Patent Publication Number: US-2020303084-A1

Title: Radiation tolerant underwater camera with high definition viewing and recording capability

Description:
BACKGROUND 
     1. Field 
     The disclosed concept generally relates to cameras, and, more particularly, to underwater cameras for use in nuclear reactor applications. 
     2. Related Art 
     Monitoring and maintenance is important in the operation of nuclear reactors. Some types of monitoring requires visual inspection of parts of the nuclear reactor. Some parts of the nuclear reactor which need to be visually inspected, such as fuel assemblies, are located in harsh underwater and irradiated environments. The harsh environment presents challenges for performing a visual inspection. 
     Some prior camera systems have been developed for performing irradiated fuel inspections. Each of the prior camera systems fill a specific role, but lack the capability and versatility to perform full visual exams of fuel assemblies including top and bottom nozzle inspections. For example, some prior low resolution cameras provide a high optical zoom 36:1, but since they are low resolution, they provide poor picture quality. As another example, some prior high definition cameras provide high resolution, but only have a 10:1 optical zoom, and they have dynamic seals that fail over time, causing the cameras to flood. 
     There is a need for camera systems suitable for performing complete visual inspections of fuel assemblies. 
     SUMMARY 
     Some example embodiments of the disclosed concept provide a radiation tolerant, underwater camera system that can display and record high definition images with an ×36 optical zoom. This system may include external digital and analog high definition outputs including a native serial digital interface (SDI) signal, high definition multimedia interface (HDMI), component video, composite video, and open network video interface forum (ONVIF) video output. 
     In accordance with an aspect of the disclosed concept, a camera system comprises: a camera assembly including a camera unit having an optical zoom of at least ×30 and a digital zoom of at least ×10; a controller structured to control one or more operable characteristics of the camera unit and to receive an output of the camera unit; and a conduit connecting the camera unit and the controller. 
     In accordance with another aspect of the disclosed concept, a method of inspecting a fuel assembly of a nuclear reactor is provided. The method comprises: providing a camera system comprising: a camera assembly including a camera unit having an optical zoom of at least ×30 and a digital zoom of at least ×10; a controller structured to control one or more operable characteristics of the camera unit and to receive an output of the camera unit; and a conduit connecting the camera unit and the controller; capturing images of the fuel assembly with the camera assembly; and viewing or storing the captured images with the controller. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A further understanding of the invention can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which: 
         FIG. 1  is an illustration of a camera system in accordance with an example embodiment of the disclosed concept; 
         FIG. 2  is an illustration of a camera assembly in accordance with an example embodiment of the disclosed concept; 
         FIG. 3A  is an isometric view of a camera housing in accordance with an example embodiment of the disclosed concept; 
         FIG. 3B  is a front view of the camera housing of  FIG. 3A ; 
         FIG. 3C  is a cross-sectional view of the camera housing of  FIG. 3B ; 
         FIG. 4A  is an illustration of a controller in accordance with an example embodiment of the disclosed concept; 
         FIG. 4B  is a view of a connection panel of the controller of  FIG. 4A ; and 
         FIG. 5  is a schematic diagram of a camera system in use in accordance with an example embodiment of the disclosed concept. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  is an illustration of a camera system  1  in accordance with an example embodiment of the disclosed concept. The camera system  1  includes a camera assembly  100  and a controller  200 , as well as one or more conduits  300  connecting the camera assembly  100  to the controller  200 . 
     The camera system  1  is structured such that the camera assembly  100  can be located in and operate in a harsh environment, such as an underwater and irradiated environment as would be found in the vicinity of a fuel assembly of a nuclear reactor. The controller  200  may be located outside the harsh environment with the conduit  300  connecting the camera assembly  100  to the controller  200 . Signals and data may be sent between the camera assembly  100  and the controller  200  via the conduit  300 . 
       FIG. 2  is an illustration of the camera assembly  100  in accordance with an example embodiment of the disclosed concept.  FIG. 3A  is an isometric view of a camera housing in accordance with an example embodiment of the disclosed concept,  FIG. 3B  is a front view of the camera housing of  FIG. 3A , and  FIG. 3C  is a cross-sectional view of the camera housing of  FIG. 3B . The camera assembly  100  includes a camera housing  110 , lighting units  120 , and a pan/tilt unit  130 . 
     The camera housing  110  includes a front cover  112 , a body  114 , and a back cover  116 . A camera unit  111  is housed within the camera housing  110 . The camera housing  110  also includes a connector  113 , which can be used to connect the conduit  300  to the camera unit  111  located within the camera housing  110 . The front cover  112  includes a transparent window  118  such that the camera unit  111  located within the camera housing  110  can capture images of objects exterior to the camera housing  110 . The transparent window  118  may be a diopter. 
     The camera unit  111  is structured is structured to capture high definition still and moving images. The camera unit  111  may capture images using a CMOS sensor or other suitable type of sensor for capturing digital images. In some example embodiments, the camera unit  111  is structured to capture high definition still and moving images at a resolution of at least 1080P. The camera unit  111  is structured to provide an optical zoom of at least ×30 and a digital zoom of at least ×10. In some example embodiment, the camera unit  111  is structured to provide an optical zoom of at least ×36, a digital zoom of at least ×30, or both. The camera unit may also have a light sensitivity of at least 0.5 lux. The camera unit  111  may also have auto focus and auto exposure capabilities. 
     In some example embodiments, the camera unit  110  is structured to output images via a high definition serial digital interface (HD-SDI). The output may be provided through the connector  113 . In some example embodiments, the camera unit  111  may be structured to output images via an analog component output. 
