GB/T 19661.2-2005 Safety requirements for nuclear instruments and systems Part 2: Radioactive protection requirements
Some standard content:
ICS 27. 120. 01
National Standard of the People's Republic of China
GB/T19661.2--2005
Safety requirements for nuclear instruments and systems-Part 2; Requirements of protection from radioactivity(IEC 60405;2003,Nuclear instrumentation—Constructional requirements and classification of radiometer gauges, MOD)2005-01-24 Issued by
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China Standardization Administration of China
2005-06-01 Implementation
National Standard "Safety Requirements for Nuclear Instruments and Systems" (referred to as this standard in the preface> is divided into two parts: Part 1: General requirements: Part 2: Radioactive protection requirements. This part is Part 2. For issues such as the overall and structure of this standard, please refer to the introduction of Part 1 of this standard. GB/T 19661.2—2005
This part specifies the radioactive protection requirements for nuclear instruments containing radioactive sources (hereinafter referred to as nuclear instruments containing sources) and systems. The safety requirements are given in the non-standard part 1, so this part should be used in conjunction with part 1. This part is modified to adopt IEC.60405:2003 Structural requirements and classification of nuclear instruments using radioactive sources (English 2nd edition). The format of this part is (GH/T1.? 2000 & Standardization J. Work Guide Part 1 : Structure and writing rules of standards" and GI3/T20000.22001≤Guidelines for standardization work Part 2: Rules for the adoption of international standards" The chapter and article numbers of this part are the same as those of IEC60405. Considering the needs of practical application, this part makes the following modifications to IEC60405. The revised clauses in the text are marked with a vertical single line in the blank space at the edge of the document. A list of these modifications and detailed reasons is given in Appendix A (see Table A, 1). This part makes the following modifications to TFC:60425 The important modifications are as follows: a) The name of the standard is changed from "Structural Requirements and Classification of Measuring Instruments Using Radioactive Sources for Nuclear Instruments" to "Safety Requirements for Nuclear Instruments and Systems Part 2: Radioactive Protection Requirements". The content of 1E60405 on structural requirements is actually the radioactive protection requirements for measuring instruments using radioactive sources (a type of nuclear instruments containing radioactive sources). 1) Chapter 1 "Scope" is compiled according to GB/T 1.12000, and the scope of application of this part is changed from "applicable to the manufacture, installation and use of measuring instruments using radioactive sources" to "applicable to the manufacture, storage, transportation, installation and use of nuclear instruments containing radioactive sources for inspection or verification", because in addition to measuring instruments using radioactive sources, for nuclear instruments containing radioactive sources for inspection or verification, even if the activity of the radioactive source is different and the use is different (the activity of the inspection source or verification source is usually lower), the protection requirements for radioactivity are the same. Chapter 2 "Normative References" and the corresponding modifications to 5.5 and 10.2 are as follows: c) Remove the IEC and IS() documents that are not referenced or not related to safety; d) Add reference to Part 1 of this standard, and remove JEC61010:2001: --· Change the international standards used to reference the corresponding national standards (GB4075--2003 and G18871-2002); h) Delete the introduction and foreword of E60405;
\) Use the decimal point symbol ",\ to replace the decimal point sign \,". Appendix A of this part is the information appendix.
This part is proposed by the National Technical Committee for the Promotion of Nuclear Instruments and Meters Standardization. This part is under the jurisdiction of the Nuclear Industry Standardization Research Institute. Drafting unit of this part: Nuclear Industry Standardization Research Institute, main drafter of this part: Xiong Zhengyuan.
