CN109284514A - A kind of design and method of construction of large space Low background radiation laboratory - Google Patents
A kind of design and method of construction of large space Low background radiation laboratory Download PDFInfo
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- CN109284514A CN109284514A CN201710600325.7A CN201710600325A CN109284514A CN 109284514 A CN109284514 A CN 109284514A CN 201710600325 A CN201710600325 A CN 201710600325A CN 109284514 A CN109284514 A CN 109284514A
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/10—Geometric CAD
- G06F30/13—Architectural design, e.g. computer-aided architectural design [CAAD] related to design of buildings, bridges, landscapes, production plants or roads
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
- E04G21/00—Preparing, conveying, or working-up building materials or building elements in situ; Other devices or measures for constructional work
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
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Abstract
The invention belongs to radiation protection technique fields, are related to the design and method of construction of a kind of large space Low background radiation laboratory.The design in turn includes the following steps with method of construction: structure and shielding design, Low background construction and the choosing of shielding material ratio, simulation calculating, Design of Ventilation System, structural member manufacture machining control, Construction control, acceptance gauging.Using the design and method of construction of large space Low background radiation laboratory of the invention, the natural radiation background in the laboratory of design and construction can be greatly reduced.
Description
Technical field
The invention belongs to radiation protection technique fields, are related to the design and construction of a kind of large space Low background radiation laboratory
Method.
Background technique
After the raising of Public environmental attitude, especially Fukushima, Japan nuclear accident, nuclear and radiation safety is concerned, core
How accurately sampling analysis is carried out to a large amount of samples after accident and other natural calamities, becomes pendulum and pacify in core and radiation environment
Problem in full monitoring emergency.In this context, the concept in large space Low background laboratory is applied and is given birth to.
Low background laboratory is that environment activity measures, work is analyzed in the measurement of the low-level radiations such as pollution monitoring in human body
Basis.It in the case of considering core and radiation accident, needs to carry out the work that accurately measures of a large amount of samples, how to design and build big sky
Between Low background laboratory become the urgent task in the field of China's radiation protection in recent years, but it is also smaller to be in progress in this regard.
Summary of the invention
The object of the present invention is to provide the designs and method of construction of a kind of large space Low background radiation laboratory, substantially to drop
The natural radiation background of low design and the laboratory built.
In order to achieve this, the present invention provides a kind of large space Low background radiation laboratory in the embodiment on basis
Design and method of construction, the design in turn include the following steps with method of construction: structure is built with shielding design, Low background
It makes with shielding material than choosing, simulation calculating, Design of Ventilation System, structural member manufacture machining control, Construction control, acceptance gauging.
In a preferred embodiment, the present invention provides the design of large space Low background radiation laboratory a kind of and builds
Method is made, wherein the structure and shielding design step are more using Low background concreting cooperation lead/carbon steel/stainless steel plate
Layer Shielding plan.
In a preferred embodiment, the present invention provides the design of large space Low background radiation laboratory a kind of and builds
Method is made, wherein the Low background is built and shielding material is than selecting step to main in lead, iron and stainless steel shielding material
Radionuclide carries out specific radioactivity choosing.
In a kind of more preferred embodiment, the present invention provides a kind of design of large space Low background radiation laboratory
With method of construction, wherein the primary radionuclides are235U、226Ra、232Th、40K、137Cs、60Co、210Pb。
In a preferred embodiment, the present invention provides the design of large space Low background radiation laboratory a kind of and builds
Method is made, includes the photon energy analysis emitted in concrete, Sources term analysis, establish coagulation wherein the simulation calculates step
Soil structure model and increase shielding layer structure model.
In a preferred embodiment, the present invention provides the design of large space Low background radiation laboratory a kind of and builds
Method is made, wherein increasing air-cooled constant-temperature constant-moisture air processing machine group in the Design of Ventilation System step, increases active carbon and inhales
The air cleaning unit of adsorption device or radioaerosol.
In a preferred embodiment, the present invention provides the design of large space Low background radiation laboratory a kind of and builds
Method is made, indoor ventilation rate is tested wherein increasing in the Design of Ventilation System step, interior is kept to be positive pressure
And/or sealing is taken to metope through hole.
In a preferred embodiment, the present invention provides the design of large space Low background radiation laboratory a kind of and builds
Make method, wherein the structural member that machining control is manufactured in the structural member manufacture machining control step include steel built-in fitting,
Shield door, shielding construction part.
In a preferred embodiment, the present invention provides the design of large space Low background radiation laboratory a kind of and builds
Method is made, wherein carrying out in the structural member manufacture machining control step to structural member material therefor, transport, manufacture overall process
The control of radioactivity Low background.
In a preferred embodiment, the present invention provides the design of large space Low background radiation laboratory a kind of and builds
Method is made, wherein avoiding polluting to auxiliary material used and tool strict control in the Construction control step；Cross-operation
When carry out linking, avoid operation due to construction or polluted with material is improper.
