SE1450349A1

SE1450349A1 - Radiation-tolerant cable reel

Info

Publication number: SE1450349A1
Application number: SE1450349A
Authority: SE
Inventors: Jan Gunnarsson; Niklas Barringer
Original assignee: Isec Ind Security Ab
Priority date: 2014-03-26
Filing date: 2014-03-26
Publication date: 2015-09-27
Also published as: WO2015144828A1

Abstract

ABSTRACT There is disclosed a cable reel for connecting a camera located in an ionizing radiationenvironment to a control arrangement. The cable reel comprises an electronic devicecomprising a signal processor arranged to convert signals which are transmitted by thecable reel betvveen the control arrangement and the camera. Moreover, the cable reelcomprises an ionizing radiation protective shield for protecting at least a portion of theelectronic device from ionizing radiation. There is also disclosed a method for manufacturing cable reel of this type. Figure for publication: Fig. 1 22

Description

RADIATION TOLERANT CABLE REEL FIELD OF THE INVENTION The present inventive concept generally relates to a cable reel. More specifically, thepresent inventive concept relates to a cable reel for connecting a camera located in anionizing radiation environment to a control system. The present inventive concept also relates to a method for manufacturing such a cable reel.

BACKGROUND ART Electronic equipment which is situated in a nuclear power plant needs to be carefullydesigned. Typical electronic equipment which is used for monitoring purposes within anuclear power plant facility includes a radiation tolerant camera. As the name suggests,the camera needs to be made tolerant to ionizing radiation, at least to a certain degree.ln order to achieve this protection against ionizing radiation, the camera may beencapsulated in a protective shield as described e.g. in the disclosureWO2010/114469.

The camera is often controlled from a control room which is located within thenuclear power plant. The control room is commonly situated in an area which isprotected against ionizing radiation. A control system in the control room is arrangedfor controlling the camera, e.g. for controlling optics of the camera.

The control system uses a specific type of software which is adapted to theparticular camera in use in order to control the camera. Moreover, cables whichconnect the camera to the control system are typically specific for the particular type ofcamera which is connected to the control system. Additionally, the cables may bepermanently installed within an existing construction in the nuclear power plant whichrenders the cables hard to access and which makes a rewiring of the cables difficult. ln view of the above, it may be cumbersome and expensive to install a new typeof camera, which necessitates a different type of cables and/or which utilizes anothertype of software, in an area within the nuclear power plant which has an existing wire laying as well as an existing electronic infrastructure.

SUMMARY OF THE INVENTION ln view of the above, it is therefore an object of the present inventive concept to providea cable reel which simplifies an installation of a camera, which is to be located in anionizing radiation environment, to a control system which is adapted to control thecamera. lt is a further object of the present inventive concept to provide a method formanufacturing such a cable reel.

According to a first aspect of the inventive concept, there is provided a cablereel for connecting a camera located in an ionizing radiation environment to a controlarrangement, comprising: an electronic device comprising a signal processor arranged to convert signalswhich are transmitted by the cable reel between the control arrangement and thecamera, and an ionizing radiation protective shield for protecting at least a portion of theelectronic device from ionizing radiation.

The ionizing radiation environment may be an environment in, or in the vicinityof, a nuclear power plant. ln particular, the nuclear power plant may comprise a nuclearreactor core, nuclear fuel, control rods, a moderator, a control room, spent fuel pools,etc. lt is clear, however, that other ionizing radiation environments are equallyconceivable, such as environments when decommissioning a nuclear power plant,environments related to radiotherapy, etc.

The ionizing radiation may comprise at least one of gamma radiation, X-rays,radiation with short wavelengths, alpha particles, beta particles, neutron radiation. lnthe present context, the ionizing radiation typically comes from nuclear reactions,radioactively decaying materials or subatomic particle decay.

The ionizing radiation may cause a direct or an indirect ionization.

The camera is adapted to monitor areas in the ionizing radiation environment.For example, the camera may be a radiation tolerant camera which provides amonitoring system in a nuclear power plant. The camera is preferably arranged toregister images by means of an electronic image sensor. Individual images may beregistered or alternatively moving images, e.g. in the form of video, may be registered.Thereby, an image signal or a video signal may be produced.

Moreover, the camera is preferably radiation tolerant. By way of example, thecamera may have a radiation shield for protecting the camera from ionizing radiation which might damage the operability of the camera. ln one example, the camera is stationary. The camera may be mounted on asupporting structure, such as a tripod or a bracket. ln another example, the camera isportable and may be moved to a desired area to be monitored. Specifically, the cameramay be transported to the desired area by using a camera transporting robot. ln a non-limiting example, the camera may be a RadCam camera.

Optionally, the camera may comprise a media device which includes functionsin addition to the image-capturing feature. For example, the media device may recordsound, vibrations, etc. The camera may also comprise a device for measuringenvironmental parameters, such as temperature, pressure, relative humidity, a level ofionizing radiation, etc. lt is understood that, according to an alternative embodiment,the device for measuring environmental parameters may be an independent unit,separate from the camera and connected to the monitoring system, and optionally alsoto the camera.

