CN110730914A

CN110730914A - Method for detecting and outputting radiation dose rate information

Info

Publication number: CN110730914A
Application number: CN201880038602.2A
Authority: CN
Inventors: M·S·诺雷尔
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 2017-05-11
Filing date: 2018-04-24
Publication date: 2020-01-24
Also published as: WO2018208496A1; EP3622324A1; JP2020521952A; EP3622324A4

Abstract

A method includes detecting a currently existing dose rate while a worker is performing an operation within a Radiation Controlled Area (RCA), and visually outputting to the worker a dose rate map of ionizing radiation within the RCA. The visual output may be visually depicted on a display worn by the worker during the operation and positioned near the eyes of the worker. The worker's location at the RCA may be stored in conjunction with the measured dose rate, and possibly a timestamp, as detected by the dosimeter worn by the worker at that location. These data are then used to generate a dose rate map of the RCA showing the individual dose rates at various locations within the RCA, and which can be visually output for viewing by a worker or other person outside the RCA.

Description

Method for detecting and outputting radiation dose rate information

Cross Reference to Related Applications

This application claims priority from U.S. provisional patent application serial No. 62/115939 filed on day 13 of year 2015 and U.S. patent application serial No. 15/043899 filed on day 15 of year 2016, the disclosures of which are incorporated herein by reference.

Background

1. Field of the invention

The disclosed and claimed concept relates generally to nuclear equipment and, more particularly, to a method of detecting and visually outputting information regarding nuclear dose rates and/or other related information related to nuclear radiation exposure rates during operation within a nuclear environment.

2. Background of the invention

As is generally understood in the relevant art, operations such as maintenance operations, repair operations, and the like are necessary or desirable to be performed in a Radiation Control Area (RCA). As is also understood in the relevant art, RCA exists in nuclear power plant facilities (such as within the nuclear containment of such facilities) and elsewhere. Many of these maintenance and other such operations within the RCA must be performed by human personnel, such as nuclear power plant workers and the like. In this case, the worker positioned inside the RCA is subjected to nuclear radiation, which is generally undesirable, and therefore, the worker is generally only able to receive, at best, a certain predetermined amount of nuclear radiation, typically measured in millirem units.

In order to determine the number of millirems to which a worker is exposed during operation within the RCA, it is known to dispatch multiple personnel to the RCA to measure the radiation dose rate at various locations within the RCA to which the worker is expected to be likely to go. Such location-based dose rates (i.e., millirem per hour) are then employed by planners in the facility to plan maintenance and other operations that are expected to occur within the RCA. The planner considers each dose rate at each location in the RCA, and the time the worker expects to spend at each location within the RCA. The estimated dose is estimated based on the individual dose rates that the worker may experience throughout the operation. Various safety factors are built into the calculations to ensure that the radiation to which the worker is exposed does not exceed the maximum allowable dose.

While systems of this type have generally been effective for their intended purposes, they are not without limitation. For example, the safety factors built into the plan to perform various operations are often in the form of additional time, and thus workers are often evacuated from the RCA after a limited amount of time to ensure that the workers are not exposed to radiation doses exceeding the allowable. This is independent of whether the worker has actually accepted the maximum allowable dose, and this increases the cost of performing maintenance and other activities in the RCA. In addition, such planned operations are based only on data collected prior to actually performing the maintenance operation, and therefore, despite safety factors and precautions built into the operation, there is still the possibility of overexposure of the workers to radiation outside the maximum allowable dose. Overexposure of workers to radiation is very costly and it is desirable to avoid overexposure of workers to radiation. Therefore, improvements are needed.

Disclosure of Invention

An improved method in accordance with the disclosed and claimed concept comprises: while the worker is performing maintenance or other operations within the RCA, the currently existing dose rate is continuously detected, and information related to the ionizing radiation to which the worker is being exposed is visually output to the worker or another person (such as a supervisor) during the operation. The visually output information may include information such as the current dose rate and the total dose the worker has been exposed to, but may also include information such as the time remaining before the worker will be exposed to the maximum allowable dose. Further, the visual display may output a visual indicia representing a comparison between the exposure to ionizing radiation that has been scheduled according to time before the operation is commenced and the actual exposure to ionizing radiation while the operation is being performed. Various visual outputs may be visually depicted on a display worn by a worker and located near the eyes of the worker during operation, such as by projecting visual information onto lenses of a pair of glasses worn by the worker. Additionally or alternatively, the same information may be output on a visual display viewed by a person outside the RCA (such as a supervisor). Additionally, the location of the worker within the RCA (such as in the form of x, y or x, y, z coordinates within the RCA) may be stored in conjunction with the measured dose rate at that location as detected by the dosimeter worn by the worker, possibly in conjunction with a time stamp. These data may be recorded in a database described in more detail below. Data in the database may then be employed to generate a dose rate map for the RCA showing individual dose rates at various locations within the RCA, and may be output visually for viewing by a worker (such as viewing on a pair of glasses as described above), and may additionally or alternatively be output for viewing by a supervisor or other person outside the RCA.

