CN1115571C - Specific radioactivity measuring method and equipment - Google Patents
Specific radioactivity measuring method and equipment Download PDFInfo
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- CN1115571C CN1115571C CN 99113984 CN99113984A CN1115571C CN 1115571 C CN1115571 C CN 1115571C CN 99113984 CN99113984 CN 99113984 CN 99113984 A CN99113984 A CN 99113984A CN 1115571 C CN1115571 C CN 1115571C
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Abstract
The present invention relates to a method and a device for carrying out site measurement to natural specific activity of environment and building materials. The measuring method comprises the following steps: an energy spectrum analyzer is used for respectively measuring QR, Qth, Qk and sigma; when the quotient of Qk and QR is smaller than or equal to 2500, Kp=(sigma-Qth/B-Qk/c)/QR; when the quotient of Qk and QR is larger than 2500, Kp=(sigma+ QR/2-Qth/B-2 Qk/c)/QR; the contents (10<-6> or g/T) of Qu, QR, Qth and Qk are converted into specific activity (Bq. Kg<-1>); the technical elements of natural radionuclide are measured; calibration is carried out through a saturated model. The device forms a computer system by a 51 series high performance CMOS single chip microprocessor and other circuit sets. The present invention can carry out the site fast determination of natural specific activity and warning.
Description
The present invention relates in the nuclear technology field tests on-site measurement method and the device of natural radioactivity specific activity in relevant environment and the building materials.
For ensureing the public and offspring's health and safety, promote the development of building materials industry, proposed to be used to build building materials finished product, lithotome product and the building materialss such as brick and tile, building block, cement, concrete porous plate, forward purchasing part of house radiomaterial standard with industrial residues, promptly limited the merchant that specific radioactivity C obtains divided by the quality m of this material for the activity A of certain material with the specific activity size:
C＝A/m
In the above-mentioned explanation nuclear technology field tests relevant building materials has been proposed, the standard that lithotome product and building materials are limited with the specific activity size with the radioactivity of industrial residue, yet radium has been proposed just, thorium, the specific activity limitation standard of potassium, the specific activity limitation standard of uranium is not proposed, trace it to its cause is that used gamma spectrum analyser can't make uranium radium separately at present, up to Mr. Feng Weiheng application " gamma energy spectrum method for determining balance COEFFICIENT K p and device " after the patent of invention of ZL91107521.6 implements, just make uranium radium separately, can record the content of uranium at the scene, specific activity limitation standard to uranium so also can be proposed, but has only activity measurement so far, and be chemical analysis at the laboratory using trace uranium, neutron activation analysis, comprehensive β+γ, the measurement result of χ+γ, in addition, after though the patented technology of mensuration coefficient of balance Kp has been arranged, can the on-site measurement environment and building materials in uranium, radium, thorium, potassium content, however Q is worked as in the restriction of condition when being limited to above-mentioned patented claim
K/ Q＞2500 o'clock, Kp=(∑-Q
Th/ B-Q
k/ c) ÷ Q
RFormula is no longer suitable.Be that uranium, radium can not separate.
The objective of the invention is in the laboratory, to measure the present situation of activity, a kind of specific activity measuring method of on-the-spot material is provided and uses this method and custom-designed device at prior art.
Technical scheme of the present invention is made up of specific activity measuring method and device two parts thereof, and the step of specific activity measuring method is:
1, utilizes energy depressive spectroscopy, measure the equivalent uranium content Q of the radium of material respectively
R, thorium content Q
Th, potassium content Q
k, total amount of material equivalent uranium content ∑,
Work as Q
k/ Q
R≤ 2500 o'clock, the formula of usefulness ZL91107521.6 patent:
Kp=(∑-Q
Th/ B-Q
k/ c) ÷ Q
R(1) works as Qk/Q
R, adopt following formula at＞2500 o'clock:
Kp=(∑+Q
R/ 2-Q
Th/ B-2Q
k/ c) ÷ Q
R(2) root cabinet (1) and (2) formula are determined feature coefficient of balance Kp, measure the uranium content Qu under the nonequilibrium condition;
2, according to the above-mentioned Q that records
u, Q
R, Q
Th, Q
kContent (10
-6Or g/T) is converted into specific activity (BqKg
-1):
(1) 1 * 10
-6Uranium (Q
u)=11.498BqKg
-1Uranium-238 (Au)
(2) 1 * 10
-6Radium (the Q of equivalent uranium
R)=12.390BqKg
-1Radium-226 (A
Ra)
(3) 1 * 10
-6Thorium (Q
Th) 4.06BqKg
-1Thorium-232 (A
Th)
(4) 1 * 10
-6Potassium (Q
k)=315.04BqKg
-1Kalium-40 (A
k);
3, measure the technology essential factor of natural radionuclide by gamma energy spectrometer:
(1) counting rate of total road integral measurement is normalized to 10 seconds numerical value automatically, and the counting rate of all the other each road differential measurements is normalized to 100 seconds numerical value automatically;
(2) bales catch removes background values, revises the dead time of instrument automatically, 14 coefficients R
1, R
2, R
3, R (0), K
1, K
2, K
3, K (0), Tc, Tc (0), directly key in energy spectrometer;
(3) a cover saturation type model that adopts the nuclear industry radioactivity to reconnoitre test satellite location is uranium model (Uy), thorium model (Ty), and potassium model (Ky), mixture model (My) and truth of a matter model (Dy) are demarcated.
