Chapter 4 - Ionizing RPE

4.0 Authorization to Use Ionizing Radiation Producing Equipment (Top)

4.1 General Requirements

4.2 Electron Microscopes (other than SEMs) and other E-Beam equipment

4.3 X-ray Diffraction Equipment

4.4 Particle Accelerators and Implanters

4.5 Radiographic Installations (Human & Animal)

A certificate of Registration issued to Cornell University by the NYSDOH authorizes the possession and use of ionizing radiation producing equipment (RPE).  New York State Sanitary Code (10NYCRR16) and standards issued by the American National Standards Institute specify the requirements for the safe use of this equipment.  This chapter describes the policies developed by the Cornell University RSC to meet these requirements and to ensure that personnel doses from the ionizing radiation are kept ALARA.

4.1 General Requirements (Top)

The requirements of section 4.1 apply in common to the use of all ionizing RPE except for equipment operating at 10 kV or less.  The sections following this section apply to the type of equipment indicated by the section heading: 4.2 Electron Microscopes, 4.3 X-ray Diffraction, 4.4 Particle Accelerators, 4.5 Radiographic.

4.1.1 Operating Permits (Top)

The RSC is responsible for ensuring that RPE is operated safely and that personnel dose from ionizing radiation produced by this equipment is kept ALARA.  A permit must be obtained from the RSO in advance of any use or acquisition (by purchase, transfer, loan, donation or otherwise) of ionizing RPE at Cornell.

The permit application includes a description of the facility, equipment, operating procedures, hazard evaluation, the qualifications of the applicant and a list of operators and users.  The level of detail in the permit application reflects the degree of risk posed by the proposed equipment.

Operators are defined as personnel with the training and expertise to use, repair, maintain, calibrate, dismantle and/or rebuild, modify (including beam paths, beam tubes, beam stops, shielding, safety interlocks and other safety systems) or some combination of the above.  Operators also establish operating parameters for users and can provide safety training to users.

Users are trained in operating RPE to obtain data, measurements, samples, etc., within the parameters approved by the permit holder and/or operator.  Users may adjust the settings of the RPE, within the boundaries provided by the permit holder or operator (e.g. the high voltage and current setting on an x-ray diffraction unit), change samples, and perform other adjustments required for the proper use of the RPE.  Users also receive safety training appropriate for the work to be performed.

4.1.1.1 Qualifications

In order to qualify for a permit, an applicant must be a member of the Cornell faculty, senior research associate, senior staff (upon approval of the department chair), or a licensed physician on staff at Gannett Health Services (for clinical, laboratory, or research use on humans).

The training and experience required to qualify for a permit depends upon the type and relative hazards associated with the equipment to be used.  In general, a permit applicant will be expected to have previous training and experience with RPE and be able to demonstrate adequate knowledge of:

4.1.1.1.1 Radiation measurements, monitoring techniques and instrumentation.

4.1.1.1.2 The biological effects of radiation.

4.1.1.1.3 Emergency procedures.

4.1.1.2 Process

To become a permit holder, an individual contacts the RSO indicating a need to use RPE.  The RSO meets with the individual to discuss the Cornell radiation safety program, explain the duties and responsibilities of a permit holder, and reviews the application form.  When completed, the permit application is submitted to the RSO who reviews it for completeness and performs a site visit.  At the discretion of the RSO, the application may be submitted to the RSC.  The RSC will either approve the application or return it to the applicant for revision.  See also 4.1.1.5, Registrations.

4.1.1.3 Permit Approvals

Permits are granted by the RSO with recommendations of the RSC, when provided.  The RSO (or RSC) may opt not to perform a site visit if the RPE is:

4.1.1.3.1 Electron microscopes that operate at 20 kV or less.

4.1.1.3.2 Diffraction units that operate a 30 KV or less and are small-contained units, dually interlocked, with no interlock by-pass available.

4.1.1.4.3 Radiographic units that operate at a maximum of about 70 kV and are self-contained small cabinet units, well interlocked, and can be operated without concern for dose to personnel.