It is, therefore, one aspect of the disclosed and claimed concept to provide an improved method of visually outputting indicia that includes information related to the actual dose of ionizing radiation to which a worker has been exposed and that is continuously updated.

Another aspect of the disclosed and claimed concept is to provide a visual output that includes indicia representative of the time remaining before a worker will be exposed to a maximum allowable dose, and may include other indicia representative of a comparison between a planned exposure to ionizing radiation and an actual exposure to ionizing radiation.

Another aspect of the disclosed and claimed concept is to visually output a dose rate map depicting individual dose rates at various locations within the RCA for viewing by a worker performing the operation and/or another person positioned outside of the RCA.

Another aspect of the disclosed and claimed concept is to provide visual information to a worker related to an operation being performed by the worker, and visually depict such information on a visual display device worn by the worker and placed near the eyes of the worker.

Accordingly, it is an aspect of the disclosed and claimed concept to provide an improved method of providing a worker with continuously updated operation-related information during an operation in which the worker is located within a Radiation Control Area (RCA), the method may be broadly defined as comprising detecting a plurality of times during the operation a plurality of measured dose rates, each measured dose rate of the plurality of measured dose rates representing a rate of exposure of the worker to ionizing radiation for a respective one of the plurality of times, periodically determining a measured cumulative dose for each of the plurality of times based at least in part on the plurality of measured dose rates, the measured cumulative dose representing a cumulative exposure of the worker to ionizing radiation since a beginning of the operation, for each of the plurality of times: subtracting the respective measured accumulated dose from the allowed maximum dose to determine a respective actual available dose representing a respective additional exposure accumulation allowed for the worker to ionizing radiation during the operation, and determining a respective actual time remaining until the worker will be exposed to the maximum allowed dose based at least in part on the respective actual available dose and a measured dose rate of the plurality of measured dose rates, and outputting a visual output comprising indicia representing at least in part the actual time remaining on the visual display at one or more of the plurality of times.

Another aspect of the disclosed and claimed concept is to provide an improved method of visually outputting a set of continuously updated data relating to a plurality of dose rates within a radiation control Region (RCA) during an operation in which a worker is positioned at an inner region of the RCA. The method may be stated generally as, for each dosimeter of a plurality of dosimeters positioned within an RCA, periodically detecting from the dosimeter a measured dose rate representative of the rate at which the dosimeter is exposed to ionizing radiation, detecting the location within the RCA at which the dosimeter is positioned when said measured dose rate is detected, and storing a data entry comprising at least said measured dose rate and said location in a memory as part of a data record. The method may be further explained as including employing the data record to determine a plurality of latest dose rates, wherein each of the plurality of latest dose rates is associated with a respective location of a plurality of locations within the RCA, the latest dose rate being representative of a rate at which a subject positioned at the respective location will be exposed to the ionizing radiation, and outputting a visual output comprising a plurality of visual objects on the visual display, at least some of the plurality of visual objects being at least partially representative of the latest dose rate of the plurality of latest dose rates and the respective location.

Drawings

A further understanding of the disclosed and claimed concept can be obtained from the following description when read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a schematic diagram of a system that may be used to perform an improved method in accordance with the disclosed and claimed concept;

FIG. 2 is a process diagram depicting certain aspects of an improved method;

FIG. 3 is an exemplary chart depicting various computational results and visual outputs that occur during the refinement method;

FIG. 4 is a diagram depicting the development of a set of dose rate and location data that may be used to create a dose rate map such as that shown in FIG. 1; and

FIG. 5 depicts a flow diagram illustrating certain aspects of an improved method in accordance with the disclosed and claimed concept.

Like reference numerals refer to like parts throughout the specification.

Detailed Description

An improved system 4 in accordance with the disclosed and claimed concept is generally depicted in fig. 1. The system 4 may be used in conjunction with a Radiation Control Area (RCA)8 that may be located, for example, but not limited to, within the nuclear containment of a nuclear power plant. The system 4 includes a computer 12 having a visual display 16 that is in wireless communication with a pair of glasses 20 that may be worn by a worker 28 and a tablet computer 24 that may be carried by the worker 28. The glasses 20 are a pair of smart glasses having wireless data communication capabilities and having as their lenses a pair of transparent visual displays on which themes may be visually output when viewed through the transparent lenses by a user performing maintenance operations or other operations within the RCA 8. The tablet computer 24 is a computerized device having a visual display and wireless data communication capabilities, and it may alternatively be in the form of, for example, a smart phone, laptop computer, or other personal mobile device. The computer 12 also includes a memory 140 having a Database (DB)170 stored therein, it being noted that this DB serves as a data record for data obtained internally from RCA 8. The worker 28 also carries a portable electronic dosimeter 32, which portable electronic dosimeter 32 may comprise a Geiger counter or other such device that measures the dose rate of ionizing radiation to which it is subjected.

