Abstract:
An enhanced method and apparatus are provided for tracking and managing a plurality of packagings, particularly packagings containing radioactive and fissile materials. A radio frequency identification (RFID) surveillance tag is provided with an associated packaging. The RFID surveillance tag includes a tag body and a back plate including predefined mounting features for mounting the surveillance tag to the associated packaging. The RFID surveillance tag includes a battery power supply. The RFID surveillance tag includes a plurality of sensors monitoring the associated packaging including a seal sensor. The seal sensor includes a force sensitive material providing a resistivity change responsive to change in a seal integrity change of the associated packaging. The resistivity change causes a seal integrity tag alarm. A tag memory stores data responsive to tag alarms generated by each of the plurality of sensors monitoring the associated packaging.

Description:
[0001]    This application claims the benefit of U.S. Provisional Application No. 61/086,698 filed on Aug. 6, 2008. 
     
    
     CONTRACTUAL ORIGIN OF THE INVENTION 
       [0002]    The United States Government has rights in this invention pursuant to Contract No. W-31-109-ENG-38 between the United States Government and The University of Chicago and/or pursuant to Contract No. DE-AC02-06CH11357 between the United States Government and UChicago Argonne, LLC representing Argonne National Laboratory. 
     
    
     FIELD OF THE INVENTION  
       [0003]    The present invention relates to an improved method and apparatus for tracking and managing a plurality of packagings, particularly packagings containing radioactive and fissile materials. 
       DESCRIPTION OF THE RELATED ART  
       [0004]    Management of multiple, such as thousands of packagings of radioactive and fissile materials, in storage, transportation and disposal is a serious challenge for United States Department of Energy (DOE) to ensure accountability, safety, security, worker and public health, and protection of the environment. Many know arrangements for inventory and quality control typically utilize paper and file systems, resulting in labor-intensive operations and often less-than-effective data management. 
         [0005]    U.S. Pat. Nos. 5,640,151 and 5,686,902 to Reis et al., and assigned to Texas Instruments Incorporated, disclose a communication system for identifying, locating, tracking and communicating for other purposes with large numbers of tags in a time and energy efficient manner. The tags are associated with items located in a communication region that is interrogated by an interrogator on a one-to-many basis using broadcast commands, on a one-to-one basis using directed commands or on a combination basis using both methods. Identification occurs through organized transmission and reception of signals between the tags and the interrogator. A batch collection protocol uses a combined one-to-many and one-to-one communication system that effectively resolves communication contentions. The batch collection protocol employs a plurality of collection periods, which communicate with large or unknown numbers of portable tags. 
         [0006]    Radio frequency identification (RFID) is one of today&#39;s most rapidly growing technologies in the automatic data collection industry. RFID technology allows objects to be automatically identified by means of radio waves. An RFID system generally consists of tags and readers. The tags are attached to the objects to be identified, and the reader communicates with the tags through radio waves. Examples of pervasive RFID applications are traffic toll collection, access control, cargo container monitoring for the military, and inventory control in the pharmaceutical industries. Passive RFID tags, which do not contain an onboard power supply or environmental sensor capabilities, are often used to replace barcode labels in retail, pharmaceutical, and military environments. 
         [0007]    Principal objects of the present invention are to provide an improved method and apparatus for tracking and managing a plurality of packagings, particularly packagings containing radioactive and fissile materials. 
         [0008]    Important aspects of the present invention are to provide such method and apparatus substantially without negative effect and that overcome some of the disadvantages of prior art arrangements. 
       SUMMARY OF THE INVENTION  
       [0009]    In brief, an improved method and apparatus are provided for tracking and managing a plurality of packagings, particularly packagings containing radioactive and fissile materials. A radio frequency identification (RFID) surveillance tag is provided with an associated packaging. The RFID surveillance tag includes a tag body and a back plate including predefined mounting features for mounting the surveillance tag to the associated packaging. The RFID surveillance tag includes a battery power supply. The RFID surveillance tag includes a plurality of sensors monitoring the associated packaging including a seal sensor. The seal sensor includes a force sensitive material providing a resistivity change responsive to change in a seal integrity change of the associated packaging. The resistivity change causes a seal integrity tag alarm. A tag memory stores data responsive to tag alarms generated by each of the plurality of sensors monitoring the associated packaging. 
         [0010]    In accordance with features of the invention, the RFID surveillance tag is adapted for extended use in an environment of radioactive and fissile materials. 
         [0011]    In accordance with features of the invention, the seal sensor has no active components, and its operation exerts essentially no load on the battery power supply. 