For using the custom-designed device of specific activity measuring method, as shown in Figure 1, it comprises high-voltage power supply, the NaI crystal, photomultiplier GDB, prime amplifier, 6 single tracks, the DC-DC transducer, counter and by 51 serial CMOS chip microprocessors, display, printer, the computer system that the AD transducer is formed, be characterized in, the certain gamma-rays of energy is absorbed by the NaI crystal, be converted to photon, be collected on the light anode by the ` high pressure on the photomultiplier (GDB), form and assembled the photoelectron that quickens, form voltage pulse signal at its anode and carry out the paraphase impedance matching by prime amplifier, main amplifier is given in the decay back, the pulse signal of output certain width, utmost point zero-compensation has been eliminated under the baseline and has been dashed, overload is recovered rapidly, for the drift of compensated foundation with counting rate, with base line restorer, in device, also used the pulse strenching technology, undertaken on steady by the timing single track, from down steady, radium, thorium, after 6 channel analyzers such as potassium carry out energy spectrometer, deliver to two 3 * 2 with the microprocessor compatibility
16Counter writes down six road umber of pulses.
Fig. 1 is the device hardware block diagram.
The present invention be based on that laboratory activity can be surveyed and existing environment and building materials in natural radioactivity specific activity limitation standard, " radiation protection standards for construction material " (GB6566-86), " lithotome radioactive protection classification control criterion " (JC 518-93), " building materials industrial residue radiomaterial limitation standard " (GB 6763-86).Key problem in technology of the present invention is: the conversion of specific activity and differentiation uranium, radium content, and directly survey uranium, thereby can record the specific activity of uranium, radium, thorium, potassium.
The conversion foundation of A, specific activity:
The grandson of Zhejiang medical college property is kind to be waited once at " Chinese radiologic medicine and protection " magazine and (has proposed the specific activity A of radium, thorium, potassium on the 5,1986, the 6th volume
Ra, A
ThAnd A
K(with BqKg
-1Be unit):
1g radium-226=3.65 * 10
10Bq
226Ra
1mg thorium=4.03Bq
232Th
1g potassium=31.00Bq
40K
The present invention is the relevant natural nucleic uranium-238 that was provided on " atomic physics " book by the publication of Guangdong education publishing house in 1988 according to Yang Fu family, radium-226, the corresponding m of thorium-232 and kalium-40 (abundance %), A (atomic weight) and T
1/2(half life period) substitution following formula:
Activity (Bq)=decay number of times/second
＝λN＝N/T
1/2
＝f(6.02×10
23m/A·T
1/2) (3)
The conversion formula of trying to achieve specific activity of the present invention is:
1g uranium=1.235 * 10
4Bq
238U
1g radium=3.655 * 10
10Bq
226Ra
1mg thorium=4.059Bq
232Th
1g potassium=31.504Bq
40K
B, distinguish uranium, radium content, directly survey the foundation of uranium:
This device is determined the equivalent uranium content (Q of radium by the bismuth-214 (the wide 1.66-1.90Mev in road) of 1.764Mev
R), can determine uranium content (Q by coefficient of balance (K) and emanation coefficient (Q) correction again
u): its expression formula is Q
U=Q
Bi/ K (1-α)
＝Q
R/Kp (4)
When uranium radium balance, Kp=K (1-α)=1, the scope of actual approval is:
Kp＝1.0±0.1 (5)
Kp when the inclined to one side uranium of balance＜0.9 (6)
Q in Kp when the inclined to one side radium of balance＞1.1 (7) formulas
RFour road gamma energy spectrometers that can be traditional provide.Kp can be by Mr. Feng Weiheng application " gamma energy spectrum method for determining balance COEFFICIENT K p and device " ZL91107521.6 patent of invention formula (1) and provide through improved formula (2), like this, can determine uranium content (Q by (4) formula
u).