The control arrangement is adapted to control the camera. For example, thecontrol arrangement may be a control system which is comprised in a monitoringsystem or a control room which is located nearby the ionizing radiation environmentwhere the camera is located. The control arrangement may be shielded from theionizing radiation environment by means of an ionizing radiation protection wall. Asexplained further below, the control arrangement may be an existing control system towhich the camera is to be connected by means of the inventive camera reel forimplementing signal conversion. lt is noted that there may be additional electronic connection stations locatedbetween the control arrangement and the camera. For instance, there may be aconnection betvveen an intermediary electronic connection station, such as anintermediary box, located within the ionizing radiation environment and the controlarrangement, wherein the intermediary electronic connection station is separated fromthe control arrangement by means of the ionizing radiation protection wall whichprovides protection against ionizing radiation.

The cable reel, or cable winder, preferably comprises a cylindrical drum forstoring and winding an electrical cable for connection to the camera: a camera cable.Moreover, the cable reel may further comprise a supporting element on which thecylindrical drum is rotatably mounted and side members for counteracting lateraldisplacements of the camera cable. A cavity within a central hub of the cable reel maycontain electrical components, such as the signal processor. By means of the cablereel, the extension of the electrical cable may be varied. Thereby, the drum of the cable reel may be placed in a first area and a distal end of the camera cable may be placed in a second area. For example, the first area may have a lower intensity of ionizingradiation than the second area.

The cable reel may be comprised out a material such as a plastic or metal.Preferably, however, the material chosen so that at least a one type of ionizingradiation may be reduced. For example, by choosing a material such as a hydrocarbonplastic, a natural and synthetic rubber, or other plastics or resins containing atoms inaddition to hydrogen and carbon, the exposure from neutron radiation may be reduced.ln particular, electrical components within the central hub of the cable reel may therebybe less exposed to ionizing radiation of this type.

The signal processor of the electronic device is arranged to implement thesignal conversion. The signal processor may be a central processing unit (CPU).Moreover, the signal processor may comprise a protocol conversion unit, or a protocolconverter. The electronic device may further comprise connectors for connecting thecable reel to the control arrangement or monitoring system as well as for connectingthe cable reel to the camera. Thereby, physical components bet\Neen the camera andthe control arrangement or monitoring system may be converted or adapted to eachother.

The signaling system of the camera uses a first type of electrical interface andthe signaling system of the control arrangement uses a second type of electricalinterface. By electrical interface is here meant the electrical characteristics of a devicewhich are used for transmitting and receiving signals. The electrical characteristics maybe based on a voltage of a signal, a current of a signal, an amplitude of a signal, afrequency of a signal, a modulation of a signal, a data rate of a signal, signalstrength/signal level of a signal, data related to an optical signal, etc. ln a first example, the first and second types of electrical interfaces are thesame. ln a second example, the first and second types of electrical interfaces aredifferent. ln non-limiting examples, the first and/or the second type of electrical interfacemay be based on an RS-232 standard, an RS-422 standard, or an RS-485 standard.Alternatively, the first and/or the second type of electrical interface may be based on IPcommunication. ln another non-limiting example, the first type and/or the second typeof electrical interface may be based on the networking platform LonWorks (localoperating network).

The ionizing radiation protective shield comprises a material which may be usedto reduce the exposure to radiation. ln particular, the protective shield may be a protective shield against gamma radiation. lt is understood, however, that the protective shield also may provide protection against other types of ionizing radiation,such as neutron radiation. For instance, the protective shield may comprise twoprotective layers: one protective layer for reducing exposure to gamma radiation andone protective layer for reducing exposure to neutron radiation. The protective layer forreducing gamma radiation may be an inner protective layer and the protective layer forreducing neutron radiation may be an outer protective layer which is arranged on theoutside of the inner protective layer. ln one example, the protective shield partly surrounds the electronic device. lnanother example, the protective shield completely encloses the electronic device. ln thelatter case, the electrical connections to the electronic device may be located outside ofthe protective shield. A minimum thickness of the protective shield may be much largerthan a maximal thickness of the signal processor. ln a non-limiting example, aminimum thickness of the protective shield may be of about a few centimeters.Specifically, the minimum thickness of the protective shield may be one centimeter, twocentimeters, or five centimeters.

The protective shield preferably comprises a cavity for keeping the signalprocessor. The protective shield may comprise two parts which may be interconnectedto each other. The shape of the protective shield may be in the form of a cylinder.Alternatively, however, the protective shield may be formed as a sphere, a rectangularparallelepiped, a cone, in a frustoconical shape, etc.

Preferably, the electronic device comprised in the cable reel is connected to thecamera by means of a distal end of the camera cable comprised in the cable reel. ln anon-limiting example, the camera cable has a length of between 10 and 50 meters.Moreover, the electronic device comprised in the cable reel is preferably connected tothe control arrangement by means of a control cable. The control cable is preferablyarranged externally to the cable reel.

The cable may be adapted to communicate data in the form of image data,video data, sound data, media data, control data, information about environmentalparameters, etc.

The camera cable and the control cable may comprise a different number ofconductors, or wires. By way of example, the control cable may be multi-unit cable. Thecontrol cable may comprise a pair of conductors for each function of the camera, wherethe function may be panning or tilting of the camera, or controlling the optics of thecamera, which inter alia includes zooming, focusing and controlling the iris of thecamera. ln this example, the camera may be controlled by means of relay control.

