ANSI HPS N43.2-2001 Radiation Safety for X-ray Diffraction and Fluorescence Analysis Equipment.pdf

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1、ANSI/HPS N43.2-2001 Health Physics Society An American National Standard Radiation Safety for X-ray Diffraction and Fluorescence Analysis Equipment ANSI/HPS N43.2-2001 An American National Standard - Radiation Safety for X-ray Diffraction and Fluorescence Analysis Equipment Approved: July 31, 2001 A

2、merican National Standards Institute, Inc. iv Forward (This forward is not part of ANSI/HPS N43.2-2001, Radiation Safety for X-ray Diffraction and Fluorescence Analysis Equipment.) The problem of radiation hazards connected with the operation of x-ray diffraction and fluorescence analysis equipment

3、has been a continuing one since the advent of such equipment. While many improvements have been made in safety since the last release of this standard, many pieces of older and custom-built equipment are still in use today. In addition, new uses have been found in areas like surface and thin film an

4、alysis that were not addressed in the original standard. This revision is meant to modernize the past recommendations (many of which are still valid, however) and to provide guidance for x-ray use in new technologies. Historically, the American Standards Association (ASA), Sectional Committee Z54, i

5、n 1946 issued American War Standard Z54.1 “Safety Code for the Industrial Use of X-rays” which included a section on x-ray diffraction. In 1967, the ASA was superseded by the USA Standard Institute, and Sectional Committee Z54 was replaced by Committee N43 under the sponsorship of the National Burea

6、u of Standards (NBS). Responsibility for the development of the original standard was assigned to Subcommittee N43-1. American National Standard N43.2-1971 “Radiation Safety for X-ray Diffraction and Fluorescence Analysis Equipment” was approved on October 6, 1971, published as NBS Handbook 111, and

7、 then reaffirmed with minor revisions in 1976. In 1985, the Health Physics Society replaced the National Bureau of Standards as the Secretariat for the N43 Committee. In 1988 Subcommittee N43.2 reformed to begin updating process and had the standard reaffirmed in March 1989. Revision work was comple

8、ted in December 1998 and the draft received N43 Committee approval April 23, 1999. Suggestions for improvement gained in the use of this standard will be welcome. They should be sent to HPS Standards Program Director, Health Physics Society, 1313 Dolley Madison Blvd., Suite 402, McLean, VA 22101, US

9、A. iii Below is the list of Members of Subcommittee N43.2 which had the responsibility for the development of ANSI/HPS 43.2-2001: Jeffrey Leavey, Chair (IBM Corporation) David Allard (Pennsylvania Bureau of Radiation Protection) Mike Byrnes (Lucent Technologies) Ted de Castro (Lawrence Berkeley Labo

10、ratory) Mark Depp (formerly with Bruker AxS) Len DeRoche (formerly with Rigaku USA) Wes Dunn (formerly with International Isotopes, Inc.) Reed Durham (Lockheed Martin Energy Systems) William Morris (Dept. of the Navy) Robert Westerdale (EDAX, Inc.) iv This standard was consensus balloted and approve

11、d by the ANSI-Accredited HPS N43 Committee on April 23, 1999. At that time, the N43 Standards Committee had the following membership: Chair John C. Taschner Vice Chair Gordon M. Lodde ABB Industrial Systems Inc. John R. Dukes Alliance of American Insurers Thomas F. Bresnahan American Automobile Manu

12、facturers Association Donald A. Greschaw William Watt (alt.) David A. Felinski (alt.) American Conference of Governmental Industrial Hygienists Gordon M. Lodde American Crystallographic Association Camden Hubbard American Insurance Services Group Stewart M. Fastman American Iron and Steel Institute

13、Anthony LaMastra Peter A. Hernandez (alt.) American Public Health Assoc., Inc. Jesse Lieberman American Society for Nondestructive Testing, Inc. K. Dieter Markert American Society for Testing and Materials Marvin M. Turkanis Atomic Energy Control Board R. E. Irwin Conference of Radiation Control Pro

14、gram Directors Mike Henry Bart Lago (alt.) Health Physics Society Jack Fix David Lee (alt.) National Institute of Standards and Technology Douglas M. Eagleson James W. Tracy (alt.) Underwriters Laboratories, Inc. Peter Boden David Dini (alt.) Univ. of California (Los Alamos Natl Lab) John C. Taschne

15、r U. S. Dept of the Air Force, Office of the Surgeon General Don Jordan U. S. Dept of the Army, Office of the Surgeon General Harris Edge Gregory R. Komp (alt.) U.S. Department of Energy Peter OConnell Joel Rabovsky (alt.) U. S. Department of the Navy David E. Farrand William Morris (alt.) Steven Do

