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X-Ray Safety Program Summary

The X-Ray Safety Program provides information regarding the proper use of X-ray machines and proper protection for operators of such devices.

This program applies to all individuals and/or departments using analytical or diagnostic instrumentation that produces X-ray radiation either directly or indirectly in the course of work. This includes bone densitometers, electron microscopes, diffractometers, and CT scanners in addition to traditional X-ray imaging equipment.

All equipment purchases must be placed by an authorized user and approved by the radiation safety officer prior to ordering. All instruments must be inspected and certified before use and all personnel involved, trained accordingly. Certification and training requirements vary by instrument type and procedures implemented. Those instruments used in the healing arts (conventional medical x-ray machines) must be certified by a state-qualified expert and records maintained as per Virginia Department of Health (VDH) regulations with Environmental Health & Safety, the Radiation Safety Office, acting as liason for VDH. 

For all other X-ray instrumentation, inspections are conducted by Environmental Health & Safety personnel, and records shared with VDH as requested. Further details and information are given in the written program.


X-Ray Safety  Online Program

Purpose

The X-Ray Safety Program is designed to provide the information needed for university personnel to work safely with equipment and procedures that generate X-ray radiation.

Scope

The program details the Virginia Department of Radiological Program and Virginia Tech requirements for equipment procurement and validation, procedure developments, and education of personnel.

Application

X-ray equipment is used in different areas and therefore, varied groups of personnel are covered by this program. That includes:

  • Medical professionals and researchers using diagnostic units.
  • Faculty, staff, and students involved in analytical research.

Any questions for clarification of use should be directed to the University Radiation Safety Office.

The following rules govern the use of analytical X-ray equipment at Virginia Tech. These rules comply with the radiation safety standards recommended by the Commonwealth of Virginia and the American National Standards Institute (ANSI).

Open and enclosed-beam analytical systems

The following are requirements for both open-beam and enclosed-beam analytical X-ray systems.

  1. Warning lights: An easily visible warning light labeled "X-RAY-ON" shall be located near any switch that energizes an X-ray tube. It is to be illuminated only when the tube is energized. This light shall be of a fail-safe design.
  2. Labeling: All analytical X-ray equipment shall be labeled with a conspicuous sign or signs that bear the radiation symbol and the words (or similar words):
  • "CAUTION - HIGH-INTENSITY X-RAY BEAM" on the X-ray source housing.
  • "CAUTION - RADIATION - THIS EQUIPMENT PRODUCES RADIATION WHEN ENERGIZED" near any switch that energizes an X-ray tube.
  • Beam trap - A beam trap or other primary beam shield shall be provided to intercept the primary beam.

Additional requirements for enclosed-beam systems 

  1. Chamber: The X-ray tube housing, sample detector, and analyzing crystal shall be enclosed in a chamber (or coupled chambers) that prevents entry of any part of the body.
  2. Ports: Access ports to the sample chamber shall be of a fail-safe design that prevents X-ray generation or entry of the X-ray beam into the chamber when any port is opened.

Additional requirements for open-beam systems

Safety device: An interlocked safety device, which prevents entry of any part of the body into the primary beam or causes the beam to shut off, shall be provided on all open-beam systems. An authorized user may seek an exemption from this requirement by applying to the Radiation Safety Committee. The application shall include: 

  1. A description of the safety devices evaluated and why they cannot be used;
  2. A description of the alternative method that will be used to minimize the possibility of accidental overexposure; and
  3. Procedures will be used to alert personnel to the absence of a safety device.

Warning devices: Open-beam systems shall be provided with the following warning devices:

  1.  X-ray tube status (ON-OFF) located near the X-ray source housing, if the primary beam is controlled in this manner; and/or,
  2. Shutter status (OPEN-CLOSED) is located near each port on the X-ray source housing, if the primary beam is controlled in this manner.
  3. These devices shall be readily visible and properly labeled as to their purpose. Warning devices shall have fail-safe characteristics.
  4. Shutters: Shutters at unused ports shall be secured in the closed position to prevent accidental opening.
  5. Ports: Each port on the X-ray source housing shall be equipped with a shutter that cannot be opened unless a collimator or other device has been connected to the port, if the system was installed after Jan. 1, 1980.

Training

All individuals independently operating analytical X-ray equipment 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. Virginia Tech radiation safety requirements for the use of analytical X-ray equipment.
  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.

Operating procedures 

  1. Procedure manual: Normal operating procedures shall be written and available to all analytical X-ray equipment users. Analytical X-ray equipment shall not be operated differently from that specified in the procedure manual unless written permission has been obtained from the Radiation Safety Committee.
  2. Bypassing safety device: A safety device shall not be bypassed unless written approval has been obtained from the Radiation Safety Officer. This approval shall be for a specified time. When a safety device has been bypassed, a conspicuous sign shall be placed on the X-ray housing bearing the words (or similar words), "SAFETY DEVICE NOT WORKING."

Radiation limits

Enclosed-beam systems: The exposure rate during normal operations shall not exceed 2.5 mrem/hr at a distance of 5 cm from the protective chamber walls.

Open-beam systems: The exposure rate at the maximum rated current and voltage with all shutters closed shall not exceed 2.5 mrem/hr at a distance of 5 cm from the X-ray tube housing.

Generator cabinet: The exposure rate at a distance of 5 cm from the surface of the X-ray generator cabinet shall not exceed 0.25 mrem/hr.

The local parts of an analytical X-ray system shall include sufficient shielding and be so located and arranged so exposure rates in unrestricted areas do not exceed 2 mrem/hr or 100 mrem/yr.

Personnel monitoring

All personnel that does alignment work on open-beam analytical X-ray equipment must wear finger dosimetry devices. Pregnant workers shall wear a whole-body personnel monitoring device during the pregnancy. No badge is required for users of enclosed-beam analytical X-ray units.

Surveys

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

  1. On installation of the equipment and at least once every year thereafter to monitor leakage radiation.
  2. On at least an annual basis, monitor area radiation levels when the equipment is operating.

