Safety Code 34. Radiation Protection and Safety for Industrial X-Ray Equipment

3. Requirements for Industrial X- ray Equipment

This part of the Safety Code outlines the regulatory requirements for industrial x-ray equipment, respecting design, compliance evaluation and enforcement; registration; and work site practice of industrial radiography.

3.1 Industrial X- ray Equipment Design Standards

X-ray equipment is federally regulated in Canada under the Radiation Emitting Devices (RED) Act ⁽⁹⁾ and companion regulations. The RED Act provides the authority to write regulations for specific classes of x-ray equipment. Where specific RED Act regulations are not available for a class of x-ray equipment, the general provisions of the RED Act respecting prohibition, deception and notification apply within the scope of ensuring worker and public safety. This is the case for industrial x-ray equipment. Thus, the importation, lease or sale of industrial x-ray equipment that does not conform with the RED Act is contrary to Canadian law. It is the manufacturer's and the importer's responsibility to ensure that the x-ray equipment available for commerce in Canada complies with the RED Act. Any violation of the RED Act is a criminal offence.

Re-sale industrial x-ray equipment shall also comply with the RED Act at time of sale. The seller is responsible for ensuring regulatory compliance of the equipment, for bearing the associated costs of compliance, and for notifying the buyer of his or her safety obligations upon acquisition of the equipment. Additional information is provided in Section 4.7 of this Safety Code.

Industrial x-ray equipment that is designed and constructed to conform with the following minimum requirements would meet the general provisions of the RED Act:

1. a control console that is equipped with:
   
   
   1. a power switch;
   2. an illuminated 'power on' indicator;
   3. a red illuminated failsafe 'x-ray on' indicator;
   4. indicators of the operational high voltage and beam current in respect of the ionizing radiation source;
   5. a lock of a type that requires the insertion of a key before ionizing radiation can be produced and for which the removal of the key terminates the production of ionizing radiation;
   6. a device that controls the duration of ionizing radiation generation;
   7. a radiation ON/OFF control that requires activation by the operator for ionizing radiation production;
   8. an emergency switch which, when activated, de-energizes the ionizing radiation source;
   9. appropriate provisions for the connections of interlock systems and of remotely positioned warning devices that provide visible and audible warnings during ionizing radiation generation;
   10. a warning sign, next to the key lock, which (a) indicates that hazardous ionizing radiation emissions are produced when the device is operating, and (b) prohibits unauthorized use;
   11. a radiation warning sign that reflects the x-ray tube logo shown in Appendix I of this Safety Code; and
   12. an identification label, respecting the industrial x-ray equipment, which indicates the name and business address of the manufacturer, the model number, the serial number, the date of manufacture and the country of manufacture.
       
       
2. A radiation-shielded assembly that contains the ionizing radiation source and is equipped with a simple battery operated laser alignment device or a suitable alternative that aids radiography set-up procedures.
3. Labels affixed on the external surface of the radiation-shielded assembly that
   
   
   1. identify the electrical connections or means that facilitate activation of audible and visible warning devices positioned on the periphery of controlled areas during ionizing radiation generation at a temporary site;
   2. display the x-ray tube logo shown in Appendix I of this Safety Code; and
   3. identify the name and business address of the manufacturer of the industrial x-ray equipment, the equipment model number, the serial number, the date of manufacture and the country of manufacture.
      
      
4. All marks, labels and signs required on the control console and on the radiation-shielded assembly that are securely affixed and are clearly visible.
5. All controls, lights, meters or other indicators on the control console and on the radiation-shielded assembly that are clearly marked as to function and conform to the following illumination and colour codes: State or condition Colour Radiation ON Red Emergency Red Warning (stand-by) Amber or yellow Radiation OFF (safe) Green Information Blue
6. Installation, operational, safety, maintenance, and disposal instructions that are provided by the manufacturer of the equipment such that, when followed, will enable the equipment to operate within the standards of functioning and performance specified for it, and to be disposed of in a safe and environmentally responsible manner.
7. Portable and mobile industrial x-ray equipment, in addition to meeting all of the above requirements, that is designed to be equipped with:
   
   
   1. means (e.g., cables of sufficient length, radiofrequency mechanisms or other accessories) for enabling activation of the radiation "ON/OFF" control from a location external to a controlled area that is established for temporary sites in accordance with Section 3.3.2. of this Safety Code;
   2. adequate support for the radiation-shielded assembly to prevent tipping, drifting or vibration during operation of the equipment; and
   3. an automatic radiation warning alarm system either comprising a beacon light/siren device, or an alternative that provides an equivalent function.

