This standard is drafted according to the rules provided in Q/CNNC JA2-2013.
This standard is prepared according to the basic requirements for radioactive solid waste containers and additional requirements for high level radioactive solid waste packages specified in EJ 1186-2005 "Characterization of Radioactive Waste Forms and Packages" and by reference to the recommendations for waste packages and containers in IAEA-TECDOC-1515 "Development of Specification for Radioactive Waste Package (October, 2006)".
This standard was proposed by China National Nuclear Corporation.
This standard is under the jurisdiction of Institute for Standardization of Nuclear Industry (ISNI).
Drafting organization of this standard: China Nuclear Power Engineering Co., Ltd.
Chief drafters of this standard: Yuan Kun, Zhang Wei, Deng Guoqing, Sun Donghui, Jin Yao and Yan Yingchun.
ENTERPRISE STANDARD
OF CHINA NATIONAL NUCLEAR CORPORATION
中國核工業集團公司企業標準
Q/CNNC JD 12-2016
Container for High level Radioactive Solid Waste
高水平放射性固體廢物容器
1 Scope
This standard specifies containers directly containing high-level radioactive solid wastes (hereinafter referred to as the "container") in terms of specification, technical requirements, performance inspection method and acceptance rules, etc.
This standard is applicable to containers directly containing high-level radioactive solid wastes and is not applicable to shielding container, transport container and (or) outer packaging container.
2 Normative References
The following documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies to this document.
GB 150 Pressure Vessels
GB/T 1804 General Tolerances - Tolerances for Linear and Angular Dimensions without Individual Tolerance Indications
GB 9133 Classification of Radioactive Waste
GB 14500 Regulations for Radioactive Waste Management
EJ 1186 Characterization of Radioactive Waste Forms and Packages
NB/T 47003.1 Steel Welded Atmospheric Pressure Vessels
NB/T 47013 Nondestructive Testing of Pressure Equipment
NB/T 47014 Welding Procedure Qualification for Pressure Equipment
3 Terms and Definitions
For the purposes of this document, the following terms and definitions apply.
3.1
High-level radioactive solid waste
Radioactive solid wastes (except ɑ waste) which contain radioactive substances whose the activity concentration of radioactive nuclide and heat release rate meet any one of the following conditions:
a) Containing radioactive nuclide with the half-life greater than 5a and less than or equal to 30a, of which the heat release rate is greater than 2kW/m3 or the activity concentration is greater than 4×1011Bq/kg.
b) Containing radioactive nuclide with the half-life greater than 30a, of which the activity concentration is greater than 4×1016Bq/kg or the heat release rate is greater than 2kW/m3.
High-level radioactive solid wastes mainly include solidified body of high level radioactive liquid wastes generated by nuclear fuel reprocessing, spent nuclear fuel prepared to be directly processed and other solid wastes with corresponding radioactive level.
3.2
Container for high-level radioactive solid waste
Containers filled with high-level radioactive solid waste directly, which are containment boundary of high-level radioactive wastes. Containers such as shielding container and transport container may be added outside as required in case of transportation and disposal.
3.3
Contents
Wastes which are filled into containers.
3.4
Integrity
No breakage of containment boundary after normal operation of waste container after packaging and falling accidents, with the purpose of ensuring the containment safety function of container to contents. Relatively large deformation is allowed, however, the deformation degree shall not influence follow-up operation of the container.
4 Container Size for High-level Radioactive Solid Waste
Containers for high-level radioactive solid wastes are classified into Type HD-I, Type HD-II and Type HD-III according to different uses. The boundary dimensions and allowable deviation shall be in accordance with those specified in Table 1.
Table 1 Boundary Dimensions and Allowable Deviation of Containers for High-level Radioactive Solid Wastes
Type External diameter
mm Diameter deviation
mm Minimum wall thickness
mm Total heighta
mm Height deviation
mm Nominal volume
L
HD-I 430 ±2 3 1338 ±2 170
HD-II 570 ±2 3 900 ±2 200
HD-III 710 ±2 3 1080 ±2 400
Type HD-I is applicable to high-level radioactive vitrification products or other applicable high-level radioactive solid wastes;
Type HD-II is applicable to applicable high-level radioactive solid wastes other than those belong to Type HD-I or Type HD-III;
Type HD-III is applicable to high-level radioactive waste filter element or other applicable large high-level radioactive solid wastes.
a Total height in the table includes container head cover; however, it excludes the partial protruded part of container used for connection with other equipment.
