GB 15146.3-2008Nuclear criticality safety for fissile materials outside reactors - Part 3: Requirements for nuclear criticality safety in the storage of fissile materials (English PDF)

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 easily outside reactors Nuclear criticality safety - Part 1 of fissile material. Nuclear Criticality Safety Administration regulations (on behalf of the For GB 15146.1-1994)

--- GB 15146.2 outside reactors Nuclear criticality safety - Part 2 of fissile material. fissile material, processing and operations processing The basic technical rules and subcritical limits (instead of GB 15146.2-1994)

--- GB 15146.3 outside reactors Nuclear criticality safety for fissile materials - Part 3. The nuclear criticality safety for fissile material storage Requirements (instead of GB 15146.3-1994)

--- GB 15146.4 fissile materials outside reactor - Nuclear criticality safety-containing aqueous solutions of fissile material for steel pipe intersections Nuclear criticality safety criteria

--- GB 15146.5 plutonium outside reactor nuclear criticality safety for fissile materials - Nuclear criticality control criteria and a mixture of natural uranium Subcritical limits

--- GB/T 15146.6 fissile materials outside reactor - Nuclear criticality safety borosilicate glass Raschig rings and its application criteria

--- GB 15146.7 easily outside reactors Nuclear criticality safety subcritical neutron multiplication of fissile material for measurements in situ

--- GB 15146.8 fissile materials outside reactor - Nuclear criticality safety - Part 8. heap outside the handling, storage and transportation of LWR fuel Nuclear criticality safety criteria for feed unit (instead of GB 15146.8-1994)

--- GB Performance and seized 15146.9 fissile materials outside reactor - Nuclear criticality safety for nuclear criticality detection and alarm systems Inspection requirements

--- GB 15146.10 Safety requirements outside reactor nuclear criticality safety for fissile material fixed neutron absorber

--- GB/T 15146.11 outside reactor Nuclear criticality safety for fissile materials based on nuclear criticality safety limits and controls moderator This section GB of Section 315 146. This Part replaces GB/T 15146.3-1994 "fissile materials outside the reactor core Pro Border security storage of fissile material for nuclear criticality safety requirements. " Compared with GB 15146.3-1994 part of the main changes are as follows:

--- Increasing the foreword;

--- The critical limit with some modifications or deletions;

1 Scope

Part 3 applies criticality safety to storage, where the hazard is different in kind from processing: the material sits still, but it sits in quantity and in arrays, and the controlling parameters become spacing, the interaction between units, the reflection from walls and floors, and the possibility of flooding or of moderator entering the store. The standard sets the requirements for the storage arrangement, the spacing and the fixed neutron absorbers, and the administrative controls that keep the configuration as evaluated. Issued on 19 September 2008, in force since 1 August 2009, replacing GB 15146.3-1994. This page is published from the official record of the standard held by the Chinese standards administration: the identification, the dates, the classification and the edition it replaces are taken from there. The clause text, the tables and the numeric limits are not reproduced on this page - they are in the document itself, which is delivered in full in English translation.

This section provides basic storage of fissile material for nuclear criticality safety requirements and limits. This section applies to storage of fissile material.

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 15146.1 fissile materials outside reactor - Nuclear criticality safety - Part 1. Nuclear Criticality Safety Administration regulations

GB 15146.2 outside reactors Nuclear criticality safety for fissile materials - Part 2. The operation of fissile material, processing, handling basic Technical Regulations and subcritical limits Performance and testing

GB 15146.9 fissile materials outside reactor - Nuclear criticality safety for nuclear criticality detection and alarm systems Claim

3 Terms and Definitions

The following terms and definitions apply to this part of GB 15146.

3.1 Be treated as a whole collection of fissile material, the material may be, a collection of material of any shape can also be separated by a number of The small components.