         [0012]    In accordance with features of the invention, the battery power supply includes multiple batteries, and a battery management function to extend the service period between battery changes. For example, the RFID surveillance tag includes four A-size Li—SOCl 2  batteries are installed, with only one battery activated at any time. The battery management function monitors a current battery being used, and automatically switches to a next battery when the current battery is discharged. 
         [0013]    In accordance with features of the invention, a low battery status sensor triggers a warning responsive to a low-battery state for the operator to take action. The tag memory is nonvolatile so that a low-battery state will not result in a loss of data. 
         [0014]    In accordance with features of the invention, the back plate includes a predefined shape selectively provided for mounting with the associated packaging, and the tag body includes a universal form for use with multiple different types of the associated packaging. The selected configuration of the back plate enables simple modifications to provide different configurations and packagings. To reduce the likelihood of unintentional bumping and impact during handling of drums, the RFID surveillance tag has a slim profile that fits within the footprint of a drum cover of the associated packaging. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0015]    The present invention together with the above and other objects and advantages may best be understood from the following detailed description of the preferred embodiments of the invention illustrated in the drawings, wherein: 
           [0016]      FIG. 1  is a schematic and block diagram representation of an exemplary radio frequency identification (RFID) surveillance tag in accordance with the preferred embodiment; 
           [0017]      FIG. 2  is a schematic and block diagram representation of an exemplary battery power supply and battery management function of the radio frequency identification (RFID) surveillance tag of  FIG. 1  in accordance with the preferred embodiment; 
           [0018]      FIG. 3  schematically illustrates not to scale an example radio frequency identification (RFID) surveillance tag of  FIG. 1  mounted on an associated packaging, for example, containing radioactive and fissile materials in accordance with the preferred embodiment; 
           [0019]      FIG. 4  schematically illustrates the exemplary radio frequency identification (RFID) surveillance tag of  FIG. 3  with a metal back plate removed illustrating interior details in accordance with the preferred embodiment; 
           [0020]      FIG. 5  schematically illustrates not to scale another example radio frequency identification (RFID) surveillance tag of  FIG. 1  in accordance with the preferred embodiment; 
           [0021]      FIG. 6  illustrates an exemplary metal back plate of the radio frequency identification (RFID) surveillance tag of  FIG. 5  in accordance with the preferred embodiment; 
           [0022]      FIGS. 7 and 8  are front and side views schematically illustrating another exemplary metal back plate of the radio frequency identification (RFID) surveillance tag of  FIG. 3  in accordance with the preferred embodiment; and 
           [0023]      FIG. 9  schematically illustrates not to scale another example radio frequency identification (RFID) surveillance tag of  FIG. 1  in accordance with the preferred embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]    In accordance with features of the invention, a radio frequency identification (RFID) surveillance tag is provided to supplement existing safeguard measures and provide real-time alarm when preset thresholds are exceeded. Active RFID surveillance tags of the invention are distinct from passive RFID tags as they are equipped with an onboard power supply as well as sensors for monitoring environmental conditions and other critical parameters, such as the status of seals and object movement. 
         [0025]    Advantages of the application of active RFID surveillance tags of the invention in nuclear materials management are enhanced safety and security, reduced need for manned surveillance, real-time access of status and history data, and overall cost-effectiveness. The RFID surveillance tags of the invention are adapted to provide adequate resistance to radiation and battery life under service conditions that include storage and transportation of radioactive materials containers. 
         [0026]    Having reference now to the drawings, in  FIG. 1  there is shown an exemplary RFID surveillance tag of the invention generally designated by the reference character  100 . RFID surveillance tag  100  includes an RFID transponder  102 , a plurality of sensors  104  and control logic functions  106  coupled to a sensor memory  108  and a central processing unit  110 . A user memory  112 , and a system memory  114  are connected to the CPU  110 . The CPU  110  is connected to and operatively controls the RFID transponder  102 . RFID surveillance tag  100  includes a battery power supply source  116  including a battery management function  118  in accordance with the preferred embodiment. RFID surveillance tag  100  includes a tag body  120  or housing  120  further illustrated and described with respect to  FIGS. 3 ,  4 ,  5 , and  9 . RFID surveillance tag  100  includes an antenna  122 , such as a patch antenna  122 , for example, as further illustrated and described with respect to  FIG. 5 , that optionally is wider and longer than the tag body  120 . 