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

  1. Following any change in the initial arrangement, number, or type of local parts.
  2. Following any maintenance that requires the disassembly or removal of a local part.
  3. During the performance of maintenance and alignment procedures that require the presence of a primary beam and the disassembly or removal of a local part.
  4. When a visual inspection of the local parts reveals an abnormality.

Each area or room containing open-beam analytical X-ray equipment shall be equipped with a suitable radiation survey instrument.

Repair and alignment procedures

The following safety precautions shall be taken to reduce risks during repair and alignment procedures:

  1. The main switch, rather than the safety interlocks, shall be used to shut down the equipment.
  2. No X-ray tube shall be used without a suitable housing to restrict the radiation to a well-defined beam.
  3. A sign stating "Interlocks Not Working" must be posted on the equipment when the interlocks have been defeated for alignment purposes.
  4. The radiation safety officer must approve alignment procedures, other than those recommended by the manufacturer.
  5. Alignment procedures must be written and available to all users.
  6. If the dose rate in an unrestricted area is exceeded during the repair or alignment procedure, temporary barriers must be set up and the area must be properly posted. The area shall be kept under surveillance until normal operations have been restored.
  7. After re-assembly, the radiation safety officer or the user shall check the X-ray equipment for leakage radiation.

The following safety precautions should be taken to reduce risks:

  1. The smallest practical voltage and current should be used during the alignment procedure.
  2. Long-handled tools and extension devices should be used to reduce the risk of the hand entering the beam.
  3. Protective glasses should be worn during alignment procedures.
  4. Temporary shielding should be added to reduce scattered radiation levels to a minimum.
  5. Alignment procedures recommended by the manufacturer should be used.
  6. Two-man teams should be used during alignment procedures. One person should make the adjustments while the other person watches for safety problems.

The Radiation Safety Committee/radiation safety officer must authorize the purchase and use of all X-ray equipment. This includes those that generate X-rays as secondary to the primary intent of operation such as electron microscopes. The following steps must be followed to apply for and obtain approval for X-ray authorization.

  • A copy of the Virginia Tech Application for Authorization to Use X-Ray Equipment must be submitted to the Radiation Safety Office for review.
  • All training requirements must be fulfilled according to details given in the Radiation Safety Training Instructions. Miscellaneous instruments, such as electron microscopes, are excluded from Environmental Health & Safety training requirements. Training for these is the responsibility of the designated Laboratory Authority for the license.
  • The applicant will be permitted to begin operations under terms of the authorization upon receipt of a copy signed by the Radiation Safety Committee chairman and the radiation safety officer.

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.

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.

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.  Virginia 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.

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 those specified in the procedure manual unless written permission has been obtained from the Radiation Safety Committee.

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.

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.

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, monitor area radiation levels and 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.

Access panel: A panel that is designed to be opened for maintenance purposes to permit access to the interior of the cabinet.

Aluminum equivalent: The thickness of type 1100 aluminum alloy affording the same attenuation as the material in question.

Analytical X-ray equipment: Equipment used for X-ray diffraction and fluorescence analysis, (excludes cabinet X-ray systems, electron microscopes, and diagnostic X-ray equipment).

Automatic exposure control: A device that automatically controls one or more technique factors in order to obtain a required quantity of radiation.

Beam-limiting device: A device that provides a means to restrict the dimensions of the X-ray field.

Cabinet x-ray system: X-ray system with the x-ray tube installed in an enclosure, which is intended to contain the object being irradiated, provide radiation attenuation, and exclude personnel from its interior during X-ray generation.

Certified components: Parts of X-ray systems that are subject to regulations adopted under the Radiation Control for Health & Safety act of 1968.

Cooling curve: The graphical relationship between heat units stored and cooling time.

Dead-man switch: A switch that can only be kept ON by continuous pressure.

Diagnostic X-ray system: An X-ray system designed for irradiation of a human or animal for the purpose of diagnosis or visualization.

Diffracted beam: A beam composed of mutually reinforcing scattered X-rays.

Direct scattered radiation: Scattered radiation that has been deviated in direction only by the object exposed to the useful beam.

Enclosed beam configuration: An analytical X-ray system in which all possible X-ray paths are fully enclosed.

Fail-safe design: A design feature that guarantees that the beam port shutters close or prevent the appearance of the primary beam in the event of failure of a safety or warning device.

Gonad shield: A protective barrier for the testes or ovaries.

Half-value layer: The thickness of a material that attenuates the beam of radiation to one-half of its original value.

Healing arts screening: The testing of humans using X-ray equipment for the detection or evaluation of health problems, when such tests are not specifically and individually ordered by a medical doctor.

Heat unit: A unit of energy equal to the product of the peak voltage, current, and seconds.

Image intensifier: A device that converts an X-ray pattern into a corresponding light image of higher energy density.

Image receptor: A device, such as a fluorescent screen or radiographic film, which transforms incident X-ray photons into a visible image.

Inherent filtration: Filtration of the useful beam provided by the permanently installed parts of the tube housing.

Miscellaneous (equipment): Equipment that produces X-rays secondary to its primary function.

Kilovolt peak (kVp): The maximum value of the potential difference across the X-ray tube during an exposure.

Lead equivalent: The thickness of lead affording the same attenuation as the material in question.

Leakage radiation: Radiation, except the useful beam, emanating from the tube housing.

Local components: Includes areas that are struck by X-rays, such as radiation source housings, port and shutter assemblies, collimators, sample holders, cameras, goniometers, detectors, and shielding; but not including power supplies, transformers, amplifiers, readout devices, and control panels.

Milliampere second (mAs): The product of tube current and exposure time.

Mobile equipment: X-ray equipment mounted on a permanent base with wheels.

Open-beam configuration: An analytical X-ray system in which some part of the body could accidentally be placed in the primary or diffracted beam path.

Primary beam: X-rays that pass through an aperture of the source housing by a direct path from the x-ray tube.

Protective apron: An apron made of radiation-attenuating materials.

Protective barrier: A barrier of radiation-attenuating materials used to reduce radiation exposure. The types of protective barriers are:

  • Primary: Material placed in the useful beam, excluding filters, to reduce radiation exposure.
  • Secondary: Barrier that attenuates leakage and scattered radiation.

