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GB 15146.2-2008: Nuclear criticality safety for fissile materials outside reactors -- Part 2: Basic technical practices and subcritical limits for handling, processing and operations with fissile materials
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Nuclear criticality safety for fissile materials outside reactors -- Part 2: Basic technical practices and subcritical limits for handling, processing and operations with fissile materials
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Nuclear criticality safety for fissile materials outside reactor-Basic technical criteria and subcritical limits for handling, processing and operations of fissile materials
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Basic data | Standard ID | GB 15146.2-2008 (GB15146.2-2008) | | Description (Translated English) | Nuclear criticality safety for fissile materials outside reactors -- Part 2: Basic technical practices and subcritical limits for handling, processing and operations with fissile materials | | Sector / Industry | National Standard | | Classification of Chinese Standard | F09 | | Classification of International Standard | 27.120.30 | | Word Count Estimation | 25,223 | | Date of Issue | 2008-09-19 | | Date of Implementation | 2009-08-01 | | Older Standard (superseded by this standard) | GB 15146.2-1994 | | Quoted Standard | GB 15146.5 | | Regulation (derived from) | Announcement of Newly Approved National Standards No. 16 of 2008 (No. 129 overall) | | Issuing agency(ies) | General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, Standardization Administration of the People's Republic of China | | Summary | This Chinese standard applies to fissile materials outside the reactor operation, processing, handling, and some basic technical rules of simple geometry fissile material monomer subcritical limits, and establish nuclear criticality safety evaluation of the effective calculation method used nature and scope of proposed requirements. For nuclear criticality safety administration 's basic requirements, see GB 15146. 1. This standard applies to fissile materials outside the reactor operation, processing and handling. This standard does not apply to fissile material under controlled conditions of assembly operations (such as critical experiments). | GB 15146.2-2008: Nuclear criticality safety for fissile materials outside reactors -- Part 2: Basic technical practices and subcritical limits for handling, processing and operations with fissile materials
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Nuclear criticality safety for fissile materials outside reactors.Part 2. Basic technical practices and subcritical limits for handling, processing and operations with fissile materials
ICS 27.120.30
F09
National Standards of People's Republic of China
Replacing GB 15146.2-1994
Nuclear criticality safety for fissile materials outside reactors
Part 2. Operation fissile material, processing, handling,
The basic technical rules and subcritical limits
Posted 2008-09-19
2009-08-01 implementation
Administration of Quality Supervision, Inspection and Quarantine of People's Republic of China
Standardization Administration of China released
Table of Contents
Introduction Ⅲ
1 Scope 1
2 Normative references 1
3 Terms and definitions
4 Basic Technical Regulations 2
Claim 5 3 Calculation Method
6 fissile nuclides single parameter limit 4
7 Multi-parameter control 5
Appendix A (informative) may cause changes in process conditions of typical events 14
Annex B (informative) Calculation method validation sample 15
Annex C (informative) discussion on the calculation method 18
References 20
Foreword
All technical content in this section is mandatory.
GB 15146 "Nuclear criticality safety for fissile materials outside reactor" has so far released the following 11 sections.
--- GB 15146.1 Part 1. Nuclear Criticality Safety Administration regulations (instead of GB 15146.1-1994)
--- GB 15146.2 - Part 2. Operation fissile material, processing and handling of basic technical rules and subcritical limits (instead of
GB 15146.2-1994)
--- GB 15146.3 Part 3. storage of fissile material for nuclear criticality safety requirements (instead of GB 15146.3-1994)
--- Aqueous solutions of fissile material for nuclear criticality safety criteria for steel - pipe intersections containing GB 15146.4
--- GB 15146.5 plutonium - natural uranium nuclear criticality control criteria and subcritical limits for mixtures
--- GB/T 15146.6 borosilicate glass Raschig rings and its application criteria
--- GB 15146.7 subcritical neutron multiplication measurements in situ
--- GB 15146.8 Part 8. heap outside the handling, storage and transport of nuclear criticality safety criteria for LWR fuel elements (instead of
GB 15146.8-1994)
--- GB 15146.9 performance and testing requirements for nuclear criticality detection and alarm systems
--- GB 15146.10 Safety requirements for fixed neutron absorber
--- GB/T 15146.11 based nuclear criticality safety limits and controls moderator
This section GB Part of 215,146.
This Part replaces GB 15146.2-1994 "for fissile materials outside reactor - Nuclear criticality safety for fissile materials operations, processing, handling,
The basic technical criteria and subcritical limits. "
Compared with GB 15146.2-1994 part of the main changes are as follows.