5 Technical Requirements for Container
5.1 Basic requirements
5.1.1 The containment of radioactivity and operability of container within 100a (before processing) design lifetime shall be ensured after the container is filled with wastes.
5.1.2 The containers shall meet other relevant requirements specified in GB 14500 and EJ 1186.
5.2 Contents suitable for filling
5.2.1 The performance of container contents shall meet the relevant requirements of high-level radioactive solid wastes specified in GB 9133 and EJ 1186.
5.2.2 The container contents shall not contain free liquid.
5.2.3 The reserved space of container after wastes filling shall be able to ensure that the container will not cause unfavorable impacts on its strength and structure on account of factors such as radiation decomposition of contents, degradation of organic matter and heat release temperature change.
5.3 Material requirements
5.3.1 The container material shall be adapted to the characteristics of filled contents and the working environment conditions of container, and shall meet relevant requirements of steel standards.
5.3.2 The mechanical performance of material shall meet the design and service requirements as well as the specific requirements in reference design standards.
5.3.3 The strength of material shall be able to bear the maximum load combinations under various operation conditions of container; see 5.4.1 for various load combinations. The toughness of material shall be able to withstand the maximum impact load possibly borne by the container.
5.3.4 The material shall be able to bear the maximum temperature under all the operation conditions. The material with high-temperature resistance (1,100℃) and good oxidation resistance shall be considered for Type HD-I containers which are filled with melted glass directly.
5.3.5 The material shall be well compatible with contents and service environment and have corrosion resistance required for design life; the test method and acceptance criteria for corrosion resistance shall be specified in design documents of the container.
5.3.6 The material shall be provided with good cold or thermal forming process and welding performance.
5.3.7 The austenitic stainless steel material is recommended in this standard.
5.4 Structure requirements
5.4.1 The design load of container structure shall consider the maximum load combination under normal operation condition and accident condition of the container; the minimum wall thickness shall meet those specified in Table l. The loads possibly borne by the container include (but not limited to):
a) Internal pressure, external pressure or maximum internal and external pressure difference of the container (with consideration of internal pressure changes of the container caused by gas possibly generated due to material degradation or decomposition within container or dropping of environment temperature);
b) Mass of the container and contents;
c) Thermal load (thermal stress generated by temperature gradient or temperature change);
d) Impact load (normal condition and accident condition);
e) Combined action of the above-mentioned loads on the container.
5.4.2 The shape and size of container shall be able to ensure the center temperature of container content is lower than design temperature limit under storage conditions and keep the physical and chemical performance of content wastes.
5.4.3 The internal structure of container shall be simple and convenient for wastes and fixed medium filling and compacting.
5.4.4 The external structure of container shall be convenient for operations such as remote-controlled transportation, storage, stacking, retrieval and seal welding, and shall match with the shielding, transportation, storage and processing container; the external surface structure shall be considered being difficult to be polluted and easy to be cleaned.
5.4.5 The structure design of container shall be beneficial to prevent concentration of various stresses, reduce geometrical discontinuity in structure and reduce the number of welded joints as much as possible. In the design, verified mechanical calculation software may be used for simulated analysis and calculation, so as to ensure integrity of container can be ensured under various operation conditions of the container.
5.4.6 The design of container head cover shall be convenient for remote-controlled welding with container cylinder after waste filling; all the welding, test, inspection, quality and other requirements of this weld (the last weld for welding at container service site) shall be specified in design documents.
5.4.7 The hoisting structure of container shall consider non-protruding structure to make it does not bear overlarge impact load directly under various operation conditions, such as falling, and to ensure integrity of the container.