Preferably, camera cables and control cables which are specifically adapted for use within a nuclear power plant are used. The cables may use specific materials,coverings, etc., and may be adapted for use within areas having high temperaturesand/or radioactivity.

The type of cable which are suitable to use between the camera and the controlarrangement may be an optical fiber cable, a coaxial cable, a twin wire, a data cable,an Ethernet cable, a serial cable, the cable may comprise copper, etc.

The signal to be converted preferably is an electrical signal or a data signal. Thesignal conversion may be accomplished by means of an active signal conversion.

Here and in the following, a signal which is transmitted from the controlarrangement for controlling the camera is referred to as a control signal. A controlsignal which has been converted by the signal processor and which is transmitted tothe camera is referred to as a camera signal. Moreover, a signal which is transmittedfrom the camera comprising media data, such as image data, video data or sounddata, is referred to as a media signal. Additionally, a signal which is transmitted fromthe camera comprising information as measured by means of the device for measuringenvironmental parameters, such as temperature, pressure, relative humidity, a level ofionizing radiation, is referred to as an environmental signal.

Thus, by way of example, a control signal may be converted into a camerasignal which is appropriate for the camera under consideration in order to obtaininteroperability between the camera and the control arrangement and particularly tocontrol the camera. Clearly, a signal transmitted in the opposite direction, from thecamera to the control arrangement or the monitoring system, may also have to beconverted by means of the inventive cable reel in order to obtain interoperability.

The inventive cable reel may be used when the camera and the controlarrangement utilize different signaling systems for transmitting and receiving signals. lnparticular, different protocols may be used. By a protocol is here meant a set of rulesfor providing communication. A protocol may be a data protocol, a communicationsprotocol, a network protocol, etc. The protocol may comprise a data format, schedulinginformation, error checking, data correction, data command, information about startbits, stop bits, control bits, etc. A protocol may be implemented by means of software,hardware or firmware.

The protocol may be a proprietary protocol. Alternatively, the protocol may bean industrial protocol. Moreover, the protocol may be comprised in a protocol familywherein a plurality of protocols are cooperating. ln a non-limiting example, the protocol of the camera may be a Pelco protocol or, more specifically, a Pelco-D protocol, which is a protocol used in the field of closed- circuit television (CCTV) for controlling Cameras.

Additionally, the protocol of the control arrangement may be based on anInternet Protocol (IP) and a Transmission Control Protocol (TCP), a so-called TCP/IP.Here, a control signal is in the form of a data block which may be converted by thesignal processor into a suitable camera signal.

The protocols may alternatively be based on relay control. For example, avoltage of the control signal may be converted by means of the signal processor into acamera signal for controlling the camera. A positive or a negative voltage of the controlsignal may correspond to an instruction to move the camera to the left or the right,respectively. Optionally, a magnitude of the voltage of the control signal may control aspeed of the movement.

An advantage of the present inventive concept is that an installation in anionizing radiation environment of a camera having a first type of signaling system, to acontrol arrangement with a second type of signaling system is simplified. The controlarrangement may be part of an existing monitoring system within a nuclear powerplant. lndeed, it is typically cumbersome and expensive to make a reinstallation of thenecessary electronic equipment comprised in the control arrangement and to exchangethe existing cables from the control arrangement to the camera. By means of the signalprocessor in the cable reel, the signaling systems of the camera and the controlarrangement may be easily adapted to each other. This may be particularlyadvantageous when the camera is to be connected to the existing control arrangementonly for a short period of time, e.g. when testing a new camera.

The first type of signaling system may be based on a first type of protocol andthe second type of signaling system may be based on a second type of protocol.

An additional advantage of the inventive cable reel is that it is portable.Thereby, the cable reel may easily be placed in a desired location, e.g. within theionizing radiation environment. lndeed, by means of the ionizing radiation protectiveshield, which may protect radiation sensitive electronic components comprised withinthe cable reel, the cable reel may be placed within the ionizing radiation environment.

Yet another advantage is that the length of the camera cable may easily bevaried by adapting the amount of Winding of the camera cable around the drum. Thisfact may be particularly advantageous when the camera is portable.

According to one embodiment, the signal processor is arranged to convertsignals by performing protocol conversion. A first type of protocol may be used by thecamera and a second type of protocol may be used by the control arrangement, wherein the second type of protocol is different than the first type of protocol. ln order relate the first and the second type of protocols, i.e. in order to obtaininteroperability between the camera and the control arrangement, the control signalmay be converted into a suitable camera signal by means of the signal processorwhich may comprise a protocol conversion unit. Optionally or additionally, the mediasignal from the camera may be converted by means of the signal processor.

According to one embodiment, the signals comprise camera movement controlsignals. The camera movement control signals may control a movement of the camera.The movement may be at least one of a movement related to panning or tilting thecamera, or a movement of the optics, including zooming, focusing and controlling theiris of the camera. Additionally, the movement may be a movement of a light devicewhich is mounted on or in proximity of the camera. Furthermore, the movement may bea movement of a supporting structure of the camera, e.g. a displacement or a rotationof the supporting structure.