In the exemplary embodiment shown, the dosimeter 32 is in wireless communication with the tablet 24 and/or with the eyewear 20 and/or with the computer 12. That is, the glasses 20, tablet 24, and the meter 32 may be in wireless communication with one another via a bluetooth wireless connection or other wireless connection. The eyewear 20, tablet computer 24, and possibly dosimeters 32 may communicate wirelessly with the computer 12 via a plurality of wireless access points 36 in electronic communication with the computer 12. As used herein, the expression "plurality of" and variations thereof shall be taken to encompass any non-zero amount, including an amount of one. The plurality of wireless access points 36 will be positioned within RCA8 and configured to not only receive wireless signals transmitted from the glasses 20, tablet 24 and dosimeter 32, but may also transmit wireless signals to such devices. Further, the plurality of wireless access points 36 are capable of detecting a particular location within the RCA8 at any given time, for example, the dosimeter 32 and/or the tablet computer 24 and/or the eyewear 20. Please see the following link to cisco's WiFi-based location analysis:

http://www.cisco.com/c/en/us/products/collateral/wireless/mobility-services-engine/white_paper_c11-728970.html

for example, the dosimeter 32 periodically measures the dose rate of ionizing radiation within RCA8, and it transmits this dose rate information, for example, to the tablet computer 24, which tablet computer 24 transmits such dose rate data to the wireless access point 36 for transmission to the computer 12. At the same time, wireless access point 36 detects the location of worker 28 along x-axis 44 and y-axis 48, and possibly along the z-axis, within RCA8 by detecting the location of dosimeter 32 and/or tablet 24 and/or eyewear 20. Thus, when the dose rates detected by dosimeters 32 are stored in a set of dose rate measurement data 40, the set of data 40 also includes the location within RCA8 at which each such dose rate was measured, and also includes a timestamp reflecting the time at which such measurements were made. The time stamp is generated by the system clock 34. This may be done simultaneously for any number of dosimeters that may be worn by other personnel within RCA8, and this may be done before or during operations involving worker 28.

Further, it should be noted that dosimeters 32 need not be worn separately by worker 28 and other personnel. For example, one of the dosimeters 32 may be placed on a movable platform 50 that is movable around the RCA 8. For example, the movable platform may be robotically operable via a wireless connection with the wireless access point 36. Alternatively, the movable platform 50 may have resident thereon its own movement routines and detection system, which enables it to travel systematically over the entire ground surface of, for example, RCA 8. As the movable stage 50 moves along the x-axis 44 and y-axis 48, the dosimeter 32 will periodically measure dose rate. For each such dose rate measurement, the measured dose rate at the time of such measurement and the corresponding location of the dosimeter 32 may be communicated as a data entry included in the database 170, and the data entry may optionally include a timestamp. The respective location may be determined using the wireless access point 36 or may be determined by the movable platform 50 itself. The movable platform 50 may have a lift mechanism that raises the dosimeter 32 to various heights above the ground of the RCA in order to develop dose rate data along the z-axis. In such a case, the elevation of the dosimeter 32 along the z-axis may be transmitted by the movable platform 50 for storage as part of a data entry included in the database 170.

It can be seen that fig. 1 depicts a plurality of exemplary locations 52 within RCA8, where the dose rate data is detected in the plurality of exemplary locations 52 and stored in a set of measured dose rate data 40 along with corresponding x, y coordinates and time stamps. Exemplary sites 52 are depicted in fig. 1 in an exemplary grid pattern, but it should be understood that individual sites 52 will likely be more irregularly located within RCA8, as they will be captured as worker 28 moves through RCA8 during operations performed within RCA 8. The worker 28 may enter an area of as low a dose rate as possible (ALARA) through the access port 54 and will start performing the task associated with the operation, either moving from one moment to the next or remaining stationary from one moment to the next all the time. Dosimeter 32 may measure dose rate a fraction of a second or more or less per second, depending on the requirements of a particular application.

As will be set forth in more detail below, the computer 12 advantageously employs a set of measured dose rate data 40 to visually depict on the visual display 16 and/or the eyewear 20 a dose rate map 55, the dose rate map 55 including a first visual object 56 representative of the RCA8 and a plurality of second visual objects 60 representative of various locations within the RCA8 and additionally describing the dose rate at each such location. The dose rate map 55 may be visually depicted on the visual display 16, which itself may be located outside the RCA8, and may additionally or alternatively be depicted on the glasses 20. In this regard, it is understood that the eyewear 20 is one or more lenses that are worn by the worker 28 and include additional visual displays on which the dose rate map 55 and other indicia may be visually depicted. Because the glasses 20 and lenses themselves are positioned near the eyes of the worker 28, the worker 28 can easily view the dose rate map 55 and other visual indicia, as well as data such as will be described in more detail below, without having to separately view another device. That is, although such visual indicia may be output, for example, on the tablet computer 24, the output of such visual indicia on the eyewear 20 facilitates the transfer of visual data to the worker 28 without having to separately view the tablet computer 24 to see such visual indicia.