The beneficial effects of the present invention are designs and construction side using large space Low background radiation laboratory of the invention
The natural radiation background in the laboratory of design and construction can be greatly reduced in method.
Detailed description of the invention
Fig. 1 is that the design of illustrative large space Low background radiation laboratory of the invention and method of construction are designed and built
Laboratory structure diagram.The laboratory is empty by concrete layer 1, shield door 2, ventilating system 3, shielded layer 4, laboratory internal
Between form.In lower part provided with shielding layer 4 again of the inner space of concrete layer 1, laboratory internal space is formed in shielded layer 4.It is logical
The bottom of wind system 3 is connected with the top 5 in laboratory internal space, and ventilating system 3 passes through shielded layer 4.In the side of concrete layer 1
Design-build has shield door 2 on the outside of face.Simulation calculates measurement point 7 and is located at laboratory internal space middle apart from 6 position of ground
At 1 meter.
Specific embodiment
A specific embodiment of the invention is further illustrated below in conjunction with attached drawing.
The design and method of construction of illustrative large space Low background radiation laboratory of the invention are as follows.
1 background survey
Low background experiment chamber background is mainly made of following four aspect: cosmic ray, radon, earth natural gamma radiation and being built
Build the radiation of material Radionuclide generation.
The proposed address area ambient radiation levels in Low background laboratory are investigated first, understand cosmic ray in region
The Dose Rate contributed.The earth natural gamma radiation (such as soil, water, air) in the proposed region in laboratory is surveyed
Amount calculates for later period simulation and provides accurate data.Especially according to GB/T11743-2013 " the γ energy of Radionuclides in Soil
Spectral analysis method " surrounding soil is analyzed, to replace surrounding soil when necessary to achieve the purpose that reduce environmental exact details.
2 structures and shielding design
General to recommend in infrastructure Low background laboratory, above-ground structures can also play the role of shielding cosmic ray,
Contribution of the cosmic ray to laboratory background values is effectively reduced.Laboratory structure design is cooperated using Low background concreting
The multilayer screens schemes such as lead/carbon steel/stainless steel plate fully consider safety, the reliability of structure.
3 Low backgrounds are built and shielding material is than choosing
Material therefor includes building to have to pass through material than choosing with shielding material, and material ratio is elected to be as Low background shielding harness
The most important link implemented, plays decisive role to the background in Low background laboratory.Material point more used than selecting
Analysis method " is used according to GB/T11743-2013 " the gamma spectrum analysis method of Radionuclides in Soil ", GB/T11743-1989
The standard method of the low specific activity gamma activity sample of semiconductor γ spectrum analysis " and GB 6566-2010 " radioactive material core
Element limitation ".To guarantee that the background values after Low background laboratory is built up reaches design objective, Building wood used in Low background laboratory
Material and built-in fitting have to pass through stringent background ratio choosing.The shielding materials such as lead, iron and stainless steel used inhale lead room air
Receive being affected for dosage rate, it is necessary to in material235U、226Ra、232Th、40K、137Cs、60Co、210The major radiations such as Pb
Nucleic is chosen low-activity material after specific radioactivity is selected and is fabricated.
4 simulations calculate
The photon energy analysis emitted in 4.1 concrete
4.1.1 238U decays234Th, the latter's decay are234mPa, and then start234The decay chain of U
Cause234Th (25.5h) and234mThe half-life period of Pa (1.17min) is shorter, with238U is in secular equilibrium (activity phase
Deng).234U half-life period is longer without the concern for decay thereafter.So only considering238U、234Th、234mOne system of Pa decay emission
Arrange X, γ photon.
The photon of transmitting: 0.063 (3.5%), 1.093 (4%), 0.765 (0.30%), 1.100 (0.6%), 0.100
(50%), 0.70 (24%), 0.90 (70%).
4.1.2 232Th decays228Ra, the latter's decay are228Ac, and then enter decay chain, until decay is208Pb is (steady
It is fixed)
Due to comparing232The half-life period of the half-life period of Th (1.41 × 1010a), the nucleic of centre decay are very short, with232At Th
In secular equilibrium (activity is suitable).So considering232Th、228Ra、228Th、224Ra、220Rn、216Po、212Pb、212Bi、208Tl declines
Become a series of X, γ photons of transmitting.
The photon of transmitting: 0.34 (15%), 0.908 (25%), 0.96 (20%), 0.084 (1.6%), 0.214
(0.3%), 0.241 (3.7%), 0.55 (0.07%), 0.239 (47%), 0.3 (3.2%), 0.04 (2%), 0.727
(7%), 1.620 (1.8%), 0.511 (23%), 0.583 (86%), 0.86 (12%), 2.614 (100%).