--- Increasing the foreword and Appendix C (informative);
--- The "Verify calculation method" (1994 edition) to "confirm the calculation method" (Chapter 5 edition), and increased general requirements;
--- The subcritical 233U limited edition included in Chapter 6;
--- For the auxiliary "shall" be changed to "shall", "should" or "may."
This part of the Annex A, Annex B and Annex C is informative appendix.
This part of the National Standardization Technical Committee proposed nuclear energy.
This part of the National Standardization Technical Committee centralized nuclear energy.
Drafting this Part. Nuclear Industry Standardization Institute, China Institute of Atomic Energy, Chinese Academy of Engineering Physics.
The main drafters of this section. Zhuo Feng official, Zhu Qingfu, Joe recorded with.
This section was first released in 1994.
Nuclear criticality safety for fissile materials outside reactors
Part 2. Operation fissile material, processing, handling,
The basic technical rules and subcritical limits
1 Scope
GB 15146 of the provisions of this part of fissile materials outside reactor operation, processing and handling of basic technical rules and some geometry
Subcritical limits simple fissile material monomers, and the establishment of nuclear criticality safety evaluation validity and scope of the proposed method of calculation
Requirements. The basic requirements for nuclear criticality safety administration see GB 15146.1.
This section applies to fissile materials outside reactor operation, processing and handling.
This section does not apply to fissile material under controlled conditions of assembly operations (such as a critical test).
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this part. For dated references, subsequent
Amendments (not including errata content) or revisions do not apply to this section, however, encourage the parties to this part of the research agreement
Whether the latest versions of these documents. For undated reference documents, the latest versions apply to this section.
GB 15146.5 outside reactors Yi Nuclear criticality safety plutonium fissile material - nuclear criticality control criteria and subcritical natural uranium mixtures
Limit
3 Terms and Definitions
The following terms and definitions apply to this part of GB 15146.
3.1
Physically, the total number of neutrons produced within a certain time interval (excluding fission neutron source intensity is not a function of the rate generated
Child) with the same time interval internal absorption and leakage loss ratio of the total number of neutrons.
3.2
Energy self-sustaining or divergent neutron chain reaction accident caused by the release event.
3.3
Criticality accident prevention and mitigation of the consequences of criticality accidents in which the most important is to prevent such accidents.
3.4
So that the numerical parameters maintained within the prescribed limits of.
3.5
A controlled parameters specified under specified conditions to make sure the system is limiting value subcritical state. This parameter limits contained
Margin of uncertainty that will remain as it is used when you export the calculation results and the experimental data, but does not include accident response (such as double batch feeding, like
Product margin analysis results are incorrect, etc.) require.
3.6
The vertical projection of the total mass per unit area in the plane of fissile material. For infinite uniform flat surface density equal to the thickness of the plate
Degree within the plate fissile material density of the product.
3.7
The results provide a computer program, including mathematical equations, approximation, assuming the relevant numerical parameters (such as cross-sectional data) and the like.
3.8
The method of calculation between calculation results with the experimental data, a measure of systematic differences.
3.9
The calculation results of a measurement of the accuracy and precision of both the experimental data and uncertainty.
3.10
Material component, geometric arrangement, neutron energy spectrum and other relevant parameters (such as non-uniformity, leakage, interaction, absorption, etc.) defined range
Wai, calculated in this (or these) range of the method of bias have been identified.
4 Basic Technical Regulations
4.1 General Requirements
Effective multiplication factor of the system (k eff) is dependent on the quality of all fissile material and other related materials, distribution and nuclear properties.
One or more parameters of the system should be controlled within subcritical limits, and stay out of subcriticality margin in response to process accident
Amount to achieve nuclear criticality safety. You can use the following methods to control the parameters of the system.
a) physical limitations, e.g., limited within the solution not greater than the diameter of the cylindrical container a predetermined value;
b) monitoring and control equipment, for example, can use to measure the concentration and preventing fissile nuclides in chemical systems in gathering equipment, fissile nuclides
The concentration is maintained at a predetermined value or less;
c) chemical means, for example, to prevent the emergence of conditions can cause the precipitation of the aqueous solution to maintain the concentration of its unique features;
d) natural or credible course of events, for example, rely on the inherent characteristics of the process, so that the density of uranium oxide is always less than the theoretical density
Some of the provisions of the share;
e) administrative procedures, for example, the quality requirements of the operating fissile material does not exceed the posted limit;
f) other means.
4.2 controlled parameter
It should be clear that all controlled parameters and their limits. We should clearly understand the impact of changes in these parameters on the system of k eff.
4.3 pairs accident principle
Process design should contain a sufficient safety factor, making it necessary to be occur in a variety of conditions related to at least two unlikely
, Independent of changes, it may lead to a critical accident.
