JPH08248135A - Radiation display system - Google Patents

Abstract

PURPOSE: To obtain a radiation display system by which a signal on an area- monitor installed inside a radiation operating area is sent to a video monitor at a radiation-operating-area entrance and by which a radiation level inside the area as a radiation map is made known well to an operator in real time. CONSTITUTION: A radiation display system is a system by which, in order to decide the operatable time inside a radiation-operating-area 1 in advance, a radiation level inside the area is displayed. Contribution rates of dose equivalent rates in a plurality of evaluation points for radiation sources 2 as radiation exposure sources inside the area are computed and found in advance. A change in the intensity of the radiation sources is found by a computer 5 on the basis of the change rate of signals on a plurality of area monitors 3, and the dose equivalent rates in the evaluation points are corrected on the basis of the change. On the basis of the dose equivalent rates, a dose equivalent rate map is created in real time so as to be displayed on a video monitor 8 at a radiation- operating-area entrance 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to correction of a dose equivalent rate based on a change rate of a signal by a plurality of area monitors with a dose equivalent rate display installed in a radiation work area, and real time based on the corrected change rate. Radiation display system for creating a dose equivalent rate map in the radiation work area at the site and displaying the radiation level in the area by a video monitor at the entrance of the radiation work area via a video adapter.

[0002]

2. Description of the Related Art In a radiation work area such as a nuclear power plant, there is a radiation source such as a pipe or a pump having a radioactive substance attached to its inner surface.

Further, a liquid containing radioactivity may flow into the inside of these pipes or pumps, or the radiation concentration of the inflowing liquid may increase or decrease. Furthermore, a shield may be installed on the radiation source, or the radiation source may be decontaminated.

In such a case, when the radiation dose equivalent rate distribution within the area changes and the radiation exposure of the worker entering to perform the work within the area increases or decreases, the worker's own work within the area Affect time.

Therefore, in order to predetermine the workable time in the radiation work area, a whiteboard or the like is generally placed at the entrance of the radiation work area and the radiation level in the area is entered and displayed.

[0006]

However, in the above-mentioned conventional system, it is difficult for the operator to sufficiently grasp the radiation level in the entire radiation work area, and the change over time is accurately tracked. Requires frequent radiation surveys and label updates by radiation managers,
These tasks can cause increased radiation manager labor and increased exposure.

The present invention has been made in view of the above circumstances, and sends a signal from an area monitor installed in a radiation work area to a video monitor at the entrance of the radiation work area.
It is an object of the present invention to solve the above-mentioned problems by making a worker aware of the radiation level in the area as a radiation map in real time.

[0008]

[Means and Actions for Solving the Problems] The radiation level in the radiation work area is non-uniform because the dose equivalent rate is higher as it is closer to the radiation source. To represent this state, the radiation dose rate in the area is represented by contour lines. A method is used in which the space between the contour lines is painted. This contour line display is called a radiation map.

Normally, the range having a high dose equivalent rate tends to be red, and the range having a low dose equivalent rate tends to be blue. The worker recognizes the dose equivalent rate from this map, reduces the staying time in the red-colored range as much as possible, and carries out the work according to the plan to suppress the radiation exposure.

For creating a radiation map in an area, usually, the radiation dose equivalent rate is measured at equal intervals (for example, at intervals of 1 m), and the same radiation dose equivalent rate range between the measurement points is obtained by using the interpolation method. , By tying this.

The present invention displays this radiation map at the entrance of the work area in real time. Multiple area monitors, a multiplexer that sends signals to the personal computer while switching signals from the area monitor, a computer that calculates the signals from the area monitor and creates a radiation map in a lethal time, a video that converts a computer screen to a video screen Consists of an adapter and video monitor.

In the present invention, first, regarding the position in the area corresponding to the measurement point necessary for creating the radiation map,
Calculate the dose equivalent rate for each single radiation source consisting of piping, equipment, and liquid containing radioactivity inside them for the case of unit radiation intensity. A list of dose equivalent rate calculation values for each individual radiation source at each calculation position and the total value thereof is called a dose matrix.

The dose equivalent rate is calculated using a publicly available QAD-CD code or span code.

The calculated value of the dose equivalent rate at the calculation position is the sum of the calculated values of the dose equivalent rate from a plurality of single sources, and if the source intensity of one of the plurality of sources changes. Changes the calculated dose equivalent rate at the calculation position, so the dose equivalent rate contribution rate at multiple evaluation points for each radiation source is calculated in advance, and the intensity of each source is calculated. The change of is calculated by the computer based on the change rate of the signals of a plurality of area monitors, and the dose equivalent rate of the evaluation point is corrected by this.

That is, the division of the radiation source for calculation is performed within the range in which the radiation source intensity may change during the period in which the display system of the present invention is installed and the installation range such as radiation shielding.

The number of area monitors with the dose equivalent rate display of the display system is set to the number of divisions of the radiation source. In addition, the installation position shall be the position where the dose equivalent rate contribution from each radiation source is the largest.

Then, by determining a coefficient for each of the divided radiation sources and multiplying it by the dose equivalent rate calculated value from the corresponding radiation source, the actual measured dose equivalent rate and the dose equivalent rate at the measurement position in the actual target area are calculated. Create a dose matrix that matches the calculated values.

