Detail of EJ/T 1144-2004

Introduction of EJ/T 1144-2004

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 of EJ/T 1144-2004

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