After a review of the application and equipment specifications, the RSO will require a pre-operational radiation survey be conducted prior to approving the permit and equipment for use.

All equipment will be reviewed by the RSO and assigned a "hazard class" that is based on factors affecting radiation safety.  Such factors include, but not limited to: equipment age; open/enclosed beams; operating voltage; inherent shielding; condition of enclosures, interlocks, and other safety equipment; etc.

4.1.1.4 Permit Issuance

When an application is approved, the applicant will receive a written copy of the permit.  The RSO and/or RSC may impose restrictions on the use of the equipment if warranted for radiation safety and ALARA reasons.  These will be stated in the permit.

Permit renewals and inspection frequencies are listed in Table 4.1 below, based on the hazard class.

Table 4.1 RPE Hazard Classes

 

Hazard Class​ ​Description

​Permit

Renewal

​RSC Site

Visit

​Inspection

Frequency

1​ ​Low ​10 years None​ 4 years​
2​ ​Medium ​5 years ​10 years ​1 year
​3 ​High ​2 years ​8 years ​6 months
 

 

Changes or modifications to RPE should be reviewed with the RSO to ensure that radiation safety is properly addressed.  In addition, some changes/modifications may require RSC review and/or approval.  The RSO will provide guidance in these situations.

Between renewals, the permit holder may submit written requests to the RSO for proposed changes to conditions specified in the permit.  The RSO will assist the permit holder as needed to provide the appropriate information.  The RSO will review the request and may, at his/her discretion, approve it or refer it to the RSC for review and recommendations.  Changes may not be implemented until written authorization is received.

For the special case where human exposure is allowed by the permit (e.g. Gannett), the AC and/or substitute permit holder must be a University physician.

When a permit holder is expected to be away for up to six (6) weeks, the AC will be in charge of the laboratory on behalf of the permit holder.  The AC will be contacted for permit related issues and will perform most of the permit holder responsibilities and functions including minor requests for permit amendments such as adding/deleting users or rooms.  The permit holder will, upon return, countersign all those items which required signatures during the absence.  When the permit holder and the AC are expected to be away at the same time, the permit holder must advise the RSO so that an alternate arrangement can be made.

When a permit holder is expected to be away from Cornell for six (6) weeks or more, the permit holder and RSO will select a substitute permit holder who has the knowledge and expertise to be responsible for the laboratory.  The substitute permit holder must  agree in writing to accept the responsibility for the permit during the leave.  A permit amendment will be issued to reflect the change.

4.1.1.5.  Registrations

Individuals with RPE in storage, dismantled, on loan or otherwise inoperable will be issued a registration.  The RSO is required to be notified before returning equipment in this category to operability and will assess if safety measures and features are appropriate.  Since a permit is required for operational RPE, a permit application will be required from new owners without a current permit, or an amendment from owners with a current permit.

          4.1.1.6.  Permit Termination

When termination of a permit is desired, the permit holder must notify the RSO as far in advance as possible.  This is particularly important when the termination is due to the permit holder's leaving the University.  The permit holder will assist the RSO to ensure that:

4.1.1.6.1 All RPE still in the possession of the permit holder is properly transferred, or disposed of.

4.1.1.6.2 Area / personnel monitoring is discontinued, where applicable.

4.1.1.6.3 Postings and labels are removed from the authorized area if equipment is removed from the premise.

4.1.1.6.4 Documentation of the transfer or disposal of any RPE.

4.1.2 New Facilities / Major Renovations (Top)

Plans and specifications for the construction of new radiation facilities, or the major modification of existing facilities, must be approved by the RSO.  The information provided to the RSO must include, at a minimum, the technical specifications of the equipment, the facility layout, beam orientation, shielding (location and construction), occupancy of adjacent areas, and a summary of proposed operations including operating voltages, beam on times, and expected radiation levels within and immediately outside controlled areas.

If deemed necessary, the RSO may also request RSC review, approval and/or a use location visit based on the level of hazard presented by the RPE.

