SNAP-8: System for Nuclear Auxiliary Power

1966 film, with transcript

Catalog description: In order to travel in space, man must take his own environment with him. This requires power to supply oxygen, drinking water, air conditioning, lighting and to operate communication systems; in short: power to maintain equipment and sustain life itself. Simulating the earth's environment is by no means a new idea. Crews of nuclear submarines live in health and comfort for months at a time while submerged in a hostile environment. This is possible because nuclear energy provides a source of continuous, uninterrupted power. Space voyagers, too, need this same kind of power, and this is where SNAP-8 comes in — using a mercury-vapor turbo-generator system to convert heat from a nuclear reactor into useful electricity. The film shows the principal components and, in animation, illustrates and explains the operation of the system. Actual fabrication of components and subsystems is also shown, as well as the extensive testing programs currently underway. Thus, SNAP-8 is not a drawing on a drafting table, but a technological reality. Animation sequences are used to depict potential missions of the SNAP-8 system, including power for: TV satellites to broadcast all over the earth, orbiting space stations to support earth observation and space research, maintenance of permanent lunar bases, and manned explorations beyond the moon.

This is film 88258 in our catalog.

Show transcript
00:30 Fortunately, on Earth, people can adapt to this situation and live without certain amenities
00:35 as generations did before them.
00:38 In space, however, lack of power is not just a temporary inconvenience, but a grim denial
00:43 of survival.
00:45 For our astronauts depend upon sensitive equipment, systems of high sophistication, bound and
00:51 ruled by one single matter of life and death.
00:54 need for energy, power, continuous and uninterrupted, for days, months, or better still, years.
01:06 True solar cells can operate some unmanned missions and fuel cells can take us briefly
01:11 to the moon, but the moon is near at hand compared to other planets in our solar system.
01:17 Close or far in space, man must take his earth environment along, and if you can't take it
01:23 with you. You just don't go. Of course simulating the Earth's environment is by no means a new
01:30 idea. Crews of nuclear submarines live in health and comfort for months at a time, submerged
01:36 in an alien and hostile environment. This is possible because their nuclear power system
01:41 operates continuously for long periods of time. Space voyagers, too, need this kind
01:47 of power. And that's where SNAP-8 comes in, a program to study the technology of converting
01:53 nuclear energy into useful electricity for space exploration. The present SNAP-8 system
02:00 is designed to operate for over a year, providing sufficient power to meet the needs of 125
02:05 earthbound Americans. In space, this means oxygen, drinking water, air conditioning,
02:11 lighting, and communication. In short, SNAP-8 is providing the technology for the maintenance
02:18 of equipment and sustenance of light. In the SNAP-8 system, an atomic reactor supplies
02:24 heat, which is transformed into electricity by the power conversion system. Some of the
02:30 principle SNAP-8 components are a boiler, condenser, turbine and associated alternator,
02:39 a container holding electrical controls, expansion reservoirs for the various system loops and
02:46 pumps. Heat from the nuclear reactor is absorbed by a liquid alloy called NaK, which is composed
02:52 of sodium and potassium. While passing through the reactor, the alloy is heated to about
02:57 1300 degrees Fahrenheit. This heat is transferred to a boiler before the NaK returns to the
03:02 reactor to be reheated. This is the first of several interrelated loops which make up
03:08 the SNAP-8 electrical power system. Of course, future developments could employ another nuclear
03:14 heat source, radioisotopes, in place of the reactor. The second loop is filled with liquid
03:19 mercury, which is vaporized in the boiler by the heat released by NaK loop number one.
03:25 These mercury vapors drive the turbine alternator, producing electrical power. After driving
03:31 the turbine, the vapors are recondensed into a liquid. The liquid then returns from the
03:36 condenser to the boiler, completing loop number two. Because NaK is an effective heat absorber
03:42 and coolant, it is used in a third loop to carry the excess heat given off by the mercury
03:48 to a radiator, where it is dissipated into space. A fourth loop, filled with oil, is
03:54 provided to cool the components and lubricate the bearings. This combination of closed loops
04:00 permits materials to be used over and over again, making such power-producing systems
04:05 capable of continuous operation for months and even years.