Usually with the balance (Q of equivalent uranium unit
R) expression radium amount Q
Ra/ 3.4 * 10
-7, therefore, radium content is:
Q
Ra=3.4 * 10
-7Q
R(8) like this, also can derive for (4) formula expression formula roughly the same:
Kp＝K(1-α)＝Q
Ra/Q
u×1/3.4×10
-7
=(Q
Ra/ 3.4 * 10
-7)/Q
uTherefore, Q
u=Q
R/ Kp
The setting of C, related standards and abnormal alarm:
The representative specific activity of building materials commonly used adopts world's building materials representative value, and radium-226 is 50BqKg
-1, thorium---232 is 50BqKg
-1, potassium---40 is 500BqKg
-1, existing " radiation protection standards for construction material " (GB6566-86), " lithotome radioactive protection classification control criterion " (JC 518-93), the common ground of " building materials with industrial residue radiomaterial limitation standard " (GB 6763-86) is A
Ra/ 200≤1.0, i.e. internal radiation standard m
RIdentical, as world building materials representative value m
R=0.25, but the outer of three standards has certain difference according to value mr.
According to " radiation protection standards for construction material " external exposure restraint-type (GB6566-86) be: mr=A
Ra/ 350+A
Th/ 260+A
K/ 4000≤1.0 (9) calculate world building materials representative value mr=0.460.
The external exposure restraint-type of " building materials with industrial residue radiomaterial limitation standard " (GB 6763-86) is: mr=A
Ra/ 330+A
Th/ 260+A
K/ 3800≤1.0 (10) calculate world building materials representative value mr=0.475.
The radium equivalent concentration restraint-type of " lithotome radioactive protection classification control criterion " (JC 518-93) is: C
C Ra=A
Ra+ 1.35A
Th+ 0.088A
K≤ 350 (11) calculate world building materials representative value C
C Ra=161.5BqKg
-1, normalization obtains warning=C
C Ra/ 350=0.461, the mr value that this value is very calculated near (9) formula.Its reason is done following derivation and is promptly known, formula (9) both sides are respectively taken advantage of 350, obtains:
350 (A
Ra/ 350+A
Th/ 260+A
K/ 4000) (12) visibles (12) proximity (11) very≤350.
The foundation that apparatus of the present invention are provided with abnormal alarm is that this warning should be satisfied hygienic standard formula (9), satisfy environmental protection standard formula (10) and building standard formula (11) again, be suitable for to blur to sell to close to discuss to ask to hand over and get little principle, select the less relatively hygienic standard formula (9) of mr for use.
The internal radiation limits value of apparatus of the present invention removes m
R=A
RaOutside/200.0≤1.0, considered gamma-rays mensuration difficulty maximum, it is to living environment, and the human influence shows the uranium specific activity that increases, m
u=Au/200≤1.0.Uranium is poisonous to kidney, and particularly oral uptake has the danger that osteocarcinoma takes place.
Mr, m are set in this device
R, m
uThree limits values wherein had a value greater than 1.0 o'clock, and this device sends warning, and expression institute's living environment of surveying or building materials radioactivity anomaly occurs and exceed standard, and can not be used as lives use the room.
Warning system of this device and specific activity displayed value are equally applicable to building material industry standard and are used for the lithotome product is carried out radioactive protection classification control:
Not reporting to the police when device is mr≤1.0, m
R≤ 1.0, m
u≤ 1.0, be the category-A product, show that its usable range is unrestricted.
When device is reported to the police, according to mr, m
RBig I divide two classes: if 2.0 〉=mr＞1.0 or 1.25 〉=m
R＞1.0 stone matter building materials are the category-B product, can be used for the interior exterior finish and the industrial plants of the buildings of all the facing in the room.If 2.86 〉=mr＞2.0 or m
R＞1.25 stone matter building materials are the C series products, can be used for the exterior finish of all buildingss.If the stone matter building materials of mr＞2.86 can be used for sea wall, bridge pier and hearstone etc.
When measuring object is phosphate fertilizer and rock phosphate in powder, can check the radium-226 after this device is reported to the police with reference to GB8921-88, perhaps whether uranium-238 content surpasses 500BqKg
-1
The present invention be to " gamma energy spectrum method for determining balance COEFFICIENT K p and device " important breakthrough of patent of invention of ZL91107521.6, it one is a specific activity with nuclear industry metering saturated model scale nucleic, the 2nd, list is measured uranium simultaneously with gamma-rays, radium, thorium, the specific activity of potassium, the 3rd, fast-field evaluation, reliable results, the 4th, device has been formed computer system by 51 series high-performance CMOS chip microprocessors and other circuit, realized timing controlled, spectrum stabilization control, coefficient is preserved, bales catch removes background, counting normalization, coefficient of balance Kp computing, limits value computing and demonstration, realized the hole system of various audible alarm functions, the device design meets the requirement of three standards.