According to one embodiment, the signals comprise at least one of imagesignals, video signals, sound signals and environmental signals, wherein theenvironmental signals comprise information about at least one of temperature,pressure, relative humidity, or a level of ionizing radiation. By means of thisembodiment, an improved monitoring of an area within the ionizing radiationenvironment may be provided. ln particular, the signals may be used for presentingimages and sound on a display and in a speaker system, respectively, comprised in themonitoring system. Additionally, the environmental signals may be used for presentingenvironmental information, e.g. in a trend diagram.

According to one embodiment, at least a portion of the ionizing radiationprotective shield is arranged in a central hub of the cable reel. The density of theprotective shield may be much larger than the density of the drum. By arranging theprotective shield in the central hub, a more well-balanced cable reel may be provided.ln particular, by adding weight to the center, the cable reel may be more stable underrotation of the drum.

According to one embodiment, the ionizing radiation protective shield comprisesat least one of lead, tungsten, and a material having a high concentration of hydrogenatoms and comprising boron. By means of lead and tungsten the electronic device maybe less exposed to gamma radiation. By means of the material having a highconcentration of hydrogen atoms and comprising boron, the electronic device may beless exposed to neutron radiation. The amount of concentration of hydrogen atoms forobtaining an acceptable reduction of neutron radiation is well-known to a person skilled in the art. lt is understood that compounds of these materials may be used. According to alternative embodiments, other materials having similar shielding properties againstionizing radiation may be used.

According to one embodiment, the electronic device comprises a first unit,which includes the signal processor and which is arranged inside the ionizing radiationprotective shield, and a second unit, which is connected to the first unit and which ismore resistant to ionizing radiation than the first unit and is located outside the ionizingradiation protective shield.

The first unit may be adapted to perform protocol conversion. The first unit maycomprise semiconductor electronic components. The first unit may be arranged on aprinted circuit card.

The second unit may comprise passive electronic components such asresistors, relays, capacitors, etc. The second unit may comprise semiconductorelectronic components. The second unit may be arranged on a printed circuit card. Apower supply may be connected to the second unit for driving the first and the secondunit. lt is understood that the second unit also may assist in performing the protocolconversion.

At least a portion of the second unit may be arranged on an outside of saidcable reel.

An advantage of the present embodiment is that only some parts of theelectronic device need to be protected by a protective shield. Thereby, less material forthe protective shield may be needed, which may reduce material costs and also maygive rise to a smaller weight of the protective shield, and consequently the cable reel. Asmaller weight may also imply a cable reel which is more easily rotated, transportedand operated.

The first unit is preferably smaller that the second unit. lndeed, by making thefirst unit small, less material for the protective shield may be needed.

According to an alternative embodiment, the ionizing radiation protection shieldencloses the first unit as well as the second unit.

According to one embodiment, the electronic device further comprises anelectronic connector element for adapting electronic equipment of the controlarrangement to electronic equipment of the camera. The electronic equipment of thecontrol arrangement may be existing electronic equipment to which the electronicequipment of the camera needs to be adapted.

More specifically, the electronic device may comprise a first signal adaptationunit for adapting an electrical interface of the control arrangement to an electrical interface of the signal processor. Further, the electronic device may comprise a second signal adaptation unit for adapting the electrical interface of the signal processor to anelectrical interface of the camera. The signal adaptation units may comprise filters,transformers, etc. Moreover, the electronic device may comprise bus communicationsystems, storage devices, etc.

The first and the second signal adaptation units may be comprised in thesecond unit.

According to an alternative embodiment, the electronic device and the ionizingradiation protective shield form a conversion module which is interchangeable. A firstconversion module may be changed into a second conversion module having adifferent electronic device and/or ionizing radiation protective shield. ln particular, theelectronic device of the second conversion module may comprise a different signalprocessor than the electronic device of the first conversion module.

Occasionally, the ionizing radiation environment where the cable reel may belocated may become very hot. Therefore, according to yet an alternative embodiment,at least a portion of the cable reel is connected to a cooling element. The connectionbetween the cable reel and the cooling element may be a thermal connection. Thecooling element may include a thermoelectric cooling module, such as a module usingthe Peltier effect. By means of the cooling element, heat from the cable reel, and inparticular the electronic device comprised in the cable reel, may be efficientlydissipated. Thereby, deterioration of the cable reel may be counteracted and,additionally, shielding from the ionizing radiation may be improved.

According to one embodiment, there is provided a camera arrangement for usein an ionizing radiation environment comprising a cable reel and a camera, wherein thecamera is connected to a cable of the cable reel. The cable may be the camera cable.The electronic device of the cable reel preferably comprises a signal processor which isadapted to the signaling system of the camera.

According to one embodiment, there is provided a camera system comprisinga camera arrangement and a control arrangement located outside the ionizing radiationenvironment, wherein the control arrangement is connected to the cable reel. Theelectronic device of the cable reel preferably comprises a signal processor which isadapted to relate the signaling system of the control arrangement with the signalingsystem of the camera. Moreover, an ionizing radiation protection wall may be locatedbetween the camera and the control arrangement for protecting the controlarrangement from radiation.

According to a second aspect of the invention there is provided a method for manufacturing a cable reel, comprising: providing a drum, providing a Conversion module comprising an ionizing radiation protective shieldand a signal processor which is adapted to perform signal conversion of signals to betransmitted to the cable reel, and which is arranged within the ionizing radiationprotective shield, and connecting the conversion module to the drum.

