Practical examination for exposure device operators
The exposure device operator (EDO) practical examination is used to determine whether a candidate has acquired, or if a certified EDO has maintained, the knowledge, skills and abilities required to operate an exposure device safely and securely. There is no alternative to successfully completing the practical examination for the purpose of applying for EDO certification.
Exposure device operator practical examination (PDF, 6 pages, 295 KB)
On this page
- EDO practical examination success criteria
- Practical examination administration
- Practical examination process
- Practical examination locations
- Reattempting the practical examination
- Stages in certification process
- Practical examination topics
EDO practical examination success criteria
- The candidate has achieved a final score of 90% or more.
- The candidate did not fail any of the steps marked by an asterisk (*).
- If the candidate fails one of these steps, the CNSC considers the candidate to have failed the examination.
Practical examination administration
The person who initials each section of the examination and signs the final page is the examination administrator, who must be
- a certified EDO who conducts examinations at a Natural Resources Canada (NRCan) test centre, or
- a certified EDO who has been certified for at least 5 years, or
- a certified EDO who has been certified for less than 5 years but has been authorized by their employer to conduct practical examinations for that employer.
Practical examination process
- Information about the candidate is filled in at the top of the examination.
- While conducting the examination, the examiner must check off each step the applicant passes or place an X in the appropriate column for each step failed.
- The examiner must initial each section.
- Only one set of initials is required per section.
- The total score for the section may be filled out at the end of the section.
- The final score is written on the final page of the examination.
- If the transportation section is not assessed, the examination is out of 55.
- If the transportation section is assessed, the examination is out of 61.
- The examiner must sign and date the final page of the practical examination.
Practical examination locations
A candidate may attempt the practical examination at any licensed location where exposure devices can be held or at an NRCan Test Centre.
Re-attempting the practical exam
Initial certification applicants
Candidates who fail the practical examination must wait 30 days and complete remedial OJT (and knowledge-based training, if necessary) before reattempting the practical examination.
The CNSC expects candidates who have failed the examination three consecutive times to repeat the OJT program before attempting the examination for a fourth time.
Certification renewal applicants
Certified EDOs who fail the EDO practical examination must cease performing duties until they successfully complete an EDO practical examination. Prior to retaking the examination, the licenced employer is responsible for documenting and implementing a remedial training program to cover any knowledge gaps the certified EDO may have. The remedial training should include on-the-job training and, if necessary, knowledge-based training.
The CNSC expects certified EDOs who fail three consecutive attempts of the practical examination to perform duties under direct and continuous supervision of another certified EDO for 160 documented hours prior to attempting the practical examination for a fourth time.
Stages in certification process
- Initial certification: The CNSC recommends candidates attempt the practical examination after completing OJT and before attempting the written examination.
- Certification renewal: The CNSC recommends candidates attempt the practical examination as close as possible to the date when they submit their application for renewal.
Practical examination topics
ALL sections or subsections identified by an asterisk (*) are MANDATORY requirements for passing the practical examination. Candidate failing any of these steps will fail the examination.
The practical examination covers the following topics:
1. Radiation protection
As per CNSC regulations, the EDO must show knowledge and capability of proper operation of all instruments and equipment. The EDO must:
- *have a direct reading dosimeter, audible alarming dosimeter, dosimeter issued by licensed dosimetry service, and a radiation survey meter in possession
- *turn on audible alarming dosimeter and survey meter before starting
- *ensure power level of batteries is sufficient for operation
- *check equipment for valid calibration dates
- *zero the direct reading dosimeter (DRD) prior to start for a minimum of 2 mSv (200 mR) total dose range
- *check function of radiation detection equipment
2. Inventory control
The EDO must demonstrate the importance of accurate documentation control and record keeping. This includes:
- proper sign out of the exposure device
- proper survey and recording for surface dose rates on the exposure device (<2 mSv/hr)
- use of all required daily records required by the licensee
- ensuring that emergency equipment is available and in good working condition
3. Preparation of work area
The EDO must demonstrate safety and security when preparing the work area by:
- initiating job hazard assessment of work area
- demonstrating knowledge to quarantine broken or deficient equipment
- *posting sufficient number of radiation warning signs and barriers at proper distances to prevent entry into controlled area.