Qualified expert: An individual, who has demonstrated by training and experience to the satisfaction of the State, that he possesses the knowledge and training to measure ionizing radiation, evaluate safety techniques, and advise others regarding radiation safety needs.

Safety interlock: Device that is intended to prevent the generation of X-rays when a door or access panel is opened.

Scattered radiation: Radiation that has been deviated in its direction during passage through an object.

Stationary equipment: X-ray equipment that is installed in a fixed position.

Technique factors: The condition of operation that is the peak tube potential in kV and either the tube current in mA and exposure time in seconds, or the product of the tube current and exposure time in mAs.

Tube rating chart: The set of curves that specify the rated limits of operation of the tube in terms of the technique factors.

Useful beam: A beam that passes through the tube housing port and the aperture of the beam-limiting device when the exposure switch is activated.

Variable aperture: A beam-limiting device that allows for stepless adjustment of the X-ray field.

X-ray source housing: That portion of an analytical X-ray system that contains the X-ray tube.

The following rules are to ensure the safe use of human-use and veterinary-use diagnostic X-ray equipment at Virginia Tech. These rules are in conformity with the radiation safety standards recommended by the Commonwealth of Virginia.

Personnel monitoring

All individuals working with diagnostic X-ray equipment shall wear a whole-body personnel monitoring device.

Operators of fluoroscopic units shall wear a ring badge and a whole-body badge.

When a lead apron or thyroid shield is worn, the whole-body monitoring device shall be worn at the collar outside the apron or shield.

Declared pregnant radiation workers shall wear a second whole-body monitoring device under the lead apron at waist level.

Patient protection

The following rules are to protect patients from exposure to ionizing radiation, except that which is intended for diagnostic purposes.

  1. The useful beam shall be collimated to cover only the area of clinical interest.
  2. All exposures shall be specifically and individually ordered by a licensed medical doctor or a doctor of veterinary medicine.
  3. Humans shall not be exposed for training, demonstration, or other non-healing art purposes.
  4. Exposure of individuals for healing arts screening is prohibited unless approved by the Radiation Safety Committee and the Virginia Bureau of Radiological Health.
  5. Procedures shall be used to keep patient exposure at a minimum, while still obtaining the necessary diagnostic information. 
  6. The film or screen must be the fastest speed that can be used, yet be consistent with the diagnostic objective.
  7. The radiation exposure to the patient must be the minimum required to produce good diagnostic images.
  8. For human-use units, other than fluoroscopy, the X-ray tube must be at least 30 cm (approximately 1 ft.) from the patient.
  9. The source-to-patient distance must be at least 38 cm for image-intensified fluoroscopic units.
  10. Gonad shielding of at least 0.25 mm lead equivalency must be used on patients of reproductive age if the gonads are in the primary beam and the shielding does not interfere with the diagnostic procedure.
  11. Aluminum filtration shall be placed in the primary beam to reduce the number of soft X-rays to the patient.

Personnel protection

The following rules are to protect operators, holders, and other people from exposure to ionizing radiation.

Stationary units
  • The operators of human-use units must stand behind the protective barrier at the controls during the exposure. The operators of veterinary-use units should stand behind the protective barriers at the controls during the exposure.
  • An operator who is required to be in the X-ray room to take an exposure of an animal must stand at least 6 feet from the useful beam and the animal.
  • Only individuals required for the radiographic procedure are to be in the room during the exposure.
  • All individuals present in the X-ray room during exposure must be protected from the primary beam by at least 0.5 mm lead equivalency and from scatter radiation by at least 0.25 mm lead equivalency.
  • Access to the X-ray room must be secured during the exposure.

Portable and mobile Units 

  • Operators shall stand at least 6 feet from the X-ray tube head and wear a lead apron of at least 0.25 mm lead equivalency.
  • The area or room where the equipment is being used shall be temporarily posted with a "Caution - X-ray Equipment" sign.
  • Bystanders must stand at least 12 feet from the X-ray tube head and the patient being X-rayed.
  • Mobile x-ray units shall not be handheld.
  • The primary beam shall not be directed at bystanders.

Holders

When a patient, animal, or film cassette must be provided with auxiliary support during an X-ray exposure: 

  • Mechanical holding devices must be used whenever possible.
  • No individual shall be used routinely as a holder, to the exclusion of others who could be used.
  • Personnel used as holders must be protected from the primary beam by at least 0.5 mm of lead equivalency, and from scatter radiation by at least 0.25 mm of lead equivalency.
  • Every effort should be made to position the holder so that the primary beam will strike no part of the body.
  • Pregnant workers will not be required to be used as holders.

Radiation limits

  • Leakage radiation from the tube head shall not exceed 100 mrem/hr at 1 meter.
  • Radiation given off by parts other than the tube head shall not exceed 2 mrem/hr at 5 cm.
  • All walls, ceilings, doors, and floor areas shall be equivalent to or provided with sufficient protective shielding to ensure that radiation levels in unrestricted areas do not exceed 2 mrem/hr or 100 mrem/yr.

Equipment requirements

The control panel shall contain the following legible and accessible warning statements:

  1. "WARNING: This X-ray unit may be dangerous to patient and operator unless safe exposure factors and operating conditions are observed."
  2. "CAUTION: This equipment produces radiation when energized, to be operated only by qualified personnel."

The total filtration permanently mounted in the useful beam shall not be less than:

  • 0.5 mm aluminum equivalent for machines operating up to 50 kilovolts peak (kVp),
  • 1.5mm aluminum equivalent for machines operating between 50-70 kVp, and
  • 2.5 mm aluminum equivalent for machines operating above 70 kVp.

The tube housing assembly support shall ensure that the tube housing remains stable during the x-ray exposure.

The technique factors to be used during an exposure shall be visible before the exposure begins.

On battery-powered equipment, visual means shall be provided on the control panel to show the charge of the battery.

A source-to-image distance (SID) indicator must be provided and be accurate to within 2% of the indicated SID.

Stationary, portable, and mobile units

A means for step-less adjustment (e.g. variable aperture collimator) of the size of the x-ray field shall be provided. Means shall be provided to visually define the perimeter of the X-ray field.

The x-ray field shall not exceed the visually defined field by greater than 2 percent.