The details and advantages of the second aspect of the invention are largelyanalogous to those of the first aspect of the invention, wherein reference is made to theabove. ln addition, it is noted that the conversion module is preferably chosen as toprovide a suitable signal conversion between a given camera having a first type ofsignaling system and a given control arrangement having a second type of signalingsystem.

Moreover, the conversion module may be adapted to be interchangeable. Theinterchangeability may be implemented by means of an easy and quick connectionfitting between the conversion module and a receiving cavity in the cable reel, such asthe central hub of the cable reel. For instance, the conversion module may therebyeasily be replaced when the signal processor or some other device comprised in themodule is defective or when the cable reel is to be used for a different type of signalconversion.

According to one embodiment, the connecting comprises arranging at least aportion of the conversion module in a central hub of the drum.

According to one embodiment, the providing an conversion module comprisesselecting the conversion module out of a plurality of modules, wherein the plurality ofmodules comprise signal processors which are adapted to perform different signalconversions. Each module may be adapted for signal conversion between differenttypes of cameras and control arrangements. This embodiment implements theinterchangeability of modules as described above.

By a radiation tolerant device or a radiation resistant device, such as a cameraor a radiation tolerant electronic component, is here meant that the device is tolerant orresistant to radiation for at least a minimum period of time. ln non-limiting examples,the minimum period of time may be a month, a year, five years or ten years.

By a radiation sensitive device, such as a radiation sensitive electroniccomponent, is here meant that the device runs the risk of being damaged under theminimum period of time referred to above, which potentially may lead to amalfunctioning of the device.

The term ”signals” as used herein is to be interpreted in a wide sense and 11 should not be limited. The signals are preferably electrical. Moreover, the signals maybe analog or digital. The signals transmitted from the control arrangement may bereceived by the camera for controlling the camera. Signals transmitted from thecamera, such as recorded media signals, environmental signals, may be received bythe monitoring system.

The term ”connected” with respect to etc. is to be construed as “electricallyconnected” unless a different meaning is clear from the context.

The term “between the control arrangement and the camera” as used above isto be interpreted in a wide sense and should not be limited. ln a first example, thesignals are transmitted from the control arrangement and are received by the camera.ln a second example, the signals are transmitted from the camera and are received bythe monitoring system. ln a third example, signals are transmitted from the camera andthe control arrangement simultaneously, which may be received by the monitoringsystem and camera, respectively.

Generally, all terms used in the claims are to be interpreted according to theirordinary meaning in the technical field, unless explicitly defined otherwise herein. Allreferences to "a/an/the [element, device, component, means, step, etc]" are to beinterpreted openly as referring to at least one instance of said element, device, component, means, step, etc., unless explicitly stated othenNise.

BRIEF DESCRIPTION OF THE DRAWINGS The above, as well as additional objects, features and advantages of the presentinvention, will be better understood through the following illustrative and non-limitingdetailed description of preferred embodiments of the present invention, with referenceto the appended drawings, where the same reference numerals will be used for similarelements, wherein: Fig. 1 schematically illustrates a perspective view of an embodiment of theinventive cable reel according to the present inventive concept.

Fig. 2 schematically illustrates the cable reel according to Fig. 1, wherein a firstcircular side member has been separated from the rest of the cable reel.

Fig. 3 is an exploded view of the cable reel in Fig. 1, wherein the main partscomprised in the cable reel are illustrated.

Fig. 4 is a schematic diagram of some electronic components comprised in the 12 electronic device of the cable reel in Fig. 1, including connections to a control systemand a camera.

Fig. 5 is a schematic diagram of an embodiment of a camera system comprisinga camera, a cable reel and a control arrangement.

Fig. 6 is a block diagram illustrating an embodiment of a method for manufacturing a cable reel according to the present inventive concept.

DETAILED DESCRIPTION OF PREFERRED E|\/|BOD||\/IENTS Next, an embodiment of the inventive cable reel Will be described With reference toFigs. 1-3. As schematically illustrated in Fig. 1, which is a perspective view of anembodiment of the inventive cable reel, the cable reel 100 comprises a cylindrical drum110, a first circular side member 120, a second circular side member 130, a supportingelement 140, and a camera cable 150 which is adapted to be connected to a camera.Fig. 2 schematically illustrates the cable reel according to Fig. 1, wherein the firstcircular side member 120 has been separated from the drum 110. ln Fig. 2 it is seenthat the cable reel 100 further comprises an electronic device 200 which in a mountedstate is arranged within a central hub 118 of the cylindrical drum 110.

The cylindrical drum 110 is adapted for storing and winding the camera cable150. ln Figs. 1-3, the camera cable 150 is shown in an unwounded state, but it is clearthat the camera cable 150 may be winded and stored on the cylindrical drum 110. lnparticular, once the camera cable 150 is fixed to the drum 110, it may be winded on asurface 115 of the cylindrical drum 110 by rotating the drum 110 and the first 120 andsecond 130 side members. According to the present embodiment, the camera cable150 does not have any additional protection against ionizing radiation.

