a. rum I '13 Ground Position Drum Release Sam? mt i .- Tube Electrically Actuated 1151!. 1 i rt "nearer-:2 Band Release Device Election Springs Coarse Control Drum Stop Shims Reflector Hinge Control Drum Figure 18. SNAP 10A Control and Reflector Assembly SNAP 10A Reactor Shie Drum Reaclor VEssel Actuator 32" 2 Control Drum Reflector Hall Radlatlon Shield Figure 21. SNAP 10A Reactor and Shield (Exploded Vlew) SNAP 10A Thermodynamic F.- PUMP FLOW 13.2 GPM AP 1.1 psi THERMAL 560 watts Ave. RAD FIN BASE TEMP. 59W CONVERSION SYSTEM REACTOR ELECTRICAL POWER 550 walls POWER 39-9 KW AVG. HOT JUNCTION TEMP. 955W 125W AVG. RADIATOR TEMP. 550 0F 1.33% VOLTAGE 23.3 Figure 23. Themodynaml: Cycle SNAP 10A TE Converter Radiator Tungsten Shoe Thermoelectric Element. SiGe Mounting Bracket - Hot Strap Insulator Tuba Electric Haduated to Space Insulator 0 4% I: H01 Electric Flew Heat Flew Figure 22. Direct Radla?ng TE Module SNAP 10A TE Pump SNAP 10A Expansion Comp SNAP 10A Support Structure li\l Hit 1 MODULE Figure 26. SNAP 10A Conical Structure SNAP Fuels-General • Fuel -A Homogenous Mixture of 235U & ZrHx For ZrHx temperatures of 1400 to 1500 F, material retains an NH near that of cold water. • Fuel Element -An unsegmented fuel rod enclosed in a Type 347 SS or Hastelloy N metal tube with end caps. Entire inside cladding surface, including end caps, was coated with a glass-ceramic mixture. SNAP Fuel Rod • Produced alloy by multiple consumable arc meltings of reactor-grade enriched uranium metal & crystal bar zirconium. • Produced alloy rods by extrusions of the alloy. • Produced UZrHx & rods by diffusion of H2 at high temperatures (isothermal at 1600 F peak). • Note: Yield of acceptable fuel rods was greatly increased with simultaneous improvements in microstructure by adding ~0.15 w% of ZrC to the melt. SNAP 10A Fuel Rods Fuel Rod [0.915 in. diam. in. long) . . [Zr - 7 $95 enrichment} Alloy. Hydrided to 6.0 1 hydrogen with 0.0025 in. Ceramic Coating Be 0.975 in. 1.5 $196! End Cap and Index Pin 14 in. Figure 14. SEFI Fuel Element 13.23 mac-r? 10.000 - \rk q?oxno - . 1.250 dlarn. .- .. . . Reilecior 1.211 in. diam. (390} End 080 in Su?aoesofCladd'n andEndCaps ?212In. lam. - Cap ("mam are Ceramic Coated 100.th5 in. Thickness Cladding 1.250 in. OD 10.014 in. wall [Haslelioy N) Figure 15. SZDR Fuel Element Cladding (Hasteiioy Tube. Internally Closure End Cap Coated with a Ceramic] Blind End 089 1.25 in. . Fuel. Hod {Hydride zru Alloy) 1 Closure End Cup '1 .m if Nollo Scale 12'? 1 Figure 16. SNAP 10A Fuel Element SNAP Fuel Microstructure • Fuels consist of uranium-rich particles & ZrC particles in a matrix of substoichiometric ZrH2 . • Uranium does not hydride and remains in micron-size particles in the UZrHx matrix. • UZrHx undergoes a series of phase changes as the H/Zr ratio increases during the hydriding process. • Phase changes are accompanied by volume changes that must be considered during the hydriding process. SNAP Fuel H2 Barrier • H2 retention: Improved by lining the inside of the cladding & end caps with a silicate composition. • Barrier Application: Separate layers were applied to permit a burnable poison (SM2O3) to be incorporated in the last layer. SNAP Fuel Element Assy • • • • • Tube cladding & one end closure were welded Internal H2 barrier layers applied Fuel rod inserted Coating on cladding fused to pre-coated plug Separate uncoated end cap welded to seal fuel element • Element tested to determine H2 permeation rate SNAP Reactor Fuel Operation • Each fuel element in core,depending on its location, is a closed individual system. • Initial uniform (H/Zr) profiles in fuel elements change because of axial and radial temperature gradients. They are not in equilibrium. • The bottoms of fuel rods, at cooler locations, had higher H/Zr than as-fabricated values. • Note: Overall, the 37 fuel rods in 10AFS-3 showed very good H2 retention. SNAP Fuel Structural