Chapter V - Radiation Control Measures for Analytical X-Ray Equipment

5.1 Administrative Requirements for Use of Analytical X-Ray Equipment
5.1.1. Registration

Analytical x-ray equipment at ASU must be registered to a single member of the faculty, academic professional, or staff who bears responsibility for safe use of the equipment by all other individuals. See Appendix F.

5.1.2. Notification of Receipt of Equipment

The Office of Radiation Safety be notified within 30 working days of the receipt of analytical x-ray equipment.

5.1.3. Radiation Surveys of Equipment

After initial installation, and upon completion of alterations or maintenance, the Office of Radiation Safety must conduct a survey for radiation leakage before the unit may be placed in service. Surveys may be scheduled through the Office of Radiation Safety. See Appendix E.

5.1.4. Maintenance

Only properly trained maintenance personnel may install, repair, or make other than routine modifications to the x-ray generating apparatus and the tube housing apparatus complex.

5.1.5 Testing of Safety Devices

Safety interlocks and other safety devices will be tested monthly by registrants. Records of these tests should be maintained by the registrant for review by Office of Radiation Safety or ARRA personnel.

5.1.6. Emergency Procedures

Written emergency procedures pertaining to radiation safety shall be established for each x-ray producing apparatus by the Radiation Safety Officer and posted in a conspicuous location. These procedures list the telephone number(s) of the Radiation Safety Officer and include the following actions to be taken in case of a known, or suspected accident involving radiation exposure:

1. Notify the Radiation Safety Officer, and

2. Arrange for medical examination.

5.1.7. Unattended Use of Equipment

Analytical x-ray equipment must not be left unattended while the tube is energized unless:

1. An interlock device is provided to prevent accidental entry into the primary beam, and

2. The stray radiation at any accessible point at a distance of 10 inches from the tube housing containnment, as measured with monitoring instrument appropriate for the energy range generated, is no greater than 2mR per hour.

5.2 Equipment Requirements
5.2.1. Labeling

All analytical x-ray equipment must be labeled with a readily discernible sign or signs bearing the radiation symbol and the words:

1. "CAUTION - HIGH INTENSITY X-RAY BEAM", or words having a similar intent, on the x-ray source housing; and

2. "CAUTION - RADIATION - THIS EQUIPMENT PRODUCES RADIATION WHEN ENERGIZED", or words having similar intent, near any switch that energizes an x-ray tube.

5.2.2. Visual Indicators

1. The primary on-off switch for each tube must include a visual indication of the tube status, in the form of a warning light on the control console and a warning light on the tube housing, wired so that the x-ray tube cannot be energized if the warning light fails. Such lights must operate at all times when the tube is energized and must light at no other times.

2. A shutter status (open or closed) indication must be provided in the area adjacent to the tube head so that the position of the shutter is readily discernible.

5.2.3. Interlocks

1. An interlock device which prevents entry of limbs, fingers, hands, wrists, etc., into the primary beam or causes the primary beam to be shut off, must be utilized, unless otherwise approved by the Radiation Safety Committee.

2. It must not be possible to resume operation without resetting the beam "ON" switch at the control panel.

5.2.4. Beam Shutters

On open-beam configurations, each port on the radiation source housing must be equipped with a shutter that cannot be opened unless a collimator or a coupling has been connected to the port.

5.3. Facility Requirements
5.3.1. Dedicated Work Space
1. X-ray diffraction and spectrographic equipment must be placed in a room separate from other work area, unless otherwise approved by the Radiation Safety Committee.

2. Access to rooms containing analytical x-ray equipment must be secured to prevent unauthorized use of equipment.

3. All installations must display warning signs on the outside of all entrances to the room. Warning signs will be supplied and posted by the Office of Radiation Safety staff.

5.4. Radiation Limits
5.4.1. General

The local components of an analytical x-ray system must be located and arranged, and must include sufficient shielding or access control such that no radiation levels in excess of 80 mR per hour will exist in areas accessible to the fingers, hands, or forearms, or in excess of 5 mR per hour will exist in areas accessible to the whole body, lens of the eyes, blood forming organs, or gonads. When analytical x-ray equipment is placed in a room utilized by personnel other than operators of the x-ray producing equipment, the limits for these radiation levels will be reduced by a factor of twenty.

5.4.2. Other Radiation Limits

1. Each x-ray tube housing must be so constructed that with all shutters closed the leakage radiation measured at a distance of 5 cm from its surface is not capable of producing a dose in excess of 2.5 mrem in one hour at any specified tube rating.

2. Each x-ray generator must be supplied with a protective cabinet which limits leakage radiation measured at a distance of 5 cm from its surface such that it is not capable of producing a dose in excess of 0.25 mrem in one hour.

3. Any apparatus utilized in beam alignment procedures must be designed in such a way that excessive radiation will not strike the operator. Particular attention should be given to viewing devices, in order to ascertain that lenses and other transparent components attenuate the beam to an acceptable level.

5.5 Requirements of Users
5.5.1. Training and Other Responsibilities

No individual will be permitted to act as an operator of a particular instrument until such individual has received an acceptable amount of training in the correct use of specific equipment and in radiation safety and is approved by the Radiation Safety Officer. Operators are responsible for:

1. Keeping radiation exposure to themselves and others as low as is practical.

2. Being familiar with safety procedures as they apply to each instrument.

3. Wearing of personnel monitoring devices, if required.

4. Notifying the Radiation Safety Officer of known or sususpected excessive radiation exposures.

5.5.2. Bypassing or Altering Interlocks and Safety Devices

If, for any reason, it is necessary to temporarily intentionally alter safety devices, such as bypassing interlocks or removing a shield, such action shall be:

1. Specified in writing and posted near the x-ray tube housing so that other persons will know the existing status of the machine.

2. Terminated as soon as possible.

5.5.3. Other

1. Personnel must not expose any part of their body to the primary beam.

2. Unused tube head ports must be secured in the closed position. These must be checked prior use when the machine has been left unattended.