16、remus (alt.) U. S. Dept of Health and Human Services - Public Health H. Thompson Heaton Frank Cerra (alt.) Individual Members John H. Weiler v Contents 1. Introduction . 1 2. Scope 1 3. Definitions . 1 4. Types of Injuries 3 5. Dose Limits . 3 6. Installation and Equipment Requirements 3 6.1 Install

17、ation requirements 3 6.2 X-ray System Classification and Requirements. 5 7. Operating Procedure Requirements . 7 7.1 Federal, State and Local regulations and Procedures. 7 7.2 Radiation Protection Surveys and Inspection 7 7.3 Normal Opertion. 8 7.4 Repair and Alignment. 8 7.5 Use of Nonstandard Acce

18、ssories. 8 7.6 X-ray Use in Vacuum Systems 8 8. Personnel Requirements 9 8.1 Responsibility . 9 8.2 Health Surveillance 9 8.3 Personnel Monitoring . 9 9. References 10 Figures Figure 1. Area Designations . 4 Tables Table 1. NCRP External Ionizing Radiation Dose Recommendations . 13 Table 2. Transmis

19、sion Through Lead of X-rays Generated at Constant Potential. 13 Table 3. Thickness of lead (mm) required for a primary beam barrier located 5 cm from focal spot. 13 Appendix A. Detection and Measurement of Radiation from X-ray Diffraction and Fluorescence Analysis Equipment 14 AMERCIAN NATIONAL STAN

20、DARD ANSI/HPS N43.2-2001 1 Radiation Safety for X-ray Diffraction and Fluorescence Analysis Equipment 1. Introduction This standard reviews the types of injuries resulting from accidental exposure to ionizing radiation resulting from the operation of analytical x-ray diffraction and fluorescence equ

21、ipment, establishes equipment design criteria, sets up requirements for approved operating procedures, and recommends the establishment of health surveillance, and personnel monitoring programs. The circumstances under which operation of equipment must be limited to specially designated areas equipp

22、ed with radiation barriers and warning signs are provided. Dose limits recommended by the National Council on Radiation Protection and Measurements are provided for reference. A list of references to selected articles on various aspects of radiation safety is given, and notes on the detection and me

23、asurement of radiation from x-ray diffraction and fluorescence analysis equipment are included in an appendix. 2. Scope This standard provides guidelines specific to the radiation safety aspects of the design and operation of x-ray diffraction and fluorescence analysis equipment. It does not include

24、 electrical safety guidelines or other safety considerations outside the realm of radiation safety. 3. Definitions The definitions and terms contained in this standard, or in other American National Standards referred to in this document, are not intended to embrace all legitimate meanings of the te

25、rms. They are applicable only to the subject treated in this standard. ALARA. As Low As Reasonably Achievable - making every reasonable effort to maintain exposures to radiation as far below the dose limits as practical, taking into account the state of the technology, the economics of the improveme

26、nts in relation to the benefits, and other societal or socioeconomic considerations. Analytical X-ray Equipment. Laboratory equipment utilizing x-ray radiation to analyze or obtain information about material properties (e.g. surface characteristics, elemental composition, material structure, etc.) u

27、sing diffraction or fluorescence techniques. Controlled Area. A specified area to which access is managed in order to protect personnel from radiation. Dose, Absorbed. The energy imparted to matter in a volume element by ionizing radiation divided by the mass of irradiated material in that volume el

28、ement. The unit is the Gray (Gy) and the special unit of absorbed dose is the rad. One Gy = 1 J/kg and one rad equals 100 ergs per gram. (1 Gy = 100 rad.) Dose Equivalent (H). The product of absorbed dose, radiation weighting factor, and other modifying factors necessary to express on a common scale

29、, for all ionizing radiation, the dose incurred by exposed persons. The unit is the Sievert (Sv) and the special unit of dose equivalent is the rem. (1 Sv = 100 rem.) Dose Rate, Absorbed. The absorbed dose per unit time. Exposure. A measure of the ionization produced in air by x- or gamma-radiation.

