Nuclear reactors for space

1961 film, with transcript

Catalog description: The SNAP program Systems for Nuclear Auxiliary Power is an AEC program to develop long-lived auxiliary power from nuclear energy for use in satellites and space vehicles. Compact atomic reactors being developed by Atomics International for use in SNAP systems are shown in this semitechnical film. Safety characteristics of the SNAP reactor during fabrication, testing, transport, installation, launching, and use in space are described. Detailed sequences filmed at Atomics International on fabrication and testing show the simplicity and compactness of the reactors. Safety features are described in scenes that illustrate shipping, launch-site activities, and launch of the reactor into space. The burnup and dispersal of the reactor during reentry into the atmosphere are shown in a detailed animation sequence. Many beneficial uses of SNAP in the U. S. national space program are illustrated. notes:

This is film 88198 in our catalog.

Show transcript
00:10 Nuclear energy, simple in original conception, complex in final achievement.
00:16 The metallurgy of uranium is less than 20 years old, yet nuclear energy is already being used
00:27 and accepted in many areas of American life. Over 750 million kilowatt hours of
00:40 electricity have been generated by atomic power. And now nuclear energy is
00:48 entering the space age.
01:18 Long-life Earth satellites for communications, weather surveillance, and a host of other
01:27 important space activities must have low weight, compact and rugged electric power sources.
01:35 Nuclear energy can provide that power reliably and safely.
01:43 Reactor systems are being designed and built by Atomics International for the United States
01:48 Atomic Energy Commission as a part of a commission program to develop devices which will generate
01:53 electricity for at least one year in space.
01:58 This development program is designated SNAP, S-N-A-P, Systems for Nuclear Auxiliary Power.
02:06 The program is based on the use of radioisotopes and nuclear fission reactors to generate electricity
02:12 for space vehicles and remote locations.
02:18 The SNAP-2 reactor system,
02:21 under development since 1957 for use by the United States Air Force,
02:25 will produce 3,000 watts of electricity
02:28 for space applications beyond 1964.
02:32 This small, lightweight reactor is coupled to a mercury vapor turbo generator,
02:37 which has only one moving part.
02:39 The SNAP-8 system, under joint development by the Atomic Energy Commission and the National Aeronautics and Space Administration,
02:48 will produce ten times the power output of SNAP-2 and will pioneer electric propulsion in America's space program after 1965.
02:57 The SNAP-10A system uses the SNAP-2 reactor
03:05 and a thermoelectric generator which directly converts heat to electricity
03:09 with no mechanical moving parts. It is capable of delivering any power below 1,000 watts.
03:15 The SNAP-10A is intended for use after 1963.
03:19 The three systems, SNAP-2, 8 and 10A
03:25 all use small, compact nuclear reactors of identical concept.
03:32 This full-scale model displays the features of the reactor.
03:36 The reactor has two main parts, the beryllium reflector and the reactor core.
03:41 This cutaway of the core vessel shows the bundle of cylindrical fuel moderator elements.
03:47 Each fuel element is clad in a thin-wall steel tube.
03:51 Liquid metal coolant removes the heat.
03:54 For minimum weight, the reactor uses beryllium reflectors.
03:58 The reflector is composed of two movable control drums to control the nuclear reaction
04:03 and two safety elements for emergency shutdown.
04:07 The reactor cannot be made to sustain a nuclear reaction,
04:11 that is, be made critical, with the reflectors in the out position or with the reflectors removed.
04:17 The reflector is completely separable from the core to ensure safe reactor ground handling.
04:24 The SNAP reactor must be capable of withstanding the shock and vibrations of a missile launch.
04:47 The reactor systems must start up in orbit by remote control and be capable of unattended, reliable, and automatic operation in space for a period of at least one year.
04:59 And they must not present a radiation hazard to operating personnel or the general public.
05:06 A dominant criteria of SNAP reactor design and resulting performance is safety.
05:13 The reactor is designed for remote startup in an orbit.
05:17 It will not be operated unless a satisfactory orbit is obtained.
05:23 This reactor is one of a series of developmental reactors
05:26 built and tested to gain the necessary performance data for the flight model designs.