A method shall be provided to show when the axis of the X-ray beam is perpendicular to the plane of the image receptor.

The exposure shall be ended at a preset time interval, a product of current and time, number of pulses, or radiation exposure to the image receptor.

The X-ray control shall provide a visual indication of X-ray production and an audible signal when the exposure is finished.

The X-ray control for stationary systems shall be permanently mounted in a protected area.

Fluoroscopic systems

X-ray production shall be controlled by a dead-man switch.

The on-time of the fluoroscopic tube shall be controlled by a timing device, which ends the exposure after 5 minutes.

An audible signal shall signal the completion of the preset on time. This signal will remain on until the timing device is reset.

Protective barriers of at least 0.25 mm lead equivalency shall be used to attenuate scatter radiation from above the tabletop (e.g. drapes, bucky-slot covers). This shielding is in addition to the lead apron worn by personnel.

Scattered radiation from under the table shall be attenuated by at least 0.25 mm lead equivalency.

The fluoroscopic imaging assembly shall be provided with a primary protective barrier, which intercepts the entire cross-section of the useful beam.

The X-ray tube used for fluoroscopy shall not produce X-rays unless the barrier is in position to intercept the entire useful beam.

Operator's booth

The operator's booth shall have at least 7.5 square feet of unobstructed floor space in the booth. The booth may be of any shape with no dimension less than 2 feet. The booth is to be located or constructed so that the direct beam and unattenuated direct scatter radiation cannot reach the operator.

Structural requirements

The booth walls shall be at least 78 inches high and permanently fixed. A door or panel that is permanently part of the booth must be interlocked. Sufficient shielding shall be provided to prevent occupational limits from being exceeded.

Control placement

The X-ray control shall be fixed within the booth at least 40 inches from the edge of the booth wall closest to the examining table. The placement of the control shall allow the operator to use most of the viewing window.

Viewing requirements

The booth must have a window that will allow the operator to view any occupant in the room and any entry into the room. Access doors that cannot be viewed by the operator must be interlocked.

The window shall have an area of at least 1 square foot with the lower edge at least 4.5 feet from the floor. The edge of the window shall be at least 18 inches from the edge of the booth. The glass shall have the same lead equivalency as the walls of the booth.

Records

The Laboratory Authority shall maintain the following records and information:

  1. An X-ray log containing the patient's name, type of examination, and the date of the examination.
  2. Maximum ratings and technique factors of the equipment.
  3. Model and a serial number of all components.
  4. Tube rating charts and cooling curves.
  5. Assembler report for certifiable units.
  6. Records of calibrations, maintenance, and modifications.
  7. Aluminum equivalent filtration of the useful beam, including any routine variations.
  8. Virginia Tech license, amendments, surveys, and inspections.

Surveys and inspections

Radiation safety and equipment performance surveys shall be performed by a qualified expert annually on human-use units and at least every 3 years on bone densitometers or veterinary-use units.

A survey for leakage radiation shall be performed following any maintenance, modification, or relocation of the system.

Radiation surveys of areas adjacent to the X-ray producing facility and in the booth will be performed after the installation of new equipment or the relocation of a unit. 

  1. The survey shall include a scale drawing of the areas adjacent to the X-ray room and an estimate of their occupancy.
  2. The drawing shall include the type and thickness of the walls or their lead equivalency.

Reports of all surveys and inspections will be maintained in the Radiation Safety Office.

Emergency telephone numbers and the laboratory line of authority should be given to everyone who works in the lab. The same information should be posted next to every telephone in the lab and outside the entrances to the lab.

Phone numbers

  • Radiation Safety Office: 540-231-5364.
  • Virginia Tech Police: 911 (non-emergency number is 540-231-6411 or 540-382-4343).
  • Virginia Tech Rescue Squad: 911.

Individuals who suspect that they have been exposed to the direct beam from an X-ray producing equipment shall:

  • Immediately turn off the equipment.
  • Call the Radiation Safety Office (8 a.m. - 5 p.m.), or call the Virginia Tech Police (after 5 p.m. and on weekends).
  • Notify one person from the laboratory line of authority (your supervisor or the principal investigator).
  • Remain in the area until the radiation safety officer or his designee arrives.
  • If a serious injury occurs, unrelated to radiation exposure, notify the Rescue Squad immediately.

The radiation safety officer will do the following:

  •  Investigate the incident and approximate the exposure to the individual.
  • Notify the following University Officials: Radiation Safety Committee chair and the department head where the incident occurred and/or the individuals involved are based.

The following rules govern the use of analytical X-ray equipment at Virginia Tech. These rules comply with the radiation safety standards recommended by the Commonwealth of Virginia and the American National Standards Institute (ANSI).

Open and enclosed-beam analytical systems

The following are requirements for both open-beam and enclosed-beam analytical X-ray systems.

  1. Warning lights: An easily visible warning light labeled "X-RAY-ON" shall be located near any switch that energizes an X-ray tube. It is to be illuminated only when the tube is energized. This light shall be of a fail-safe design.
  2. Labeling: All analytical X-ray equipment shall be labeled with a conspicuous sign or signs that bear the radiation symbol and the words (or similar words):
  • "CAUTION - HIGH-INTENSITY X-RAY BEAM" on the X-ray source housing.
  • "CAUTION - RADIATION - THIS EQUIPMENT PRODUCES RADIATION WHEN ENERGIZED" near any switch that energizes an X-ray tube.
  • Beam trap: A beam trap or other primary beam shield shall be provided to intercept the primary beam.

Additional requirements for enclosed-beam systems 

  1. Chamber: The X-ray tube housing, sample detector, and analyzing crystal shall be enclosed in a chamber (or coupled chambers) that prevents entry of any part of the body.
  2. Ports: Access ports to the sample chamber shall be of a fail-safe design that prevents X-ray generation or entry of the X-ray beam into the chamber when any port is opened.

Additional requirements for open-beam systems

Safety device: An interlocked safety device, which prevents entry of any part of the body into the primary beam or causes the beam to shut off, shall be provided on all open-beam systems. An authorized user may seek an exemption from this requirement by applying to the Radiation Safety Committee. The application shall include:

  • A description of the safety devices evaluated and why they cannot be used.
  • A description of the alternative method that will be used to minimize the possibility of accidental overexposure.
  • Procedures will be used to alert personnel to the absence of a safety device.

