Integrated dosimeter

Abstract

The present invention relates to an integrated dosimeter comprising: a plurality of filters having different energy responses according to the type of incident radiation; a dose unit including a plurality of dose elements which are positioned to correspond to each filter and which generate light by radiation passing through each filter; and a plurality of optical amplification elements for converting the light generated from each dose element into current signals, wherein the plurality of filters include: a first filter, a second filter and a third filter having selective energy responses to beta rays, gamma rays and X-rays, respectively; and a fourth filter and a fifth filter having selective energy responses to neutrons, and also having selective energy responses to energy level of the neutrons.

Description

Integrated dosimeter

[0001] The present invention relates to an integrated dosimeter capable of measuring exposure doses of beta rays, gamma rays, X-rays, and neutrons.

[0002] Radiation workers must wear a personal dosimeter for reading external exposure doses when entering a radiation controlled area. A personal dosimeter refers to a dosimeter utilizing chemical action, excitation, or fault induction; direct-reading (active) dosimeters utilizing ionization are not included.

[0003] Personal dosimeters cannot check the radiation exposure dose in real time, and the exposure dose can only be determined by reading the radiation dose accumulated over a certain period using a separate reader.

[0004] Therefore, radiation workers at domestic nuclear power plants wear thermoluminescent dosimeters, which are statutory dosimeters, and Auto Dose Reading dosimeters (ADRs) capable of real-time exposure dose verification and alarm functions.

[0005] When entering a general radiation controlled area, an ADR for gamma ray measurement and a personal dosimeter, which is a statutory dosimeter, are worn because radiation protection targets are primarily gamma rays. However, when entering a reactor building that is in operation at full power, radiation measurements for neutrons and gamma rays are required, so ① an ADR for gamma ray measurement, ② an ADR for neutron measurement, ③ a personal dosimeter, and ④ a dosimeter dedicated to neutron measurement are worn. Consequently, there are problems such as reduced work efficiency due to the wearing of multiple dosimeters, the cost of establishing ADR and personal dosimeter systems, and differences in measurement values ​​caused by the position of the dosimeters and device characteristics.

[0006] Therefore, the objective of the present invention is to provide an integrated dosimeter capable of measuring exposure doses of beta rays, gamma rays, X-rays, and neutrons.

[0007] The objective of the present invention is achieved by an integrated dosimeter comprising: a plurality of filters having different energy reactivity depending on the type of incident radiation; a dosimeter unit including a plurality of dosimeter elements positioned corresponding to each of the filters and generating light by radiation passing through each of the filters; and a plurality of light amplification elements that convert the light generated from each of the dosimeter elements into a current signal, wherein the plurality of filters include a first filter, a second filter, and a third filter having selective energy reactivity for beta rays, gamma rays, and X-rays, respectively; and a fourth filter and a fifth filter having selective energy reactivity for neutrons and also having selective energy reactivity for the energy level of neutrons.

[0008] It may further include a microprocessor that receives a current signal converted from the above-mentioned optical amplifier and derives the exposure radiation dose according to the type of radiation.

[0009] It may further include a display unit that displays the exposure radiation dose according to the type of radiation derived from the above microprocessor.

[0010] The device further includes a main body that accommodates the dose unit, the optical amplification element, and the microprocessor, and the main body may have an insertion port formed therein for inserting and withdrawing the dose unit.

[0011] The above filter may be mounted in a row on one side of the main body.

[0012] The dose element corresponding to the first filter, the second filter, and the third filter includes an Al2O3:C element, and the dose element corresponding to the fourth filter and the fifth filter may include an Al2O3:C + 6Li2O3 element.

[0013] The first filter may be made of polyethylene phthalate, the second filter may be made of copper, the third filter may be made of aluminum, the fourth filter may be made of ABS resin (acylonitrile butadiene styrene), and the fifth filter may be made of cadmium.

[0014] According to the present invention, an integrated dosimeter capable of measuring exposure doses of beta rays, gamma rays, X-rays, and neutrons is provided.

[0015] FIG. 1 is a perspective view of an integrated dosimeter according to an embodiment of the present invention, and

[0016] FIG. 2 illustrates the attachment and detachment of a dose unit in an integrated dosimeter according to an embodiment of the present invention, and

[0017] FIG. 3 is a cross-section along III-III' of FIG. 1, and

[0018] FIG. 4 shows the operation of an integrated dosimeter according to an embodiment of the present invention.

[0019] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0020] To clearly explain the present invention, parts unrelated to the explanation have been omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0021] In addition, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, so the present invention is not necessarily limited to what is illustrated.

[0022] The present invention will be described below with reference to the drawings.

[0023] An integrated dosimeter according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3.

