Abstract: A nuclear fuel identification system for use in nuclear power plants has an imaging system having a video camera and an array of illuminators surrounding the video camera and positioned to shine onto a nuclear fuel cell. The illuminators are sequentially activated to provide a series of images each having a different shadow pattern. These images are then digitized and stored until a complete set of the images are available. At that time, the images are superimposed and optimized for improved contrast. By viewing the distinct shadow patterns on the nuclear fuel cell, the identifying markings are readily visible. In addition to the shadow imaging system, a variety of laser devices are used to accomplish similar image generating functions. Such laser devices include a laser scanner, a distance laser device, an interferometer, a holographic interferometer, and a bi-refringent crystal prism.

Abstract: The underwater portable drop light for use illuminating work sites in nuclear facilities has a high pressure sodium arc lamp sealed to a stainless steel base with a flexible, radiation-resistant seal to provide a watertight and shock-absorbing connection. A wet-mateable connector is attached to the base to permit underwater-changeable connection to a cable which supplies power from a ballast power supply. A light-transmissive, impact-resistant cover is formed around the arc lamp and attached to the base. The cover has openings through which water can flow in and out to conduct heat away from the arc lamp. The combination of the above elements creates a compact modular unit which is replaced as a whole when the arc lamp burns out, and which may be replaced in or out of the water, allowing maintenance work to continue essentially uninterrupted when radiation exposure time is an issue.

Abstract: The underwater illumination apparatus for use in nuclear facilities has a high pressure sodium arc lamp sealed to a stainless steel base with a flexible, radiation-resistant seal to provide a watertight and shock-absorbing connection. A wet-mateable base connector is attached to the base to permit connection to a lower cable. A light-transmissive, impact-resistant cover is formed around the base and the arc lamp. The cover has holes through which water can flow in and out to conduct heat away from the arc lamp. The combination of the above elements creates a modular unit which is replaced as a whole when the arc lamp burns out. The lower cable which provides power to the arc lamp is attached at its other end to a ballast power supply which is hermetically sealed in a stainless steel housing. Wet mateable connectors are attached at the inlet and outlet of the ballast power supply to attach to the lower cable and to the upper cable connection to a 120 VAC source.

Abstract: The underwater illumination apparatus has a high pressure sodium arc lamp sealed to a stainless steel base with a flexible, radiation-resistant potting material to provide both a watertight seal and a shock-absorbing connection. A wet-mateable base connector is attached to the base to permit connection to a lower cable. A transparent, impact-resistant cover is formed around the base and the arc lamp. The cover has holes through which water can flow in and out to conduct heat away from the arc lamp. The combination of the above elements creates a modular unit which is replaced as a whole when the arc lamp burns out. The lower cable which provides power to the arc lamp is attached at its other end to a ballast power supply which is hermetically sealed in a stainless steel housing. Wet mateable connectors are attached at the inlet and outlet of the ballast power supply to attach to the lower cable and to the upper cable connection to a 120 VAC source.

Abstract: A synthesizer for complex acoustic signatures includes a generator for an ectrical analog of a complex acoustic waveform corresponding the the "shaft rub" noise produced by the interaction of a marine propeller shaft and a stern tube or other through-the-hull marine fitting. This circuitry employs digital random generators to produce a nonrecurring characteristic signal synthesizing this acoustic noise. An arrangement to process this signal with other simulation circuitry is also disclosed.

Abstract: A depth monitoring device monitors the period of a diver's maximum depth. A aximum depth display is coupled to the depth monitor to enable the diver to quickly determine, at any given time during the period, his maximum depth of submergence. When the diver reaches a preselected critical maximum depth, an audio alarm coupled to the depth monitor is activated to alert the diver.

Abstract: In a diver's navigation system employing a receiver having three equal, alarly disposed hydrophone locations, a digital signal processing circuit is employed which receives frequency shift keyed digital data from remote beacons. Circuitry is provided to process this data to derive a bearing indication to the beacon.