Warning devices: Open-beam systems shall be provided with the following warning devices:

  •  X-ray tube status (ON-OFF) located near the x-ray source housing, if the primary beam is controlled in this manner; and/or,
  • Shutter status (OPEN-CLOSED) located near each port on the x-ray source housing, if the primary beam is controlled in this manner.
  • These devices shall be readily visible and properly labeled as to their purpose. Warning devices shall have fail-safe characteristics.
  • Shutters: Shutters at unused ports shall be secured in the closed position to prevent accidental opening.
  • Ports: Each port on the x-ray source housing shall be equipped with a shutter that cannot be opened unless a collimator or other device has been connected to the port, if the system was installed after Jan. 1, 1980.

Training

All individuals independently operating analytical X-ray equipment 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. Virginia Tech radiation safety requirements for the use of analytical X-ray equipment.
  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.

Operating procedures 

  1. Procedure manual: Normal operating procedures shall be written and available to all analytical X-ray equipment users. Analytical X-ray equipment shall not be operated differently from that specified in the procedure manual unless written permission has been obtained from the Radiation Safety Committee.
  2. Bypassing safety device: A safety device shall not be bypassed unless written approval has been obtained from the radiation safety officer. This approval shall be for a specified time. When a safety device has been bypassed, a conspicuous sign shall be placed on the X-ray housing bearing the words (or similar words), "SAFETY DEVICE NOT WORKING."

Radiation limits

Enclosed-beam systems: The exposure rate during normal operations shall not exceed 2.5 mrem/hr at a distance of 5 cm from the protective chamber walls.

Open-beam systems: The exposure rate at the maximum rated current and voltage with all shutters closed shall not exceed 2.5 mrem/hr at a distance of 5 cm from the X-ray tube housing.

Generator cabinet: The exposure rate at a distance of 5 cm from the surface of the X-ray generator cabinet shall not exceed 0.25 mrem/hr.

The local parts of an analytical X-ray system shall include sufficient shielding and be so located and arranged so exposure rates in unrestricted areas do not exceed 2 mrem/hr or 100 mrem/yr.

Personnel monitoring

All personnel that does alignment work on open-beam analytical X-ray equipment must wear finger dosimetry devices. Pregnant workers shall wear a whole-body personnel monitoring device during the pregnancy. No badge is required for users of enclosed-beam analytical X-ray units.

Surveys

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

  1. On installation of the equipment and at least once every year thereafter to monitor leakage radiation.
  2. On at least an annual basis to monitor area radiation levels when the equipment is operating.

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

  1. Following any change in the initial arrangement, number, or type of local parts.
  2. Following any maintenance that requires the disassembly or removal of a local part.
  3. During the performance of maintenance and alignment procedures that require the presence of a primary beam and the disassembly or removal of a local part.
  4. When a visual inspection of the local parts reveals an abnormality.

Each area or room containing open-beam analytical X-ray equipment shall be equipped with a suitable radiation survey instrument.

Repair and alignment procedures

The following safety precautions shall be taken to reduce risks during repair and alignment procedures:

  1. The main switch, rather than the safety interlocks, shall be used to shut down the equipment.
  2. No X-ray tube shall be used without a suitable housing to restrict the radiation to a well-defined beam.
  3. A sign stating "Interlocks Not Working" must be posted on the equipment when the interlocks have been defeated for alignment purposes.
  4. The radiation safety officer must approve alignment procedures, other than those recommended by the manufacturer.
  5. Alignment procedures must be written and available to all users.
  6. If the dose rate in an unrestricted area is exceeded during the repair or alignment procedure, temporary barriers must be set up and the area must be properly posted. The area shall be kept under surveillance until normal operations have been restored.
  7. After re-assembly, the radiation safety officer or the user shall check the x-ray equipment for leakage radiation.

The following safety precautions should be taken to reduce risks:

  1. The smallest practical voltage and current should be used during the alignment procedure.
  2. Long-handled tools and extension devices should be used to reduce the risk of the hand entering the beam.
  3. Protective glasses should be worn during alignment procedures.
  4. Temporary shielding should be added to reduce scattered radiation levels to a minimum.
  5. Alignment procedures recommended by the manufacturer should be used.
  6. Two-man teams should be used during alignment procedures. One person should make the adjustments while the other person watches for safety problems.

Although occupational radiation doses at Virginia Tech are very low and current occupational limits provide a very low risk of injury, the administration at Virginia Tech recognizes that it is sensible to avoid unnecessary exposure. It is therefore the policy of Virginia Tech to reduce occupational exposures to a level that is as low as reasonably achievable (ALARA). This will be accomplished through sound radiation protection planning and practice, and a commitment to policies that promote vigilance against unsafe practice.

Radiation exposure limits

Radiation workers shall not receive a dose in one calendar quarter over the following limits:

  • Deep Dose Equivalent                                      1,250 millirem (mrem)
  • Lens Dose Equivalent                                       3,750 mrem
  • Shallow Dose Equivalent (skin of body)            12,500 mrem
  • Shallow Dose Equivalent (extremities)              12,500 mrem

Individuals under 18 years of age are not permitted to receive a dose greater than 10% of the above limits.

The maximum permissible whole-body dose to a declared pregnant radiation worker during the pregnancy must not exceed 500 mrem.

Radiation levels in unrestricted areas shall not exceed 2 mrem/hr or 100 mrem/yr.

Personnel monitoring

All personnel who enter an area where it is likely they will receive greater than 25% of the maximum occupational dose limit shall wear a personnel monitoring device. The need for a personnel monitoring device will be determined by the Radiation Safety Office. That office will supervise the ordering, distribution, and collection of personnel monitoring devices. Whole-body personnel monitoring devices will be worn routinely on the shirt pocket or collar. The position of the monitoring device shall remain constant during a reporting period. Personnel monitoring devices designed to measure beta or low-energy or gamma radiation shall not be worn inside of a pocket or obstructed in any manner.