4.4 Geometry Control
Whenever possible, it is desirable to rely on limiting device geometry design rather than administrative measures to implement the critical control. Equipment design
When geometry, can take advantage of the characteristics of nuclear materials and technology equipment. Before starting the operation should be run to verify all depend on the implementation of the provisional
Geometry and characteristics of the nuclear industry control, and shall take appropriate measures so that they can be maintained.
4.5 Application of neutron absorber
You can use the neutron absorbing material (such as cadmium and boron) added to the process equipment or materials or means to implement both among the critical control.
It shall take appropriate measures so that the neutron absorbing material is added continued to maintain its intended distribution and concentration. Neutron absorber solution
When, in particular, should take effective control measures.
4.6 subcritical limits of determination
As long as a suitable experimental data, it should be based on experimental data to establish the subcritical limits, and should consider the use of inaccurate data
Given the appropriate degree of left margin. In the absence of direct use of experimental data can be derived from the calculation times provisional boundaries
Value, but the calculation method used should be in accordance with the provisions of Chapter 5, by comparison with experimental data proved valid.
Claim 5 Calculation Method
5.1 General Requirements
There are many suitable calculation method to determine the system of sub-critical state. They are based on a variety of forms and, for the field of nuclear criticality safety
Different circumstances which apply to a broad range of value is not the same, therefore, the calculation method used for nuclear criticality safety evaluation, whether by
According to how the form, in accordance with provisions of this chapter shall first establish the validity and scope of the system being evaluated.
5.2 bias determined 1)
1) No test data are available, it is impossible to determine the bias calculation method, making it impossible to meet the requirements of 5.2. By other terms and calculation methods
Comparison of calculation results to confirm the calculation method is unacceptable.
Calculation method should determine bias, bias should be determined by establishing the critical test data with the corresponding experimental system between the calculated result
Relationship to (see Appendix B). Typically, you should use the calculated value k eff under critical state experimental system for the calculation and experimental results
Correlation between the results in this case, the bias value is calculated k eff with respect to the deviation of 1.
You can also take advantage of the physical state and other parameters, to establish the correlation between the experimental data and calculation results between the corresponding experimental system to determine
Bias calculation method.
It should be used to bias the computation method standardization within its scope of application, making it possible to predict the critical strip within the limits of bias Uncertainty
Member. Bias and uncertainty is usually not constant, both of which may be a function of composition and other variables.
5.3 bias tends to extend the scope of application
Scope calculation method can be extended to the area outside the experimental conditions, provided that within the scope of the use of experimental conditions tend to bias
It has been determined that the deflection region. Large regional expansion, should be supplemented by other calculation methods, so that the extended region bias (esp
Which is a bias uncertainty) estimates more reliable and consistent proof of the results.
Uncertainty subcritical margin of 5.4 degree of bias
Uncertainty of bias should cover corresponding to the following Uncertainty k eff (or other parameters) of the amount of deductions, these packages uncertainty
Including the uncertainty of experimental conditions, calculation methods lack accuracy and precision, the scope expansion introduced uncertainty and so on.
Determine the accuracy and precision and deduct an amount corresponding to the bias and uncertainty corresponds to the calculation method later, you should k eff (or
He related parameters) to impose appropriate criticality margin times; the allowance should be large enough to ensure that the case by this method calculated in virtually certain
It is subcritical; and bias and uncertainty as to the margin may change with composition and other variables (see Appendix B and Appendix C).
Check 5.5 computer program
The calculation method is included in a computer program, it should be verified to confirm the mathematical operation is carried out as intended. For computer programs
Order was amended, should be re-verified.
5.6 kernel parameters
Nuclear characteristic parameter calculation method used (such as cross-sectional data) should be consistent with its experimental results.
5.7 confirmation report
You should prepare a written confirmation reports. This report should.
a) the method of calculation in sufficient detail to make clear and precise description so that others can independently reproduce the results;
b) specify the method of calculation used to confirm the experimental data, and lists the parameters derived from the experimental data;
c) description of the scope of application of the calculation method;
d) Description of bias and subcriticality margin within the scope of application and demonstration of subcritical margin determined is appropriate.
6 fissile nuclides single parameter limits
6.1 Application limits - General requirements
6.2,6.3,6.4,6.5 and 6.6 lists some of the fissile nuclides isolated monomers single parameter limits, they are made to meet the Chapter 5
Calculation requirements calculated. If these limits conditions are met, then a limit to comply with any of them, fissile material
Operation, handling and processing can be performed safely. Only when it can be proved that the material monomers around (including near other fissile material) make
When increasing the effective multiplication factor (k eff) is not greater than tightly wrapped infinitely thick layer of water so that the monomer increase k eff, said limits allowed applications.