Advantageously, the visual display 16 and the eyewear 20 may additionally visually depict other indicia based on the detected dose rate as detected and recorded in a set of measured dose rate data 40. Even more advantageously, such detected dose rate information in the set of measured dose rate data 40 may be compared to expected exposure to ionizing radiation and the difference between the expected and actual measured values may be presented on the eyewear 20 and/or the visual display 16. That is, not only may actual numerical data be output, but also simpler and easier to visually understand indicia may be output for quick recognition and understanding by worker 28 and/or another person who may be outside of RCA8 and who may be viewing visual display 16.

By way of example and as generally shown in fig. 2, the computer 12 may include a planner routine 64 that may be executed on the processor of the computer 12 and that may employ any dose rate data that is currently present, such as from previous operations that other workers within the RCA may have performed and/or from dose surveys that may have been previously conducted within the RCA. Planner routines 64 will additionally include data regarding the various tasks that must be performed as part of the operation and the paths that workers 28 must follow through RCA8 in order to perform the various tasks. The planner routines 64 will additionally include data about the task itself (such as the amount of time a task will typically require), and will also additionally include data about the level of experience of the worker 28 (such as if the worker was a highly skilled person who has performed the same task in the past, or if the worker was inexperienced with such a task). The planner routine 64 then determines a profile from the planned dose rate for each of the plurality of times during the operation and a planned accumulated dose 72, the planned accumulated dose 72 being based on the planned dose rate 68 and the planned time the user will spend at various locations within RCA 8. All of this information will be compared to a radiation dose limit 76 that represents the maximum dose of ionizing radiation to which worker 28 is permitted to be exposed. Based on these data, the planner routine 64 may calculate a remaining planning time 80 for each time during the operation, the remaining planning time 80 being calculated by subtracting the planned cumulative dose 72 from the radiation dose limit and dividing it by the planned dose rate 68 that the worker is expected to experience at the respective time. An example of such a set of data is generally depicted in FIG. 3. Each row in fig. 3 depicts an exemplary six minute period during operation, which is a time period equal to one-tenth of an hour. Planned accumulated dose 72 is calculated by multiplying planned dose rate 68 by the relevant time period that worker 28 is expected to be exposed to planned dose rate 68, and accumulating these values during operation.

In addition, dosimeter 32 detects the actual radiation dose rate 84, and such dose rate data and corresponding position data and a time stamp are shown in FIG. 1 and stored. Actual radiation rate 84 is effectively multiplied by the amount of time that worker 28 experiences actual radiation rate 84, and such exposures are accumulated to determine accumulated radiation dose 88. Computer 12, having received actual radiation rate 84, may calculate an actual accumulated radiation rate 88 and may further calculate an actual time remaining 92 based on such data. The actual time remaining may be calculated at any given time by subtracting the radiation dose limit 76 from the actual cumulative radiation dose and dividing the result by the actual radiation dose rate 84. Note that the remaining planned time 80 and the remaining actual time 92 may be digitally output as time periods measured in hours in fig. 3. Again, such time periods may be continuously updated on the eyewear 20 or on the visual display 16 or both to depict such time periods. Since the data is digital in nature, worker 28 will need to read the number and mentally process the number in order to understand the content of the visual output.

By advantageously employing and providing actual data via dosimeter 32 and planning data via planner routines 64, additional useful information may be developed and visually depicted as visual indicia on eyewear 20 and/or visual display 16. For example, the remaining difference time (variance time)96 may be calculated by dividing the remaining actual time by the remaining planned time and subtracting one therefrom. If the resulting value is greater than 0.1, for example, a visual indicia 102 (such as an upwardly pointing arrow) may be output on the eyewear 20 and/or the visual display 16, as at 100, to indicate that the remaining variance time trend at any given moment is advantageous. On the other hand, if the value is less than-0.1, as determined at 106, a substitute visual indicia 110 depicting an exemplary downward pointing arrow may be visually output on the eyewear 20 and/or the visual display 16 to indicate that the remaining variance time trend is unfavorable. Still alternatively, if the remaining difference time determined at 96 is neither greater than 0.1 nor less than-0.1, another alternate indicia 114 may be visually output on the eyewear 20 and/or the visual display 16 to indicate that the remaining difference time trend is substantially normal.