Effects • Microstructural effects of fission products and neutrons appeared to be relatively slight. • Fuel material is brittle and strong. • Tensile strength increases with temperature. • Swelling was observed due to accumulated fission products and showed small micron size of the uranium particles. SNAPSHOT SPACE TEST General Background By: Glen Schmidt February 7, 2011 SNAPSHOT SPACE TEST Major Milestones: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. Spacecraft launched Reactor startup Criticality & heat shield ejection Full-power operation Failure/surge battery switched off Secondary payloads power check Ion engine operation Passive attitude control Temperature switch override Controller off First indication of failure SNAPSHOT SPACECRAFT ?ll?Flu 103.3 ft UPPER STAGE 3 BOOSTER 4: SNAP 13A AGENA +123 234330 [b i 12.240 113 - jJWTOTAL DRY WEIGHT 1?.53? lb SNAPSHOT SPACECRAFT ATTITUDE MONITOR BOOM a EQUIP. I ANTENNA NULTAGE REGULATOR - BOOM POWER TAPE RECORDER EQUIP. TELEMETRY EQUIP. CONTROL NONENTH RESISTOR PANEL 5 A1 '11-?53; SNAP 10A JUN ENGINE 2-5?65 7561-02312A Figure 5. Spacecraft Configuration SNAPSHOT LAUNCH SIREN On 01bit Con?guration Hose Fairing Atlas Boester Heat SHIEM Miss Suslamer Flgure SNAP 10A Heat Shield Ejeclion Sequence SNAPSHOT SPACE TEST 1. • • • • • • 2. • • Spacecraft launched Liftoff from VAFB on Saturday, April 3,1965 at 13:24 PST Ascent was normal-Atlas booster, sustainer, vernier engine cutoffs occurred at specified times. Nose-cone separation and ignition of Agena first-burn verified. Second Agena burn occurred & indicated nominal orbit was achieved. Apogee of 705 nmi & perigee of 695 nmi and with an orbital period of 111.4 min. Long-lived orbit was achieved. Reactor startup was authorized by AEC. Reactor startup Startup command verified on Rev 2 at 17:05 PST, April 3, 1965. Receipt of startup command verified by squibs being energized, coarse drums snapping to full-in position, and both control drums stepping in at a period of 150 sec, SNAPSHOT SPACE TEST 3. • 4. • 5. • • Criticality and heat shield ejection Observed increased reactor outlet temperature and verification that heat shield were ejected at beginning of Rev 6. Full power operation Initial controller deactivation and reflector full power operation observed during data acquisition on Rev 7 (outlet temperature of 1015 F and converter power in excess of 500 w). Failure battery/surge battery switching Failure batteeries used to support pre-startup batteries were switched “off” and surge was switched “on” on Rev 8. Secondary payload groups were sequentially operated to obtain a power loading profile. SNAPSHOT SPACE TEST 6. • 7. • • • • Secondary payloads power check Within the first 24-hours of reactor full-power operation, the ion engine was turned “on”. Ion engine operation After ion engine warm-up, spurious data occurred with widely fluctuating control drum position readings. Other instruments were observed to be equally noisy. During the following, Rev 9, the ion engine had been turned “off” by its own timer. All reactor parameters were again indicating normally. SNAPSHOT SPACE TEST 8. • • 9. • • Passive attitude control After several days, active attitude control was turned “off” because control gas was gradually being depleted. Stability of spacecraft in nose-up attitude was maintained by gravity gradient effect and assisted passively by damping effects of control moment gyros. Temperature switch override The planned nominal sequence required reactor malfunction and failure sensing system to be turned “on” on Rev 55. It was not turned “on”. A revised sequence was followed because of uncertain ion engine operation. SNAPSHOT SPACE TEST 10. • • • 11. • • • Controller off On April 9, 1965 (six days and four hours after reactor startup), two additional control drum steps were inserted by ground command to provide extrapolated power level of more than 