4.1.3 226Ra decays222Rn, the latter's decay are218Po, and then enter decay chain, until decay is210Pb
(21a)
Due to210The half-life period of Pb is longer, without the concern for decay thereafter.It is contemplated that226Ra、222Rn、218Po、214Pb、214Bi、210Tl、210A series of X, γ photons of Pb decay emission.And since the above nucleic half-life period is shorter, with226Ra
In secular equilibrium (activity is equal).
The photon of transmitting: 0.189 (4%), 0.510 (0.07%), 0.295 (19%), 0.352 (36%), 0.609
(47%), 1.12 (17%), 1.764 (17%), 0.799 (0.014%), 0.296 (80%), 0.795 (100%), 1.31
(21%).
4.1.4 it is 1.460MeV, the γ photon that branching ratio is 11% that 40K, which launches energy,
4.2 Sources term analysis
238The source item that the decay of U nucleic generates:
| Energy MeV | 0.063 | 1.093 | 0.765 | 1.100 | 0.100 | 0.70 | 0.90 |
| Activity Bq/m3 | 723.68 | 827.06 | 62.03 | 124.06 | 10338.3 | 4962.38 | 14473.62 |
232The source item that the decay of Th nucleic generates:
| Energy MeV | 0.084 | 0.214 | 0.55 | 0.239 | 0.3 | 0.04 | 0.727 |
| Activity Bq/m3 | 262.18 | 49.16 | 606.29 | 11.47 | 7701.56 | 524.36 | 327.73 |
226The source item that the decay of Ra nucleic generates:
| Energy MeV | 0.189 | 0.510 | 0.295 | 0.352 | 0.609 | 1.12 | 1.764 |
| Activity Bq/m3 | 801.44 | 14.03 | 3806.86 | 7213 | 9416.97 | 3406.14 | 3406.14 |
40The source item that the decay of K nucleic generates:
| Energy MeV | 1.460 |
| Activity Bq/m3 | 15647.94 |
4.3 establish concrete structure model
Concrete structure model is established using Mercurad software, six surface concrete thickness degree are greater than 500mm.According to each group
Dose Rate in concrete structure is calculated through software simulation at source item information.
4.4 increase shielding layer structure model
Increase shielded layer on the basis of concrete structure model using Mercurad software, and will be in shielding material238U
、232Th、226Ra、40K、60Co、137Cs、210The nucleic source item Input Software such as Pb carries out simulation calculating.Simulation calculates measurement point 7 such as
Shown in Fig. 1, being located at laboratory internal space middle apart from 6 position of ground is at 1 meter, to obtain Dose Rate reason
It is laboratory theory background values by value.
5 Design of Ventilation System
Since Low background laboratory has higher requirements to temperature, humidity and radon daughter concentration, air-cooled constant temperature and humidity need to be increased
Air-treatment unit is to guarantee indoor constant temperature, constant humidity requirement.Indoor air-changing number is greater than 5 times/hour.
The adsorbent equipment of active carbon or the air cleaning unit of radioaerosol etc. and the wall to laboratory need to be increased
And ground is sealed using steel surface application, makes indoor radon and radon daughter concentration to reduce the precipitation of radon in the civil engineering building materials of laboratory
It is as low as possible.Furthermore indoor ventilation rate is tested by increase, holding interior is positive pressure, it is close to take metope through hole
The measures such as envelope, are effectively reduced indoor radon daughter concentration.
6 structural members manufacture machining control
Structural member needed for Low background laboratory is built includes steel built-in fitting, shield door, shielding construction part etc., is needed to knot
The overall processes such as component material therefor, transport, manufacture carry out the control of radioactivity Low background, reach needs of expected design to ensure.
7 Construction controls
Auxiliary material and tool need strict control used in the process ofs work progress is installed, decorated etc., avoid in above-mentioned mistake
It is polluted in journey.Cross-operation part should carry out linking, avoid operation due to construction or polluted with material is improper.
Various pipelines are carried out after Low background laboratory concrete layer and shielded layer, supplement protection and encapsulation process.
It cut, drilled, polish etc. for stereotype in work progress when operating, controlled the generation of lead oxides, avoid
Environmental pollution.
The sealing welding of strict control outermost layer stainless steel shielded layer is entered the room with the radon for preventing building to be precipitated.
Obviously, various changes and modifications can be made to the invention without departing from essence of the invention by those skilled in the art
Mind and range.If in this way, belonging to the model of the claims in the present invention and its equivalent technology to these modifications and changes of the present invention
Within enclosing, then the present invention is also intended to include these modifications and variations.Above-described embodiment or embodiment are only to the present invention
For example, the present invention can also be implemented with other ad hoc fashions or other particular form, without departing from of the invention
Main idea or substantive characteristics.Therefore, the embodiment of description is regarded as illustrative and non-limiting in any way.This
The range of invention should be illustrated that any variation equivalent with the intention and range of claim also should include by appended claims
Within the scope of the invention.