5.4.8 The structure of container shall be easily processed and manufactured and feature in material saving, cost reduction and storage space narrowing.
5.5 Processing and manufacturing requirements
5.5.1 General requirements
The processing and manufacturing herein include the last weld after waste filling and container sealing. The manufacturing of container shall meet not only the requirements of this standard, but also the relevant requirements of design drawing. In the manufacturing, the method to reduce material thickness, such as embossed stamp, shall not be adopted on the material of container cylinder as the material processing confirmation mark.
5.5.2 Forming requirements
The forming requirements for cylinder and shell of the container are in accordance with those specified in GB 150; where there are special requirements, the requirements higher than standard may be proposed.
5.5.3 Limit deviation requirements for linear size of machined and un-machined surfaces
The limit deviation for linear size of machined and un-machined surfaces shall meet the requirements of Class m and Class c in GB/T 1804.
5.5.4 Welding requirements
5.5.4.1 Preparation before welding
The requirements of preparation before welding and welding environment specified in GB 150 shall be met.
5.5.4.2 Welding procedure requirements
The welding procedure qualification before welding of container shall be carried out in accordance with those specified in NB/T 47014. The storage life of documents such as welding procedure qualification report, welding procedure specification, welding record and welder identification marker shall be at least 10a.
5.5.4.3 Boundary dimension and appearance requirements of welded joint surface
The welded joint of container shall meet those specified in GB 150; where there are special requirements, the requirements higher than standard may be proposed.
5.5.4.4 Repairing requirements of welded joint
Where the welded joints of container need repairing, the repairing and welding procedure shall be in accordance with 5.5.4.2; the same part shall not be repaired for more than two times.
5.5.5 Surface treatment requirements
The external surface of container shall be polished; the surface roughness shall be lower than Ra1.6μm; the roughness of weld shall be polished lower than Ra1.6μm.
5.5.6 Non-destructive testing requirements
5.5.6.1 Non-destructive testing methods and requirements of raw materials, parts and components
The non-destructive testing methods and requirements of raw materials, parts and components of the container shall be in accordance with corresponding requirements of NB/T 47013.
5.5.6.2 Non-destructive testing method and qualified requirements of welded joint
The non-destructive testing of welded joint of the container shall be carried out in accordance with the requirements and methods of design drawing. The testing standard shall be in accordance with those specified in NB/T 47013; the radiographic testing not lower than Grade II is regarded as qualified and the penetration testing of Grade I is regarded as qualified.
5.5.6.3 Testing requirements of repair welding area
The repair welding shall be carried out after the unallowable defects (if any) are removed; after repair welding, this part shall be retested with former testing method.
5.6 Requirements for last weld after container sealing
5.6.1 The seal weld after waste filling and container sealing is not completed within the container manufacturer; however, the welding procedure qualification, welding test and non-destructive testing of this weld within the manufacturer shall be carried out according to the design requirements and automatic welding procedure adopted by the using unit in the process of type identification test in the manufacturer. The welding, test, inspection, quality and other requirements of this weld shall be proposed in design documents of the container.
5.6.2 The using unit of container shall carry out welding procedure qualification, welding test, non-destructive testing and test welding to this weld according to the design requirements before wastes filling; if the design requirements are met, the welding may be carried out officially according to the same welding procedure qualified after wastes filling.
5.6.3 For non-destructive testing of this weld, the qualification of welded joint shall be carried out according to the requirements of NB/T 47013 in the process of type identification test in the manufacturer and seal welding test by the using unit of container before waste filling. The testing qualified requirements are as specified in 5.5.6.2. The seal weld after waste filling may not be subjected to non-destructive testing, and its testing method shall be specified in design documents of the container.
Foreword I
1 Scope
2 Normative References
3 Terms and Definitions
4 Container Size for High-level Radioactive Solid Waste
5 Technical Requirements for Container
6 Inspection Method of Container
7 Type Identification Test and Acceptance Requirements of Container
8 Ex-factory Inspection Rules of Container Products
9 Marks
10 Packaging, Storage and Transportation of Container Products
11 Product Quality Assurance
Bibliography