When a limit is applied to the above mixture of fissile nuclides should be the mixture of each fissile nuclide having deemed
The kind of radionuclide minimum limit to consider.
It should be emphasized that the process specification must leave appropriate criticality margin times to cope with uncertainty and limits of process variables is accidentally
exceed.
6.2 homogeneous aqueous solution
Maintaining a uniform aqueous premise, i.e., to maintain the concentration of the aqueous solution does not exceed the value of the saturated solution, in Table 1 can be any of a limit value
To use. If the concentration of plutonium -240 greater than the concentration of plutonium-241, and in the calculation of the mass or concentration of plutonium-241 as plutonium-239, plutonium-239 is
Limits may also be used a mixture of various plutonium isotopes. (For a mixture of plutonium isotopes plutonium -240 considerable case 7.4
Some of the more lenient provisions limit). Atomic ratio limits and concentration limits are equivalent, but the former is also applicable to non-aqueous solution, and
Regardless of the chemical form of the fissile nuclides.
6.3 aqueous mixture
The areal density limits in Table 1 can be used for fissile material having any chemical composition. In the areal density is uniform under the premise, with their
The mixture has a density gradient is also effective. For subcritical mass may not be uniform mixture, uranium-233, uranium-235 and plutonium-239
Limits were 0.50kg, 0.70kg and 0.45kg, and has nothing to do with the chemical composition.
Table 1 fissile nuclides homogeneous aqueous solution of a single parameter limits
parameter
Subcritical limits
233UO2F2 233UO2 (NO3) 2 235UO2F2 235UO2 (NO3) 2 239Pu (NO3) 4
Quality fissile nuclide/kg 0.54 0.55 0.76 0.78 0.48
Diameter cylinder solution/cm 10.5 11.7 13.7 14.4 15.4
Solution plate thickness/cm 2.5 3.1 4.4 4.9 5.5
Volume of the solution/L 2.8 3.6 5.5 6.2 7.3
The concentration of fissile nuclides/(g/L) 10.8 10.8 11.6 11.6 7.3
Hydrogen atoms of fissile nuclides than a 2390 2390 2250 2250 3630
Fissile nuclides areal density/(g/cm2) 0.35 0.35 0.40 0.40 0.25
a lower limit.
6.4 aqueous mixture enrichment limit
Table 2 lists the U-235 enrichment limit uniformly mixed with water several uranium metal and uranium compounds. Here, a mixture of uranium metal
Mass or concentration of metals and uranium compounds are not limited.
Note. When calculating these limits, the average particle size "homogeneous" mixture of dry UO3 normalized to 60μm. UO2 (NO3) 2 hydrate dihydrate flat
Average particle size of about 100μm. Mixtures of various nitrate ratio of hydrogen atoms of uranium-235 (H/U) are 0.32cm thick polyethylene ball
Shell reflection conditions under.
Table 2 and the water evenly mixed uranium-235 enrichment of uranium metal limits and several uranium compounds
Or metal compound 235U enrichment limit /%
Uranium metal
UO2, U3O8 or UO3
UO2 (NO3) 2
0.93
0.96
1.96
6.5 of metal
2) users should note that the material (especially UO3) density may exceed the full density in Table 4, Table 4 height limit for compacted oxide
It was not applicable.
Table 3 lists the mass of uranium enrichment limits and no limits apply to the concave surface of a single component, it can be extended for single widget pile, strip
No member is interspersed between small parts of moderator material.
If the calculation of the mass of uranium -234 as uranium-233 or uranium-235, uranium-233 and uranium-235 is the limit also applies to uranium-233 or uranium -
Uranium-235 and -234, -236 uranium or uranium-238 mixture. If the concentration of plutonium -240 greater than the concentration of plutonium-241 and calculate the mass of the
There are as plutonium isotopes plutonium-239, plutonium-239 the limits also apply to a mixture of plutonium isotopes. You can press the isotopic composition of the density limit
Value adjustments.
Table 3 metal single parameter limits monomers
parameter
Subcritical limits
233U 235U 239Pu
Quality fissile nuclide/kg 6.0 20.1 5.0
Cylinder diameter/cm 4.5 7.3 4.4
Plate thickness/cm 0.38 1.3 0.65
235U enrichment of uranium mass fraction /% - 5.0 -
Quality and size limits in effect maximum density/(g/cm3) 18.65 18.81 19.82
6.6 Oxide
The mass fraction of the limits in Table 4 and Table 5 applies only to water is less than 1.5% oxide. Wherein the mass limits apply to non-concave
A single component, and can be extended to the individual widgets heap, with the proviso that no additional interspersed between widgets moderator material.