4.1.3 Purchases/ Transfers / Dispositions (Top)

All acquisitions or disposition of RPE must be reviewed and approved in advance by the RSO.  All purchase requisitions must be reviewed and approved by the RSO before the purchase may be processed.

4.1.3.1 Transfers within Cornell

Transfer of RPE between permit holders is sometimes permissible, but only with approval by the RSO before the equipment is moved.  The RSO must have the opportunity, in advance, to review the new location, qualifications of the receiving permit holder, and the expected operating parameters in the new location.  If the new owner is not a permit holder, a permit must be obtained before the transfer can occur.

4.1.3.2 Procurement and Transfers to or from Cornell

When a transfer or purchase of RPE to Cornell is in the planning process, the owner must notify the RSO in writing and must receive written permission.  The individual who plans to receive said equipment is responsible for making this requirement known to the owner.

When a transfer of RPE from Cornell is in the planning process, the sender must notify the RSO.  The RSO will determine whether or not Cornell has permission to allow the transfer and will notify all the appropriate agencies.

State and Federal regulation requires Cornell to track the possession, use and transfers of RPE.

4.1.3.3 Disposal

When the disposal or scrapping of a piece of RPE is under consideration, notify the RSO during the planning process.  The device must be rendered inoperable by removal of the tube or filament.  All labels, signs and notices will be removed by the RSO.

4.1.4 Instruction For Operators and Users (Top)

For Operators:

4.1.4.1 All individuals operating equipment capable of emitting a level of radiation greater than 0.5 mrem/hr at 5 cm from the surface must be instructed in the health risks associated with ionizing radiation exposure.  This must include: the biological effects of ionizing radiation, procedures to minimize dose, the function and implementation of warning lights, status indicators, protective devices and shielding, operation of radiation monitoring equipment, how radiation is produced within the equipment and a summary of relevant regulations.

4.1.4.2 Safe operating procedures and radiation safety precautions must be clearly documented in a manual which must be available to the operator at all times. (See 4.1.7.2.3)

4.1.4.3 The permit holder must develop an equipment specific training program, train new operators / users and evaluate the competency of existing and new operators / users in the safe use of the equipment.  The RSO or designee will approve the contents of the training program.

4.1.4.4 All training must be documented.  The date(s), topics covered, and signatures of the permit holder and the trainee must be included.

4.1.4.5 Access to areas containing the operating controls for RPE must be restricted to authorized personnel only regardless of the dose rates in the area.

For Users:

4.1.4.6 All individuals using equipment capable of emitting a level of radiation greater than 0.5 mrem/hr at 5 cm from the surface must be instructed in the health risks associated with ionizing radiation exposure.  This must include: the biological effects of ionizing radiation, procedures to minimize dose, the function and implementation of warning lights, status indicators, protective devices and shielding, operation of radiation monitoring equipment, how radiation is produced within the equipment and a summary of relevant regulations.

4.1.4.7 Safe operating procedures and radiation safety precautions must be read, understood and followed by all users.

4.1.4.8 All users must receive equipment specific training in the safe use of the equipment from the permit holder or an operator.

4.1.4.9 The permit holder or operator must record the training dates and signatures of all users.

4.4.4.10 Access to areas containing the operating controls for RPE must be restricted to authorized personnel only regardless of the dose rates in the area.

4.1.5 Radiation Monitoring (Top)

4.1.5.1 Personnel dosimetry (i.e. body badge and/or extremity badge) may be required if a potential for exposure exists and for certain types of equipment.  Consult the appropriate section (4.3.2.5 Diffraction, 4.4.5.1 Accelerator, 4.5.8 Radiographic) of this chapter for additional details.  When not required (e.g. electron microscopes), the decision to use personnel monitoring is left to the discretion of the permit holder in consultation with the RSO.

4.1.5.2 Area dosimetry badges or monitoring equipment are required for all equipment capable of emitting a level of radiation greater than 0.5 mrem/hr at 5 cm from the surface.  Dosimeters are available through the RSO.