04:10 Development of the SNAP-8 electrical power conversion system is now in progress at Aerojet General's von Karman Center
04:15 under direction of the National Aeronautics and Space Administration.
04:19 Simultaneously, development of the nuclear reactor
04:22 is underway at Atomics International for the Atomic Energy Commission.
04:26 The Aerojet test complex is the center of all non-nuclear SNAP-8 testing activities.
04:31 Here, massive heaters supply the thermal energy,
04:34 which in space will be supplied by a compact nuclear reactor.
04:38 Each heater brings NaK liquid alloy to high temperatures,
04:42 while pumps and pipes transport it to the test bays where it is used to test SNAP-8 components.
04:48 The complex is a maze of closed loops and sealed parts.
04:51 Only instrument readings indicate that tests are going on,
04:55 all different kinds, such as the recently completed 3,000-hour hot test of the NaK pump shown here.
05:01 For not only must designs be evaluated and improved, but the materials themselves must
05:08 be studied, as they are subjected to high temperatures, low pressures, and radiation
05:13 for months on end.
05:16 The components for these and future tests are fabricated and assembled in special dust-free
05:21 clean rooms, for even a little dust can cause parts to fail.
05:26 Thus, SNAP8 is not a paper study but a very important advanced technology program based
05:32 on well-established principles.
05:34 Here, consoles monitor SNAP8 test hardware during development tests and endurance runs.
05:40 Of course, this is an experimental system, an earthbound, greatly enlarged version of
05:45 a possible future flight system on which arrangements and functions of components can be studied
05:50 as they work together producing SNAP8 power.
05:54 Today, successful proof testing of individual components has led to a progressive buildup
06:00 of a complete power conversion unit, a necessary step before integrated testing with the reactor.
06:07 This power conversion system buildup is proceeding in four major steps. Checkout of boiler, condenser
06:13 and mercury pump, addition of the turbine alternator, NaK pumps, and finally, after
06:22 startup equipment is checked out, a 10,000-hour endurance test of the entire system. Only by such
06:28 exhaustive testing can we thoroughly understand a new system and its capabilities. For instance,
06:35 development of the nuclear submarine, which later became the indispensable platform for the Polaris
06:40 missile, was started immediately after the war, but it wasn't developed overnight. In fact, it took
06:46 nine years, nine years, accepted today as time well spent.
07:00 Snap-8 technology needs this same kind of long lead time. For when a system must be
07:05 built to operate for years, its basic concept and the actual hardware must be proven by
07:10 years of testing. And when lives of men are at stake, one dares not and does not take
07:17 risks. SNAP-8 is the only major technology program of its kind conducted today. Obviously,
07:26 future space missions and their associated power supplies must be planned years in advance.
07:32 The knowledge gained from the SNAP-8 program will allow them to become realities. The desirable
07:39 The desirable features of nuclear systems make them candidates for many kinds of missions.
07:45 One of the earliest applications might be for TV satellites capable of broadcasting educational and informational programs directly to homes all over the world.
07:56 Large orbiting space stations could use nuclear electric power to support earth observation and space research
08:03 or make them useful springboards for deep space exploration.
08:08 Permanent bases on the Moon would also require large quantities of power to bore into and thoroughly explore the lunar surface.
08:15 And as we continue to reach farther and farther into space,
08:19 requirements for life-sustaining and equipment-maintaining power will become progressively heavier.
08:25 All this may be nearer than we think.
08:28 Ten years ago, the Moon looked very far away,
08:31 and yet today it is not only a realistic goal, but the focal point of our national space effort.
08:36 And just as our present objectives exceed those of a decade ago, so our goals for 1975
08:43 are likely to exceed any predictions we make now.
08:46 But whatever our goals, we will need the technology being built today in the SNAP-8 program.
08:53 For without it, our manned explorations could remain confined to very limited horizons.
08:59 If space is this century's frontier, we must recognize that compared to the great voyagers
09:04 of the past we are barely out of port but to travel beyond our earth and its companion
09:11 satellite to other planets in our solar family we must have a continuous source of substantial
09:16 electrical power for months or better still years snappy technology can supply this power