500 w after end of 90 days. Reactor power level increased to 590 w. Reactor controller was turned “off”. First indication of failure On May 16, 1965 after 43 days of operation, the spacecraft did not respond to ground command or interrogation of Rev 555. Later data indicated the reflectors had ejected, the controller was stepping the control drums, and the electrical power was zero. Failure was caused by the bus voltage regulator located in the Agena spacecraft. Heat Shield Temperature SNAPSHOT ORBIT South Pool 400 - Vehicle Vehicle Enter Shade Leave Shade Equator Iur'ehir?e Enter Shade 300*- 13w. NEH Ternperature\ . '1 Han: Freezing In. Poin112?F One Drbil Sysiem Time {Sec )1 103} Figure 2B. SNAP 10A Heal Shleid Temperature (Prior to Ejection) REACTOR OUTLET TEMPERATURE IOBO IO5O 030 1020 IOIO I000 990 SNAPSHOT ORBIT I REVOLUTION 9 DATA I I TAPE RECORDER 1 I Jim 4' I I TWO DRUM I I I STEPS INSERTED BY GROUND COM DEACTIVATED 0 ON LINE DATA FROM HULA '3 ON LINE DATA FROM BOSS A ON LINE DATA FROM COOK IOO TIME FROM POWER (hr) I50 REACTOR THERMAL POWER kw) SNAPSHOT ORBIT CALENDAR DAY 4-4 442 4-20 4-28 5-6 5-I4 5-OFF LINE DATA OON LINE DATA FROM HULA ON LINE DATA FROM COOK 13 ON LINE DATA FROM BOSS 36 NUCLEAR GROUND TEST DATA GROUND TEST CONTROLLER OFF FLIGHT TEST CONTROLLER OFF 4 ?9-65 AT 2 123 TIME FROM INITIAL FULL POWER (day) SNAPSHOT ORBIT CALENDAR DAY 4?4 4?20 4?28 5?6 5?OFF LINE DATA ON LINE DATA FROM ON LINE DATA FROM COOK A. El ON LINE DATA FROM BOSS 91-: 980 - NUCLEAR GROUND TEST DATA 960 not; '51 AD CODE D: I: 950 EI Lu 0: GROUND TEST CONTROLLER OFF 940 - FLIGHT TEST CONTROLLER OFF 4*9?65 AT 2 :23 QEOJ TIME FROM INITIAL FULL POWER (day) 7?7-65 Figure 2.5. 756l-02684A Reactor Average Coolant Temperature CONVERTER POWER OUTPUT Ion?rI SNAPSHOT ORBIT CALENDAR DAY ?4 442 4-20 4-28 5?6 5?l4 5-OFF LINE DATA A 0 ON LINE DATA FROM HULA BOO A ON LINE DATA FROM COOK A CI ON LINE DATA FROM BOSS 520 PREDICTED PERFORMANCE ON NUCLEAR GROUND TEST DATA) BOO GROUND TEST CONTROLLER OFF TEST CONTROLLER OFF 4?9-65 AT 2 :TIME FROM FULL POWER (day) 756I-0269IA PUMP FLOW (gpm) SNAPSHOT ORBIT CALENDAR DAY 4'4 4-I2 4-20 428 5-6 5-22 5-30 6-7 6-I5 6-?4'5 0 ON LINE DATA FROM HULA 1 ON LINE DATA FROM COOK I ON LINE DATA FROM BOSS -- NUCLEAR GROUND TEST DATA In OFF LINE DATA 4.0 I35 i II- ., 0 out I30 -GROUND TEST . CONTROLLER OFF 4? FLIGHT TEST CONTROLLER OFF 125*" {4-9-65 AT 2 323 TIME AFTER INITIAL FULL POWER (day) SNAP 10A Lessons Learned Development of processing and production control techniques and equipment to provide predictable. consistent, and acceptable fuel elements for more than one core loading required additional planning and effort than anticipated. Revisions in the design of fuel elements between the experimental and development reactor tests required improvements in the processing and production control techniques. The final configuration of a compact space reactor required consideration of many competing factors to accommodate the assembly, nuclear qualification and acceptance test, and launch sequence and were not anticipated prior to design and testing of the experime ntai reactor. Two nuclear reactor tests and a non-nuclear reactor mockup test were required to assure that design of reactor fuel elements, core vessel internals, and reflector subassembiies were ready for nuclear qualification and flight demonstration. Each test was required to verify design improvements, provided'new information and was different than previous tests. - The experimental reactor test must be followed by a development reactor test and be completed before final design of the flight system. A non-nuclear mockup of the flight design containing flight components must be tested prior to start of the nuclear qualification test. SNAP Reactors Overview U.S. Space Reactor Power Trends .I . {a a .1 (1 kwa) a" .1 ?1 ?Wei rmin '80 '90 2 TOPAZ Space Power Systems HY-LIFE Test Setup