1 Scope
Safety requirements for nuclear instruments and systems
Part 2: Radioactive protection requirements
GB/T 19661.2-2005wwW.bzxz.Net
/19661 This part of GB/T 19661 specifies the radioactive protection requirements for nuclear instruments and systems, including the classification of radioactive protection, protection against ionizing radiation, determination of dose equivalent rate, test methods, level codes and signs, accompanying documents, etc. This part applies to the manufacture, storage, transportation, installation and use of nuclear instruments and systems containing nuclear sources (hereinafter referred to as nuclear instruments). This part does not apply to portable nuclear instruments and nuclear instruments with X-ray tubes. It can be applied to these nuclear instruments by reference. 2 Normative referenced documents
The clauses in the following documents become the clauses of this standard before being referenced by this standard. For all referenced documents with a date, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, the parties who have reached an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For undated referenced documents, their latest versions are applicable to this standard. GB4075 Sealed radioactive sources - Requirements and classification GB4075--2003.eqVJSO2919:909)GE18871-2002 Basic standard for protection against ionizing radiation and safety of radiation sources (International Atomic Energy Agency Safety Book No. 115, 1996 edition)
GB/T 19661.1 Safety requirements for nuclear instruments and systems Part 1: General requirements IS0 921 Nuclear energy vocabulary (IS0 921:1997) 1EC60476 Nuclear instruments General requirements for electrical measurement systems and instruments using ionizing radiation sources (1E:C60476:1993) 3 Terms and definitions
In addition to the definitions in ISO921 and IEC.6076, this part also uses the following definitions: 3. 1
Radiometric gauge A control and measurement device for non-destructive measurement of the measured object, which contains at least one radioactive source, at least one detector and related electromechanical equipment.
Note: In this standard, the measuring device using a radioactive source is referred to as the measuring device. 3.2
Fixed mounted measuring instrument [ermanenlyiastaled radiomctricgauge] A measuring device using a radioactive source fixedly installed at the measuring location. Note: The measuring device can also be located on mobile equipment (e.g., on ships and vehicles). The installation of the detector and the source box can be either fixed or movable. 3.3
Sealed source scalcd snurcc
Radioactive material sealed in a shell or tightly combined with a certain material. Under the specified conditions of use and under normal wear, this cladding and bonding material can be sufficient to maintain the sealing of the source. 3.4
Suurce holder
A fixed or movable mechanical device used to fix or carry the source. 3.5
measuring head
It includes one or more radioactive sources and detectors and (when necessary) sensitive elements for compensation. It also includes units that can be used to measure GB/T19661.2--2005
and correct the influencing factors.
Note: The measuring head can be composed of separate micro-boxes and detector covers, etc., and can also include electronic units for signal processing. 3.6
Source housing
The part of the measuring head that contains the radioactive source, source holder and basic shielding and the gate mechanism (if any). 3.7
Detector housing
The part of the measuring head that covers the detector.
Note: The detector housing can also be combined with the source box, especially for the backscatter measurement system. 3.8
Useful radiation
Useful radiation
Useful beam
sefulbcar
The part of the radiation emitted by the radiation source and used for measurement. 3.9
Collimation device
Equipment that limits useful radiation to one or more directions and ranges. 4 Classification and grading
By-beam nuclear instruments are Class A nuclear instruments, including those equipped with collimators (see Figure 1 for Class A measuring instruments). Fixed level meter or density meter Fixed thickness meter · Detector:
Radioactive source. Follow-up level meter
Mobile thickness meter
Figure 1 Schematic diagram of the structure of Class A measuring instrument
Radioactive source
Level meter or density meter placed in the dry material container
Radioactive detection
Class A nuclear instruments should be designed so that, in addition to the useful beam, the radiation attenuation meets the requirements of this standard. 4.2 Nuclear instruments with omnidirectional beams
GB/T 19661.2--2005
Nuclear instruments with omnidirectional beams are Class B, including nuclear instruments without collimators or other nuclear instruments that do not comply with Class A requirements (Class B measuring instruments are shown in Figure 2)
Measurement instruments with radioactive sources in the material container
Detector:
Radioactive source.