05:31 The use of metallic uranium, U-235,
05:35 alloyed with zirconium hydride and clad in steel,
05:39 guards against the spread of any radioactivity during storage and handling.
05:44 No shielding is required for technical personnel.
05:48 The configuration of the fuel in the core allows technicians to fabricate, assemble, and install the reactor without shielding or remote control devices.
06:00 Extensive testing of the SNAP reactor is demonstrating the inherent safety characteristics.
06:07 Critical assembly tests have measured the effect of various materials surrounding the reactor core.
06:12 The test shown here indicated the reactor can be constructed so it will not start up even if water or rocket fuel surrounds the reactor core.
06:29 Shock and vibration tests are establishing reactor resistance to accidental shock and the vibration of missile launching.
06:42 Even after acceptance tests are performed, the low amount of radioactivity generated presents no significant radiation problem.
06:50 After a short shutdown period, the reactor can be handled and disassembled for shipment.
06:56 The design of the reactor assures against an accidental operation, or criticality, during shipment.
07:04 The reflector apparatus, including the safety and control elements, is removed and shipped separately to the launch site.
07:12 In place of the reflector assembly, a sleeve will be mounted around the reactor.
07:17 The SNAP reactor cannot operate with the sleeve surrounding the core.
07:22 The system with radiator and accessories will then be packaged in a separate shipping container.
07:28 In this manner, the reactor can be safely transported through populated areas.
07:33 Shipment can be made by truck, train, or airplane.
07:42 The reactor cannot become critical from transportation accidents involving sudden and violent shock.
07:50 If water immersion should occur during shipment, the reactor will remain subcritical.
07:56 And the reactor system cannot become critical in accidental fires.
08:05 Shipping procedures for nuclear material have been followed safely and satisfactorily for many years,
08:10 in accordance with Interstate Commerce Commission and other governmental regulations.
08:15 The shipment of the SNAP reactor will follow these methods.
08:22 When the SNAP unit arrives at the launch site, it will be assembled in a controlled area.
08:28 The assembly of the reactor will be done with the control and safety elements
08:31 mechanically safe-locked in the non-operative position.
08:36 The reactor power unit will then be transferred to a holding rack
08:39 and prepared for installation on a satellite vehicle.
08:46 This shows the mating of a non-nuclear nose cone to an Agena vehicle
08:51 before a successful Air Force launching in 1960.
08:55 The SNAP units are designed so that established mating operations need not be changed.
09:03 Here, the Agena and the nose cone are mated to an Air Force missile.
09:08 The inherent safety of the SNAP auxiliary power unit
09:11 will allow personnel to prepare and check out the missile and its payload.
09:16 The long-life auxiliary electric power needed by America's satellites
09:20 will be provided without altering the proven methods and procedures
09:23 of pre-launch missile preparation.
09:26 During this operation, the reactor control system is mechanically locked
09:30 in a non-operative condition.
09:33 The safety mechanism will remain on the reactor
09:36 until vehicle fueling operations require launch pad evacuation.
09:41 When personnel withdraw from the launch pad,
09:44 the mechanical safe lock is removed from the reactor.
09:49 Accidental startup is then prevented by interlocked controls in the launch control center.
09:55 During the launch of all large booster missiles,
09:58 an exclusion radius is established to protect launch site personnel
10:02 from possible fires or explosions caused by the chemical fuel.
10:06 The distance needed to ensure safety from nuclear hazards during the launch of a SNAP
10:13 reactor is less than that distance already established for missile fuel hazards.
10:19 There will be no significant hazards added to our space programs by the use of SNAP reactors.
10:27 If liquid fuel fires or explosions should cause accidental start-up of the reactor,
10:32 the nuclear operation would be momentary.
10:36 The immediate area of the launch pad might be contaminated, but this contamination would
10:41 rapidly decay.
10:44 Cleanup would then be accomplished quickly and thoroughly by well-established procedures.
10:54 During the flight of a vehicle carrying the SNAP reactor, the reactor will not be in operation.
11:00 Therefore, no radioactive material will have been produced.
11:04 If the vehicle should malfunction during flight, mechanical devices will keep the reactor inoperative.
11:12 The vehicle can be safely destroyed as shown in this scene from the historical film archives of the United States Air Force.