Apparatus of the present invention are tested the radioactive level of Beijing's subway part platform, and are as shown in table 1.Can illustrate from table 1:
1, naturally occurring radioactive substance (U, Ra, Th, K) and the coefficient of balance thereof to 21 platforms of Beijing's subway carries out the not damaged detection, and every platform is measured secondary, each Measuring Time 120S.
2, the coefficient of balance Kp average out to 1.01 of 21 platforms of Beijing's subway satisfies equilibrium condition
(Kp＝1.01)。
As Beijing Station (1.04), station, Qianmen (0.96), He Ping Men station (1.06), long Chinese toon southern station (1.06), station, Wu Ke Song (1.00), Fuchengmen station (1.04), Che Gongzhuan stand (0.96), station, Xizhimen (1.03), drum tower station (0.92), Gate of Stability station (1.09), station, Yonghe Palace Temple (1.06), 40 stations (0.93), east and station, Jianguomen (1.03).
3, the part belongs to unbalanced platform, wherein Kp＜inclined to one side uranium of 0.9 balance in respect of station, Xuanwumen (0.81), station, anistree village (0.80), station, ponding pool (0.75), station, Chaoyang Men (0.88) and station, Dongzhimen (0.89); What belong to Kp＞inclined to one side radium of 1.1 balances stands (1.41) station, Chongwenmen (1.13) and Nan Lishi way station in respect of reviving door.
4, respectively the stand gamma-radiation rate of building materials of investigation after tested, Beijing Metro all is lower than 5.2nC/kgh, internal radiation limits value m
R, m
UAll＜1.0, external exposure limits value m
rAll＜1.0, can be used as residential house and public life uses with the room.With the average specific activity of China's house mixing building materials (
226R
a43.7BqKg
-1,
232T
h50.4BqKg
-1,
40K665.6BqKg
-1, m
r0.49, m
R0,22) and the average specific activity of world's building materials (
226R
a50BqKg
-1,
232T
h50BqKg
-1,
40K500BqKg
-1,, m
r0.46, m
R0,25) compares, remove
40Outside the K, all low, be safe therefore.
In the warehouse of one tame sino-america joint-venture gold remittance secondary metal smeltery, Shanghai Zhou Pu area, measure uranium, radium specific activity severe overweight
238U is 6471.4BqKg
-1,
226Rawei16903.6BqKg
-1Waste and old steel from Ivory Coast import, import and export by Shanghai City and in time to be transferred to radioactive waste warehouse, Shanghai City after commodity inspection office and Environmental Protection Agency confirm.If with becoming secondary metal after this " invisible Kill hand " remelting, be used for building iron, its consequence is hardly imaginable.
Claims (3)
1, a kind of specific radioactivity measuring method, it comprises the following steps:
A, utilize the gamma spectrum analyser, measure the equivalent uranium content Q of the radium of material respectively
R, thorium content Q
Th, potassium content Q
k, total amount of material equivalent uranium content ∑, work as Q
k/ Q
R≤ 2500 o'clock, the formula of usefulness ZL91107521.6 patent:
K
p=(∑-Q
Th/ B-Q
k/ c) ÷ Q
R(1) works as Q
k/ Q
R, adopt following formula at＞2500 o'clock:
K
p=(∑+Q
R/ 2-Q
Th/ B-2Q
k/ c) ÷ Q
R(2) according to (1) and (2) formula, determine feature coefficient of balance Kp,
Q
U=Q
R/ Kp (3) measures the uranium content Qu under the nonequilibrium condition;
B, according to the above-mentioned Q that records
u, Q
R, Q
Th, Q
kContent (10
-6Or g/T) is converted into specific activity (BqKg
-1):
(1) 1 * 10
-6Uranium (Q
u)=11.498BqKg
-1Uranium-238 (Au)
(2) 1 * 10
-6Radium (the Q of equivalent uranium
R)=12.390BqKg
-1Radium-226 (A
Ra)
(3) 1 * 10
-6Thorium (Q
Th) 4.06BqKg
-1Thorium-232 (A
Th)
(4) 1 * 10
-6Potassium (Q
k)=315.04BqKg
-1Kalium-40 (A
k);
C, measure the technology essential factor of natural radionuclide by gamma energy spectrometer:
(1) counting rate of total road integral measurement is normalized to 10 seconds numerical value automatically, and the counting rate of all the other each road differential measurements is normalized to 100 seconds numerical value automatically;
(2) bales catch removes background values, revises the dead time of instrument automatically, 14 coefficients R
1, R
2, R
3, R (0), K
1, K
2, K
3, K (0), Tc, Tc (0), directly key in energy spectrometer;
D, a cover saturation type model that adopts the nuclear industry radioactivity to reconnoitre test satellite location are uranium model (Uy), thorium model (Ty), and potassium model (Ky), mixture model (My) and truth of a matter model (Dy) are demarcated.
