X-Ray Safety | Environmental, Health and Safety Services | Virginia Tech
Environmental, Health and Safety Services

X-Ray Safety Cabinet Systems

7.0 Cabinet X-ray Systems

The rules in this section apply to cabinet X-ray systems. These requirements are in conformity with Title 21 of the Code of Federal Regulations, Part 1020 (21 CFR 1020), and the Rules and Regulations for the Use of Ionizing Radiation in the Commonwealth of Virginia.

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7.1 Requirements For Cabinet X-ray Systems

A key-activated control shall be provided to ensure that X-rays will not be generated when the key is removed.

Each door of a cabinet X-ray system shall have a minimum of two safety interlocks. Each access panel shall have at least one safety interlock.

A control, other than the safety interlock, shall be provided to resume X-ray generation following X-ray interruption by a safety interlock.

Two independent means shall be provided to indicate when X-rays are being generated. One may be a millimeter labeled to indicate X-ray tube current, the other indicator shall consist of an easily seen warning light labeled "X-RAY ON."

A clearly legible and visible label bearing the statement: "CAUTION: X-RAYS PRODUCED WHEN ENERGIZED" shall be posted near the controls that energize the X-ray tube.

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7.2 Training

All individuals independently operating cabinet X-ray systems shall receive instructions in and demonstrate ability in:

    1. General properties of ionizing radiation.
    2. Principles of radiation detection.
    3. Radiation hazards associated with the use of the equipment.
    4. Biological effects of ionizing radiation.
    5. Procedures to minimize exposure.
    6. Proper operating procedures for the equipment.
    7. Va Tech radiation safety requirements for the use of cabinet X-ray systems.
    8. Purposes and functions of the radiation warning and safety devices incorporated into equipment and, if not installed, the extra precautions required.
    9. Proper procedures for reporting an actual or suspected over-exposure.

Ability shall be demonstrated by passing a written examination administered by the Radiation Safety Office. Exceptions to radiation safety training will not be granted because of previous education, training, or experience.

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7.3 Operating Procedures

Normal operating procedures shall be written and available to all cabinet X-ray equipment users. Cabinet X-ray systems shall not be operated differently from that specified in the procedure manual unless written permission has been obtained from the Radiation Safety Committee.

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7.4 Radiation Limits

Radiation emitted from a cabinet X-ray system shall not exceed an exposure rate of 0.5 mrem/hr at any point 5 cm from the external surface at the maximum rated current and voltage.

A cabinet X-ray system shall contain sufficient shielding and be located so exposure rates in unrestricted areas do not exceed 2 mrem/hr, or 100 mrem/yr.

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7.5 Personnel Monitoring

All users of the system shall wear a whole-body personnel monitoring device unless a variance has been granted by the state. However, a variance cannot be sought that would exempt the heaviest user and pregnant workers from being required to wear whole-body monitoring devices.

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7.6 Surveys

Radiation surveys shall be performed and documented by the Radiation Safety Office:

    1. When the equipment is installed and at least once every year thereafter to monitor leakage radiation.
    2. On a monthly basis to monitor area radiation levels and to test the integrity of the interlock system if a variance to the personnel monitoring requirement, as described in the previous section, has been granted.
    3. After maintenance or system relocation.

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