All texts respecting radiation warning signs and labels required in this part shall be in black on a yellow background and be written in both English and French.

3.2 Legal Registration of Industrial X- ray Equipment in Federal Facilities

Any activity that might involve an assembled or ready-to-use industrial x-ray equipment carries an element of radiation risk. To ensure that the associated risks remain low, a system of control necessitating industrial x-ray equipment evaluation and operational review must be in place. This requirement exists in the Canada Labour Code Part II, Occupational Safety and Health Regulations, Part X, Section 10.26 ⁽⁵⁾ : essentially, all federal departments and agencies under federal jurisdiction must register their x-ray equipment with the regulatory authority, Health Canada. The registration process involves:

1. a submission of (a) a filled-in registration form that requires details on various elements (e.g., the facility, x-ray equipment, trained personnel, maintenance provider , personnel dosimetr y services, radiation survey meters), and (b) supportive documentation on emergency, safety and disposal procedures;
2. an evaluation of the submitted material by the regulatory authority; and
3. the issuance by the regulatory authority of a confirmation of registration valid for 3 years.

Where a confirmation of registration has been granted to a federal facility in accordance with Section 3.2.(iii) of this Safety Code and the facility subsequently makes a material change to the industrial radiography operation, safety procedures, permanent installation or to the industrial x-ray equipment, a supplementary report that clearly describes the change shall be submitted to the regulatory authority, Health Canada, for review within 14 calendar days of the said change. In this context, industrial x-ray equipment that has been re-sold, removed from service or transferred to other users or to another facility shall be reported. Failure to file such a supplementary report would automatically invalidate the confirmation of registration.

Re-registration shall occur every three years, unless specified otherwise. Afacility that operates industrial x-ray equipment without a valid confirmation of registration would be in contravention of the federal Occupational Safety and Health Regulations ⁽⁵⁾.

3.3 Job Site Requirements for Industrial Radiography

Radiography may be carried out in a permanent installation site and/or at a temporary job site. These sites are characterized by differences in work conditions and therefore hazard reduction strategies must integrate both the industrial x-ray equipment and human factors.

3.3.1 Permanent installation

In the majority of cases industrial radiography is carried out in a shielded enclosure. When a shielded enclosure is properly designed and constructed using sound engineering principles and operated within the design limitations, no 'Controlled Area' external to it is created. However, if conditions do not merit a controlled area, the occupational exposure conditions need to be kept under review by the RSO. This scenario would constitute a 'Supervised Area' for which the following actions are required:

1. delineate the supervised area by suitable means;
2. display suitable and sufficient signs in appropriate positions of the area to warn of the radiation sources and the associated risks; and
3. conduct periodic review of conditions to determine a need for protective measures or safety provisions or changes to the boundaries defining the area.