4.1.5.3 After installation and after each structural or operational modification of the equipment, the permit holder, operator, or the RSO or designee must perform and record an instrument survey to determine any change in the radiation field.  This survey must be documented and precede the return of the equipment to service.

4.1.5.4 Other surveys must be performed in accordance with procedures appropriate to the equipment.  Consult the section of this chapter applicable to the specific type of equipment for details.

4.1.6 Personnel Dose Limits (Top)

The university policy requires that radiation doses be maintained ALARA.  Chapter 8 of this manual specifies the limits and guidelines for radiation workers, pregnant radiation workers, non-radiation workers and members of the public.  Section 4.3.4.4 of this chapter specifies additional limits for diffraction equipment users.

4.1.7 Area Classification, Dose Limits & Identification (Top)

Areas where personnel may be exposed to radiation are classified according to the dose rates listed in Table 4.2.  The RSO, or designee will make designation of controlled areas, during a pre-operation equipment survey.  Only the RSO, or designee may make changes in designations.

4.1.7.1 Noncontrolled Area: An area to which access is neither controlled nor restricted.

4.1.7.2 Controlled Area: An area authorized for the use and/or possession of RPE where access is restricted to authorized radiation users and accompanied visitors.

4.1.7.2.1 Temporary access to radiation and high radiation areas is allowed only to qualified personnel with permission of the RSO.  Personnel monitoring devices are required and portable survey instruments must be used during access to all such areas.

4.1.7.2.2 Portable radiation survey instruments must be available to personnel who work in a controlled area or above, or adjacent to radiation area or above.

4.1.7.2.3 Written safety operating procedures must be prepared by the permit holder and approved by the RSO, in which all area designations, safety procedures and precautions must be clearly spelled out.  All qualified workers must be required to be familiar with the provisions of this manual before starting work.

 4.1.7.3 Radiation Area: An access controlled area that now requires the posting of RADIATION AREA signs. 

4.1.7.4 High Radiation Area: An access controlled area that now requires the posting of HIGH RADIATION AREA signs.  ALL high radiation areas require the review and apprval of the NYS DOH.

4.1.7.5 Exclusion Area: An area authorized for RPE use where access is prohibited while equipment is in operation.

4.1.7.5.1 Provisions of Sec 4.4.3.2 must apply where applicable.

4.1.7.5.2 Continuously operating radiation monitoring devices must be installed in and adjacent to these areas.  Such devices must provide an audible and visual warning to personnel in the vicinity when preset maximum rate is exceeded.

Table 4.2 Classification of areas and dose limits.

Area ​Dose
Noncontrolled​ ​Less than 2.0 mrem in 1 hour and less than 100 mrem in 1 year*
​Controlled ​More than 2.0 mrem in 1 hour or more than 100 mrem in 1 year*
​Radiation area ​More than 5.0 mrem in 1 hour @ 30 cm
​High Radiation Area ​More than 100 mrem in 1 hour @ 30 cm
​Exclusion ​Potential dose exceeds a high radiation area
  *A year is defined as January 1 to December 31.

    4.1.8 Security / Access To Areas (Top)

    4.1.8.1 All RPE must be secured against unauthorized operation when left unattended by the permit holder or a trained operator.  When the unit is not in use, security may be accomplished by locking the power switch, the high voltage supply, or the door to the facility.  When a unit is operating and unattended security may be accomplished by preventing access to the controls and controlled areas.

    4.1.8.2 The access to controlled areas and above must be limited by means of barriers, and interlocks as appropriate, and indicated by the posting of the appropriate signs.

4.1.9 Posting of Notices (Top)

These documents must be posted in control rooms:

4.1.9.1 A current copy of the NY State required "Notice to Employees"

4.1.9.2 A copy of the New York State Certificate of Registration

4.1.9.3 Radiation Safety Manual, Chapter 4, which includes operating procedures, and operating permit.

4.1.10 Inspections (Top)

See Section 4.1.1.4, Permit Issuance for a discussion of RPE inspections.  The permit holder must take steps to correct any violations upon receipt of such notice.