Claims (10)
1. a kind of design and method of construction of large space Low background radiation laboratory, which is characterized in that the design and construction
Method in turn includes the following steps: structure is built with shielding design, Low background and shielding material is than choosing, simulation calculating, ventage
System design, structural member manufacture machining control, Construction control, acceptance gauging.
2. design according to claim 1 and method of construction, it is characterised in that: the structure is adopted with shielding design step
Cooperate lead/carbon steel/stainless steel plate multilayer screen scheme with Low background concreting.
3. design according to claim 1 and method of construction, it is characterised in that: the Low background is built and shielding material
Than selecting step to carry out specific radioactivity choosing to the primary radionuclides in lead, iron and stainless steel shielding material.
4. design according to claim 3 and method of construction, it is characterised in that: the primary radionuclides are235U
、226Ra、232Th、40K、137Cs、60Co、210Pb。
5. design according to claim 1 and method of construction, it is characterised in that: it includes coagulation that the simulation, which calculates step,
The photon energy analysis that emits in soil, Sources term analysis establish concrete structure model and increase shielding layer structure model.
6. design according to claim 1 and method of construction, it is characterised in that: increase in the Design of Ventilation System step
Add air-cooled constant-temperature constant-moisture air processing machine group, increases the air cleaning unit of activated carbon adsorption device or radioaerosol.
7. design according to claim 1 and method of construction, it is characterised in that: increase in the Design of Ventilation System step
Add the indoor ventilation rate of experiment, keep interior to be positive pressure and/or sealing is taken to metope through hole.
8. design according to claim 1 and method of construction, it is characterised in that: the structural member manufacture machining control step
The structural member of manufacture machining control includes steel built-in fitting, shield door, shielding construction part in rapid.
9. design according to claim 1 and method of construction, it is characterised in that: the structural member manufacture machining control step
The control of radioactivity Low background is carried out to structural member material therefor, transport, manufacture overall process in rapid.
10. design according to claim 1 and method of construction, it is characterised in that: to institute in the Construction control step
With auxiliary material and tool strict control, avoid polluting；Linking is carried out when cross-operation, avoid operation due to construction or with material not
When polluting.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113187274A (en) * | 2021-04-22 | 2021-07-30 | 中国辐射防护研究院 | Tumor radiotherapy center individual layer building plane layout structure |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5416330A (en) * | 1992-11-18 | 1995-05-16 | Technology International Incorporated | Radiation monitoring system for containers, livestock, and foodstuff |
| CN102644393A (en) * | 2012-04-26 | 2012-08-22 | 中国核电工程有限公司 | Design method for central laboratory of whole nuclear power station |
| US20140027676A1 (en) * | 2012-07-12 | 2014-01-30 | Petr Kovár | Shielding composite building materials with a low internal level of ionising radiation |
| CN205451796U (en) * | 2015-12-18 | 2016-08-10 | 中国辐射防护研究院 | Low background shield assembly |
| CN106312245A (en) * | 2015-09-28 | 2017-01-11 | 中国辐射防护研究院 | Welding method for steel linear of low-background laboratory |
| CN106340335A (en) * | 2015-09-28 | 2017-01-18 | 中国辐射防护研究院 | Low-background laboratory shielding structure |
| CN106646584A (en) * | 2016-10-28 | 2017-05-10 | 中国计量科学研究院 | Shielding box |
-
2017
- 2017-07-21 CN CN201710600325.7A patent/CN109284514A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5416330A (en) * | 1992-11-18 | 1995-05-16 | Technology International Incorporated | Radiation monitoring system for containers, livestock, and foodstuff |
| CN102644393A (en) * | 2012-04-26 | 2012-08-22 | 中国核电工程有限公司 | Design method for central laboratory of whole nuclear power station |
| US20140027676A1 (en) * | 2012-07-12 | 2014-01-30 | Petr Kovár | Shielding composite building materials with a low internal level of ionising radiation |
| CN106312245A (en) * | 2015-09-28 | 2017-01-11 | 中国辐射防护研究院 | Welding method for steel linear of low-background laboratory |
| CN106340335A (en) * | 2015-09-28 | 2017-01-18 | 中国辐射防护研究院 | Low-background laboratory shielding structure |
| CN205451796U (en) * | 2015-12-18 | 2016-08-10 | 中国辐射防护研究院 | Low background shield assembly |
| CN106646584A (en) * | 2016-10-28 | 2017-05-10 | 中国计量科学研究院 | Shielding box |
Non-Patent Citations (1)
| Title |
|---|
| 焦保良等: "低本底实验室设计", 《核技术》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113187274A (en) * | 2021-04-22 | 2021-07-30 | 中国辐射防护研究院 | Tumor radiotherapy center individual layer building plane layout structure |
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