The first commercial use of one of these “atomic batteries” began in 1965 when the SNAP-7B 60-watt generator went into operation on an unmanned Phillips Petroleum Company offshore oil platform, 40 miles southeast of Cameron, Louisiana. The generator operates flashing navigational lights and, in bad weather, an electronic foghorn (see page 49). This unit will be tested for 2 years to determine the economic feasibility of routinely using isotopic power devices on a commercial basis. [Illustration: Acoustic pulses.] Buoyancy tank Sound amplifier Nuclear-powered sound source Ocean bottom [Illustration: _The SNAP-7E isotopic generator powers an undersea acoustic beacon, which produces an acoustic pulse once every 60 seconds. In addition to being a navigation aid, the beacon is used to study the effects of a deep-ocean environment on the transmission of sound over long distances._] [Illustration: Diagram.] Total height: 10 ft 2 in Armored cable Pressure vessel Capacitor bank Fuel capsules Biological shield Equipment package Voltage converter Depleted uranium Thermoelectric generator System support structure [Illustration: _Details of the Phillips Petroleum platform, which uses the SNAP-7B nuclear generator._] [Illustration: _The final electrical connection is made from the nuclear generator to the platform’s electronic foghorn and two flashing light beacons._] [Illustration: Diagram] Fog Horn Beacon Beacon Snap-7B nuclear generator The radioisotope-powered devices previously described were developed by the AEC under the SNAP-7 Program.[16] The testing of these units has demonstrated the advisability of developing reliable and unattended nuclear power sources for use in remote environments without compromise to nuclear safety standards. As a result of the success of these tests, a variety of potential oceanographic applications have been identified. A study, conducted by Aerojet-General Corporation in conjunction with Global Marine Exploration Company and Northwest Consultant Oceanographers, Inc., described ocean applications including underwater navigational aids, acoustic beacons, channel markers, cable boosters, weather buoys, offshore oil well controls along with innumerable oceanographic research applications. This study was sponsored by the AEC Division of Isotopes Development. In order to satisfy the requirements for these and other applications, the AEC has begun developing a series of compact and highly reliable isotope power devices that are designed to be economically competitive with alternative power sources. Currently underway are two specific projects, SNAP-21 and SNAP-23.