The planning of a permanent installation should follow life-cycle management concepts. Though not exhaustive, a number of factors need to be considered: siting, location, construction, commissioning, operation, maintenance and decommissioning based on present and foreseeable future needs. Drawings of the enclosure and its surroundings should be prepared; entrances should be identified; and dimensions and personnel occupancy areas need to be specified as well. Heating, lighting, ventilation and utility requirements also merit attention. Shielding, interlocks, warning indicators, emergency activators, and radiation control systems and stations require in-depth consideration because of their importance to radiation safety. Generally, limitation of external radiation exposure to personnel, due to the use of ionizing radiation sources present inside the installation, requires shielding. Estimates of shielding thickness may be determined using established methods ⁽¹⁵⁾ ; users of this reference should ensure appropriate dose limits are used when determining shielding estimates. Often, depending on the nature of the work or location of the installation, penetration of the shielding will be necessary for various reasons, such as, to place or remove heavy test objects in the primary beam using overhead cranes, robots or conveyor; to provide in the enclosure access for personnel entry and exit; to facilitate passage of utility pipes and x-ray control or imaging cables; to affix lights; and to provide essential heating and ventilation duct systems. Inadequate shielding at such discontinuities might lead to unacceptable levels of stray radiation, which potentially could expose personnel or the public, thereby increasing radiation risks. Guidance for effective shielding at such discontinuities is available ⁽¹⁵⁾ . Though infrequent, operational demands may involve the replacement of an existing radiation source with one of a higher beam penetration capability (that is, higher energy x rays), and this may require changes to the installation shielding or re-consideration of primary and secondary barriers or to occupancy of surrounding areas. Based on the foregoing, it is essential that a radiation protection adviser be consulted (or hired) to advise on matters relevant to radiation safety. The expert may be a consultant who is competent in the field of ionizing radiation protection and safety and has several years experience in the design of ionizing radiation shielded facilities. However, responsibility for compliance with the relevant regulations and standards remains with the organization or agency having ownership of the permanent installation. The minimum requirements for a permanent installation are:

1. shielding of sufficient thickness that assures protection of individuals surrounding the installation;
2. warning signs of the type shown in Appendix I of this Safety Code that are affixed on all doors or panels or openings which provide partial- or whole-body entry into the permanent installation;
3. a radiation control station that (i) is suitably designed and positioned external to the permanent installation, (ii) contains the ionizing radiation source control console, (iii) provides for the operator direct visual or electronic surveillance of the interior of the permanent installation during radiography, and (iv) facilitates real-time imaging display and assessment capabilities;
4. two independent interlocks that are affixed on the main door which is nearest the control console and which provides whole-body entry to the permanent installation, and they shall be designed in such a manner that, when activated, they shall promptly terminate x-ray production and require a manual reset at the control console to resume x-radiation generation;
5. one interlock, which trips a safety relay thereby removing power from the x-ray generator, shall be affixed on all remaining doors that provide whole-body entry to the installation, including any panel that permits partial-body entry to the permanent installation;
6. clearly visible red 'radiation-on' warning indicators that are failsafe and that illuminate when x-radiation is generated: one indicator shall be prominently positioned inside the permanent installation on a fixed vertical structure at a height of 2 metres above the installation floor and, at least one indicator on the outside of the permanent installation, near each entry door or panel that provides access to the interior of that installation;
7. clearly visible yellow or amber 'stand-by' warning indicators that illuminate when ionizing radiation is not generated: one indicator shall be prominently positioned inside the permanent installation on a fixed vertical structure at a height of 2 metres above the installation floor and, at least one indicator on the outside of the permanent installation, near each entry door or panel that provides access to the interior of the permanent installation;
8. inside the permanent installation, an audible warning signal that (i) is distinct and loud enough to gain the attention of an individual, and (ii) is initiated for at least 5 seconds preceding ionizing radiation generation;
9. clearly labelled red 'emergency' activators that (i) are installed inside the permanent installation at 1 metre above the floor in such a way that they can be activated without passing through the primary beam, and (ii) function in a manner that when any su ch activator is activated it shall: (a) promptly terminate ionizing radiation generation; (b) automatically open the main door, referred to in Section 3.3.1.4. of this Safety Code, which is nearest the control console and which provides whole-body entry to the permanent installation; and (c) require a manual reset within the permanent installation, before ionizing radiation generation can be resumed at the control console; and
10. all controls, lights, warning signals or other indicators associated with the permanent installation must: (i) be clearly labelled, (ii) be imbedded with the appropriate warning text, and (iii) be in conformance with the following illumination and colour coding:

Illumination and colour coding:

State or condition	Colour
Radiation ON	Red
Emergency	Red
Warning (stand-by)	Amber or yellow
Radiation OFF (safe)	Green
Information	Blue

All texts respecting radiation warning signs and labels required in this part shall be in black on a yellow background and be written in both English and French. Before a newly constructed or modified permanent installation is commissioned for use, an on-site evaluation must be conducted.

