TWI317023B - Measurement and calibration method of volume source calibration phantom - Google Patents

Description

1317023 IX. Description of the invention: [Technical field of the invention] The present invention relates to a method for correcting a prosthesis and a correction method, in particular, directly using a body source source of various densities to correct a prosthesis to obtain a calibration curve of the species efficiency. The density of the nuclear waste sample is used to correct the measurement efficiency of the prosthesis, and the total activity or specific activity of the different density of the object can be measured, and the two samples of the accurate measurement result can be used to correct the prosthesis and Its measurement and correction methods. Seed source [Prior Art] Up to now, the instrument for measuring the total activity of very low activity volume nuclear waste is a large area plastic flash detection. r), the advantages are the spoke sample = short, the waste volume is not limited, and the shortcomings of the loss are not = the use of the waste activity monitor has the following correction method, "% _ (1) live measurement Underestimation or high-profile, g # μ & on the same waste physics reading to consider the weight and neglect the ineffective ^ correction ^ degree, the seam produced by the self-absorption effect (7) measured vertical density "usually use early - substance shielding in the monitor In-body construction: a slight sample is not a single substance composition (7) the sample measurement position is not set, when the fish is changed to test the sample - the law is placed in the shield body under the direction of the general-purpose threat... read misplaced (4) sample Non-conformity, device distance is not - diligence = large volume t ' and efficiency correction time from each side of the fire safety management H reading analysis 4 difference; therefore can not meet the radiation protection 'in the male activity requirements of waste activity analysis. (5) There is no correction for the total live measurement error caused by the light energy and multi-nuclear time of various nuclear species in 1317023, vegetables and samples. In addition, the researcher* is more advanced and can replace the original method of correcting the source efficiency of the activity monitor. The implementation of nuclear waste plus horse, χ>" X^^' is used to judge nuclear waste and As for the classification of waste without waste, the current efficiency correction method for plastic scintillation detectors is (1) US Th circle-Eberllne uses the penetration factor (tr_issiQn facto) to correct the different standard mass self-absorption effects. The formula is TF = shielded shot. The net count of the source/net count of the no-screen source, which is generally used as compensation for the correction efficiency of the unshielded source in the geometric center of the air, within the efficiency of the water prosthesis correction that the efficiency calibration target will be established. The penetration factor parameter is set to i, and the weight is input in the quality parameter (every 10kg I-unit); then the sample weight of the different materials to be tested will be relative to the weight of the slaves who have been used as slaves. (4) The corrected sample is added to the total Activity; (2) multi-density correction efficiency of German Rna company using single substance iron plate; (3) Japan (japan Nuclear Energy Saf milk)