[0024] FIG. 1 is a perspective view of an integrated dosimeter according to an embodiment of the present invention, FIG. 2 shows the attachment and detachment of a dosimeter unit in an integrated dosimeter according to an embodiment of the present invention, and FIG. 3 is a cross-sectional view along III-III' of FIG. 1.

[0025] The integrated dosimeter (1) includes a main body (10), a filter (20), a dosimeter unit (30), an optical amplifier (40), a microprocessor (50), and a display (60).

[0026] The main body (10) has a flat cuboid shape, but is not limited thereto. Although not illustrated, the main body (10) may further include fastening means for wearing on a user's work clothes, etc.

[0027] The filter (20) is arranged in a row on the side of the main body (10) and is exposed to the outside. The position and arrangement method of the filter (20) are not limited thereto. Although not illustrated, the main body (10) has a fixing means for fixing the filter (20) or an exposure window formed therein for exposing the filter (20) to the outside.

[0028] The filter (20) includes a first filter (21) to a fifth filter (25). Each filter (21 to 25) is made of a material with a different energy reactivity depending on the type of incident radiation.

[0029] The first filter (21), the second filter (22), and the third filter (33) each have selective energy responsiveness for beta rays, gamma rays, and X-rays, respectively. Each filter (21 to 25) may be in the form of a thin plate.

[0030] Specifically, the first filter (21) may be made of polyethylene phthalate, the second filter (22) may be made of copper, and the third filter (23) may be made of aluminum.

[0031] The thickness of the first filter (21) may be 0.20 to 0.35 cm, but is not limited thereto. The thickness of the second filter (22) may be 0.03 to 0.10 cm, but is not limited thereto. The thickness of the third filter (23) may be 0.10 to 0.18 cm, but is not limited thereto.

[0032] The fourth filter (24) and the fifth filter (25) have selective energy reactivity for neutrons and also have selective energy reactivity for the energy levels of neutrons. The distinguishing energy levels may be determined according to regulations, etc., and, for example, may be two levels of 1.5 to 2.5 MeV and 4.0 to 5.0 MeV.

[0033] The fourth filter (24) may be made of ABS resin (acylonitrile butadiene styrene) and the fifth filter (25) may be made of cadmium. Since the neutron absorption cross-sectional area of ​​the cadmium filter is larger than that of the plastic filter, the difference in reactivity between the two materials can be used to distinguish neutron energy.

[0034] The thickness of the fifth filter (25) may be 0.02 to 0.08 cm, though not limited thereto.

[0035] The dose unit (30) includes a support (31) and a dose element (32). The dose element (32) generates light through radiation that has passed through the filter (20).

[0036] The dose element (32) includes five dose elements (32a to 32e) corresponding to each filter (21 to 25), and each dose element (32a to 32e) is arranged to be adjacent to and facing the corresponding filter (21 to 25).

[0037] The support body (31) is in the shape of a long rod, and the dose element (32) is mounted on the support body (31). In other embodiments, the dose unit (30) can be modified into various shapes.

[0038] The first dose element (32a), second dose element (32b), and third dose element (32c) corresponding to the first filter (21), second filter (22), and third filter (33) include an Al2O3:C element, and the fourth dose element (32d) and fifth dose element (32e) corresponding to the fourth filter (24) and fifth filter (25) include an Al2O3:C + 6 It includes a Li2O3 element.

[0039] When an Al2O3:C device is irradiated, the light emitted within a short period of time is called RL (Radio Luminescence), the light generated when photostimulation is applied is called OSL (Optically Stimulated Luminescence), and the light generated when heat is applied is called TL (Thermo Luminescence).

[0040] RL is used for real-time exposure dose measurement because it is generated immediately when radiation is applied to an Al2O3:C device, and OSL and TL are used for cumulative dose measurement because they are light and heat generated when applied, respectively.

[0041] As described above, the reactivity of the dose element (32) varies depending on the type and energy of the radiation passing through the filter (20). For example, when only beta radiation is irradiated onto the integrated dosimeter (1), the amount of light generated from the first dose element (32a) located after the first filter (21) becomes greater than the amount of light generated from the other four dose elements (32b to 32e), so the reactivity is high.

[0042] Since copper and aluminum have different attenuation coefficients for the photons gamma rays and X-rays, respectively, the difference in reactivity between the two devices is used to distinguish between the types of gamma rays and X-rays. Similarly, AlO2O3:C+ that has passed through plastic and cadmium filters 6 Thermal neutrons and fast neutrons are distinguished by using the difference in reactivity of the Li2CO3 element.

[0043] The dose unit (30) can be inserted into or withdrawn from the main body (10) through an insertion port (11) provided in the main body (10).

[0044] The optical amplification element (40) is also provided in five units corresponding to each dose element (32a to 32e) and is positioned close to the corresponding dose element (32a to 32e). The optical amplification element (40) converts the light generated from each dose element (32a to 32e) into a current signal.