Although the remaining differential time trend determined at 96 is of a trending nature rather than an instantaneous value, it should be noted that the set of measured dose rates 40 may be further manipulated as at 118 and 122. More specifically, the remaining difference time determined at 96 may be subtracted from the immediately previous remaining difference time value to provide a more instantaneous determination of the remaining difference time. For example, if the difference between any given remaining difference time and the immediately preceding remaining difference time is greater than 0.1, it may be advantageous to output another visual indicia 130 on the eyewear 20 and/or the visual display 16 to indicate the instantaneous remaining variable time by depicting an upwardly directed arrow. Alternatively, if the difference is determined to be less than-0.1 at 134, the instantaneous value may cause another visual indicia 138 to be output as represented by the downwardly pointing arrow, which would indicate that the instantaneous difference is unfavorable, meaning that the remaining difference time becomes unfavorable. Still alternatively, if it is determined at 134 that the difference determined at 118 and 122 is not less than-0.1, another visual indicia 142 may be output on the eyewear 20 and/or the visual display 16 in the form of a horizontal arrow indicating that the instantaneous value is normal.

It should be appreciated that the

visual indicia

102, 110, and 114 reflect trends in the remaining difference time. In contrast, the

visual markers

130, 138 and 142 point more to the instantaneous value of the remaining difference time than to the trend. In this way, the instantaneous remaining variance time 122 and trend variance 96 may be completely different from each other.

A cumulative dose variation trend calculated by dividing the actual cumulative radiation dose 88 by the planned cumulative dose 72 and subtracting one therefrom may also be determined, as at 146. If the result value is less than-0.1, as determined at 150, an additional visual indicia 154 depicted as an exemplary upwardly pointing arrow may be output on the eyewear 20 and/or the visual display 16, indicating that a trend of variance in cumulative dose is advantageous. On the other hand, as at 158, it may be determined that the difference trend cumulative dose is greater than 0.1, in which case an alternative visual indicia 162 may be output on the eyewear 20 and/or the visual display 16 indicating that the cumulative dose difference trend 146 is adverse. Still alternatively, if it is determined at 158 that the differential trend is not greater than 0.1, another alternative visual indicia 166 may be output on the eyewear 20 and/or the visual display 16 in the form of an exemplary horizontal arrow indicating that the differential trend cumulative dose 146 is normal.

Note that the remaining difference

time trend markers

102, 110, and 114 are alternatives to each other, and that only one of these markers is visually output at any given time. Likewise, the

visual markers

130, 138, and 142 are alternatives to each other and only one of them is output at any given time. Further, the

visual markers

154, 162, and 166 are alternatives to each other and only one of them is output at any given time. It should be noted, however, that in addition to displaying any of the

indicia

102, 110, and 114 and any of the

indicia

154, 162, and 166, any of the display

visual indicia

130, 138, and 142 will also be output. As such, the eyewear 20 and/or the visual display 16 will include one of the

indicia

102, 110 and 114 representing a trend in the remaining difference time in addition to one of the

indicia

130, 138 and 142 representing an instantaneous remaining difference time and one of the

indicia

154, 162 and 166 representing a trend in the cumulative dosage difference.

It can thus be seen that the eyewear 20 and/or the visual display 16 may not only output the planned time remaining 80 and the actual time remaining 92 in digital form, but the eyewear 20 and/or the visual display 16 may also include a visual depiction of the trend in time remaining, the instantaneous time remaining, and the cumulative dosage of the trend in difference. The latter three values will be depicted in an easily understood form (such as the above-described upward pointing arrows, downward pointing arrows, and horizontal arrows or other such indicia), and may additionally or alternatively include colors such as green, red, yellow, etc., to indicate favorable, unfavorable, and normal values. Other variations will be apparent.

Fig. 4 depicts in schematic form various data sources that generate data that are stored together as the set of measured dose rate data 40 in a database 170, which database 170 may be understood to be approximately in the form of a table that includes a location within RCA8 in x, y coordinates, a dose rate designated as "DR" and being the dose rate detected at that location, and a "TIME" value as a timestamp when the dose rate was detected at that location. For example, the various data values are continuously recorded, and the system may include a loop to delete duplicate values that may be recorded while worker 28 is stationary.

Not only may the data values and visual indicia shown in fig. 2 be visually output on the eyewear 20 and/or the visual display 16, the set of measured dose rate data 40 may also be employed to generate and output the dose rate map 55 depicted in fig. 1 as an output on the visual display 16. It is expressly noted that the dose rate map 55 may additionally or alternatively be output on eyewear 20 for use by worker 28.