The cylindrical drum 110 comprises a first cylindrical drum member 112 and asecond cylindrical drum member 113. The first 112 and second 113 drum members arearranged in locking abutment with each other to form the smooth cylindrical surface115. The first 112 and second 113 drum members each have annular cross sections,Whereby there are cavities within them for arrangement of electronic equipment, suchas the electronic device 200. The central hub 118 of the cylindrical drum 110 comprisesthese cavities. The first drum member 112 is provided with a circular hole (not shown)in its surface 115 for leading through the camera cable 150 into its interior, within thecavity.

The first circular side member 120 is releasably engaging with an annular top 13 portion 114 of the first drum member 112. The first Circular side member 120 mayengage with the annular top portion 114 by means of tight-fitting, snapping, screwing,or similarly. Moreover, the first circular side member 120 comprises a control systemconnector 122, or control arrangement connector 122. The control system is adapted tocontrol the camera and the control system connector 122 is adapted to receive acontrol cable which is connected to the control system. This will be explained more indetail further below.

The second circular side member 130 is permanently attached to an annularbottom portion 116 of the second drum member 113. Moreover, it comprises a centralattachment device (not shown) for rotational engagement with a protruding element(not shown) of the supporting element 140.

The first 120 and second 130 circular side members serve at least a dualpurpose. Firstly, they may be used when rotating the cylindrical drum 110 for windingor unwinding the cable 150. Secondly, they may be used for supporting the cameracable 150, preventing lateral displacements of the cable 150 beyond the circular sidemembers 120, 130. lt is noted that the first 112 and second 113 drum members may comprisehydrocarbon plastics (such as polyethylene, polypropylene and polystyrene), naturaland synthetic rubber (such as silicone rubber), and other plastics or resins containingatoms in addition to hydrogen and carbon (such as acrylic, polyester, polyurethanesand vinyl resins). These organic polymers show a high effectiveness of shieldingagainst neutrons due to a high concentration of hydrogen atoms in these materials.Fast neutrons that are slowed down by repeated collisions with light nuclei formthermal neutrons that can be absorbed by nuclear reactions. The total neutronshielding ability of polyethylene may be improved by adding to it a material having ahigh thermal neutron absorbing capacity. A suitable thermal neutron absorbing materialmay be e.g. boron. Thereby, a protective cover against neutron radiation may beprovided by the drum 110.

The first 120 and second 130 circular side members may be made out of a rigidmaterial, such as a plastic material, or metal.

As seen in Fig. 1, the supporting element 140 comprises two elongated legs142, 144 for rigidly supporting the cable reel 100 against a supporting ground such as afloor in a nuclear power plant. Furthermore, the supporting element 140 comprises ahandle 146 for carrying the cable reel 100.

Fig. 3 is an exploded view of the cable reel in Fig. 1, wherein the main parts comprised in the cable reel 100 are illustrated. lt is understood that in a mounted state 14 of the cable reel 100, the parts are assembled together as in Fig. 1.

The electronic device 200 comprises a first unit 210 and a second unit 220which in a mounted state are connected to each other by means of wires 212. Thewires 212 may be part of a ribbon cable. According to the present embodiment, thewires 212 are not encapsulated by a shield against ionizing radiation.

The first unit 210 comprises a first printed circuit board, PCB board, withsemiconductors which are sensitive to ionizing radiation. The first PCB boardcomprises a signal processor in the form of a CPU 218 and is provided with wires 212for connection to the second unit 220. The CPU 218 is adapted to perform protocolconversion. ln a mounted state, the first unit 210 is arranged in a recess 233 Which isprovided in a carrier 232. Moreover, in a mounted state, a cover 234 tightly fits aroundthe carrier 232. The carrier 232 and the cover 234 provide an ionizing radiationprotective shield 230 for protecting the first PCB board from ionizing radiation in theform of gamma radiation, cf. Fig. 4. For example, the carrier 232 and the cover 234may comprise lead or tungsten. The cover 234 comprises an aperture 236 for leadingthe wires 212 through the cover 234, thereby providing an outside connection to thefirst unit 210 which is enclosed in the ionizing radiation protective shield 230. Anextension of the cylindrically shaped ionizing radiation protective shield 230 in an axialdirection is four centimeters and a diameter of a circular cross-section of the protectiveshield 230 is ten centimeters.

According to an alternative embodiment, the wires 212 may be arranged in a“staircaselike” shape, e.g. by being sandwiched bet\Neen an outer surface of the carrier232 and an inner surface of the cover 234, for reducing the exposure to radiation andfor leading out the wires 212 from the first unit 210.

According to the present embodiment, the first unit 210 together with theionizing radiation protective shield 230, including the carrier 232 and the cover 234,forms a cylindrically shaped conversion module 240. The conversion module 240 isindicated by a box with broken lines in Fig. 3. Afirst conversion module 240 comprisinga first CPU may be interchanged with a second conversion module 240 comprising asecond CPU, wherein the first and the second CPU:s are adapted for different types ofsignal conversions. lncidentally, it is noted that according to an alternative embodiment, also thesecond unit 220 may be comprised in the conversion module.

The second unit 220 comprises a second PCB board with semiconductors which are more tolerant to ionizing radiation than the first PCB board. Therefore, the second unit 220 does not need any additional ionizing radiation protective shield 230against gamma radiation. As explained above, the second unit 220 is connected to thefirst unit 210 by means of the wires 212. Furthermore, in a mounted state the secondunit 220 is connected to camera cable 150 which has been lead through a circular holein the surface of the first drum member 112. Additionally, the second unit 220 isconnected to the control system connector 122. Preferably, a power supply (not shown)is connected to the second unit 220 for driving the first 210 and second 220 unit. lt is stressed that there are two kinds of ionizing radiation protective shieldsaccording to the present embodiment.