3.2 The storage unit is placed therein, and the volume of space having a defined boundary.

3.3 Rules set by the storage unit has a number of storage element composed of a gate arrangement.

3.4 Calculation methods recognized in accordance with the provisions of GB 15146.2.

Appendix A

(Informative) Storage limits and conditions of use of highly enriched fissile material A. Appendix 1 shows the mass fraction of uranium enrichment 235U not less than 30%, 233U and plutonium metals and oxides reservoir Deposit limits, given its quality limits and spatial separation limits. These fissile material different in different mass fractions single enrichment, different H/U (Pu) ratio, different grid sizes and storage arrays Limit the number of quality Yuan (expressed in kg), as shown in Table A. 1 ~ A. 11 listed. A. Limits given in Annex 2 for the main arrays ideal given. In practice, there are certain differences between the ideal and the actual array of arrays. However, the limits given in this annex may provide a starting point for establishing the actual safe storage array. A. Quality limits given in Appendix 3 unit is obtained under the following conditions.

a) calculated by the calculation method after confirmation.

b) according to the array neutron multiplication factor of less than

0.95 calculated conditions.

c) to around 20cm thick with water reflection layer critical computing data cube array as the basis.

d) calculations are for units placed in the center square of the grid, for the case of a sphere of fissile material carried. A.

4 This appendix gives 235U highly enriched uranium limits, and 233U mass fraction should be less than 1%, it should be outside 238U The uranium isotopes are considered 235U; when using 233U limits, should be the other isotope of uranium 233U is also considered; if the 240Pu Concentration greater than the concentration of 241Pu and calculate H/Pu atomic ratio and when the quality or concentration as 239Pu to 241Pu, 239Pu limits are available Apply a mixture of various plutonium isotopes. A.

5 For oxide fissile material, its storage limit is based on the calculated dioxide derived. These limits also apply to their He oxides, and fluorides, chlorides, nitrates or other salts of these compounds as long as the hydrogen content does not exceed the value given in the table, easily Density of fissile material does not exceed dioxide characteristic value. A. Several mass limits listed in the table unit of Figure 6 is greater than the critical mass of water reflective sphere. In Table A. 1 ~ A. 11, where the quality limit Values greater than 90% water by mass critical reflection sphere values are added to the label. For these marked increase over the unit, should take appropriate control measures Applied to ensure that the sub-critical, for example, geometric control, and should meet the A.

8.9 requirements. A.

7 Application of tabular data should be cautious. These data only provides a gate element volume (size) and quality limits gate element, must be used Use can effectively ensure criticality safety measures. Taking into account the operation of some practical factors should be smaller limits. A.

8 Use Table A. 1 ~ A. The mass limits listed in 11, the following should be considered. Where these cases, should be Table A. 1 ~ A. 11 as a starting point, consider new quality limits and (or) to consider new quality limit conditions of use. A.

8.1 moderation. hydrogen atom ratio of fissile material is determined by the fissile material itself, not including the adjacent hydrogen-containing material. Table Regulation Given the quality of the limits contained in the safety margin, sufficient to compensate for situations such as the kind of slowing down with a thin plastic wrap unit time. This situation is more than As a significant moderator effect, the calculation method is appropriate after confirmed estimates. A. Location

8.2 units in the gate elements. each unit should be located in the center of the gate element, gate element deviate from the center of the grid cell size must not exceed the 10%. If the cell mass limit down to 60% of the listed value, the unit in the horizontal position of the gate element can be unrestricted. If after reduction Quality is still more than 20 percent of the ball bare critical mass, the cell surface minimum distance should not be less than 15.2cm. A.

8.3 Other reflective materials. mass limits listed in the table also apply to the case of the reflective layer is thinner than the concrete of 12.7cm (Coagulation Soil surface density rho = 290kg/m 2). When the thickness of the concrete when the reflective layer is 20.3cm, mass limits should be reduced to 75% of the listed value. When the thickness of the concrete additional reflective layer, the quality limit should be reduced to 60% of the values listed. Other equivalent thick masonry materials Degree can be determined by its surface density. A.