[0045] The optical amplification element (40) may use a silicon photomultiplier tube (SiPM), although not limited thereto. The SiPM has an effective area of ​​4 mm 2 ~ 36 mm 2 It is small and is positioned near an Al2O3:C element (diameter about 1.7 mm) to process the light generated by the interaction between radiation and the Al2O3:C element.

[0046] The microprocessor (50) receives the current signal converted from the optical amplifier (40) and derives the exposure radiation dose according to the type of radiation. That is, the microprocessor (50) measures the X-ray, gamma ray, beta ray, and neutron doses in real time through a built-in dose reading algorithm using the difference in responsiveness of each dose element (32).

[0047] The display (60) is provided on the front of the main body (10) and displays the radiation exposure dose according to the type of radiation derived from the microprocessor (50), and this may be a real-time display.

[0048] In another embodiment, the integrated dosimeter (1) further includes a wireless communication means and can transmit the exposure radiation dose to a control room, etc. In addition, in another embodiment, additional types of radiation can be measured, or neutrons can be distinguished into three or more energy levels for measurement, in which case the number of filters, etc. may be increased.

[0049] The operation of an integrated dosimeter according to an embodiment of the present invention will be explained below with reference to FIG. 4.

[0050] The worker inserts the dose unit (30) through the insertion port (11), attaches the integrated dosimeter (1) to the work clothes, etc., and performs the work.

[0051] Radiation irradiated to the worker during work is also irradiated to the filter (20). The filter (20) is composed of five different filters (21 to 25) made of materials with different energy reactivity depending on the type of incident radiation, and filters beta rays, gamma rays, X-rays, and neutrons and supplies them to the dose unit (30). In addition, neutrons are separated by energy level and supplied to the dose unit (30).

[0052] Each dose element (32) generates light in response to incident radiation, and the light amplification element (40) converts the generated light into current and transmits it to the microprocessor (50). The microprocessor (50) calculates the exposure dose for each type of radiation based on the input current value. The calculated exposure dose is displayed on the display (60), allowing the worker to check it in real time.

[0053] After working for a certain period of time, the dose unit (30) can be withdrawn and the accumulated dose for each type of radiation can be determined using a separate reader.

[0054] For example, the domestic Atomic Energy Safety Act requires that the cumulative dose be read every three months. Therefore, to read the cumulative dose of a radiation worker, the dose unit (30) of the integrated dosimeter (1) can be taken out to the outside and the cumulative dose can be read with a reader.

[0055] Previously, four dosimeters were required to enter and exit the building of a reactor in operation, but when using the dosimeter of the present invention, real-time exposure dose measurement and cumulative dose reading for X-rays, gamma rays, beta rays, and neutrons are possible with a single dosimeter.

[0056] The aforementioned embodiments are examples for explaining the present invention, and the present invention is not limited thereto. Since a person skilled in the art to which the present invention pertains can implement the present invention by making various modifications therefrom, the technical scope of protection of the present invention should be determined by the appended claims.

Claims

1. In an integrated dosimeter, Multiple filters with different energy reactivity depending on the type of incident radiation; A dose unit comprising a plurality of dose elements positioned corresponding to each of the above filters and generating light by radiation passing through each filter; and It includes a plurality of optical amplifier elements that convert light generated from each of the above dose elements into a current signal, and The above plurality of filters are, A first filter, a second filter, and a third filter having selective energy response for each of beta rays, gamma rays, and X-rays; and An integrated dosimeter comprising a fourth filter and a fifth filter having selective energy reactivity for neutrons and selective energy reactivity for neutron energy levels.

2. In Paragraph 1, An integrated dosimeter further comprising a microprocessor that receives a current signal converted from the above-mentioned optical amplifier and derives an exposure radiation dose according to the type of radiation.

3. In Paragraph 2, An integrated dosimeter further comprising a display unit that displays the exposure radiation dose according to the type of radiation derived from the above-mentioned microprocessor.

4. In Paragraph 3, It further includes a main body that accommodates the above dose unit, the above optical amplification element, and the above microprocessor, and An integrated dosimeter having an insertion port formed in the main body for inserting and withdrawing the dose unit.

5. In Paragraph 4, The filter above is an integrated dosimeter mounted in a row on one side of the main body.

6. In Paragraph 4, The dose element corresponding to the first filter, the second filter, and the third filter comprises an Al2O3:C element, and The dose element corresponding to the above-mentioned fourth filter and the above-mentioned fifth filter is an integrated dosimeter comprising an Al2O3:C + 6Li2O3 element.

7. In Paragraph 6, The first filter mentioned above is made of polyethylene phthalate, and The above second filter is made of copper, and The above third filter is made of aluminum, and The above-mentioned fourth filter is made of ABS resin (acylonitrile butadiene styrene), and The above-mentioned fifth filter is an integrated dosimeter made of cadmium material.

Images