         [0027]    In accordance with features of the invention, the multiple sensors  104  of the RFID surveillance tag  100  includes a seal sensor  124  to ensure safety, security, and life cycle management of an associated fissile material packaging, such as a fissile material packaging  302 , for example, as further illustrated and described with respect to  FIG. 3 . The seal sensor  124  is adapted for bolt attachment to an associated fissile material packaging, such as a fissile material packaging  302  with a supporting back plate, such as supporting back plate  304  illustrated and described with respect to  FIG. 3 . 
         [0028]    U.S. Pat. No. 5,222,399 to Kropp issued Jun. 29, 1993 discloses a load washer comprising a pair of thin metal washers between which a contact sensor is positioned. The contact sensor includes pairs of confronting electrodes at a plurality of spaced zones with a pressure sensitive resistive material between each pair, which, under pressure, provide an indication of the force applied to the load washer. The seal sensor  124  advantageously is implemented with a load washer and contact sensor as disclosed in U.S. Pat. No. 5,222,399. 
         [0029]    The subject matter of the above-identified U.S. Pat. No. 5,222,399 is incorporated herein by reference. 
         [0030]    The multiple sensors  104  of the RFID surveillance tag  100  optionally further includes a radiation dosimeter sensor  126 , a humidity sensor  128 , a temperature sensor  130 , a shock sensor  132 , a battery status sensor  134 , and a global positioning sensor (GPS)  136 . The condition of low-battery status detected by battery status sensor  134  triggers a warning for the operator to take action to replace the battery power supply  116 . The humidity sensor  128 , temperature sensor  130 , and shock sensor  132  can be implemented with temperature, humidity, and shock sensors of the type available in a commercially available device ST-676, manufactured and sold by Savi Technology Corporation. See http://www.savi.com/index.shtml. By a judicious selection of the trip points, these sensors  128 ,  130 ,  132  provide valuable data to the surveillance effort during all operational phases of nuclear materials management. For instance, the threshold of shock sensor  132  may be set high for the drum transport, and reset low for the storage to trigger an alert with the slightest movement. Because all sensor actions are recorded in memory  108 , a life-long history is automatically created for every associated drum and is instantly retrievable by the operator. A compact radiation dosimeter sensor  126  is provided for the RFID surveillance tag  100 . 
         [0031]    Radio frequency identification (RFID) transponder  102  advantageously is used for automatic data collection with the RFID surveillance tag  100  because it is not an optical technology, no inherent line of sight is required between a reader  140  and a tagged RFID object. In addition, the RFID tags  100  transmits data wirelessly and is a read-write technology, so RFID tags  100  can update or change the data encoded in the tag  100  during the tracking cycle. The reader  140  can be implemented with a Signpost SR-650 reader including ultrahigh frequency, 433 MHz operations so that the tags  100  can be read up to 90 m away in line-of-sight. Using the Signpost low frequency, 123 kHz operations that primarily serves as a portal, the tags  100  have a read range up to 2.5 m. Both ranges can be reduced by adjusting the RF power level. A potential application of this feature is confining the RF communication inside a predefined region, for example, a portion of a vault or a truck, to enhance security. 
         [0032]    An application software resident on a host desktop or handheld computer  142  consisting of three key components: a Graphical User Interface, a feature set, and an underlying software architecture, is provided with the RFID system including multiple RFID surveillance tags  100 . The host computer  142  with the resident computer software receives signals from the readers  140  and the tags  100  filters the data for duplicate or erroneous reads, applies rules-based business logic, and presents the data to the user in an easy-to-understand way. The user is also able to control and program the readers and the tags by sending commands to them through the software. For example, the software can allow the user to change sensor thresholds on a tag or to modify beaconing rates. The software can also store the information in a database for archiving or sharing the information with remote users through a secure network. Once set up, the software can work with the readers and the tags autonomously, requiring no human intervention. 
         [0033]    Host computer  142  includes a user-friendly Graphical User Interface to present all relevant information in an intuitive way on the console screen (not shown) so that the user can take immediate actions based on the information presented. The user should be able to retrieve all pertinent information easily by instructions provided with a few mouse clicks. For example, the user can click on a specific region in a display to zoom in and, when a drum status becomes abnormal, the symbol turns to yellow (warning) or flashing red (alarm). As the drums may be stacked in storage, the user can select and view the stacked drums in the side-view pane on the right of the screen. By clicking on a drum, the detailed information of the drum, including its environmental conditions and battery status, is displayed in a pop-up window. Also the display includes a current status pane, a history event pane, and a search pane. 