The inner ionizing radiation protective shield 230 which is formed by the carrier232 and the cover 234 reduces the exposure to gamma radiation to the first unit 210.

The outer ionizing radiation protective shield, which is formed by the cylindricaldrum 110, reduces the exposure to neutron radiation to the first unit 210 as well as thesecond unit 220.

Fig. 4 is a schematic diagram of some electronic components comprised in theelectronic device 200 of the cable reel 100 in Fig. 1. As detailed above, the electronicdevice 200 comprises a first unit 210 and a second unit 220.

The second unit 220 is connected to a control system by means of a controlcable 160 and to a camera by means of a camera cable 150. The connections to thecontrol system and the camera will be described further below. The camera utilizes afirst type of protocol and the control system utilizes a second type of protocol. Bymeans of the electronic device 200 comprised in the cable reel 100, control signalsbased on the second protocol may be converted into camera signals based on the firstprotocol.

The second unit 220 comprises a first signal adaptation unit 222 which providesadaptation between an electrical interface of the control system and an electricalinterface of the first unit 210. The second unit 220 further comprises a second signaladaptation unit 224 which provides adaptation between the electrical interface of thefirst unit 210 and the camera. The first 222 and second 224 signal adaptation units maycomprise electronic components according to well-known techniques for a personskilled in the art. For example, the signal adaptation unit 222, 224 may compriseelectronic components such as filters, transformers, etc.

The first unit 210 comprises a bus receiver 214, a bus driver 216 and a signalprocessor in the form of a CPU 218. The bus receiver 214 is connected to the firstsignal adaptation unit 222 by means of conductors 226, and is also connected to theCPU 218. Moreover, the bus driver 216 is connected to the CPU 218 and also to the 16 second signal adaptation unit 224 by means of conductors 228. The conductors 226and 228 are comprised in the ribbon cable 212.

The first unit 210 is encapsulated by means of the ionizing radiation protectiveshield 230, which is indicated by a dashed line in Fig. 4. Reference to the above ismade for a more detailed explanation of the ionizing radiation protective shield 230.

Reference is now made to Fig. 5, which is a schematic diagram of anembodiment of a camera system comprising a camera 300 and a monitoring system400 which are connected to each other by means of the cable reel 100. The monitoringsystem 400 may be a control room.

According to the present embodiment, the monitoring system 400 is an existingsystem to which the camera 300 is to be connected.

The camera 300 is located in an ionizing radiation environment 700 within anuclear power plant. ln operation, the camera 300 is monitoring and recording aprocess related to an apparatus 600 which is a source of ionizing radiation R. lt isnoted that the cable reel 100 is located further away from the apparatus 600 than thecamera 300, which means that the cable reel 100 is less exposed to ionizing radiation.More specifically, the drum 110 of the cable reel 100 is located in a first radiation area702, and a distal end 152 of the camera cable 150 is located in a second radiation area704, wherein the first radiation area 702 is less exposed to ionizing radiation than thesecond radiation area 704. The separation between the first 702 and the second 704radiation areas are indicated by the broken vertical line in Fig. 5.

The camera 300 records images and sounds and thereby produces a mediasignal which is adapted to be transmitted to the monitoring system 400. Additionally,environmental signals may be produced and transmitted to the monitoring system 400.Moreover, the camera 300 is connected to the cable reel 100 by means of the cameracable 150.

The monitoring system 400 is located in an area 800 which is outside of theionizing radiation environment 700. More specifically, the monitoring system 400 islocated behind an ionizing radiation protection wall 500 which reduces the exposure ofionizing radiation to the monitoring system 400. The monitoring system 400 isconnected to an existing intermediary box 430 which is located within the ionizingradiation environment 700 by means of a penetration cable 170 which is penetratedthrough the ionizing radiation protection wall 500 in a hole. The intermediary box 430 isconnected to the cable reel 100 by the control cable 160.

The monitoring system 400 comprises a control system 410 for controlling the camera 300 and a receiving system 420. The receiving system 420 receives the media 17 signal and processes and stores the data from the media signal. The receiving system420 includes a display screen and a speaker for presenting the images and soundsrecorded by the camera.

The control system 410 may control the camera 300 by transmitting a controlsignal in the penetration cable 170, via the intermediate box 430, and further on to thecable reel 100 in the control cable 160. As explained in the above, the control signal isconverted in the cable reel 100 and is then transmitted to the camera 300 as a camerasignal. Reference is also made to the above as how the camera 300 may be controlled.ln particular, the camera 300 utilizes a first type of protocol while the monitoring system400, including the control system 410, utilizes a second type of protocol. Thus, in orderto allow for communication between the monitoring system 400 and the camera 300,the first and second types of protocols need to be related. This is achieved by means ofprotocol conversion executed by the CPU comprised in the cable reel 100.