When the area monitor is installed, the correction coefficient of the dose equivalent rate instruction value of each area monitor is set to 1, and when the dose equivalent rate instruction value of each area monitor changes, the dose matrix is corrected using the change rate as the correction coefficient. To do.

The dose equivalent rate between the calculation points is obtained by interpolation using the total value of the dose equivalent rates of the modified dose matrix, and a radiation dose equivalent rate map is created.

The prepared radiation dose equivalent rate map is displayed on the video monitor at the entrance of the radiation work area via the video adapter.

The real-time radiation map display system of the present invention performs manual radiation measurement in the work area when the area monitor is installed, and creates a dose matrix to track the radiation level in the work area. Can be displayed, eliminating the need for manual radiation measurement.

This makes it possible to reduce the radiation measurement labor and radiation exposure of the radiation manager.

Further, by displaying the radiation map in real time on the video monitor at the entrance of the work area, the worker can grasp the radiation situation in the work area and avoid entering into the range of high radiation level as much as possible. As a result, work exposure can be reduced.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a system configuration according to this embodiment. As shown in the figure, the radiation display system according to the present embodiment includes an area monitor 3 installed near a plurality of radiation sources 2 in a work area 1 and a multiplexer that performs transmission while switching signals from the area monitor 3. 4, a computer 5 that calculates a radiation map in real time by calculating signals from the multiplexer 4, a video adapter 6 that converts the screen of the computer 5 into a video screen, and a work area connected to the video adapter 6. The video area 8 of the entrance 7 is provided.

FIG. 2 shows a dose matrix 9 that matches the measured dose equivalent rate values stored in the main memory of the computer 5, and FIG. 10 shows the dose matrix 9 after being changed by the rate of change of the signal of the area monitor 3. 2 shows a dose matrix 10 of

In this embodiment, as shown in FIG.
The doses of the radiation sources A and B at the calculation points 1 and 2 are A1 and A, respectively.
2 ..., B1, B2 ..., and the total doses thereof were 1, 2, ..., However, as shown in FIG.
By multiplying the dose of radiation source A by A1 × X, A2 ×
X ..., the dose of the radiation source B is B1 × Y, B2 × Y ..., and the total dose is 1Z, 2Z.

FIG. 4 shows contour lines of the dose equivalent rate, and FIG.
Shows a radiation map. That is, the radiation equivalent map between the calculated positions is obtained by the interpolation method, the contour lines 11 of the dose equivalent rate shown in FIG. 4 are drawn, and then, as shown in FIG. Create 12.

The radiation dose equivalent rate map 12 thus created is displayed on the video monitor 8 at the radiation work area entrance 7 via the video adapter 6.

According to the real-time radiation map display system of this embodiment, the radiation level in the work area 1 is changed by manually measuring the radiation in the work area when the area monitor 3 is installed and creating the dose matrix 9. The radiation map 12 that follows can be displayed, and it is not necessary to manually perform radiation measurement.

This makes it possible to reduce the radiation measurement labor and radiation exposure of the radiation manager, and to display the radiation map 12 in real time on the video monitor 8 at the work area entrance 7 so that the worker can manage the radiation within the work area 1. By understanding the radiation situation, it is possible to avoid entry into the high radiation level range as much as possible, and work exposure can be reduced.

[0032]

As described in detail in the above embodiments, according to the present invention, the radiation measurement in the work area is manually performed when the area monitor is installed, and the dose matrix is created, thereby A radiation map that follows changes in radiation level can be displayed, eliminating the need for manual radiation measurement.

This makes it possible to reduce the radiation measurement labor and radiation exposure of the radiation manager.

Further, by displaying the radiation map in real time on the video monitor at the entrance of the work area, the worker can grasp the radiation situation in the work area and avoid entering into the range of high radiation level as much as possible. As a result, work exposure can be reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a radiation display system according to the present invention.

FIG. 2 is a diagram showing a dose matrix created in the embodiment.

FIG. 3 is a diagram showing a dose matrix after being modified in the embodiment.

FIG. 4 is a diagram showing contour lines of dose equivalent rate in the above-mentioned embodiment.

FIG. 5 is a diagram showing a radiation map in the embodiment.

[Explanation of symbols]

 1 Working Area 2 Radiation Source 3 Area Monitor 4 Multiplexer 5 Computer 6 Video Adapter 7 Working Area Entrance 8 Video Monitor 9,10 Dose Matrix 11 Contour 12 Radiation Map

Claims (3)

[Claims] 1. A system for displaying a radiation level in a radiation work area in order to predetermine a workable time in the radiation work area, wherein a plurality of evaluation points for each radiation source serving as an exposure source in the area are displayed. Dose equivalent rate contribution rate is calculated in advance, and changes in the intensity of each radiation source are calculated by a computer based on the rate of change of signals from multiple area monitors, and the dose equivalent rate at the evaluation point is corrected by this. Radiation display system. 2. A radiation display system characterized in that a dose equivalent rate of a plurality of evaluation points corrected by the system of claim 1 is calculated by a computer, and a dose equivalent rate map is created in real time based on this. 3. A radiation display system, wherein the dose equivalent rate map created by the system of claim 2 is displayed on a video monitor at the entrance of the radiation work area via a video adapter.