Organization) The multi-nuclear calibration efficiency of metal tubes and metal plates; (4) US Technology Corporation uses multi-core seed source and single material Brazilian logs (density 1) to determine the multi-weight (〇~60Kg) correction efficiency. However, at present, (4) these correction methods are widely reduced to consider only large _ weight and geometry 'but 疋 & have sufficient correction of the material mass self-absorption effect of the sample and the reaction of various substances with energy' can not get the correct sample of the horse degree. In summary, there is a need for a body source calibration prosthesis and its measurement and correction methods to solve the problems associated with conventional techniques. [Summary of the Invention] 7 1317023 The purpose of the test is to provide a seed source correction prosthesis and its quantity to obtain the poor disk == use a variety of different density of the body source to correct the prosthesis to close the production of the second; The calibration curve 'measures the measurement efficiency of the new ^^ ' ' mountain body source correction prosthesis according to the nuclear waste sample to be tested, and can measure the fine addition and the same fruit of the sample of different nuclear samples. U-horse activity or specific activity, to achieve accurate measurement of the knot. The second project of the invention is to provide the purpose of correcting the activity of the various types of artificially-corrected false f and JL. For the measurement and provision of the sample - the source of the source correction of the prosthesis and the accuracy of its measurement of the efficiency of the analysis of the sample activity, to achieve the above purpose, the present invention provides, the supervision: there = Correction of the prosthesis package without 15 = body "and at least - the source plate body, the system stack ® in the container; the plate system and the plurality of plates stacked on the solid source" the at least - source Preferably, the "metal material" is "iron", preferably the dry plate body can be - non-selected as cardboard, wood, gypsum, fort; Among them, the rubber and the glass - preferably, the source is a -r source. [, the optional 1317023, please refer to Figure 1, the waste activity monitor and body The source 'correction prosthesis diagram. The waste activity monitor 丨 is a six-sided cubic shield 10 having the same thickness lead combination, and the shield 10 has a detection space 100 in the detection space 100. There are six radiation active detectors 11 of the same large area on the inner wall surface. In this embodiment, the spokes The activity detector U is a plastic scintillation detector. The detection space 100 is provided with a weight meter for measuring the weight of the object to be tested. The activity monitor further has a microcomputer processor 12, which utilizes the microcomputer. The library software and calibration parameters can be used to read the total activity (Bq) or specific activity (Bq/g) of the sample and background, the efficiency calibration and the minimum measurable activity of the instrument, and can be printed. And displaying the analysis result. In the detection space 100, there is a body source for the uniform activity to correct the false body 2. As shown in FIG. 1A, the periphery of the body source correction prosthesis 2 is a standard valley. In the state 20, the internal system 20 has an internal space 21. Referring to Figure 2B, the figure is a stack of the plate body and the source plate. The inner space 21 can be stacked with a plurality of uniform materials. The plate body 22 and the source plate body 23. The material of the plate body 22 may be a metal material or a non-metal material. The metal material is selected as an iron plate; the non-metal material is cardboard, wood board, gypsum, acrylic, rubber, Glass. In this embodiment, there will be seven kinds of The material is cut into a large area uniform material with a length of 33cm, a width of 33cm and a thickness of lcm, and each material is re-stacked to form a uniform corrected prosthesis with a length of 33cm, a width of 33cm and a height of 30cm, which is similar to the size of the sample preparation container. The weight ranges from 5 kg to 1 〇〇kg, and the relative weight of the material weight (33αη3) gives the average density of the corrected prosthesis, and the paperboard (density of 0.15 gon 3), wood board (density 〇 55gcm 3 ), gypsum (density) 75 75gcm 3), acrylic (density 1.13gcm3), rubber (density 18〇gcm3), glass (density 1317023 degrees 2. curry and iron plate (density 3) to form a calibration prosthesis of various densities. In the seven density individual correction prostheses, seven large-area of the source plates are symmetrically equally spaced. Please refer to FIG. 3A, which is a cross-sectional view of a preferred embodiment of the present invention. The source plate body is strong, has a top layer of 23B, a source layer 23, a leak-proof filter paper layer, and a protective layer 233. The leakage filter paper layer is formed on the lower shell layer. The long-range source layer 231 is formed on the leak-proof filter paper layer 232. The source layer 231 has a plurality of emitters. a layer 23〇 formed on the leakage preventing paper layer 32, the upper shell layer 23〇 and the lower shell layer 2 are provided to provide protection for the source layer 23 八八': the source is a 7 Source. The 7-ray source can be selected as „Cobalt, 37 、, Μ, and its constituents. Next, the method of forming the plurality of shots is described, please refer to Figure 3Β, in the leakage prevention. The filter paper layer 232 is evenly cut into 36 points, and the mother point is evenly dropped into the crucible. The 2CC liquid source 2310 has a total of 36 drops, and each drop source 2310 is diffused into a circle of less than 5 cm in diameter, and each circle is adjacent but not Overlapping nuclear species. The total activity of each of the seven large-area sources of 57Co, l37Cs, 54Mn and 6°Co were 58 kBg, 72 kBg and 90 kBg, respectively. Through four nuclear species Co, Cs, 54Mn and 6°Co, a total of four different energy and seven different densities of uniform density of the body source corrected prosthesis can be formed. Please refer to FIG. 4, which is a schematic diagram of a preferred embodiment of the measurement and correction method of the present invention. The steps are as follows: (1) 岔 degree and measurement efficiency correction - the calibration method 3 has the following steps: First, step 30 is performed using a set of multi-nuclear large-area surface source and solid density of 7 kinds of density. The source corrects the rice limb and contains a wide range of energy and density. Then proceed to step 31, in the geometric position of the 1317023 heart, and the correction of the (4) photon energy dependence ft energy plus the energy phase ns energy difference, in the geometric center of the waste debt detection ,, respectively, to place a large area plus the source of the horse. (Can = 1^136_, _ 662 _, 5%1 (energy 834 _, 5 and Co / energy 1173 (four) and 1332 keV) measurement, get the horse nuclear

