1 Scope
This standard specifies the requirements for concrete radiation shielding structures.
This standard is applicable to the shielding structures of high-radioactive laboratory, radioactive chemical station, test device and nuclear power station.
2 Normative References
The following standards contain provisions which, through reference in this text, constitute provisions of this standard. For dated reference, subsequent amendments to (excluding correction to), or revisions of, any of these publications do not apply. However, the parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards. For undated references, the latest edition of the normative document referred to applies.
GB/T 1596-1991 Fly ash used for cement and concrete
GB/T 2847-1996 Pozzolanic materials used for cement production
GB 50204-1992 Code for construction and acceptance of concrete structures
GBJ 5-1988 Code for design of timber structures
GBJ 9-1987 Load code for the design of building structures
GBJ 18-1987 Technical code of cold-formed thin-wall steel structures
EJ/T 317-1997 Design criterion of radiation shield in the PWR nuclear power plant
EJ/T 1062-1998 Code for design of steel structures
JGJ 18-1996 Specification for welding and acceptance of reinforcing steel bars
JGJ 51-1990 Technical specification for light weight aggregate concrete
JGJ 55-2000 Specification for mix proportion design of normal concrete
3 Terms and Definitions
The following terms and definitions apply in this standard.
3.1
Admixture
Admixture is a kind of materials which is different from water, aggregate or cement used in concrete before or during mixing.
3.2
Conventional placement
In this kind of method, concrete compositions such as normal cement, water, fine aggregate, or coarse aggregate are mixed, and then conveyed to the formwork by virtue of gravity through pump, conveyer, trolley, bucket or wheelbarrow.
3.3
Preplaced aggregate (PA) method
In this kind of method, the formwork shall be filled with graded coarse aggregates, and then structural mortar shall be pressurized into the gaps between aggregates.
3.4
Puddling method
In this kind of method, first placing a layer of mortar in the formwork, above it placing a layer of coarse aggregate, fully vibrating to make the coarse aggregate entirely sunken into the mortar, and then repeating the whole process until reaching the prescribed height
3.5
Pressure grouting
In this kind of method, liquid mortar is pumped into the gaps under pressure. This method is used to fill the gaps and cracks in the concrete generated by other placing methods.
3.6
Embedment
Embedment is an object partly or entirely embedding into the concrete, except the devices required for reinforcement and structure.
3.7
High density concrete
High density concrete refers to the concrete composed of special heavy aggregate (concrete whose density is greater than 2.56g/cm3) for improving shielding performance.
3.8
Jacket
Jacket is a block of metal entirely or partly covering the penetration plug or shielding block.
3.9
Liner
Liner is a kind of permanent metal plate covering the surface of concrete radiation shielding structures.
3.10
Liner screed
Liner screed is a kind of embedment, generally embedded rolled structural shapes, on which is liner.
3.11
Movable shielding wall
It refers to a kind of movable shielding wall which is able to move as an entirety.
3.12
Normal concrete
Normal concrete is a kind of concrete made of normal gravel aggregate and whose density is 2.35g/cm3.
3.13
Penetration
Penetration is a kind of component in the shielding wall or penetrating the shielding wall for installing shielding windows, viewing devices, piping, manipulators as well as other components and devices.
3.14
Plug, shielding plug, penetration plug, roof block
They refer to the radiation shielding device that may be temporarily installed and removed in the penetration to prevent radiation leak through shielding.
3.15
Pumping method
It refers to the method conveying concrete, mortar or grout to the placing site by pump through rigid or flexible piping.
3.16
Radiation shielding
Radiation shielding refers to the barrier material that is set between the staff and the radiation source to reduce the ionizing radiation to as low as reasonably achievable (ALARA) level.
3.17
Radiation streaming
Radiation streaming is the radiation leak through holes, cracks or gaps in the shield.
3.18
Removable shielding wall
It refers to a kind of removable permanent or temporary shielding devices that are composed of single devices made of blocks or prefabricated by shielding materials.
3.19
Service environment, service condition
Under normal conditions, radiation shielding will suffer the influence of hot, cold, humidity, pressure, corrosion, abrasion, impact, vibration or other environmental factors.
3.20
Window, shielding window, viewing window
The are a kind of direct viewing devices in the shielding walls, made of special high-density radiation shielding glass or glass case with radiation-absorbent liquid in it; their biological shielding effect are basically equivalent to concrete shielding.
3.21
Window liner
Window liner refers to the metal covering layer used as the liner of window.
Contents
Foreword i
1 Scope
2 Normative References
3 Terms and Definitions
4 General Provisions
5 Concrete Composition and Mix Proportion
6 Formwork, Formwork Manufacture and Concrete Reinforcement
7 Embedment
8 Concrete Placement
9 Surface Covering
10 Roof, Movable Roof Shielding Block, Penetration Plug and Other Shielding Component
11 Quality Assurance