When not in use, personnel monitoring devices shall be stored in an area where they will not be exposed to ionizing radiation above background levels. Personnel monitoring devices shall not be deliberately exposed to radiation except under the supervision of a radiation safety officer. Personnel monitoring devices are not to be worn during non-occupational exposures such as medical X-rays. When a lead apron or thyroid shield is worn, the monitoring device shall be worn on the outside of the protective device at the collar.

Declared pregnant radiation workers shall wear a whole-body personnel monitoring device during the pregnancy.

Specific requirements

  • Diagnostic: All users shall wear a whole-body monitoring device. Fluoroscopy users will also wear a ring badge.
  • Analytical: Users of open-beam analytical X-ray equipment that conduct alignment of the system are required to wear a ring badge. Badges are not required for users of closed systems.
  • Cabinet: All users shall wear a whole-body badge.
  • Miscellaneous: Personnel monitoring is not required.

Exposure records

The Radiation Safety Office will maintain exposure records and will provide exposure results as necessary, usually on an annual basis. The office will provide a radiation exposure report to the worker, or an employer at the request of the worker. The Radiation Safety Office will supply the worker with a written report if a dose over 25% of the occupational limits is received.

Pregnant authorized users

A user has the option to formally declare a pregnancy to their supervisor in order to take advantage of reduced occupational exposure limits for the entire term of the pregnancy. This declaration is voluntary and can be kept confidential. The Radiation Safety Office is available to answer any questions that may arise whether or not a formal declaration of pregnancy is made. To become a declared pregnant worker the supervisor needs the following information:

  • Estimated date of conception
  • Expected date of birth

Pregnant authorized users shall: 

  • Wear a whole-body personnel monitoring device if working with penetrating X-ray-producing equipment.
  • Wear a second whole-body monitoring device under a lead apron at waist level, when a lead apron is required to be worn.
  • Not be required to hold patients, animals, or film cassettes during x-ray exposure.
  • Be informed of her radiation exposure on a quarterly basis.

Pregnant authorized users should:

  • Notify the radiation safety officer as soon as her pregnancy is known (confidentiality will be maintained).
  • Limit her exposure to less than 500 mrem during the pregnancy.
  • Keep her exposure to the very lowest practical level by reducing the amount of time spent in a radiation area, increasing the distance from a radiation source, and using shielding.
  • Inform her obstetrician about her work with X-ray-producing equipment

X-ray exams of potentially-pregnant women:

A sign bearing the words or similar words "Caution: If you are pregnant or think you are pregnant, please inform the technologist before X-rays are taken" shall be conspicuously posted in the x-ray room. Before ordering x-rays of the abdominal or pelvic area of a fertile woman, the examining physician will order a pregnancy test unless a medical situation precludes the testing (e.g. medical emergencies).

The X-ray technologist will check the requisition for the results of the pregnancy test before taking X-rays of the abdominal or pelvic area of a fertile woman. If a pregnancy test has not been performed, the technologist will refer the patient back to the examining physician.

The physician's approval to x-ray pregnant women is not required when x-rays of areas other than the abdominal or pelvic area are ordered, provided the abdomen is shielded on all sides by 0.25 mm lead equivalency.

The abdominal and pelvic area of fertile women shall be covered with a lead apron of 0.25 mm lead equivalency when x-rays are ordered for areas other than the abdominal or pelvic region.

Fertile women should consider pregnancy testing before receiving bone density scans. Women in their childbearing years who participate in research studies involving DXA scans will be required to undergo a pregnancy test, and receive a negative result (not pregnant) before a scan is performed. Women who are pregnant will be advised to consult with their personal physician as to the advisability of their continued participation in the study, and if cleared by their physician, they may undergo the scan.

Posting

Each area or room where fixed diagnostic, analytical, or cabinet X-ray equipment is located shall be conspicuously posted with:

  • A sign bearing the radiation symbol and the words (or similar words) "CAUTION: X-RAY EQUIPMENT."
  • State Form RH-F-12 "Notice to Employees - Standards for Protection Against Radiation: Notices, Instructions, and Reports to Workers; Inspections."
  • A notice that describes where the University Radiation Safety Manual, registration, surveys, and inspections may be examined.
  • Procedures to be followed if there is a radiological emergency.
  • Each area or room where mobile x-ray equipment is used shall be temporarily posted with a "Caution: X-ray Equipment" sign.
  • No area posting is required for Miscellaneous x-ray equipment.

Removal of notices

Any sign, notice, warning, or label applied by the Radiation Safety Office to equipment or the facilities of a licensed user shall not be removed, defaced, or concealed without written permission from the Radiation Safety Office.

All licensed activities are subject to inspection by the Radiation Safety Office. Inspections may be announced or unannounced and will be conducted at least every year. Miscellaneous x-ray systems are inspected at least every five years and administrative checks are made every year.

A written report specifying any deficiencies will be sent to the Laboratory Authority who must correct the deficiencies within the time specified in the report unless a variance or an extension of time has been granted by the Radiation Safety Committee. A Laboratory Authority that disagrees with the deficiencies specified in the report may appeal in writing to the chairman of the Radiation Safety Committee and request a hearing before the Committee.

The rules in this section apply to the following miscellaneous -ray producing equipment: electron microscopes, electron microphones, luminoscopes, and cold-cathode gas discharge tubes. These requirements are in conformity with title 21 of the Code of Federal Regulations, Part 1020, and the Rules and Regulations for the Use of Ionizing Radiation in the Commonwealth of Virginia.

Posting

No area posting is required for miscellaneous x-ray equipment.

Warnings and labels

A clearly legible and visible label bearing the statement: "CAUTION: THIS EQUIPMENT PRODUCES X-RAYS INCIDENTAL TO ITS PRIMARY FUNCTION - TO BE OPERATED BY QUALIFIED PERSONNEL ONLY" shall be posted on all miscellaneous X-ray producing equipment.

In addition to the above requirement, cold-cathode gas discharge tubes shall bear the following labels: 

  1. A label stating the maximum safe operating voltage.
  2. A label that identifies the correct polarity of the terminals.