The nuclear species measurement efficiency of C〇H and 137Cs is divided by the energy branch ratio of each nuclear species (96% for 3⁄4, 85% for 137CS, 1% for % and 200% for %), and 57C is obtained. The energy and photon detection efficiency of 54Mn, 6°Co and l37cs at different average densities are shown in Figure 7. It shows that the photon detection rate increases and increases, and the density changes to photon detection efficiency at high energy. The influence is large. On the contrary, the change of density at low energy has a small response to photon detection efficiency. In addition, the detection efficiency of photon energy of different densities 57C〇, 54Mn, 6QC◦ relative to Cs is shown in Table 1, as sample non- The total activity of the single nuclear species is calculated. One

Table 1. ----- Guangduo Miri photon energy detection efficiency ratio density 57Co / 137Cs Cg/cm3) 54Mn / 137Cs 60C〇 / 137C 0.15 0.40 1. 25 1.49 0.5 0.32 1.18 1.44 0.75 0. 26 1. 13 1.41 1.13 0. 23 1.01 1.30 1.8 0. 17 0.79 1. 11 2.5 0. 16 0. 77 0. 99 3.0 0.08 0.63 0.85 1317023 (3) Sample measurement then proceed to step 32 to treat a waste sample & The same volume of the standard container to form - check:, f and body source correction false step 33, using the monitor to break the weight of the test sample ° ° ° = down to the density of the product (weight / suspect and then Should: Positive =:= 叩 corresponds to the total activity of the horse. Finally, the step %, and then (4) 胄men•=(relative to the nuclear energy) and the multi-nuclear gamma total activity correction, you can get the correct The total activity of the gamma. Τι△ type (4), verification analysis of the whole box live measurement instrument needs to have the correct total activity of the gamma meter. Method, (four) the requirements of the difficulty of activity, the New Zealand certificate#:

For multinuclear species (mainly 1n, c〇), the accuracy of the individual nuclear species analysis results is within the acceptable range. X (4.1) Minimum measurable activity (MDA) • The minimum measurable activity of the US Nuclear Regulatory Commission's NUREG-1507 (1998) is calculated as follows: jW; ext MDy4 = 3 + 4.65 where: (detector limit , 95〇/〇 trustworthiness)

Cm. Background count rate (CpS) f: Nuclear measurement efficiency t: Measurement time (sec)

Although the average background count is 1500, the results of the average average density of 5ΐ〇, 54Mn, (3) and the lowest measurable 1317023 calculated by Eberline WCM-10PC for 2 minutes are shown in Table 2 and Figure 5. (7) and (3) The lowest measurable activity has a value of the same, when the average density is 丨g/cm3~2 g/cm, the Co and 37cs have the lowest value of -a; when the average density is <;lg/ The MDA values of 6°Co and I37Cs at cm3 and >2 g3/cm3 are slightly higher than 2 times of the MDA value of 1 g/cm3~2 g/cf, which is about 0.003 Bq/g&〇.〇1〇 Bq/g,s

The change in the i-rate is a linear trend, and the change in the efficiency of the nuclear geometric center is the trend of the a number. Therefore, when the weight is too light or too heavy, the change in efficiency is greater than the weight of the MDA at 6QC〇 at various same densities. All are lower than l37Cs.