2, the described method of a kind of use claim 1 and custom-designed device, it comprises high-voltage power supply, the NaI crystal, photomultiplier GDB, prime amplifier, 6 single tracks, the DC-DC transducer, counter and by 51 serial CMOS chip microprocessors, display, button seal device, the computer system that the AD transducer is formed, it is characterized in that, the certain gamma-rays of energy is absorbed by the NaI crystal, be converted to photon, be collected on the light anode by the ` high pressure on the photomultiplier (GDB), form and assembled the photoelectron that quickens, form voltage pulse signal at its anode and carry out the paraphase impedance matching by prime amplifier, main amplifier is given in the decay back, the pulse signal of output certain width, utmost point zero-compensation has been eliminated under the baseline and has been dashed, overload is recovered rapidly, for the drift of compensated foundation with counting rate, with base line restorer, in device, also used the pulse strenching technology, undertaken on steady by the timing single track, from down steady, radium, thorium, after 6 channel analyzers such as potassium carry out energy spectrometer, deliver to two 3 * 2 with the microprocessor compatibility
16Counter writes down six road umber of pulses.
3, device according to claim 2 is characterized in that, is provided with internal radiation m in the described microprocessor
R, m
uAnd external exposure m
rAlarming value:
m
R＝A
Ra/200≤1.0
m
u＝Au/200≤1.0
m
r＝A
Ra/350+A
th/260+A
k/4000≤1.0
A
Ra, A
U, A
Tb, A
KBe respectively the specific activity of radium, uranium, thorium, potassium.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 99113984 CN1115571C (en) | 1999-08-18 | 1999-08-18 | Specific radioactivity measuring method and equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 99113984 CN1115571C (en) | 1999-08-18 | 1999-08-18 | Specific radioactivity measuring method and equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1295256A CN1295256A (en) | 2001-05-16 |
| CN1115571C true CN1115571C (en) | 2003-07-23 |
Family
ID=5277116
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 99113984 Expired - Fee Related CN1115571C (en) | 1999-08-18 | 1999-08-18 | Specific radioactivity measuring method and equipment |
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| Country | Link |
|---|---|
| CN (1) | CN1115571C (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103135118B (en) * | 2011-11-25 | 2015-04-29 | 中国原子能科学研究院 | Gamma radioactive source absolute activity measuring method |
| CN102621170B (en) * | 2012-03-09 | 2013-11-06 | 湖北方圆环保科技有限公司 | Method for automatically determining measurement time in detection of energy spectrometer |
| CN103308936A (en) * | 2013-06-18 | 2013-09-18 | 中国原子能科学研究院 | Reactor pool cleaning method used for miniature neutron source reactor decommissioning |
| CN103728648B (en) * | 2013-12-18 | 2015-12-09 | 中国原子能科学研究院 | Determine the method and apparatus of uranic hexafluoride gas uranium abundance measurement device background |
| CN105425274A (en) * | 2015-12-02 | 2016-03-23 | 中国原子能科学研究院 | Measurement and determination method for age of uranium sample |
| CN105572716A (en) * | 2016-01-27 | 2016-05-11 | 上海出入境检验检疫局动植物与食品检验检疫技术中心 | Quick detection method for radioactive caesium in cosmetic |
| CN106569246A (en) * | 2016-10-28 | 2017-04-19 | 南京理工大学 | Method for analyzing radioactive activity based on heavy metal content in sludge |
| CN110082812B (en) * | 2018-01-25 | 2022-11-25 | 中国辐射防护研究院 | Improved energy track counting redistribution method for gamma spectrum analysis |
| CN108457640B (en) * | 2018-01-26 | 2021-08-06 | 东华理工大学 | Uranium mine logging quantitative method for correcting natural gamma total amount by fusing prompt neutron time spectrum |
| CN110727020B (en) * | 2019-10-11 | 2022-11-11 | 中广核研究院有限公司 | Measuring and scaling method, device and system for medium-low level waste and storage medium |
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