Radiological health protection standard for industrial X-ray detection
GBZ 1 17-2002
1 range
This standard specifies the radiation protection requirements for industrial X-ray flaw detection devices, flaw detection workplaces and related personnel.
This standard is applicable to the production and use of industrial X-ray flaw detection devices below 500kV (hereinafter referred to as X-ray devices).
2 normative reference documents
The clauses in the following documents become the clauses of this standard by reference. All subsequent modifications (excluding errata) or revisions of dated reference documents are not applicable to this standard. However, parties who have reached an agreement according to this standard are encouraged to study whether the latest versions of these documents can be used. For undated reference documents, the latest edition is applicable to this standard.
GB 8703 radiation protection regulations
3 Terms and definitions
The following terms and definitions apply to this standard.
3.1special room for X-ray flaw detection.
Working process of X-ray flaw detection for internal defects in special flaw detection room.
3.2 X-ray field flaw detection X-ray defect field detection
The working process of using mobile or portable X-ray flaw detection equipment to carry out X-ray photographic inspection of internal defects of objects outdoors, in the production workshop or at the installation site.
3.3 Inspection Room in Inspection Room
An irradiation room where the X-ray device and the detected object are placed for X-ray fluoroscopy and has a certain shielding effect.
Radiological health protection requirements for X-ray flaw detection equipment
4. 1 technical requirements for protection
4. 1. 1 X-ray tube head
4. 1. 1.65438+
4. 1. 1.2 X-ray tube head shall be equipped with beam limiting device.
4.1.1.3 The aperture of the X-ray tube head window should not be larger than the size required for the rated maximum useful beam injection.
4. 1. 1.4 X-ray tube head must have the following marks:
A) the name or trademark of the manufacturer;
B) Model and serial number;
C) rated tube voltage and rated tube current of X-ray tube;
D) the position of the focus;
Date of manufacture.
4. 1.2 Specific release kinetic energy rate of leaked radiation air
Under rated working conditions, the specific release kinetic energy rate of leaked ray air at X-ray tube focus 1m shall meet the following requirements:
Tube voltage, kV
Air specific release rate of leaked rays, mgy h- 1.
& lt 150
& lt 1
150~200
& lt2.5
& gt200
& lt five
4. 1.3 controller
4. 1.3. 1 The controller must be equipped with on or off display devices for X-ray tube voltage, X-ray tube voltage, tube current and irradiation time.
4. 1.3.2 X-ray devices working under fixed tube voltage or fixed tube current must be equipped with numerical values indicating tube voltage or tube current on the controller.
4. 1.3.3 The controller must be equipped with an external alarm or indication device connected with high voltage.
4. 1.4 connecting cables
For mobile or portable X-ray equipment, the connecting cable between the controller and the X-ray tube head or high-voltage generator shall not be shorter than 20m.
4. 1.5 product description
The product manual shall indicate the model, specifications, main technical indicators and protective performance of the X-ray device.
4.2 Test conditions for specific release kinetic energy rate of leaked rays to air
A) The maximum effective cross-sectional area of the X-ray tube head window is shielded with 10 layer of half-value absorption material, as shown in Appendix A (informative appendix);
B) Under rated working conditions, measure the specific kinetic energy rate of air on the spherical surface with the focus as the center and the radius of 1m with a dose rate meter, which should be the average measured value of 100cm;
C) The monitoring error of leaked rays should be less than 30%.
4.3 Acceptance Rules
4.3. The protective performance of1X-ray device meets the requirements of this standard, which shall be inspected by the inspection department of the production unit and sampled by the radiation health protection supervision department.
4.3.2 Type test (inspection according to the items specified in this standard) shall be carried out under the following circumstances.
A) Before the new product or old product brick factory is put into production;
B) Continuously produced products are produced at least once a year;
C) When it is put into production at intervals of more than one year;
D) When the design, process or material of the product changes, which may affect the protective performance of the product.