The maximum measurable activities of Mn, 6°Co and I37CS are 〇. 〇〇9Bq /g, 0.001 Bq /g and 〇. 〇1〇Bq /g, 54Mn and mCs are closer to their various enthalpies. The materials such as cloth, water, iron pipe and steel bar are very similar. In addition, the minimum measurable activity (Bq/g) of Mn, Co and 137Cs can meet the ex-factory release limit of the competent authority, and the minimum measurable activity of the measuring instrument should be lower than the IAEA of the International Atomic Energy Agency. The requirements for the nuclear export derivation limits of the specification (eg, 54 Mn, % 〇, and 137 Cs are 0. lBq/g). In addition, refer to the operation manual of the cleaning waste monitor of Antech Company type 3300-200. The minimum measurable activities of the instruments measuring 6QCo and 137Cs in the background of 2 minutes are 〇. 〇〇9 Bq /g and 0. 015 Bq/g' is similar to the lowest measurable activity of the instrument of this study activity monitor. In addition, 'observing the relationship between the minimum measurable activity (MDA) and the day ττ of the plastic flash detector, 'when the s ten time is lmin, 2 min, 5 min, 8 min and 10 min, The change of the lowest measurable activity of the 6CCo and the 137Cs is reduced by 1.9 times and the minimum measurable activity of the 137Cs is reduced by 1 min when the measurement time is extended from 5 min to 5 min. 2. 0 times; the minimum measurable activity of 6GCo and 137Cs is reduced by 2.5 times and 2.7 times when the measurement time is extended from 1 min to 1 〇min, respectively, when it is extended from 8 111 丨 11 to 1 〇 111 丨 11 The lowest measurable activity of 6()(^〇 and 137匚5 1317023) also changed little, only 9% and 15% respectively. Table 2. Minimum measurable activity of waste activity monitor (Bq/g Density (g/cm3) 57Co 54Mn, 37Cs 60C〇0.15 0. 059 0.018 0.019 0.0095 0.5 0. 021 0.0058 0.0061 0.0029 0.75 0. 018 0.004 0.0042 0. 002 1.13 0. 013 0. 003 0.0032 0.0014 1.8 0.0084 0. 0017 0.0018 0.00075 2.5 0.0088 0. 0018 0.0018 0.00083 3.0 0. 015 0. 0019 0. 002 0.0008 (4-2) Calculate the total formula Μ 2 A, · p, K ! +RX EX/) For: 137Cs nuclear activity (Bq) f / : 137Cs energy 662 keV photon detection efficiency (%) A : 137Cs energy 662 keV photon branch ratio (%) A: activity of each nucleus relative to 137Cs than five X : Detection efficiency ratio of each nucleus to 137Cs (8) Nuclear activity ratio = / is C: a nuclear activity (HPGe analysis result) (b) Nuclear detection efficiency ratio = / f / A. Waste detection A certain horse energy photon efficiency (%): a nuclear emission photon branch ratio (%) 1317023 . · (C) shows the total activity of the horse is = from / private * 137Cs detection efficiency five / = heart corpse (^) Index nuclear activity cold = is /1 < / + rule ^: five ^ 'any nuclear activity ^ x = A, · X Rx (8) external release derived limit Σ times / person, ^ 7 4, 〆 a k species Activity limit (export limit) (4-3) Multi-nuclear analysis placed seven uniform surface sources n7cs (72〗 05Bq), Lu 54Mn (45309Bq), 6°Co (86048Bq) and 57C in the calibration prosthesis 〇 (42777Β (〇, its standard total activity is 246239Bq, nuclear activity ratio 57Co: 54Mn: 6QC0: 137Cs is 0.593: 0.628: 1.19 : :1). Calculate the density using l37Cs efficiency. The total activity of the samples of lgcm_3, 1 ·8 gem 3 and 2.5 gcm_3 is shown in Table 3' and the total activity of the standard point source is corrected after the four nucleus activities of the sample are corrected by the above formula. The differences in accuracy were 1.82%, 2.59%, and 1.74%, respectively. (Private 3-1) Density l lgcm-3 false 馥 137Cs efficiency measurement index nuclear activity Ai is l37cs total activity At== 321197 Bq '57C〇, 54Mn and 6°C〇 relative to 137Cs is 0.23 , 1. 01 and 1· 30 :