Training

Individuals who wish to operate miscellaneous equipment are not required to complete documented radiation safety training. However, all individuals should receive hands-on instruction and training (e.g. working with experienced users, reading the manufacturer's operation manual) before independently using a miscellaneous system.

Operating procedures

Operating procedures shall be written and available to all users.

Radiation Limits

Radiation emitted from electron microscopes, electron microprobes, and luminoscopes shall not exceed an exposure rate of 0.5 mrem/hr at 5 cm from the external surface.

Radiation exposure from cold-cathode gas discharge tubes shall not exceed 10 mrem/hr at 30 cm from the external surface averaged over 100 square centimeters.

All miscellaneous x-ray-producing equipment shall contain sufficient shielding, and be located and operated so exposure rates in unrestricted areas do not exceed 2 mrem/hr or 100 mrem/yr.

Personnel monitoring

Personnel monitoring is not required for users of miscellaneous X-ray-producing equipment.

Potential X-ray exposure from magnetic-effect tubes

Magnetic-effect tubes demonstrate that cathode rays carry an electrical charge that can be deflected by a magnetic field. These tubes may produce X-rays incidental to their intended use and should be used with caution. Where there is a source of electrons, a target, sufficiently high voltage, and tube gas pressure within the proper range, X-ray production will occur. X-ray output from magnetic-effect tubes, however, is unpredictable and intermittent. Under identical operating conditions, it may vary from one tube to another; one tube may be an X-ray producer while another may not. X-ray production may vary during a given period of operation or from day to day for the same tube.

Since the educational benefits derived from these tubes are gained by visual observation of their operation, unshielded operation of these tubes is required; with the subsequent potential for student and operator exposure. To keep exposures to a minimum, requirements for the safe use of these tubes are as follows:

  1. Magnetic-effect tubes must be used only for demonstrations conducted by the instructor.
  2. The instructor should stand as far as practical from the tube during the demonstration.
  3. Only the instructor shall operate a magnetic-effect tube.
  4. Bystanders should stand at least 8 feet from an operating tube.
  5. Tubes must always be operated with the correct polarity and the lowest practical current and voltage.
  6. Operating time is to be kept to a minimum.

 

Surveys

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

  • When installed and at least once every three years thereafter or any time the instrument(s) are moved or major repairs are done.  This is to monitor leakage and area radiation levels.
  • Administrative checks are done by the Radiation Safety Office once each year between surveys to verify location, operational use, and user listings as appropriate.   

All X-ray equipment purchases must be approved by the Radiation Safety Officer regardless of classification. Items no longer being used or needed may be disposed of through Surplus Property or transferred, after notifying the radiation safety officer. Instrument details and transfer information must be recorded by Environmental Health & Safety personnel. In either case, one must contact the Radiation Safety Officer prior to purchasing or removing X-ray instrumentation. 

The Radiation Safety Committee is the highest decision-making body for all radiation safety matters at Virginia Tech. This committee reports to the vice president for research. Virginia Tech Environmental Health & Safety administers the university radiation safety policies on a daily basis, through its Radiation Safety division.

Radiation Safety Committee

The university has established the Virginia Tech Radiation Safety Committee (RSC) as a University Operational Committee with the authority to regulate the safe use of ionizing radiation by university personnel. The RSC develops rules for this purpose and oversees their implementation.

The vice provost for research appoints members of the RSC. The Radiation Safety Officer is an ex officio member. A representative of the vice provost for research administrative unit will be an ex officio member representing university top management. At least two active users of radioisotopes, one user of x-rays, and other members, as necessary, are appointed on the basis of their experience with radiation. An individual with administrative experience and responsibilities serves as chairman of the Committee. Members of the RSC shall serve a three-year term and may be reappointed for additional terms. A member who misses three consecutive meetings without the approval of the chairman for adequate cause shall be considered to have resigned.

A meeting of the RSC will be held at least quarterly. The chairman shall call additional meetings as necessary. Minutes of the meetings shall be recorded and distributed to selected persons. A quorum shall consist of half of the members plus one and must include the chairman, the Radiation Safety Officer, and the top management representative or their designees. Decisions shall be based upon the approval of a majority of the members present. In the event of a tie, the chairman may vote.

The RSC may delegate its authority to the chairman (or whoever the chairman designates in writing as an alternate), and to the Radiation Safety Officer. The delegates would have the authority to act on the RSC's behalf on such occasions that arise between normal meeting dates that do not warrant a special meeting of the full Committee. An example would be the approval of an authorization amendment, such as the addition or deletion of personnel in an individual laboratory.

The RSC shall:

Approve all applications for use of radiation devices and radioactive material by university personnel.

Approve radiological hazard analyses of new procedures used by laboratories. Each new procedure or experiment must include:

  • Purpose of the experiment.
  • Description of the experiment.
  • Analysis of the possible radiation levels produced by the experiment.
  • Hazards associated with the performance of the experiment.

Approve each use of unsealed radioactive material at temporary job sites and monitor the user's operations with these materials and equipment.

Ensure any modifications or improvements it considers necessary in the interest of radiation safety or compliance with federal, state, or internal regulations are implemented.

Review the radiation protection program content and implementation on an annual basis.

Administer disciplinary actions for violations by an ad hoc disciplinary subcommittee composed of:

  • RSC chairman (unless an alternate is designated in writing to avoid a potential conflict of interest).
  • Radiation safety officer.
  • Individuals with experience relevant to the incident (can be from outside of the RSC).

Virginia Tech Environmental Health & Safety

Environmental Health & Safety is charged with the responsibility for the coordination of all safety and environmental safety programs at the university not specifically assigned elsewhere. The Radiation Safety Office is a division of this department.

Radiation safety officer

The radiation safety officer is a staff member of Environmental Health & Safety who by reason of education, training, and experience, is qualified to advise others in the safe use of ionizing radiation and to supervise the health physics program of the university.