4.1.11 Violations (Top)

4.1.11.1 Major

Deviations from approved procedures which pose a potential for dose in excess of legal dose limits (see Chapter 8) must be considered a major violation.  Such deviations must cease immediately and the RSO must be advised.

          4.1.11.2  Minor

Situations not posing a potential for excessive radiation dose to personnel, but violating any item of this chapter, must be designated minor violations.  The RSO must be advised promptly and steps to correct this type of violation must be taken within a period of time specified by the RSO.

4.1.12 Exceptions (Top)

Any exception to the requirements of this chapter must be applied for in writing and granted by the RSC upon demonstration by a permit holder that the requirement is unreasonable and that radiation safety can be maintained.

4.2 Electron Microscopes (other than SEMs) and other E-Beam equipment (Top)

4.2.1 Labels (Top)

A label bearing the radiation symbol and words indicating that the equipment produces X-rays must be posted near any switch which energizes the equipment.

4.2.2 Shields (Top)

Inherent shields must be such that when the equipment is operating at maximum potential, the radiation levels from the surface must not exceed 2 mrem/hr at 5 cm at any area of the column.  Exceeding this limit may require additional shielding.  Dose due to unwanted radiation such as from high voltage rectifiers, must not exceed 0.25 mrem/hr at 5 cm from the external surface.  Note that area monitors are required at 0.5 mrem/hr at 5 cm per section 4.1.5.

4.2.3 Repair (Top)

4.2.3.1 No individual must bypass a safety device or remove shielding without approval of the permit holder.  If a safety device is bypassed or shielding removed for a period of time, the permit holder or a designated person must maintain visual contact with the affected area while the unit is operational.

4.2.3.2 The electron gun must be made inoperable when repairs or modifications necessitate the disassembly of the column.

4.2.3.3 After each repair which involves the removal and replacement of shielding or which could affect X-ray production, a survey must be performed and recorded by the RSO to ensure continued safe conditions.

         
     
    4.2.4.1 Surveys will be performed annually as part of the inspection program provided by RSO.
     
    4.2.4.2 Surveys must be performed following repairs referenced in 4.2.3.3.

4.3 X-ray Diffraction Equipment (Top)

4.3.1 General Requirements (Top)

Analytical X-ray equipment (diffraction and fluorescence) must comply with the ANSI/HPS N43.2-2001 standard Radiation Safety for X-ray Diffraction & Fluorescence Analysis Equipment.  Copies are available from EH&S.

4.3.1.1 Labels and Signs

4.3.1.1.1 Each entrance or access point to a controlled area must be conspicuously posted with a sign bearing the radiation symbol and wording appropriate for the level of radiation that might to be encountered. (Refer to Table 4.2).

4.3.1.1.2 A label bearing the radiation symbol and words indicating that the equipment produces x-rays must be posted near any switch which energizes an X-ray tube and another near the port.

4.3.1.2 Tube Housings

 4.3.1.2.1 X-ray tube must not be operated without a suitable housing which restricts the radiation to a well defined beam.

4.3.1.2.2 The inherent shielding of the housing must be such that when the tube is operating at maximum potential and all shutters are closed, the radiation levels at 5 cm must not exceed 2.0 mrem/hr.

4.3.1.2.3 Tube housings must be equipped with an interlock which disables the tube if the housing is removed or dismantled.

4.3.1.3 All ports and shutters should be of the type described in 4.3.2.

4.3.1.4 A beam trap or similar barrier with sufficient shielding so that the dose rate due to the primary beam does not exceed 0.25 cm mrem/hr at 5 cm from the posterior surface must be used.

4.3.1.5 A warning light or other device of fail-safe design bearing the words, "X-RAY ON" must be conspicuously located near any switch which energizes the X-ray tube.  A similar light or device must also be mounted near the radiation tube housing.

4.3.1.6 Interlocks must be of such design that after an interruption, high voltage may be restored or shutter may be reopened only by manually resetting the controls.