Ai = At / Σ(^+ RxE^ ) -321197 / [ 1+(0.593x0.23)+(0.628xl.01)+(1.19x ' 1.30)] - 73500 Bq * Ax = Ai x ^x, 57Co =Ai x 0.593 = 43586 Bq 54Mn=Ai x 0.628-46158 Bq 6〇c〇=Ai x 1.19 = 87465 Bq Corrected total activity of the gamma At = 250709 Bq i6 .1317023 Standard point source plus horse total activity = 246239 Bq corrected total activity and standard total activity difference = 3.36% (4-3-2) density 1. 8gcnf3 prosthesis 137Cs efficiency measurement index nuclear activity Ai is mCs total activity At = 327780 Bq, , 54Mn and 60C 〇 relative to 137Cs &amp; 0.17, 0.79 and 1. 11 :

Ai=At/Z(l+^^) =327780 / [ 1+(0.593χ0.17)+(0.628x0.79)+( 1.19X 1.11)] = 74058 Bq Ax = Ai x Rx » 57Co = Ai x 0.593 = 43916 Bq 54Mn=Ai x 0.628 = 46508 Bq 60C〇-Ai x 1.19- 88129 Bq Modified total activity of the gamma At = 252611 Bq Standard point source plus total activity = 246239 Bq Total activity and standard total Activity difference = 2.59% Density 2. 5 gcm-3 prosthesis u7Cs efficiency measurement index Nuclear activity Ai is 137Cs total activity At = 325651 Bq, 'Co, 54Mn and 60c 〇 relative 137Cs &amp; 0.16, 0. 77 and 0. 99:

Ai=At/X(l+^£x) = 325651 / [ 1+(0.593χ0.16)+(0.628χ0.77)+(1.19χ 0.99)]二 185345 Bq

Ax=Ai X brother, 57Co = Ai x 0.593 = 43552 Bq 54Mn=Ai x 0.628 = 46123 Bq 1317023 60Co=Ai x 1.19 = 87398 Bq Corrected total activity of the gamma At = 250517 Bq Standard point source Jiama total live Degree = 246239 Bq Corrected difference between total activity and standard total activity = 1.74 % Parameter gem'3 57Co 54Mn ^Co Rx 0.593 0.628 1.19 Px 96% 100% 200% ί'.ν 1.1 3.5 % 14.5% 16.6% 1.8 2.5 % 11.4% 14.1 % 2.5 2.4 % Π.1 % 12.7% 137

Cs 1 85% The following advantages are provided by the above-mentioned body provided by the present invention (1) The t, the two bodies, and the (four) decision (Bq/g) of the system can meet the requirements of the lower limit of the c° of the competent authority, and are suitable for Calculate the bribes evenly _ = quasi _ export limited evaluation results, such as samples are non-single-nuclear discards. (2) The nature of the system Correspondence value, energy dependence, 需, according to the nuclear density and 欵 马 活 计算 计算 计算 , , , 验 验 验 验 验 验

At 5%. (3) Single-average of four nuclear species;: = difference of activity of the positive activity The uniformity of activity of the positive prosthesis &lt;7.9%. The multi-density body of the shell consists of a wide range of densities and energies, and the built-in multi-twisted body source is the accuracy of the released material. Then the political rate of the South to measure the nuclear facilities 丨 1317023