     In some example embodiments, the camera unit  111  is structured to fit within an envelope size of 11″×5″×5″. 
     In some example embodiments, the camera assembly  100  is able to operate in water depths of up to 50 feet. Also, the camera assembly  100  is structured to operate in water having a temperature in a range from 60° F. through 122° F. In some example embodiments, the camera assembly  100  is structured to be radiation tolerant to 5×10 4  rads Cobalt-60 equivalent. 
     The transparent window  118  may be a diopter. In some example embodiments, the diopter can be interchanged easily. For example, the transparent window  118  may be interchanged with a +0.5 diopter, +0.75 diopter, or a +1 diopter to change the focal length of the camera assembly  100 . 
     In some example embodiments of the disclosed concept, the camera assembly  100  has a weight of 10 lbs. or less. 
     The lighting units  120  are structured to emit light. The lighting units  120  may include any suitable light source such as, without limitation, light emitting diodes (LEDs). In some example embodiments, the lighting units  120  are 120V lights with up to 250 W max output. The lighting units  120  may also be dimmable. 
     The pan/tilt unit  130  is structured to pan and tilt to control where the camera housing  110  is facing. The controller  200  may control operation of the pan/tilt unit  130  via the conduit  300 . 
       FIG. 4A  is an illustration of the controller  200  and  FIG. 4B  is a view of a connection panel  206  of the controller  200 . The controller  200  includes a display  202  and a number of control elements  204  located on its front side. The controller  200  includes a connection panel  206 , which may be located on one of its sides, which includes various connectors which may be used to connect the controller  200  to the camera assembly  100  via the one or more conduits  300 . 
     The controller  200  may include a processor and a memory. The processor may implement one or more programs stored on the memory. The memory may also be utilized to store moving or still images received from the camera assembly  100 . 
     The controller  200  is structured to control one or more operable characteristics of the camera assembly  100 . In some example embodiments, the controller  200  is structured to control at least one of a zoom, focus, exposure, auto focus, and auto exposure of the camera assembly  100 . The controller  200  may also control at least one of pan, tilt, and lighting of the camera assembly  100 . 
     The controller  200  may communicate with the camera assembly  100  using any suitable protocol. In some example embodiments, the controller  200  communicates with the camera assembly ONVIF protocol. When the ONVIF protocol is used, the conduit  300  may be an Ethernet cable. Additionally, in some example embodiments, the controller  200  may be a computer that communicates with the camera assembly  100  via Ethernet. In some example embodiments, the controller  200  communicates with the camera assembly  100  using a video system control architecture (VISCA) protocol. When the controller communicates with the camera assembly  100  using the VISCA protocol, the conduit  300  may be a Serial RS-485 half or full duplex cable. The controller  200  may include one or both of connectors to support Ethernet and Serial RS-485 connections. The controller  200  may also include other types of connectors such as universal serial bus (USB), analog component, composite, SDI, HDMI, power, and audio connectors. The controller  200  may also include a built in circuit breaker and/or ground fault circuit interrupter (GFCI). 
     The controller  200  is structured to display (via the display  202 ) and/or store images captured by the camera assembly  100  and communicated to the controller  200  via the conduit  300 . The display  202  is able to display the images at a resolution of at least 1080p and, similarly, the controller  200  is able to store the images at a resolution of at least 1080p. In this manner, a user located outside the nuclear reactor may view captured images via the controller  200  to perform a visual inspection of the fuel assembly. In some example embodiments, the controller  200  is also structured to provide integrated high definition video capture with h.264 compression. Also, in some example embodiments of the disclosed concept, the controller  200  is structured to provide text overlay to images displayed on the display  202  and/or in captured and stored images. 
     The display  202  may be a touch screen display. User inputs may be received via the display  202 . The controller  200  may also have physical controls elements  204 . The controller  200  is structured such that a user may control one or more characteristics of the camera assembly  100  via the display  202  and/or the control elements  204 . 
       FIG. 5  is a schematic diagram of the camera system  1  in use in accordance with an example embodiment of the disclosed concept. As shown in  FIG. 5 , the camera assembly  100  is disposed in a harsh environment in the vicinity of the fuel assembly of a nuclear reactor. The camera assembly  100  is connected the controller  200  via the conduit  300  and the controller  200  is located outside the harsh environment. The controller  200  may be used to control operations of the camera assembly  100 . The controller  200  may also receive, store, and display data received from the camera assembly  100  such as high definition still or moving images. 
     In accordance with some example embodiments of the disclosed concept, the disclosed concept may be implemented as a method of inspecting a fuel assembly of a nuclear reactor. In accordance with such a method, the camera system  1  may be provided. The camera assembly  100  may be placed inside the nuclear reactor in the vicinity of the fuel assembly, as shown for example in  FIG. 5 . The controller  200  may be placed outside the nuclear reactor. The camera assembly  100  may be used to capture images and/or video of the fuel assembly. The controller  200  may be used to view or store the captured images. In some example embodiments, the controller  200  may also be used to control at least one of a zoom, focus, exposure, auto focus, and auto exposure of the camera assembly  100 . 
     In accordance with example embodiments of the disclosed concept, the camera system  1  is a versatile and durable camera system that is capable of performing full visual inspections of fuel assemblies in nuclear reactors. The particular capabilities of the camera system  1  make it suitable for performing full visual inspections of fuel assemblies in nuclear reactors, which prior camera systems are not suited for. 
     While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular embodiments disclosed are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the appended claims and any and all equivalents thereof.