         [0034]    Host computer  142  includes a feature set capable of monitoring thousands of drums simultaneously. If the status of any drum becomes abnormal, the software will bring the user&#39;s attention to the situation immediately by triggering an alarm, which, depending on facility provisions, could be a siren, flashing lights, and/or signals sent to the responsible protective force. At the console (not shown), the operator or security personnel will see a flashing red symbol on the screen, with the cause of the alarm highlighted. The software also provides a convenient interface for the user to send commands to the readers  140  and the tags  100 . These commands include changing the alarm thresholds of the environmental sensors, resetting the alarm state after the corrective actions, updating the drum locations after movements, reading the history file from the tag memory, and searching for specific drums. Some command functions are only available to a system administrator for security and logistic reasons. 
         [0035]    Host computer  142  includes software that automatically records in the computer database all the information retrieved from the tags  100  and commands sent to the tags  100 . It also routinely reads the inventory and history files from the tag memory and compares them to the record in the database to guarantee data integrity. The database can be made compatible to the existing systems at each storage site. Privileged remote users can access the data through a secured network. A search function is extremely useful for the inventory management, especially when the size of the inventory is large. This ability allows the operator instant access to information of all packagings that fit the search criteria. The software supports multiple search functions on criteria such as the drum ID, originating site, originating date, arrival dates, and materials stored. In laboratory tests, the search function performed as expected and located the subject drums instantaneously. Authorized system administrators can readily customize the search functions. The search function and the information registered in the tags provide a powerful basis for a statistical sampling strategy regarding the facility&#39;s materials surveillance program for the contents in the drums. 
         [0036]    Host computer  142  includes prototype software that is written in Microsoft Visual C# and developed for the Microsoft .NET framework. The forward-looking design of the software provides excellent computing performance, lowers the future maintenance effort and cost, and reduces the vulnerability of the software and computers to security threats. The software employs multi-thread technology that is able to handle a large quantity of tags simultaneously and respond to multiple RFID events instantly. 
         [0037]    In accordance with features of the invention, optionally when no RF operation is taken, the tag  100  is in a sleep mode. When the tag  100  is polled by the reader  140  and initiates an RF operation, RFID surveillance tag  100  goes through a cycle of three stages. The first is the wake-up stage, which takes 4 to 5 seconds. The second is the operating stage, during which the real operation, such as querying sensors, memory read/write and status transmission, and the like, takes place. This stage usually lasts less than 1 second. The third is the back-to-sleep stage, which takes about 30 seconds. As the current drain is modest in all three stages, a set of four batteries could last more than 10 years if the polling frequency is no more than once or twice daily. 
         [0038]      FIG. 2  illustrates an exemplary battery power supply  116  and battery management function  118  of the radio frequency identification (RFID) surveillance tag  100  in accordance with the preferred embodiment. The battery power supply  116  includes a plurality of parallel batteries  200 , BAT # 1 -# 4 , such as four A-size Li—SOCl 2  batteries, managed by the battery management function  118  providing a smart switching circuit. For example, only one battery is activated at any time, and the batteries  200 , BAT # 1 -# 4  are arranged to preclude leakage loops between batteries. As the self-drain of the Li—SOCl 2  battery is miniscule, the multiple batteries  200 , BAT # 1 -# 4  effectively extend the service period between battery changes. 
         [0039]    In accordance with features of the invention, the battery management function  118  is arranged to extend the service period between battery changes for the RFID) surveillance tag  100 . With the RFID surveillance tag  100  including four A-size Li—SOCl 2  batteries, with only one battery is activated at any time. The battery management function  118  monitors a current battery being activated and used to supply power to the tag  100 . The battery management function  118  automatically switches to a next battery when the current battery is discharged. 
         [0040]    The battery management function  118  of the radio frequency identification (RFID) surveillance tag  100  includes a respective diode  202  connected between a respective positive terminal of the multiple batteries  200 , BAT # 1 -# 4  and a positive voltage supply rail Vout. A capacitor  203  is connected between the positive voltage supply rail Vout and ground potential. A four-way multiplexer (MUX)  204  receives four inputs of the respective positive terminal of the multiple batteries  200 , BAT # 1 -# 4  and providing a selected battery output OUT applied to a positive terminal of a power supply connector  206 . The battery management function  118  includes a low power voltage reference generator  208  with a bias circuit formed by capacitor C 2 , and a pair of resistors R 1 , R 2  providing an input to an operational amplifier  210  and an input to an AND gate  212  connected to the output of the operational amplifier  210 . A output of AND gate  212  is coupled by a bias circuit formed by a resistor R 3 , a capacitor C 4 , and an inverter  214  and applied to applied to a second input to the AND gate  212 . The output of multiplexer  204  is applied to a second input to the operational amplifier  210  via a resistor R 4 . A pair of logic D-output gates  216 ,  218  receive the output of AND gate  212 , and provide respective selection inputs to the four-way multiplexer (MUX)  204  for sequentially selecting the battery of the multiple batteries  200 , BAT # 1 -# 4  to be used. 
