GB 10252-2009Regulations for radiation protection and safety of gamma irradiation facilities (English PDF)

Foreword

All the technical contents of this standard is mandatory. This standard replaces GB 10252-1996 "radiation protection and safety standards cobalt-60 irradiation facilities." This standard compared with GB 10252-1996, the main changes are as follows:

--- By the name of the standard "cobalt-60 radiation protection and safety standards irradiation apparatus" with "radiation protection and safety gamma Irradiation Facilities specification";

--- "Scope" to add a chapter include some content, expanding the scope of application;

--- "Normative references" All has been modified;

--- Added "Terms and Definitions" chapter;

--- "Radiation and Pollution Control" made some changes;

--- Remove the original "division and workplace requirements" chapter, "non-restricted zone" a;

--- Increased "radiation protection and safety," a chapter;

--- Increased "environmental assessment irradiation apparatus" chapter;

--- Original "radiation protection and safety management" with "Radiation Safety Management";

--- Remove the original "technical requirements for radiation protection and safety" and "security analysis irradiation apparatus" two chapters;

--- Original "inventory and inventory of radiation sources" to "Management of Radioactive Sources";

--- The original "Radiation protection and safety testing content" and "radiation monitoring" Merge to "detect radiation safety";

--- Added "retired irradiation apparatus" chapter;

1 Scope

China's mandatory national regulations for the radiation protection and safety of gamma irradiation facilities. These are the industrial plants that expose products to a cobalt-60 or caesium-137 source to sterilise medical devices, treat food, or modify polymers - and the source inside them is among the most dangerous objects in civilian industry: unshielded, it delivers a lethal dose in minutes. The whole safety case rests on never letting a person be in the cell with the source raised, and the standard is built around that single proposition. It specifies the shielding, the source hoist and its fail-safe return to the pool, the interlocks on every entrance, the search-and-secure procedure before a run, the radiation monitors and their independence from the control system, and the emergency stops inside the cell. The accidents that have happened worldwide were all defeats of these barriers by people who believed the source was down.

This standard specifies the use of gamma irradiation apparatus I class sources of radiation and pollution control division, radiation protection and radiation in the workplace Environmental evaluation of safety design, the irradiation apparatus and the radiation safety management, radiation safety testing, irradiation facilities decommissioning and emergency requirements. This standard applies to the use of the site class I gamma irradiation apparatus radioactive sources, design, construction, operation and decommissioning of radiation protection and safety.

2 Normative references

The following documents contain provisions which, through reference in this standard and become the standard terms. For dated references, subsequent Amendments (not including errata content) or revisions do not apply to this standard, however, encourage the parties to the agreement are based on research Whether the latest versions of these documents. For undated reference documents, the latest versions apply to this standard.

GB 3095 Ambient Air Quality Standard

GB 17568 gamma irradiation facilities design and construction specifications and use

GB 18871-2002 ionizing radiation protection and safety of radiation sources basic standards (IAEA Safety Series, NEQ) HJ/T 2.2-1993 Environmental Impact Assessment Technology Guidelines

3 Terms and Definitions

GB 17568 and established in the following terms and definitions apply to this standard.

3.1 Within the irradiation facility enclosed by a radiation-shielding material with, radiation processing and in working condition due to safety measures for personnel can not enter the interlock Space.

3.2 Penetrating power strong radiation in matter, generally refers to gamma radiation, X-radiation and neutron radiation. This standard refers specifically to shield the irradiation chamber wall table Surface water surface, the roof and a reservoir wells transmission out of gamma radiation.

3.3 Important safety control system irradiation apparatus, wherein the operation of such components are interrelated, each action parts are subject to pre-regulation Given state and (or) controlled conditions, so long as either a component of any state and (or) does not meet the pre-conditions for the provisions of irradiation can be prevented Sources from the storage device state put into use, or to have been put into use radioactive sources or are immediately returned to the storage state, or resistance Personnel from entering the irradiation device is irradiated from the irradiation chamber to make it.

3.4 The source or the use of a particular practice is possible to predict and estimate the impact on the environment carried out, including the size of the source or practice with special Of the overview of the status of the site or workplace environment analysis and environmental impact under normal, abnormal and may cause accidents or consequences Analysis.

3.5 Environmental protection department under the State Council issued on the basis of the safety review, together with its holder to comply with the specific requirements and conditions Radiation safety license.

3.6 Reached the end of life of the radionuclide or find a leak or licensees are no longer expected to use radioactive sources specified by the manufacturer.

9 Radiation Safety Testing

9.1 routine daily inspection should include at least the following.

a) Working status indicator;

b) Radiation safety interlock control room display condition;

c) Lift the source and delivery system conditions;

d) personal alarm dosimeters and portable Dose Monitor;

e) a reservoir well water level;

f) ventilation systems.

9.2 regular monthly examination should include at least the following.

a) irradiating an indoor stationary radiation monitors.

b) a source of emergency lowering system.

c) source and a guide wire rope hoist, conveyor systems. If the tether appear overused phenomenon, should be replaced.

d) fill the water replenishment should check whether it is normal. As an exception, you should check wells for leaks and check the water supply system operation situation.

9.3 General six months examination should include at least the following.

a) with annual maintenance of detection;

10 Supervised area

4 Overalls, gloves, work shoes Control area Supervised area Hands, skin, underwear, socks, work 4 × 10-

Appendix A

(Informative) Irradiation chamber shielding and protection design calculation A. 1 irradiation chamber shielding wall thickness determination For gamma irradiation means radioactive source is a board made up of many sources of rod-shaped, usually for 1.85 × 1016Bq (

50 Wan Habitat In) below the rank of sources, since the source frame size is small relative to the size of the irradiation chamber, when gamma radiation shielding calculation approximate the following points Source computing model does not produce large errors; but when reached one million sources Curie level and above, due to the larger size frame source, point source near this Like computing model it is not reasonable. Therefore, the use of foreign mature point kernel integral Shielding Calculation programs such as QAD-CG calculation. In the absence of the medium between the point source and probe points situation, gamma-ray energy flux density probe points is calculated as shown in Equation (A.1). Phi = S04piR2 (A.1) Where. Phi

--- gamma-ray energy flux density, in units of MeV seconds per square centimeter [MeV/(cm2 · s)]; S0

--- point source energy intensity per unit of MeV (MeV/s); R

--- from the point source and detection points between centimeters (cm). Converted by number ICRP

74 Publications (1996) Richard gamma photon energy corresponding to the energy flux density 1.25MeV when the dose rate due to Sub Hp = 1.765 × 10-5 (mSv/h)/[MeV/(cm2 · s)], obtained by the conversion rate of the probe point no dose shield when D. Multiple needs effectively weaken the concrete shielding wall calculation see equation (A.2). K = D Dm (A.2) Where. Effectively weaken multiples k

--- shield body; Dose rates D

--- no shield case of probe points, units per hour microsieverts (µSv/h); Dm

--- shielded Area vitro detection point dose constraint value corresponding to the dose rate in units of micro Greek per hour (µSv/h). The k value, you can find the required concrete shielding wall thickness value. For a reservoir wells, water shield can be used to determin...