4.3.1.7 No individual must bypass a safety device or interlock without the approval of the permit holder.  The permit holder or designated person must be in visual contact with the affected area while the unit is operated with a safety device or interlock bypassed.

4.3.1.8 The dose due to unwanted radiation such as that from high voltage rectifiers must not exceed 0.25 mrem/hr at a 5 cm distance from the outside surface of the equipment.

4.3.1.9 A survey instrument calibrated in mrem/hr must be readily available.  All authorized operators must know its location.

4.3.2 Open Beam Configurations (Top)

An open beam system is one in which enclosure is not provided in all possible X-ray paths.

4.3.2.1 Each port of the tube housing must be provided with a beam shutter interlock which interlocks the collimator or X-ray accessory apparatus coupling, in such a way that the unit will operate with the port open only when the collimator or coupling is in place.

4.3.2.2 A shutter at an unused port must be secured to prevent its casual opening.

4.3.2.3 All operative shutters must be provided with a "shutter open" indication of fail-safe design, whether the high voltage and beam are on or off, and be operated remotely.

4.3.2.4 A guard should be provided which prevents casual entry of any part of the body into the primary beam.

4.3.2.5 Operators must wear body and extremity badges.

4.3.3 Closed Beam Configurations (Top)

A closed beam system is one in which all possible X-ray paths are full enclosed.

4.3.3.1 The inherent shielding of the enclosure walls must be sufficient to limit the dose to 0.25 mrem/hr at 5 cm.

4.3.3.2 The enclosure must be interlocked with the X-ray source high voltage supply or a shutter, preventing the beam from entering the sample chamber while it is open.

4.3.4 Alignment & Repair (Top)

4.3.4.1 After each change in configuration or repair of a device which could affect X-ray production, a survey must be performed and recorded by the permit holder, a designated operator, or the RSO or designee, to ensure compliance with this section.  For new configurations, refer to section 4.1.5.3.

4.3.4.2 No operation involving the removal of shielding materials or tube housings or modifications to shutters, collimators or beam stops must be performed without ascertaining that the tube is turned off and that it will remain off until safe conditions have been restored.

4.3.4.3 If an alignment procedure may result in raising the dose rates above the limits of the area designation, the person must erect temporary barriers and signs as required and maintain surveillance until normal operating conditions are resumed.

4.3.4.4 Alignment procedures should be such that a dose to the skin and extremities would not exceed 25 mrem/hr, or to the whole body, total organ, or lens of the eye would not exceed 2.5 mrem/hr.  In keeping with ALARA, dose per alignment procedure should not exceed 50 mrem total dose to extremities or 10 mrem total dose to whole body, organs, or eyes.

4.4 Particle Accelerators and Implanters (Top)

All accelerators including those operated steady state and those pulsed intermittently are covered by this section.

4.4.1 Shields & Barriers (Top)

4.4.1.1 The shields around a particle accelerator must reduce radiation hazard in the surrounding area to levels which will not exceed the allowable dose rates described in section 4.1.7.

4.4.1.2 Radiation attenuation can be accomplished by a reasonable combination of barriers at a distance from radiation sources and physical shielding.

4.4.2 Control of Access & Operation (Top)

4.4.2.1 The primary controls influencing the production of radiation must be attended by the designated operator(s) during the time that the accelerator is operational.  The controls must be secured when unattended in order to prevent unauthorized use.

4.4.2.2 Access to radiation areas should be limited to individuals directly concerned with the operation and maintenance of the facility, experimental or production work, radiation safety or approved visitors accompanied by facility personnel.

4.4.3 Interlocks & Warning Devices (Top)

4.4.3.1 Where visual contact with the entire exclusion area can be maintained by the operator, a visual check and audible warning will be required before commencing operation.

4.4.3.2 In larger facilities where the entire exclusion area(s) is not readily visible to the operator:

4.4.3.2.1 All entrances to exclusion areas must be provided with interlock systems, which if tripped, must render operation of the equipment impossible.

4.4.3.2.2 All exclusion areas must be provided with scram switches or other emergency power cutoff switches within easy reach and easily identifiable as to their purpose.