         [0041]    It should be understood that the present invention is not limited to the illustrated arrangement of the battery management function  118 . Various other circuit implementations could be used to provide the battery management function  118 . 
         [0042]      FIG. 3  illustrates not to scale an example radio frequency identification (RFID) surveillance tag  100  of  FIG. 1  mounted on an associated packaging or drum  302 , for example, containing radioactive and fissile materials in accordance with the preferred embodiment. A back plate  304  is used to mount the seal sensor  124  to the associated packaging or drum  302 . The tag body  120  is shown mounted onto the back plate  304 . The drum  302 , for example, is a 35-gallon drum with a bolted closure lid, used for storage and transportation of fissile and radioactive materials. 
         [0043]    The RFID surveillance tag  100  can be attached onto the drum  302  by two bolts, as shown in  FIG. 3 . In operation, if either of the bolts is loosened, the seal sensor  124  triggers an alarm. RFID surveillance tag  100  sends the alarm to the reader  140  immediately and record the event in the tag memory  108 . The software of host computer  142  shows the alarm on the computer screen, and sends the alarm to a central station (not shown) for action. 
         [0044]      FIG. 4  schematically illustrates the exemplary radio frequency identification (RFID) surveillance tag  100  of  FIG. 3  with a metal back plate  304  removed illustrating interior details of the RFID tag  100 . 
         [0045]    As shown in  FIGS. 3 and 4 , the back plate  304  includes a predefined shape selectively provided for mounting with the associated packaging  302  and the tag body  120  includes a universal form for use with multiple different types of the associated packaging. A selected configuration of the back plate  304  enables simple modifications to provide different configurations and packagings. To reduce the likelihood of unintentional bumping and impact during handling of drums, the RFID surveillance tag  100  has a slim profile that fits within the footprint of a drum cover of the associated packaging  302   
         [0046]    In accordance with features of the invention, the overall form factor of the RFID surveillance tag  100  is designed to be universal for drum-type packaging, so that only the supporting back plate  304  and seal sensor  124  need to be customized for bolt attachments. 
         [0047]    Referring now to  FIGS. 5 and 6 , there is shown another example radio frequency identification (RFID) surveillance tag  100  of  FIG. 1  in accordance with the preferred embodiment. In  FIG. 5 , an example patch antenna  122  and another example back plate  504  are shown, each mounted to the tag body  120 . The back plate  504  has an overall L-shape and includes a pair of holes  506  for receiving flange bolts mounting the seal sensor (not shown) with the associated packaging or drum (not shown).  FIG. 6  provides a side view of the metal back plate  504  of the radio frequency identification (RFID) surveillance tag  100 . 
         [0048]    Referring now to  FIGS. 7 and 8 , there is shown another exemplary metal back plate  704  of the radio frequency identification (RFID) surveillance tag  100  in accordance with the preferred embodiment. The back plate  704  has a upper L-shape includes a pair of holes  706  in an upper flange  708  for receiving flange bolts mounting the seal sensor (not shown) with the associated packaging or drum (not shown) and a lower portion  710 .  FIG. 8  provides a side view of the metal back plate  704  of the radio frequency identification (RFID) surveillance tag  100 . 
         [0049]      FIG. 9  schematically illustrates not to scale another example radio frequency identification (RFID) surveillance tag  100  in accordance with the preferred embodiment. In  FIG. 9 , an example patch antenna  122  and another example flange plate  900  are shown with cables  902 ,  904 ,  906  respectively connecting a pair of compressive discs  908  of the seal sensor  124  and the patch antenna  122  to the tag body  120 . 
         [0050]    In brief summary, significant benefits result with the application of the multi-functional RFID surveillance tags  100  in nuclear materials management including enhanced safety via continuous monitoring of the environmental conditions, lower radiation exposure to workers due to reduced need for manned surveillance, real-time access of status and history data, and enhanced security via continuous monitoring of location and movement. 
         [0051]    While the present invention has been described with reference to the details of the embodiments of the invention shown in the drawing, these details are not intended to limit the scope of the invention as claimed in the appended claims.