A) and d) Type tests shall be attended by radiation health technical service institutions designated by local provincial health administrative departments. The results of the type test shall be sent to this institution for filing.
5 Radiological health protection requirements for X-ray flaw detection workplaces
5. 1 X-ray special flaw detection room
5. 1. 1 The setting of special flaw detection room must fully consider the surrounding radiation safety, and the flaw detection room must be separated from the operation room.
5. 1.2 The shielding design of flaw detection room should fully consider the irradiation direction and range of useful beams, the workload of the device and outdoor conditions, and ensure that the annual effective dose of outdoor personnel is less than its corresponding limit.
5. 1.3 The protective performance of the door of the flaw detection room shall be the same as that of the same side wall, and the door-machine interlocking safety device and lighting signal indicator shall be installed. X-ray equipment can only be used for radiographic inspection after the door is closed.
5. 1.4 The window of the flaw detection room must avoid the irradiation direction of the useful wire harness, and should have the shielding and protective performance of the same side wall.
5.2 X-ray on-site flaw detection operation
5.2. 1 During X-ray flaw detection, factors such as the distance between the controller and the X-ray tube and the object to be detected, irradiation direction, time, shielding conditions, etc. must be considered to ensure that the irradiation dose of the flaw detection operator is lower than the dose limit and should be as low as possible.
5.2.2 When the specific kinetic energy rate of the air around the inspected object is above 40μ Gy h- 1, it can be classified as a control area. See Appendix B (normative appendix) for special circumstances. A clearly visible warning sign "Do not enter the X-ray area" must be hung at the boundary of the control area, and the flaw detection operator should operate outside the boundary, otherwise protective measures must be taken.
5.2.3 During radiographic inspection, when the specific kinetic energy rate of the air outside the boundary of the control area is above 4 μ Gy h- 1, it can be classified as a management area. Warning signs, such as signal lights, electric bells, warning ropes, etc., must be set on the boundary, and a clearly visible warning sign "No entry for irrelevant personnel" should be hung. When necessary, a special person should be assigned to give a warning. It should also be noted that there should be no frequent public near the boundary of the control management area.
6 radiation protection monitoring
6. 1 Personal dose monitoring of on-site flaw detection operators must be strengthened.
6.2 After the completion of the special flaw detection room, acceptance monitoring must be carried out, and on-site monitoring should be paid attention to when the working conditions change.
6.3 When on-site flaw detection and on-site working conditions change, on-site monitoring must be carried out, and the determined control area and management area shall be verified.
Appendix a
(Information Appendix)
Half-value layer of X-ray protective material
A. 1 approximate half-value layer of wide X-ray beam shielding material
See table A. 1.
Table A. 1 Approximate half-value layer of wide X-ray beam for lead and concrete
X-ray tube voltage
D1/2cm
kilovolt
lead to
specific
50
0.005
0.4
75
0.0 15
—
100
0.025
1.6
150
0.029
2.2
200
0.042
2.6
250
0.086
2.8
300
0. 17
3.0
celebrity
0.25
3.0
500
0.3 1
3.6
Additional record b
(normative appendix)
Determination of control area and management area of X-ray field flaw detection operation
B. 1 Define the specific kinetic energy rate of the air at the boundary of the control area as 4o μ gy h-1,and calculate it according to three tenths of the annual effective dose limit of radiation workers (15mSv) and the actual start-up time of 7.5h per week. If the actual start-up time t per week is greater than 7.5h, the specific kinetic energy rate of the boundary air in the control area shall be calculated as follows:
K = 300/ ton (B. 1)
Where: k refers to the specific kinetic energy rate of the boundary air in the control area, μ Gy h-1;
T- actual startup time per week, h
300- 15 msv is distributed to the value of 50 weeks per year, that is, 300μSv.
At the same time, the specific kinetic energy rate of the air at the boundary of the management area also changes accordingly.