As shown in fig. 1, the first visual object 56 is a schematic depiction of RCA 8. The second visual object 60 is positioned relative to the first visual object 56 in a manner that represents an arrangement of various locations within the RCA8 where various dose measurements are recorded. The second visual object 60 also depicts the recorded dose rate. In the exemplary embodiment shown, these rates are depicted digitally by the second visual objects 60, meaning that the second visual objects 60 each include indicia in at least a first digital form, but it should be understood that data may alternatively or additionally be communicated in terms of color or the like to additionally depict rate data. The dose rate data may be obtained directly from the set of measured dose rate data 40, or may be averaged in any of a variety of ways or may be otherwise processed. Still alternatively, the values may be normalized, if appropriate. Furthermore, it will be appreciated that the dose rate output on the visual display 16 will be the latest dose rate available, which means that it reflects the latest dose rate measurement taken for a given area within RCA 8. For example, due to the repeated dose rate measurements of dosimeter 32, the displayed dose rate in the vicinity where worker 28 is located may be accurate and correct, i.e., current. On the other hand, only a single dose rate may be recorded for other locations within RCA8, and that single dose rate may have been recorded at some point in the past. If the single dose rate is the latest dose rate available within the set of measured dose rate data 40, the single dose rate will still be output. In this regard, it should be understood that the set of measured dose rate data 40 is a data record that is continuously updated with each additional stored data entry in the form of a new measurement of dose rate from the dosimeter 32 or another such dosimeter, the corresponding location where the dose rate is measured, and a time stamp at the time the dose rate is measured. Whatever data is up to date may be used to generate the second visual object 60. Only a representative number of second visuals 60 are depicted in fig. 1, and it should be understood that more of such second visuals 60 may be output on the eyewear 20 and/or the visual display 16 as the set of measured dose rate data 40 may be developed over time.

FIG. 5 depicts a flow diagram illustrating certain aspects of an improved method in accordance with the disclosed and claimed concept. As described above, dosimeter 32 may be located on worker 28 so as to move with worker 28 from one location within RCA8 to another location when worker 28 must advance to perform a maintenance operation or other operation within RCA 8. Likewise, any number of other dosimeters 32 may be positioned in the RCA8, such as placing them on other workers or securing them at one location or another within the RCA8, and so forth. For any one or more dosimeters 32 within RCA8, the method begins at 205, where a measured dose rate representative of the rate at which dosimeters 32 are exposed to ionizing radiation is periodically detected from dosimeters 32.

Processing continues as at 210, with detection of the position within RCA8 at which the dosimeter 32 is located when a dose rate measurement is detected. In this regard, it should be noted that the expression "position" and variations thereof herein refers to the x, y, z coordinates at which dosimeter 32 is located within RCA8 at the time of measurement of dose rate. As will be set forth in more detail below, the expression "location" and variations thereof is intended to refer to the x, y, z coordinates within RCA8 that output the dose rate on visual display 16. Although the location may be the same as the location, it may also be different. In this regard, it is expressly noted that each dosimeter 32 can detect actual dose rate at multiple locations within the RCA, and that many such dose rate measurements can be in close proximity to one another. As such, it is more visually understandable for worker 28 to output a set of latest dose rates at regularly spaced locations within RCA8 as dose rate maps 55, where such locations are located on a virtual grid within RCA 8. In the exemplary embodiment shown, the virtual grid will virtually define a plurality of three-dimensional rectangular virtual areas within the RCA, and each time it is determined that a dose rate measurement from a dosimeter 32 has been measured in any particular virtual area, the detected dose rate is determined to be the latest dose rate in that virtual area. Thus, instead of outputting a large dose rate very close to each other, the dose rate map 55 will only include a single dose rate as the most recent dose rate for the entire virtual area. The latest dose rate for the virtual area will be determined based on the dose rate detected within the virtual area. For example, the latest dose rate may be the highest dose rate detected in the virtual area, or may be based on an average of the dose rates measured in the virtual area, or it may be based on any calculation method that is preferred in any particular virtual area for any particular maintenance or other operation. Other variations on how this is accomplished will be apparent and are considered to be within the spirit of the present disclosure.

Thus, in some embodiments of the disclosed and claimed concept, the dose rate map 55 may include a visual object representing the actual location within RCA8 where the actual dose rate was detected. However, it is noted that in other embodiments of the disclosed and claimed concept, the actual measured dose rate may be employed to calculate a set of calculated dose rates at a particular location within the RCA, such as via interpolation, averaging, or the like, to create a dose rate map 55. Any such method will result in an up-to-date set of dose rates depicted via dose rate map 55.

It is noted that the predetermined locations do not have to be evenly spaced along the grid, but may be chosen as the case may be. For example, the bottom of a flight of stairs may not be associated with the actual dose rate measured at the bottom of the stairs, but it may be worthwhile to employ data from other locations within the RCA where the dose rate data is actually recorded in order to generate and output an estimate as to what dose rate is understood to be located at the bottom of the stairs (based on the recorded dose rate data). Other examples will be apparent.