3.3.2 Temporary job site

The use of engineering controls at temporary job sites is limited. Consequently, strict adherence to administrative measures is necessary to reduce the likelihood of radiation accidents and unintentional exposures. Individuals must therefore receive training and instructions commensurate with the work procedures, and they must be committed to safety. To the extent practical, radiography should be performed at times when personnel occupancy of the ambient area is lowor zero. Use should be made of collimators and secondary shielding (walls, shielded enclosures, vehicles unoccupied by humans, mobile lead screens), where practical, to reduce dose levels.

The minimum requirements for radiography at a temporary job site are:

1. A controlled area must be established to facilitate the radiographic work required. It shall be clearly designated by
   
   
   1. written warnings and safety instructions that are strategically posted external to the controlled area to warn against unauthorized entry; and
   2. barriers that prevent entry into any area within which the equivalent dose rate exceeds 0.1 mSv per hour ⁽¹⁴⁾ as a result of use of the industrial x-ray equipment.
      
      
2. Appropriate signals (visible from at least 10 metres) and audible warnings (loudspeaker, horns) that alert unauthorized personnel of radiography in the designated controlled area.
3. At least two individuals, authorized by the RSO, are required to monitor or patrol the boundary of the established controlled area and to ensure unauthorized individuals do not enter inside the controlled area during ionizing radiation generation. One of the authorized personnel shall be a certified industrial radiographer and the other should be a safety officer or an equivalent designate who have read and understood the safety procedures relevant to industrial radiography at temporary job sites. The RSO can also function as the other authorized individual.
4. A calibrated and functional survey meter(s), as outlined in Section 2.2.1.10. of this Safety Code, shall be used to ensure that the equivalent dose rate at the boundary of the designated controlled area, where authorized personnel might be present does not exceed 0.1 mSv per hour ⁽¹⁴⁾ .
5. Protocols that specify work set-up procedures, such as repositioning of the radiography test object or the radiation source or its support assembly or the image receptor procedures, are completed before x-radiation is generated.
6. A temporary radiation control station that is positioned external to the designated controlled area for the initiation, generation or termination of ionizing radiation and for real-time image acquisition and assessment. Every effort must be made to establish such a control station.
7. The attendant industrial radiographer must have appropriate documentation which substantiates that the portable x-ray equipment that is used on site has been duly registered. In cases where portable industrial x-ray equipment registered at a specific facility (resident facility) is used elsewhere, the resident facility RSO shall provide the attendant industrial radiographer with written confirmation that the portable x-ray equipment has been duly registered in conformity with the validated confirmation of registration.
8. All controls, lights, warning signals or other indicators associated with industrial radiography at a temporary site must: (i) be clearly labelled, (ii) be imbedded with the appropriate warning text, and (iii) be in conformance with the following illumination and colour coding:

Illumination and colour coding

State or condition	Colour
Radiation ON	Red
Emergency/P>	Red
Warning (stand-by)	Amber or yellow
Radiation OFF (safe)	Green
Information	Blue

All texts respecting radiation warning signs and labels required in this part shall be in black on a yellow background and be written in both English and French.

3.4 Facility On- site Evaluation

On-site evaluation is intended to ensure compliance with the requirements of this Safety Code. It must be conducted by the regulatory authority; equivalents may be permitted provided that prior consent has been obtained from the regulatory authority. Such an evaluation should confirm that

1. permanent installations are adequately constructed;
2. safety systems and components function as intended;
3. warning signs are appropriate and are correctly deployed;
4. emergency procedures are clearly posted at the control console and are understood by all industrial radiographers, other users and allied personnel associated with the industrial radiography operation;
5. stray radiation levels external to the permanent installation are within limits to ensure that no undue risks are presented;
6. radiographers, other users and allied personnel are trained and are competent to use the radiation survey meter(s);
7. radiographers and other users are trained to conduct checks that establish the proper functioning of safety components associated with the ionizing radiation producing equipment or the permanent facility or the temporary job site; and
8. perso nnel monitoring and control are in accordance with the requirements of Sections 2.2.1.16.; 2.2.1. 20-24.; and 2.3.6-8. of this Safety Code.

On-site evaluations may be conducted periodically or at any time.