Each of the cables 150, 160 and 170 may comprise a plurality of conductors forproviding communication between the monitoring system 400 and the camera 300. Thecables 150, 160 and 170 may allow for two-way communication, whereby on the onehand the control signal may be transmitted to the camera 300 from the control system410, and on the other hand the media signal may be transmitted to the receivingsystem 420 from the camera 300. ln one example, the two-way communication may beimplemented by using one camera cable 150, one control cable 160 and onepenetration cable 170. ln another example, the two-way communication may beimplemented by using a plurality of camera cables, control cables and penetrationcables. ln the latter example, communication in a first direction may be implemented bya first set of cables, and communication in a second direction, opposite to the firstdirection, may be implemented by a second set of cables.

According to the present embodiment, the cable reel 100 is connected to acooling element 190 which is used for dissipating heat from the cable reel 100 and itscomponents. The cooling element 190 comprises a thermoelectric cooling module.lt is understood, however, that other cooling elements 190 may be used for cooling thecable reel 100, such as conventional air and/or fluid systems.

Fig. 6 is a block diagram illustrating an embodiment of a method 900 formanufacturing a cable reel according to the present inventive concept.

First, a cylindrical drum 110 which is arranged on a supporting element 140 isprovided (Box 910). The drum 110 comprises a central hub 118 in which there is acavity. Moreover, a second circular side member 130 is permanently attached to an annular bottom portion 116 of the drum 110. 18 Then an ionizing radiation protective shield 230 and a signal processor in theform of a CPU 218 are provided (Box 920). The CPU 218 may be comprised in a firstunit 210 as explained above. The first unit 210 may further comprise a bus receiver 214and a bus driver 216 which are connected according to the above. Thereafter, aconversion module 240 is formed by arranging the first unit 210, comprising the CPU218, as well as a second unit 220 which is connected to the first unit 210 by means of aribbon cable, within the ionizing radiation protective shield 230 (Box 930). As explainedabove, the second unit 220 may comprise electronic components which are moretolerant to ionizing radiation that electronic components comprised within the first unit210.

The conversion module 240 is subsequently connected to the drum 110 byarranging it in the central hub 118 (Box 940). Next, the second unit 220 is connected tothe camera cable 150 which is led through a circular hole in the surface of the drum110.

Finally, the method according to the present embodiment comprises arrangingthe first circular side member 120 on an annular top portion 114 of the drum 110,thereby sealing the interior of the drum 110 from the outside. The first circular sidemember 120 comprises a control system connector 122 for connection to the controlsystem 410.

The invention has mainly been described above with reference to a fewembodiments. However, as is readily appreciated by a person skilled in the art, otherembodiments than the ones disclosed above are equally possible within the scope ofthe invention, as defined by the appended patent claims. For example, the order of thesteps comprised in the manufacturing method may be varied. Also, the conversionmodule in the described manufacturing method above may include only the first unit and the ionizing protective shield, excluding the second unit. 19

Claims

CLA||\/IS

1. A cable reel for connecting a camera located in an ionizing radiation environment to a control arrangement, comprising: an electronic device comprising a signal processor arranged to convert signalswhich are transmitted by the cable reel between said control arrangement and saidcamera, and an ionizing radiation protective shield for protecting at least a portion of said electronic device from ionizing radiation.

2. A cable reel according to claim 1, wherein said signal processor is arranged to convert signals by performing protocol conversion.

3. A cable reel according to any of claims 1 to 2, wherein said signals comprise camera movement control signals.

4. A cable reel according to any of claims 1 to 3, wherein said signalscomprise at least one of image signals, video signals, sound signals and environmentalsignals, wherein the environmental signals comprise information about at least one of temperature, pressure, relative humidity, or a level of ionizing radiation.

5. A cable reel according to any of the preceding claims, wherein at least aportion of said ionizing radiation protective shield is arranged in a central hub of said cable reel.

6. A cable reel according to any of the preceding claims, wherein said ionizingradiation protective shield comprises at least one of lead, tungsten, and a material having a high concentration of hydrogen atoms and comprising boron.

7. A cable reel according to any of the preceding claims, wherein saidelectronic device comprises a first unit, which includes said signal processor and whichis arranged inside said ionizing radiation protective shield, and a second unit, which isconnected to the first unit and which is more resistant to ionizing radiation than the first unit and is located outside the ionizing radiation protective shield.

8. A cable reel according to any of the preceding claims, wherein said electronic device further comprises an electronic connector element for adapting electronic equipment of said control arrangement to electronic equipment of said Camera.

9. A camera arrangement for use in an ionizing radiation environmentcomprising:a cable reel according to any of the preceding claims, anda camera, wherein said camera is connected to a cable of said cable reel.

10. A camera system comprising:a camera arrangement according to claim 11, anda control arrangement located outside said ionizing radiation environment, wherein said control arrangement is connected to said cable reel.

11. A method for manufacturing a cable reel, comprising:providing a drum,providing a conversion module comprisingan ionizing radiation protective shield anda signal processor which is adapted to perform signal conversionof signals to be transmitted to the cable reel and which is arranged within saidionizing radiation protective shield, and connecting said conversion module to said drum.

12. A method according to claim 11, wherein said connecting comprises arranging at least a portion of said conversion module in a central hub of said drum.

13. A method according to claim 11 or 12, said providing a conversion modulecomprises selecting the conversion module out of a plurality of modules, wherein saidplurality of modules comprise signal processors which are adapted to perform different signal conversions. 21