Processing then continues as at 215 with the dose rate and the corresponding position of the measured dose rate within RCA8 being recorded as a data entry in database 170. In this regard, the data entry may additionally include a timestamp generated by system clock 34, and thus the data entry will include the measured dose rate, the corresponding location at which the dose rate was detected, and the corresponding time at which the dose rate was detected. Although such a time stamp is optional, it can be used to determine what is the most recent data value that has been recorded, and such a time stamp is further useful for determining dose rate trends and the like.

Processing then continues as at 220, with the data records (i.e., database 170 including data entries) being employed to determine a plurality of most recent dose rates and corresponding locations. As described above, "site" may refer to where the dose rate is actually measured directly via dosimeter 32, or may refer to where the dose rate is calculated based on a nearby directly measured dose rate. The dose rate determined at 220 will most typically be based on the most recent dose rate, i.e. the most recently detected and recorded dose rate compared to other dose rate data that has been measured at the same place at an earlier time. Since it is not possible to detect dose rates at the same time anywhere within RCA8, it will be appreciated that some dose rate data may be more up-to-date than others, but in general the dose rate determined at 220 for use in dose rate map 55 will be based on any up-to-date dose rate data.

Processing then continues as at 225 with computer 12 outputting a visual output in the form of a dose rate map 55 on visual display 16 or eyewear 20, or both. The dose rate map 55 includes a plurality of visual objects that each represent the latest dose rate and corresponding location. In this regard, the dose rate map 55 includes the aforementioned first visual object 56 in the form of a representation of RCA 8. The plurality of second visual objects 60 each comprise one or more markers representing the latest dose rate and the corresponding location at which the latest dose rate is present, as it were.

In the exemplary embodiment shown, one marker owned by each second visual object 60 is a digital representation of the current dose rate. Each second visual object 60 also includes as another marker its own relative position on the visual display 16 with respect to the first visual object 56, which is indicative of the respective location in RCA8 associated with the current dose rate. That is, an exemplary one of the second visual objects 60 shown in FIG. 1 includes the number "25" representing the current dose rate as one marker, and such an exemplary second visual object 60 also includes another marker positioned in the upper right-most corner of the dose rate map 55 (the positioning representing the current dose rate "25" positioned in the upper right-hand corner inside the RCA8 represented by the first visual object 56). This double marking indicates the current dose rate "25" and the corresponding location within RCA8 where the current dose rate "25" is present.

In the exemplary embodiment shown, each second visual object 60 in fig. 1 comprises further markers further representing the dose rate. That is, each second visual object 60 includes a color representing the dose rate as another marker in addition to the marker of each second visual object 60 that digitally depicts the current dose rate. For example, the highest dose rate may be depicted by a number in red, while lower dose rates may be indicated by numbers depicted in other colors than red. For example, three of the second visual objects 60 depicted in the upper right of the dose rate map 55 are surrounded by a border 65 and are additionally output in red numbers. Additionally, boundary 65 may itself be red, or may be another color, or may flash, or may provide some other visual indicia that draws attention to the fact that these three adjacent locations in RCA8 (as indicated by the location where second visual object 60 is positioned relative to first visual object 56) are at a relatively high dose rate to worker 28, meaning that any object placed at such a location will experience a high dose rate of ionizing radiation.

In contrast, another set of second visuals 60 is depicted in fig. 1 as being positioned to the lower left of the dose rate map 55, and each second visual 60 in such an area is formed by a number representing that a relatively lower dose rate is present in such an area (which may be an ALARA area). This ALARA area is surrounded by another border 69 which is also intended to visually draw the attention of the worker 28. In addition to including digitally outputting the number of the current dose rate at such a location, the second visual object 60 positioned within the boundary 69 itself is also depicted using a number printed in a color such as blue, which represents the fact that the dose rate at such a location is relatively low.

In this regard, it can be seen that the blue color used to depict the second visual object 60 within the boundary 69 is a different color than the red color used to depict the second visual object 60 within the boundary 65. This difference between red and blue is intended to visually draw the attention of worker 28 to the fact that the dose rates for the two different regions within RCA8 are significantly different. Colors between the aforementioned exemplary blue and red colors may then be assigned based on the most recent dose rate at any given location, and such colors may, for example, span the visible spectrum between blue and red when changing from a relatively low dose rate to a relatively high dose rate.

It is noted that such a color may be selected, for example, based on a predetermined threshold value of the dose rate. For example, a dose rate represented by the number 1.0 or less may be depicted in blue, while a dose rate represented by the number 30 or more may be indicated in red. Variations will be apparent. The boundary 69 itself may likewise be depicted in blue and/or may flash to further quickly draw the attention of the user. In this regard, the boundary 65 may flash at a relatively fast rate and the boundary 69 may flash at a relatively slow rate, such varying flash rates further indicating the dose rates of the locations contained within

such boundaries

65 and 69. Further, shadows, cross-hatching, and the like may also be present within

such boundaries

65 and 69 if deemed desirable to make them more readily visible to the worker 28.