4.4.3.2.3 When an interlock system has been tripped, it must only be possible to resume operation by manually resetting controls at the location where the interlock had been tripped.

4.4.3.2.4 When necessity dictates that a safety interlock be temporarily bypassed, such action must be [1] authorized by the permit holder, [2] recorded in a log or other record and a notice posted at the control console, and [3] terminated as soon as possible.

4.4.3.2.5 No interlocks must be permanently bypassed without the written authorization of the RSO.

4.4.3.2.6 Exclusion areas and their entrances, must be equipped with easily observable flashing or rotating red lights which must operate during any radiation production.

4.4.4 Safety Checks (Top)

All safety and warning devices, including interlocks, must be serviced and checked for proper operation at six month intervals and after any modification to the system. Documentation of the date, results and changes must be maintained.

4.4.5 Radiation Monitoring (Top)

4.4.5.1 Personnel monitoring is required for individuals who could be exposed to a dose rate in excess of 2.0 mrem/hr.

4.4.5.2 Area monitoring is required in controlled and adjacent uncontrolled areas.

4.4.5.3 A survey instrument calibrated in mrem/hr must be available and its location must be made known to all authorized operators.  Survey instruments are not required for pulsed intermittent equipment installations.  

4.5 Radiographic Installations (Human & Animal) (Top)

Procedures and auxiliary equipment designed to minimize patient and personnel dose commensurate with the needed diagnostic information must be utilized.

4.5.1 Equipment (Top)

4.5.1.1 The protective tube housing must be of diagnostic type (<100 mrem/hr @ 1 meter when operated at maximum continuous current).

4.5.1.2 Collimating devices capable of restricting the useful beam to the area of clinical interest must be used and must provide the same degree of protection as is required of the tube housing.

4.5.1.3 The aluminum equivalent of the total filtration in the useful beam must not be less than that shown in table 4.3.

Table 4.3 Minimum total filtration 

                           Operating kVp                                                               Inherent + Added

Below 50  kVp 0.5 mm Aluminum
 50 - 70     kVp  1.5 mm Aluminum
Above 70 kVp​
 2.5 mm Aluminum

 
4.5.1.4 The exposure switch must be of the dead-man type.

4.5.1.5 A timing device must be employed which terminates the exposure automatically after a preset time or interval.

4.5.2 Structural Shielding For Fixed Equipment (Top)

4.5.2.1 Control apparatus for the radiographic equipment must be located in an adjacent room or in a fixed booth within the same room provided such booth is composed of radiation shielding to a minimum height of seven (7) feet.  The control booth either must be so arranged that the radiation has to be scattered at least twice before entering the booth or must be provided with a protective door that is interlocked in such a way that the X-ray tube(s) cannot be energized unless the door is in the closed position.

4.5.2.2 The operator must be able to see the patient by means of a mirror or through a window of lead equivalent material sufficient for the required protection, and so placed that the operator is always in a shielded position.

4.5.2.3 The exposure switch must be arranged so that an individual outside the shielded control area cannot operate it.

4.5.2.4 Interlocks installed on all doors leading to the procedures room must be checked semiannually for operability.

4.5.3 Holding of Subjects & Films (Top)

4.5.3.1 When a subject must be secured in position during exposures, mechanical restraining or supporting devices must be used.  Occupationally exposed individuals should hold subjects or films only when clinically necessary under extreme conditions.  Such individuals must wear protective gloves having at least 0.5 mm lead equivalent, a protective apron of at least 0.25 mm lead equivalent, and must keep all body parts out of the useful beam.  Declared pregnant women and individuals under age 18 must not hold patients or films under any conditions.

4.5.1.2 No person must  be regularly employed to hold human patients, animals or films during exposures.

4.5.1.3 Any procedure, which requires the holding of a human patient, animal or film, must be approved by the permit holder and documented.

4.5.1.4 Lead aprons and gloves mustl be inspected semiannually via radiograph for cracks or tears.

4.5.4 Portable/Mobile Unit Considerations (Top)

4.5.4.1 All portable/mobile equipment must be provided with a device which creates a minimum source-to-skin distance of at least 12 inches.