4.3 Radiation protection classification of nuclear instruments
Measurement instruments with radioactive sources and detectors in the material container
Figure 2 Schematic diagram of the structure of Class B measuring instruments
For the values of dose efficiency in accordance with Chapter 8: Nuclear instruments should be classified according to Table 1. Table 1 Radiation protection classification Sperm protection classification Maximum dose rate at 5 cm distance Maximum dose rate at 1 m distance Not tested Not tested 4, 4 Gate and source support temperature classification 2>1 mSv/h>0, 5 mSv/h1 mSw/h>25 μSv/hs:100 Sv/h Follow-up level meter with radioactive source in material container 0. 05 mSv/h2-7.5 μS/h0. 5 mSv/h7. 3 μSr/h
3:50 jμ5v.h
-2, 5 μSvh
25 μSv/h 1 ≤7.5 μSv/h
?.5 μ5v/h「Special
2.5μSv/l,, Special
Based on the designed maximum and minimum operating temperatures, the gates and source holders of nuclear instruments shall be temperature graded according to Table 2: Temperature classification of gates and source holders
Special Grading
Most Commercial, 1. Operating Temperature/TC
Minimum Operating Temperature/℃
Not Tested
Not Tested
GB/T 19661.2--2005
5 General requirements
5.1 Measuring gap
To prevent workers from putting their hands or any other part of their body into the useful beam, the measuring instrument should be constructed to keep its measuring gap to the minimum practical. This also includes any other point that may come close to the useful beam. If necessary, the user should install additional protective facilities.
5.2 Source support
The design and structure of the source support should:
a) be easy to install the radioactive source under radiation safety conditions; b) be easy to reliably position the radioactive source under radiation safety conditions. 5.3 Source box
The design and structure of the source box should:
a) protect the radioactive source from collisions that could damage it under normal working conditions, and provide other means to protect the radioactive source if it is used in nuclear instruments. b) prevent unauthorized persons from disassembling the radioactive source (e.g., provide a safety lock, use special tools to open the source box or a confidential packaging procedure, etc.), and prevent the expected adverse physical and chemical effects according to user information (e.g., install attached protective measures or connect any other protective measures related to the installation); d) prevent the radioactive source from falling off or being torn in the event of mechanical damage or fire to the source box to ensure the safety of the radioactive source, and e) complete the leakage test of the radioactive source under radiation safety conditions: 5.4 Collimation of useful beams The radioactive source is paired with a detector head so that the collimator of the Class A nuclear instrument can limit the useful beam so that when there is no material between the source and the test plate, the dose of the useful beam passing through the detector or its shielding meets the requirements of 6.1. For Class B nuclear instruments, the source holder should reduce the dose equivalent rate outside the useful beam as much as possible. 5.5 Other requirements
In addition to the above requirements, the general requirements for nuclear instrument safety are as follows (B/T19661.1, and the safety requirements for the used nuclear sources are as follows GB4075. 6 Protection against ionizing radiation
6.1 General requirements
The design of the nuclear instrument or the installation of the nuclear receiver shall ensure that the dose equivalent rate at the place where non-professional radiation personnel (public) can enter does not exceed the prescribed value for continuously manned workplaces in the corresponding national regulations. For the prescribed location, see GB18871:202. The accompanying document should include the following information, namely, the user is responsible for complying with the radiation signs and shielding or barriers and ensuring that the actual limit values prescribed in the corresponding national regulations are not exceeded.
6.2 Requirements for Class A nuclear instruments
The source box shall ensure that the dose equivalent rate of the corresponding radiation protection classification complies with the provisions of 4.3: The source box shall be equipped with a door that can block the useful beam. For remote-controlled or servo-mechanism-controlled equipment The gate should be automatically closed when any fault occurs in the control circuit (such as power supply failure). The gate should not be opened automatically after the fault is eliminated until the system returns to normal operation mode by human intervention. 6.3 Requirements for Class B nuclear instruments
For Class B nuclear instruments, an attached shielding cover should be provided to store source holders and (or) sources in a non-use state, unless the source is contained in a source box with a gate.