11:30 Today missiles are rising successfully from launch pads, proving flight system reliability
11:38 and performance refinements.
11:40 These successful launches are building the foundation in technology needed for advanced
11:45 space satellites.
11:49 Such a typical launch will carry a satellite containing the SNAP reactor into space.
11:56 Several phases of the flight pattern will be tracked.
11:59 Ground receiving stations will relay tracking information to central control.
12:03 Altitude and orbit calculations will be performed.
12:08 When a safe and stable orbit has been achieved and flight geometry and orbital life have
12:12 been established, the SNAP reactor will be made critical to furnish the satellite with
12:17 the all important auxiliary power, electricity.
12:22 Then and only then will radioactive material be produced by the reactor.
12:32 After a normal operating period of one year, the reactor will shut down and continue to
12:36 orbit the Earth.
12:38 The initial flights of SNAP reactors will be at altitudes greater than about 700 miles,
12:43 in orbits of at least 300 years' life.
12:47 Orbits lasting 300 years guarantee the decay of all radioactive material to safe limits prior
12:52 to reentry. Sometime during the seventh decade of the 23rd century, the orbit of this original
13:00 but long dead reactor-powered satellite will end. Even though the intact reentry of a SNAP
13:09 reactor after 300 years in orbit results in no undue radiation hazard, the reactor is
13:16 being designed to ensure complete burn-up above 100,000 feet by means of reentry aerodynamic
13:22 heating.
13:25 This tumbling model of a SNAP reactor fuel element is undergoing a reentry heating test.
13:31 Test conditions simulate the aerodynamic heating at various altitudes.
13:35 The test shown here demonstrates the melting and burning that occurs at an altitude of
13:39 220,000 feet.
13:43 These reentry heating experiments indicate that complete meltdown and burnup will occur
13:48 when a SNAP reactor enters the Earth's atmosphere from an orbit.
13:58 Guaranteed burnup and dispersal of the reactor during reentry will permit the safe use of
14:03 SNAP reactors in our space programs at any altitude and orbit lifetime.
14:09 To facilitate exposing reactor fuel elements to aerodynamic heating, the structural materials
14:14 surrounding the reactor are designed to separate and allow the reactor to fall apart and burn
14:20 up on re-entry to the atmosphere.
14:28 This simulation shows a reactor satellite at an altitude over 400,000 feet, approximately
14:34 eighty miles.
14:40 As the reactor orients ahead of the payload,
14:43 heating of the vehicle is slight.
14:47 The heating increases.
14:53 The payload and the reactor power unit soon separate.
15:00 At an altitude of 320,000 feet, heating of the reactor power unit is apparent and reflector
15:09 elements are released.
15:12 By 300,000 feet the reactor core assembly separates from the vehicle.
15:17 The assembly begins to tumble.
15:20 Then the fuel elements are ejected from the melting core.
15:26 At an altitude of over 100,000 feet, 20 miles above the surface of the Earth,
15:31 the ignited particles oxidize and disperse with no radiation risks to the Earth's population.
15:40 Today's systems for nuclear auxiliary power are being developed
15:43 to furnish the needed electricity for America's space programs.
15:48 Safety is an integral part of all SNAP reactor development.
15:52 The safety studies and safety tests are demonstrating
15:55 the dependability of nuclear power for many remarkable and beneficial uses.
16:03 The world can confidently look forward to enjoying the maximum benefits from our national space program.
16:11 For example, three reactor-powered satellites in equatorial orbit about 22,000 miles above the Earth
16:18 can be used to accomplish international telecasting.
16:21 The satellites, acting as relay transmitters, can provide a television network to cover the planet and furnish worldwide communications, even to the remotest underdeveloped areas of the world.
16:38 High-altitude satellites can provide weather surveillance to furnish accurate long-range weather forecasts for agriculture and commerce.
16:46 Earth satellites can be used for navigation,
16:53 for air traffic control,
16:56 and for commercial radio telephone global communications.
17:00 Finally, the availability of nuclear reactors
17:07 as a safe and dependable source for electric power
17:10 provides mankind the dramatic and profound opportunity
17:14 for probes into deep space and interplanetary travel.