4.5.4.2 The exposure switch must be provided with a cord sufficiently long so that the operator can stand at least six feet from the patient, X-ray tube and the useful beam.

4.5.4.3 Protective aprons of at least 0.25 mm lead equivalent mustl be worn by all operators of portable/mobile equipment when taking images.

4.5.5 Fluoroscopic Considerations (Top)

4.5.5.1 Equipment must be so constructed that the entire cross section of the useful beam is always intercepted by a primary protective barrier (usually an image intensifier assembly).  The exposure must automatically terminate when the barrier is removed from the useful beam.

4.5.5.2 Protective aprons of at least 0.25 mm lead equivalent must be provided and must be worn by all persons in the room.

4.5.5.3 Only persons needed in the fluoroscopic room must be present during the exposure.

4.5.5.4 For Mobile Fluoroscopic Equipment:

4.5.5.4.1 In the absence of a tabletop, a cone or spacer frame must ensure a source-to-skin distance of greater than 12 inches.

4.5.5.4.2 Image intensification must always be provided and the equipment rendered inoperable unless the useful beam is intercepted by the image intensifier.

4.5.5.5 A survey for radiation scatter at the operator position must be conducted semiannually.

4.5.6 Patient Shielding (Top)

For protection to the human patient during radiographic procedures in which the gonads are in the useful beam, gonadal shielding of not less than 0.5 mm lead equivalent must be used for patients who have not passed the reproductive age, except for cases in which this would interfere with the diagnostic procedure.  This shielding must be inspected semiannually for cracks or tears. 

4.5.7 Quality Assurance (For Human Subjects) (Top)

A program of Quality Assurance (QA) must be established for the Gannett Clinic radiographic installation. This program for minimizing human patient dose must be developed based upon the NYSDOH requirements and the recommendations and requirements of the RSO, or designee, and must become part of the Operating Permit.

A QA Committee must be established.  The membership must include the Clinic Director or designee, the RSO, the Chief Radiological Technologist, and a Radiologist (usually from an external facility).  The QA Committee must meet at least annually to review the QA program.

The program must include the following reviews:

  1. kV consistency
  2. Timer consistency
  3.  mA stability 
  4. Focal spot size
  5. Collimator accuracy
  6. Beam alignment
  7. Half value layer
  8. Photo timer consistency (if applicable)
  9. Darkroom environment
  10. Film storage
  11. Chemical storage
  12. Screen integrity
  13. Cassettes
  14. Retake analysis
  15. Apron, glove and patient shields integrity test
  16. Interlock operability

4.5.8 Personnel Monitoring (Top)

4.5.8.1 All operators, attendants, technicians and physicians involved with the use of radiographic equipment must wear personal monitors.  A worker who declares a pregnancy (see chapter 8.3) must wear two personal monitoring devices; one at the collar and one at the waist.

4.5.8.2 When involved in portable or fluoroscopic radiography, personal monitoring devices must be worn outside any protective apparel.

4.5.9 Qualifications (Top)

Only physicians, veterinarians and those technologists licensed by the NYS DOH and/or the NYS DOE must operate radiographic equipment.

4.5.10 Pregnant Patient Medical Doses (Top)

A sign must be conspicuously posted in the radiology waiting area which instructs all females who may be pregnant to inform the technician of that possibility.  In addition, the attending physician and the technician must ask each female patient of child bearing age if there is any chance of their being pregnant.  Radiography of the lower back, abdomen or pelvis must be confined to the 10 days after the onset of menses in women of child bearing age and avoided completely in pregnant patients.  The decision to proceed with a radiograph is those cases where the radiograph is deemed essential is left to the discretion of the attending physician and/or consulting radiologist.

When the presence of a pregnancy is unsure, a positive or negative indication must be determined before proceeding with the examination.  Radiography of other body parts may be done at any time provided the dose is limited to the particular area of interest by collimation and shielding.