GB/T19661.2—2005
The strict design of the shielding cover should ensure that the dose equivalent rate outside does not exceed the value of level 6 in the radiation protection classification of 4.3. If the dose equivalent rate of a Class B nuclear instrument exceeds the national standard value, a shielding cover should be configured and form a solid integral component with the nuclear instrument. || tt||The shielding cover shall include a safety lock to prevent unauthorized use of the source holder and (or) source. 6.4 Fire protection of source box
When the fire reaches an ambient temperature of 800°C and lasts for 3°C Tir, the structure of the source box and its shielding equipment (if any) shall ensure that the dose equivalent rate does not exceed the limit prescribed by the state, and the radioactive source is still gradually shielded. 6.5 Detector cover
The design of the detector cover of the measuring instrument shall meet the requirements of the specified radiation protection level so that the dose equivalent rate of the corresponding grade meets the requirements of 4.3.
6.6 Measuring head
When the source and detector are contained in a shell to form an integral part of the measuring head, it shall meet the requirements of both the source box and the detector cover.
7 Other safety devices
7.1 General requirements
In addition to the requirements of Chapters 5 and 6, nuclear instruments should be provided with safety devices specified in 7.2 to 7.4. If necessary, they should also be equipped with safety interlocking devices that interlock with the source door (see 8.2.2 of B/T19661.1). They should work together with the safety devices specified in 7.2 to 7.2 to ensure the safety of the radiation source.
7.2 Prevention of unauthorized use
Nuclear instruments should include safety calming functions to prevent unauthorized use (such as operating the reading door or moving the source). 7.3 Door position indication
A special indicator device should be provided near the source box equipped with the door: it should clearly indicate whether the door is open or completely closed. The door position indicator should be designed not to provide a false indication of "safe state" in the event of a failure. Note: If a gate indicator fails, it should be taken out of service until repaired. 7.4 Additional alarms and
A telemeter with a remotely controlled gate, when routine operations are required to be completed manually (e.g., insertion of the measured material) in the vicinity of the instrument, should also be equipped with a light alarm to indicate the gate position. Unless the application or national regulations specify other requirements related to the system, a red alarm light should be used to indicate that the gate is "not closed" and a green alarm light should be used to indicate that the gate is "fully closed". These additional alarm lights should be installed in close proximity to the instrument so that they can be easily observed. 8. Determination of the most appropriate efficiency
8.1 Overview
The dose equivalent rate near the nuclear instrument should be measured or calculated. Under each of the working conditions mentioned below, the maximum dose equivalent rate at 5 cm and 100 cm from the most accessible outer surface of the combined source and (or) detector should be determined (see Figures 3 and 4). In addition, for any dose equivalent rate specified by the relevant national regulations, the maximum distance from the nuclear instrument should be given (see 6.1), unless the radiation distribution is extremely non-uniform, in which case the average value of the dose equivalent rate can be determined over the entire range of 100 cm. For non-uniform radiation fields, the dose rate should be averaged over the entire area representing the beam size or 10 cm (the larger of the two).
GB/T 19661.2--2C05
a Door in the closed position
Distance between boxes or covers 10 cm
1 Detector cover;
Note: No measurements are made in the shaded area.
The door is in the closed position
The distance between the box or container is ≤10cm
Radioactive thickness gauge surface equidistant diagram Figure 3
Entire channel or container
Level meter and density meter
Leak detector cover:
S---source box;
SD combined source profit detector rate.
Standardized sample
Unit: cm
Gate is in open position
Unit: cm
b) Reflection type measuring instrument
Figure 4 Schematic diagram of equal distances on the surface of measuring instruments such as level meters. The local dose equivalent rate should be determined under the following working conditions: a
Gate (if any) is in the normal position, the nuclear instrument is not in working position (the operating beam is shielded, and the source is in the protection position); gate (if any) is in the open position, and the nuclear instrument is in working position b)
The instrument should be in the simulated operating position.