In nuclide mass and an oxide (including moisture) given the quality of the quality limits are equivalent. It should be emphasized that in Tables 4 and 5
The only limit in the overall density limits specified conditions are met before you can use 2). When the water content is limited to 1.5% in
The next, in Table 2 of 235U enrichment of uranium oxide limit can be increased to 3.2%.
7 Multi-parameter control
7.1 General requirements limit the application
7.1 ~ 7.4 gives a particularly useful example of several multi-parameter control. These limits are used to meet the requirements of Chapter 5 Calculation Method
Method calculated. Only when it can be proved that the surrounding material so that the system increases the effective multiplication factor (k eff) is not greater than the tightly wrapped the system infinitely thick
The aqueous layer so that k eff increases when the above limit allowed applications.
It should be emphasized that the process specification must leave appropriate criticality margin times to cope with the uncertainty of process variables and a limit is
Accident exceeded.
Book Book Book
. 5
Pu
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. 2
. 2
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,water
. 5
Low enriched uranium 7.2 degrees - a mixture of water and uranium oxides - water mixture
One use multi-parameter control is a simultaneous control parameters of uranium-235 enrichment of uranium and the provisions of Chapter 6. Figs. 1 to 5 stars
Off subcritical limits with the enrichment of uranium do not give the water gate of the mass of uranium, cylinder diameter, plate thickness, volume and other parameters of the surface density
System, they apply to uranium metal or uranium oxide in various sizes and various shapes (UO2) systems and small water.
U-235 enrichment /%
1 uranium boom quality limits
U-235 enrichment /%
Figure 2 cylinder diameter limit of uranium boom
U-235 enrichment /%
Figure 3 uranium boom plate thickness limits
U-235 enrichment /%
Figure 4 limits the volume of uranium boom
U-235 enrichment /%
The areal density of 5 uranium boom limits
7.3 Low 235U enrichment of uranium solution
Another application of multi-parameter control for maintaining a uniform aqueous solution of uranium U-235 while controlling uranium enrichment and Table 1 in Regulation
Given a parameter. Table 6 lists the enrichment in control prescribed limit, homogeneous aqueous solution parameters uranium subcritical limits.
Here, the concentration of uranium homogeneous aqueous solution should not exceed its saturation concentration of the solution (for UO2F2, saturated aqueous solution concentration is taken
5mol/L, for UO2 (NO3) 2 solution, take 2.5mol/L).
Table 6 Low enriched uranium homogeneous aqueous solution of subcritical limits
Parameter 235U enrichment /%
Subcritical limits
UO2F2 UO2 (NO3) 2
Quality 235U/kg 10.0
5.0
4.0
3.0
2.0
1.07
1.64
1.98
2.75
8.00
1.47
3.30
6.50
Table 6 (Continued)
Parameter 235U enrichment /%
Subcritical limits
UO2F2 UO2 (NO3) 2
Cylinder diameter/cm
Plate thickness/cm
Volume/L
Uranium concentration/(g/L)
10.0
5.0
4.0
3.0
2.0
10.0
5.0
4.0
3.0
2.0
10.0
5.0
4.0
3.0
2.0
10.0
5.0
4.0
3.0
2.88
2.0
1.45
20.1
26.6
30.2
37.4
63.0
8.3
12.6
15.1
20.0
36.5
14.8
30.6
42.7
77.0
340.0
123.0
261.0
335.0
470.0
770.0
1190.0a
25.2
42.7
58.6
11.9
23.4
33.7
26.7
111.0
273.0
128.0
283.0
375.0
594.9a
a saturated solution.
7.4 P u (NO3) 4 homogeneous aqueous solution containing plutonium - 240
For containing 240Pu of Pu (NO3) 4 homogeneous aqueous solution, in accordance with the abundance of plutonium isotopes 240Pu, the table Pu (NO3) 4 was dissolved 1
Liquid limit increase. But it increases the amount subject to 241Pu abundance. Table 7 shows the three different isotopic composition of Pu (NO3) 4 uniform
Sub-critical water limit. When calculating isotopic composition shall be the presence of 238Pu and 242Pu ignored.
In the case of plutonium and natural uranium completely mixed, which limits may be further relaxed. Limits See this case GB/T 15146.5.
Table 7 subcritical containing plutonium -240 of P u (NO3) 4 homogeneous aqueous solution limits
parameter
Subcritical limits
240Pu mass fraction ≥5%
241Pu mass fraction ≤1%
240Pu...
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