It should be appreciated that virtually any type of visual element may be used if the visual element is configured to represent the latest dose rate to worker 28. For example, in some embodiments, color alone may be employed to depict the dose rate, or only the blink rate of the visual object may represent the current dose rate (i.e., faster blinking would indicate a higher dose rate, and vice versa).

It should be appreciated that by visually outputting first visual object 56 and second visual object 60 on visual display 16, a supervisor or technician or other individual may use rate map 55 to draw an exit path and/or an entry path for worker 28 along the minimum rate path. Also, a dose rate map 55 depicted on eyewear 20 may be viewed by worker 28 and used by worker 28 to identify a path to reduce dose rate. In this regard, the instantaneous location of worker 28 may be output as another visual object on rate map 55 to suggest to worker 28 the location at which worker 28 was located in RCA8 at any given time.

Thus, it can be seen that the system 4 can advantageously output a continuously updated set of data represented by any of a variety of visual indicia, either in a digital or symbolic format or in one or more colors or any combination thereof, on the eyewear 20 and/or visual display 16, and can additionally visually display thereon a dose rate map 55. Such visual output helps the worker determine whether worker 28 needs to exit RCA8 or whether worker 28 has additional time to complete the various tasks of the operation. Such data output on visual display 16, which may be located outside of RCA8, enables a supervisor or other individual to monitor the progress of worker 28 and draw out various tasks to be performed by worker 28 and the particular path to follow in RCA 8. By providing the data continuously updated, workers 28 and other personnel are continually updated as to the dosage rate and time remaining, as well as the temporal and trending aspects of these values, and other values. Providing such data can make the most efficient use of the time of workers within the RCA, thereby saving costs and improving performance. Other benefits will be apparent.

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.

Claims

1. A method of visually outputting a set of continuously updated data relating to a plurality of dose rates within a radiation-controlled region, RCA (8), during operation of a worker (28) located within an inner region of the RCA, the method comprising:

for each dosimeter (32) of a plurality of dosimeters positioned within the RCA:

periodically detecting a measured dose rate from the dosimeter, said measured dose rate being representative of the rate of exposure of the dosimeter to ionizing radiation,

when the measured dose rate is detected, detecting the location at which the dosimeter within the RCA is located, an

Storing a data entry comprising at least the measured dose rate and the position in a memory (140) as part of a data record;

employing the data record to determine a plurality of up-to-date dose rates, each of the plurality of up-to-date dose rates being associated with a respective location (52) of a plurality of locations within the RCA, the up-to-date dose rates representing rates at which a subject positioned at the respective location will be exposed to ionizing radiation; and

outputting, on a visual display (16), a visual output comprising a plurality of visual objects (56, 60), at least some of the plurality of visual objects each at least partially representing an up-to-date dose rate of the plurality of up-to-date dose rates and the respective location.

2. The method of claim 1, further comprising: visually displaying a dose rate map (55) as part of the visual output, the dose rate map comprising a first visual object (56) of the plurality of visual objects and further comprising a plurality of second visual objects (60) of the plurality of visual objects, wherein the first visual objects represent at least a portion of RCA and the second visual objects each comprise at least one marker that at least partially represents a most recent dose rate of the plurality of most recent dose rates and the corresponding location.

3. The method of claim 2, wherein the plurality of second visual objects are positioned relative to the first visual object in a manner representative of an arrangement of the plurality of locations within a RCA.

4. The method of claim 3, wherein at least some of the plurality of second visuals each include a visual element as the at least one marker, the visual element including at least a first number representing a latest dose rate.

5. A method according to claim 4, wherein the first subset of the at least some second visual objects each comprise a second mark in the form of a first color representing the latest dose rate, and wherein the second subset of the at least some second visual objects each comprise a further second mark in the form of a second color representing the latest dose rate, the first and second colors being different from each other and representing the latest dose rate in the first subset being different from the latest dose rate in the second subset.

6. The method of claim 3, wherein at least some of the plurality of second visuals each include a visual element as the at least one marker, the visual element including a color representative of a latest dose rate.

7. The method of claim 1, further comprising depicting the visual output on a visual display (20) positioned on the worker and disposed near an eye of the worker.

8. The method of claim 1, further comprising: storing, as part of the data entry, a respective time at which the measured dose rate is detected, the respective time being at least one of before and during the operation.

9. The method of claim 1, further comprising positioning a dosimeter (32) of the plurality of dosimeters in proximity to the worker to enable the dosimeter to move with the worker within an RCA.

10. The method of claim 1, further comprising:

positioning a dosimeter (32) of the plurality of dosimeters on a movable platform (50) movable about an RCA; and

moving the movable platform around the RCA such that the dosimeter moves with the movable platform within the RCA.