The radiation safety officer shall:

  • Be responsible for personnel monitoring, training, maintenance of exposure records, radioactive material inventories, survey methods, waste disposal, and inspections to assure compliance with radiological safety practices.
  • Approve in writing all activities and procedures that involve actual or potential exposure of personnel to radiation or the release of radioactive materials to the environment, and ensure such activities are brought before the Committee for review and approval.
  • Conduct radiological hazard analyses on all new procedures used by laboratories.
  • Be available to consult with all users of ionizing radiation and give advice in radiological safety practices.
  • Shall suspend any operation causing, or believed capable of causing, an excessive radiation hazard as rapidly as possible.
  • Ensure radiation safety violations are treated according to the Disciplinary Procedures Section of this manual.
  • Perform routine and special radiation surveys as considered necessary in the interest of radiation safety.
  • Provide the RSC a quarterly resume of incidents, inspections, material received, an inventory of radioactive material, a summary of exposures, and a list of authorized users of radioisotopes.
  • Provide the RSC a quarterly report on x-ray laboratories to include a summary of exposures, a current list of authorized users, and any abnormal occurrences.
  • Complete duties in a timely manner:
    •  A monthly frequency is plus or minus one week.
    • A quarterly frequency is three months plus or minus two weeks.
    • A semi-annual frequency is six months plus or minus one month.
    • An annual frequency is twelve months plus or minus two months.

Emergency Contacts: Posted on the entrance door to provide general contact information.

Caution X-Ray: Posted on the entrance door and received from Environmental Health & Safety office.

Emergency Procedures: Posted in the space to detail what to do in case of emergency.

X-Ray Medical Operators List: Listing of authorized users for specific equipment in an area.

X-Ray Non-Medical Operators List: Listing of authorized users for specific equipment in an area.

X-Ray Machine Certification: Virginia State Certification Forms for Diagnostic Units.

Food Permitted

Food Prohibited

Survey meter details: A graphic explanation of some of the important points of a Geiger-Muller Survey Instrument. To activate a text pane, hover the mouse over the numbered areas of the image. For additional information, click on the numbered area. If you have any questions, please call 540-231-5364.

Survey meter response: Survey meter response should be verified for instruments in use. The Radiation Safety Office prepared check sources using small quantities of uranyl acetate to simplify this step. The material is encapsulated in heavy tape and affixed to the side of the meters with labeling. If the meter does not show a response to the source and/or if you suspect the protective tape has been compromised, please contact the radiation safety officer at 540-231-5364.

Changing batteries: Click here for more information.

Analytical X-Ray Equipment Operations Certification

All users of analytical X-ray units must complete this training prior to working with the equipment.

Refresher training required every 5 years.

Diagnostic X-Ray Equipment Operations Certification

All users of diagnostic X-ray equipment designated as operators must take this training prior to working with the equipment. Please designate the location as either Veterinary Teaching Hospital or Equine Medical Center. If you are functioning both as an operator and holder, you need only enroll in this class.

Refresher training required every 5 years.

Ancillary Nuclear Medicine Initial Certification

All users of diagnostic X-ray equipment designated as holders must take this training prior to working with the equipment. Please designate the location as either Veterinary Teaching Hospital or Equine Medical Center. If you are designated as an X-ray operator, please refer to that training.  

Refresher training required every 5 years.

Cabinet X-Ray Equipment Operations Certification

All users of cabinet X-ray units must complete this training prior to working with the equipment.

Refresher training required every 5 years.

Diagnostic Holder Certification

All users of diagnostic X-ray equipment designated as operators must take this training prior to working with the equipment. Please designate the location as either Veterinary Teaching Hospital or Equine Medical Center. If you are functioning both as an operator and holder, you need only enroll in this class.

Refresher training required every 5 years.

Occasionally personal dosimeter readings have been reported that were higher than expected. Usually, the cause is related to air travel. Remember to keep dosimetry badges in carry-on items as the exposure levels from X-ray scanners are much lower for them than checked luggage.


Frequently Asked Questions

Details are given in number 4 of the meter image.

The Radiation Safety Committee/radiation safety officer must authorize the purchase and use of all X-ray equipment. This includes those that generate x-rays as secondary to the primary intent of operation such as electron microscopes. The following steps must be followed to apply for and obtain approval for X-ray authorization.

  • A copy of the Virginia Tech Application for Authorization to Use X-Ray Equipment must be submitted to the Radiation Safety Office for review.
  • All training requirements must be fulfilled according to details given in the Radiation Safety Training Instructions. Miscellaneous instruments, such as electron microscopes, are excluded from Environmental Health & Safety training requirements. Training for these is the responsibility of the designated Laboratory Authority for the license. 
  • The applicant will be permitted to begin operations under terms of the Authorization upon receipt of a copy signed by the Radiation Safety Committee chair and the radiation safety officer.

All X-ray equipment purchases must be approved by the radiation safety officer regardless of classification. Items no longer being used or needed may be disposed of through surplus property or transferred, after notifying the radiation safety officer. Instrument details and transfer information must be recorded by Environmental Health & Safety personnel. In either case, one must contact the radiation safety officer prior to purchasing or removing X-ray instrumentation. 

A graphic explanation of some of the important points of a Geiger-Muller Survey Instrument. To activate a text pane, hover the mouse over the numbered areas of the image. For additional information, click on the numbered area. If you have any questions, email dcon@vt.edu.

Survey meter responses should be verified for instruments in use. The Radiation Safety Office prepared check sources using small quantities of uranyl acetate to simplify this step. The material is encapsulated in heavy tape and affixed to the side of the meters with labeling.  If the meter does not show a response to the source and/or if you suspect the protective tape has been compromised, please contact the radiation safety officer.

Occasionally personal dosimeter readings have been reported that were higher than expected. Usually the cause is related to air travel. Remember to keep dosimetry badges in carry on items as the exposure levels from X-ray scanners are much lower for them than checked luggage.

Is training mandatory? If so, when? Yes. Persons working with X-ray producing equipment must complete the training applicable for the type of equipment in use. General awareness training on the requirements of the X-ray Safety program is available from Environmental Health & Safety upon request.

Class length: Variable.

Available online: Yes.

When is refresher training required? Never.

Please see the online class schedule for more information.


Documents


Contact Information

Donald Conner, Radiation Safety Officer

Phone: 540-231-5364
Email: dcon@vt.edu 

Cynthia Strader, Assistant Radiation Safety Officer

Phone: 540-231-2699
Email: cynth@vt.edu