Measurement of dose equivalent rate with closed gate
For transmission type measuring instruments, no measured material is placed. For reflection type, when the distance between the source box and the detector cover is ≤13m1, the radiation measurement of the gap between the boxes (covers) can be omitted. 8. 3 Measurement of dose equivalent rate with open gate: Radiation measurement is performed in the useful radiation plan. The dose equivalent rate should be measured on a surface parallel to the virtual surface surrounding the source box and detector cover. 8.4 Dose equivalent rate measurement procedure
Remember to use a suitable dose measuring instrument to measure the dose equivalent rate GR/I19661.2—2005
a) When measuring to determine the deep dose equivalent rate of penetrating radiation (photon irradiation), the measuring instrument used should be calibrated for the measured radiation energy range of 5keV~3MeV. When measuring the dose equivalent rate of low penetration deep radiation (3 mm radiation) for 1 mm thick tissue equivalent material (corresponding to the instrument tissue equivalent window thickness of g/ctn), the measuring instrument used is used to measure the superficial dose equivalent rate and the eye dose equivalent rate. The superficial dose equivalent rate is applicable to the external irradiation of the human body surface and limbs at a depth of 0.07 mm (for the instrument surface tissue equivalent window thickness of 7 mm/ctn). Similarly, the eye dose equivalent rate is applicable to the external irradiation of the lens of the eye at a depth of 3 mm tissue (300 mg/cm) without the protection of the eye by glasses or other barriers. :) Neutron dose equivalent rate is determined by dosimeter, and other methods are also used for measurement or calculation. 8.5 Determination of dose equivalent rate related values
To calculate the dose equivalent rate used in Table 1, the equivalent value of the deep dose of penetrating radiation (total external irradiation) should be used. The photon radiation value is directly used as the measured value. Organ dose risk weighting factors of 1/10 and 1/3 apply to the measurements of superficial and clothing dose equivalent rates, respectively.
When mixed radiation is present and the measured superficial dose equivalent rate exceeds the deep dose equivalent rate by 10 times, the value obtained by dividing the superficial clothing dose equivalent rate by 0 should be used. Similarly, if the measured eye dose equivalent rate exceeds the deep dose equivalent rate, the value obtained by dividing the clothing dose equivalent rate by 3 should be used. The highest of the three dose equivalent rates is selected for use in determining the radiation protection level in the table. 9 Test methods
9.1 General
When the required characteristics are not confirmed by other methods (e.g. calculation and evaluation of material properties), they shall be verified by type tests as specified in 9.2 to 9.5.
Qualified characteristics are considered to be qualified. Unless otherwise specified, these tests shall be completed by the manufacturer on prototypes (machines) or components with similar structural characteristics, and the results shall be included in the test report.
9.2 Temperature Cycle Test of Doors and Source Holders
9.2.1 Requirements
It shall be verified through temperature cycle tests that the inherent performance of the safety devices (doors, source holders) will be guaranteed within the specified operating range. In special cases, this test may be limited to certain functions of safety-related nuclear instrument components. The temperature cycle test shall be carried out in an artificial climate chamber at the highest and lowest temperatures of the levels specified in Table 2: During the test, the accuracy of the functions of safety devices such as source boxes shall be verified: 9.2.2 Procedure
The time required for the source box to reach a certain temperature in the artificial climate chamber (called "stabilization time", that is, the time required for the source box to reach and remain at this temperature) shall be determined by test and calculation.
Test procedure is shown in Figure 5.
Before starting the test (tn), the distance from the source box should be measured and recorded.5 Determination of relevant values of dose equivalent rate
To calculate the corresponding dose equivalent rate used in Table 1, the equivalent value of the deep dose of penetrating radiation (total external irradiation) is used. The photon radiation value is directly used as the measured value. The organ dose risk weighting factors of 1/10 and 1/3 are applied to the measurement of superficial dose equivalent rate and clothing dose equivalent rate, respectively.