30、 This unit is considered obsolete. It is the sum of the electrical charges on all of the ions of one sign produced in air when all electrons liberated by photons in a volume element of air are completely stopped in the air, divided by the mass of the air in the volume element. The special unit of ex

31、posure is the roentgen (R) which = 2.58x10-4Coulomb/kg. Exposure Rate. The exposure per unit time. Fail-safe Design. A design in which all realistically anticipated failures of indicators or ANSI/HPS N43.2-2001 2 safety components result in a condition in which personnel are safe from exposure to ra

32、diation. For example: if a light indicating “X-RAY ON“ fails, the production of x-rays shall be prevented, or if a shutter status indicator fails, the shutter shall close. High Radiation Area. Any area accessible to individuals, in which radiation could result in an individual receiving a deep dose

33、equivalent in excess of 1.0 mSv (100 mrem) in any one hour at 30 cm (1 foot) from the source or from any surface that the radiation penetrates. Note: other definitions of high radiation area may exist, see Section 7.1. Installation. A room or other space with defined boundaries where analytical x-ra

34、y equipment is located. Installation Enclosure. That portion of an installation which clearly defines the transition from an uncontrolled to a controlled area, and provides such shielding as may be required to limit the dose rate in the uncontrolled area during normal operation. For example, the wal

35、ls of a room containing an x-ray unit may be the installation enclosure. Normal Operation. Operation under conditions suitable for collecting data as recommended by a manufacturer of the x-ray system. Recommended shielding and barriers shall be in place. Primary Beam. Ionizing radiation from an x-ra

36、y tube anode or secondary target which is allowed to pass by a direct path through an aperture in the radiation source housing for use in conducting x-ray measurements. Primary Radiation. Ionizing radiation coming by direct path from the x-ray tube anode and/or secondary target. Qualified Expert. A

37、person having the knowledge and training necessary to measure ionizing radiation, analyze the significance of and evaluate the potential for health effects, and advise regarding radiation protection as it pertains to x-ray diffraction and fluorescence analysis x-ray equipment. (Where guidance is nee

38、ded as to the competence of an individual to discharge the responsibilities of a qualified expert, it may be obtained from a national certifying board or through local, state, or other regulatory agencies.) Qualified Operator. A person involved with the routine operation of analytical x-ray equipmen

39、t who has had adequate instruction and training in the operation and safety as required by the relevant regulations, person in charge, or supervisor of the equipment. Quality Factor. An energy dependent dimensionless factor by which absorbed dose is to be multiplied by to obtain, for radiation prote

40、ction purposes, a quantity that expresses on a common scale for all ionizing radiation, the magnitude of radiation effects likely to be incurred by exposed persons. The quality factor (Q) for x-rays is 1.0. This term has been superseded by the radiation weighting factor (WR). Radiation Area. Any are

41、a accessible to individuals, in which radiation could result in an individual receiving a deep dose equivalent in excess of 0.05 mSv (5 mrem) in any one hour at 30 cm (1 foot) from the source or from any surface that the radiation penetrates. Note: other definitions of radiation area may exist, see

42、Section 7.1. Radiation Safety (or Protection) Officer. One who has the knowledge and responsibility to apply appropriate radiation protection regulations. He or she may be the owner or the person in charge of the controlled area, a qualified expert, or a technically competent person appointed by the

43、 person in charge. Radiation Source. An apparatus or a material emitting or capable of emitting ionizing radiation. Radiation Source (or X-ray Tube) Housing. That portion of an x-ray system which contains the x-ray tube and/or secondary target. Often the housing contains radiation shielding material

44、 or inherently provides shielding. Radiation Survey. An evaluation of the radiation hazard in and around an installation. It customarily includes a physical survey of the arrangement and use of the equipment and measurement of the exposure rates under the full range of expected and “worst case” oper

45、ating conditions. ANSI/HPS N43.2-2001 3 Radiation Weighting Factor (WR). A linear-energy-transfer dependent factor by which absorbed doses are to be multiplied in computing the dose equivalent. (Note: this term was formerly known as the Quality Factor Q.) Shall. Where “shall“ is used for a provision

46、 specified herein, that provision is intended to be a requirement. Should, is Recommended. “Should“ or “is recommended“ is used to indicate provisions which are not required but which are here recommended as good practices for many facilities. System Barrier. That portion of an x-ray installation wh

47、ich clearly defines the transition from a controlled area to a radiation area and provides such shielding as may be required to limit the dose rate in the controlled area during normal operation. For example, an interlocked enclosure immediately around the x-ray unit could be a system barrier. Uncon

48、trolled Area. Any area to which access is not controlled for purposes of radiation protection (see 6.1.3). X-ray Accessory Apparatus. Any portion of an x-ray installation which is external to the radiation source housing and into which an x-ray beam is directed making x-ray measurements or for other

49、 uses. X-ray Generator. That portion of an x-ray system which provides the accelerating (high) voltage and current for the x-ray tube. X-ray Installation. One or more x-ray systems, the surrounding room or controlled area, and the installation enclosure. X-ray System. Apparatus for generating and using ionizing radiation, including all x-ray accessory apparatus. 4. Types of Injuries Analytical x-ray diffraction and fluorescence analysis equipment have the potential to generate high intensity ionizing radiation In cases of accidental exposure, severe burns affecting the upper e