The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto. That is, the equivalent changes and modifications made by the invention in accordance with the scope of the present invention will remain without departing from the scope of the present invention and should be considered as further implementation of the present invention. 19 1317023 [Simple description of the diagram] Figure 1 is a schematic diagram of the dental activity monitor and the body source calibration prosthesis. Figure 2A is a perspective view of a standard container. Figure 2B is a schematic diagram of stacking of the plate body and the source plate body. Figure 3A is a cross-sectional view showing a preferred embodiment of the source plate of the present invention. FIG. 3B is a schematic diagram showing the source distribution of the source plate body of the present invention. Figure 4 is a schematic diagram of a preferred embodiment of the measurement and correction method of the present invention. Figure 5 shows the minimum measurable activity of instruments of different density nuclear species. Figure 6 shows the relationship between the minimum measurable activity of the instrument and the measurement time. Figure 7 shows the various energy photon efficiencies of different density corrected prostheses. [Main component symbol description] 1- Waste activity monitor 10 - Shield 100 - Detection space 11 - Radiation activity detector 12 - Microcomputer processor 2 - Body source calibration prosthesis 20 - System container 21 - Internal Space 22 - Plate 23 - Source plate 230 - Upper shell layer 20 1317023 231 - Source layer 2310 - Source 2 3 2 _ Leak proof; Paper layer 233 - Lower shell layer 3 - Correction method 30~ 34-flow

Claims (1)

1317023 (Amendment of the specification of the patent No. 095138162) X. Patent application scope: 1. The seed source correction prosthesis is set in the monitor. . The interior has a accommodating space, and the accommodating space is provided with a degree detector, the body source calibrating prosthesis comprising: a Koda field shooting a container; a plurality of slabs stacked in the container; At least one source plate body, the money has a plurality of paving sources, and the charm plate system and the plurality of plates are stacked in the container. , 彳', wherein the plate of the gold wherein the plate is the non-rubber and wherein the shot is the r 2 · the application of the general (4) item can be a metal material. 3. If the application for patent _ Item 2 of the body source correction prosthesis material is an iron plate. 4. The body source calibrated prosthesis as described in claim 1 may be a non-metallic material. 5. The body-source hybrid prosthesis metal material as described in the application for patent (4) 4 may be selected from one of cardboard, wood, plaster, and acrylic glass. The body source calibration prosthesis source as described in claim 1 of the patent scope is a 7-ray source. 7. If the body source calibration prosthesis described in claim 6 is applied, the source may be 57 lead, 137 planer, 54 fierce, 6. The limbs are one of them. 8. For example, please ask the patent Fanyuan! The calibrated prosthesis of the item, wherein the circular source. The body axis is 9. The body axis correction prosthesis described in Item 8 of the application butterfly (4), wherein the circle 22 surgical menstruation correction replacement page 1317023 (correction of the specification of the case No. 095丨38162) Less than 5cm. The body-source calibration prosthesis of claim 1, wherein the source plate further comprises: a protective shell layer; a leak-proof filter paper layer formed on the lower shell layer The leakproof filter paper layer further has the plurality of emitters; and an upper shell layer is formed on the leakproof filter paper layer to provide protection for a plurality of sources. 11. A method of measuring and correcting, comprising the steps of: providing a plurality of body source calibration prostheses, each individual source correction prosthesis having a different density; using the plurality of body source sources to correct the prosthesis Obtaining a calibration curve of the relationship between the density and the measurement efficiency in a monitor; loading a waste sample into the valley of the same volume as the body source calibration prosthesis to form a test sample; using the Detecting the density of the test sample, and correcting the curve to obtain one of the test samples corresponding to the total activity of the horse; and correcting the corresponding total activity of the horse in a correction manner to obtain the correct total activity of the horse. 13. The metal material of the 12th patent application is an iron plate. The measurement and correction method described in the item, wherein the 23 ice department monthly correction replacement page 13.17023 - (the amendment to the specification of the patent number No. 095 丨 38162) 14. The measurement and the measurement described in claim 12 The method of calibration, wherein the non-metallic material can be selected from the group consisting of cardboard, wood, stone, acrylic, rubber, and glass. 15. The method of measuring and correcting according to claim 12, wherein the source of the body source correction prosthesis is a T source. ^ 16. For the measurement and correction method described in claim 15 of the patent application, the r source may be selected to be 54 violent, 6. Record and its composition: Measurement and correction methods, which are corrected according to the energy dependence factor and multiple lines. 17. The correction method described in item 11 of the scope of patent application is to calculate the total activity of the horse plus the total activity of the corresponding horse. twenty four