When mixed radiation is present and the measured superficial dose equivalent rate exceeds the deep dose equivalent rate by 10 times, the value obtained by dividing the superficial dose equivalent rate by 0 should be used. Similarly, if the measured eye dose equivalent rate exceeds the deep dose equivalent rate, the value obtained by dividing the exposure dose equivalent rate by 3 should be used. The highest of the three dose equivalent rates is selected for determining the radiation protection level in the table. 9 Test Methods
9.1 General
When the required characteristics are confirmed by other methods (e.g. calculation and evaluation of material properties), they shall be verified by type tests as specified in 9.2 to 9.5.
Qualified characteristics are considered to be qualified. Unless otherwise specified, these tests shall be performed by the manufacturer on prototypes (machines) or components with similar structural characteristics. The results shall be included in the test report.
9.2 Temperature Cycle Tests on Doors and Sources
9.2.1 Requirements
It shall be verified by temperature cycle tests that the inherent performance of the safety device (doors, source) will be guaranteed within the specified operating range. In special cases, this test may be limited to certain functions of the safety-related nuclear instrument components. The cycle test shall be carried out in the artificial climate room at the highest and lowest temperatures specified in Table 2: During the test, the accuracy of the functions of the safety devices such as the source box shall be verified: 9.2.2 Procedure
The time required for the source box to reach a certain temperature in the artificial climate room (called "stabilization time", that is, the time required for the source box to reach and remain at this temperature) shall be determined by test and calculation.
The test procedure is shown in Figure 5.
Before starting the test (tn), the distance from the source box 5 should be measured and recorded.5 Determination of relevant values of dose equivalent rate
To calculate the corresponding dose equivalent rate used in Table 1, the equivalent value of the deep dose of penetrating radiation (total external irradiation) is used. The photon radiation value is directly used as the measured value. The organ dose risk weighting factors of 1/10 and 1/3 are applied to the measurement of superficial dose equivalent rate and clothing dose equivalent rate, respectively.
When mixed radiation is present and the measured superficial dose equivalent rate exceeds the deep dose equivalent rate by 10 times, the value obtained by dividing the superficial dose equivalent rate by 0 should be used. Similarly, if the measured eye dose equivalent rate exceeds the deep dose equivalent rate, the value obtained by dividing the exposure dose equivalent rate by 3 should be used. The highest of the three dose equivalent rates is selected for determining the radiation protection level in the table. 9 Test Methods
9.1 General
When the required characteristics are confirmed by other methods (e.g. calculation and evaluation of material properties), they shall be verified by type tests as specified in 9.2 to 9.5.
Qualified characteristics are considered to be qualified. Unless otherwise specified, these tests shall be performed by the manufacturer on prototypes (machines) or components with similar structural characteristics. The results shall be included in the test report.
9.2 Temperature Cycle Tests on Doors and Sources
9.2.1 Requirements
It shall be verified by temperature cycle tests that the inherent performance of the safety device (doors, source) will be guaranteed within the specified operating range. In special cases, this test may be limited to certain functions of the safety-related nuclear instrument components. The cycle test shall be carried out in the artificial climate room at the highest and lowest temperatures specified in Table 2: During the test, the accuracy of the functions of the safety devices such as the source box shall be verified: 9.2.2 Procedure
The time required for the source box to reach a certain temperature in the artificial climate room (called "stabilization time", that is, the time required for the source box to reach and remain at this temperature) shall be determined by test and calculation.
The test procedure is shown in Figure 5.
Before starting the test (tn), the distance from the source box 5 should be measured and recorded.
Delete referenced document 1F 6lc:1:20o1&Safety requirements for measurement and control. Iud laborulcry usr --Fart 1, Genetal requirements\, add reference to GB/1961.1&Nuclear instruments and "Part 1; General requirements"
System safety requirements
Not referenced in this part
Safety requirements that do not belong to radiation protection
GB/T: 19G61.1 has included the relevant contents of JF: 61010
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