- *performing thorough sweep, and evacuating all persons from inside controlled area
- using collimator and/or effective use of shielding to control radiation levels
- ensuring all equipment has been safely placed to prevent any incidents
4. Use of exposure devices
The EDO must demonstrate a good basic understanding of the exposure device being used, and the ability to monitor radiation levels during setup and conduct all the necessary equipment checks. This includes:
- *using survey meter during equipment assembly for operation
- *performing device checks – review of company contact labels (name/job title and telephone number), source tag, trefoil radiation label, fasteners, locking mechanism, shipping plug/safety covers, and protective covers
- *performing remote control checks – inspection of full assembly handle, fittings, brake, conduit fasteners, protective covers; checking for dents, cuts, damage or debris that may affect safe operation
- *completing remote control drive cable checks – free movement, flex test, visual checks for fraying, kinks, rust, or corrosion
- *completing guide tube checks – inspection of guide tube conduit, fittings, connectors, threads, source stop. Checks for dents, cuts, damage or debris that may affect safe operation
- *performing source assembly inspections - Able to demonstrate all go/no-go checks (if applicable to device)
- demonstrating ability to connect the remote controls, the guide tube, collimator and device together to prepare for an operation
- showing knowledge of emergency equipment requirements (cutting tool, tunnel/shielding, 1.5-meter long-handled tongs)
This is the most important part of the work process. The EDO must demonstrate proper control of the high-risk source and device to ensure safety and security at all times. This includes:
- *demonstrating proper use of survey meter during all operational procedures
- *unlocking and safely connecting the exposure device and associated equipment in the correct order according to the manufacturer's specification
- *demonstrating safe operations during the cranking and exposing the source assembly to the exposure position (position, observing survey meter, monitoring area)
- *verifying barrier dose rates and radiation warning sign positions on first exposure using the survey meter
- *demonstrating safe operations during the retracting of the source assembly to the shielded position (position, observing survey meter, posilock function)
- *demonstrating observation of survey meter and audible alarming dosimeter during source movements and approach towards device
- demonstrating observation of proper operation and location of source position indicator
- *after each attempt to move the source assembly to the shielded position within the exposure device, demonstrating the use of a survey meter to ensure that the source assembly has returned to the safe shielded position
- demonstrating the ability to follow all company and regulatory operational procedures
- demonstrating implementation of ALARA and basic radiation protection principles (time, distance, shielding)
6. Post Exposure
The EDO must demonstrate how to secure the device and verify the safety of the worksite in the proper order after completion of exposures. This includes:
- *demonstrating continual use of survey meter post exposure when preparing to complete operations and to disassemble associated equipment
- *ensuring that the safety lock indicates that the source is locked and in the safe position (may not be applicable for some devices)
- *disassembling the equipment safely and in the correct order according to the manufacturer's specifications
- *installing all retaining safety plug and/or port and lock safety covers
- *securing and locking the exposure device, properly store with protective covers and caps
- performing a final site survey with a survey meter to ensure radiation levels are safe
- *removing the posted radiation warning signs and barriers
- placing exposure device back in to secure storage area
7. Record Keeping
Maintaining accurate records is a regulatory requirement. The EDO must show how to record all radiation readings properly as well as the results of equipment checks. This includes:
- documenting device sign out (dates/names/locations of use)
- documenting survey reading on surface of device
- documenting all equipment checks required by licensee
- recording daily DRD readings
- completing the trainee supervisor consent form (as needed)
8. Emergency Preparedness
The EDO must explain how to identify different emergency or dangerous occurrences and describe the process for mitigation. This includes:
- *demonstrating an ability to recognize an emergency situation
- *demonstrating knowledge of required emergency equipment and location
- *demonstrating knowledge of emergency procedures location at the jobsite
- *demonstrating knowledge of initial emergency steps to be followed
- *demonstrating proper use of long handled tongs and shielding material
- *demonstrating knowledge of correct contact for a retrieval person
9. Transportation (if applicable)
Although the EDO cannot transport the device without transportation of dangerous goods training, they must show knowledge of the transport requirements including all package, signage and security measures. This includes:
- verifying that the device is locked and secured
- ensuring that all requirements for the appropriate shipping document have been met
- ensuring that type A or Type B package requirements are met
- displaying knowledge of use of transportation overpack and use
- ensuring proper labelling/placarding (Class 7) bearing the radiation symbol, UN number, and making sure that contact information is completed
- ensuring that the device is properly placed and secured within the vehicle for transport
An EDO must exercise proper security when using a device. The EDO must demonstrate:
- *control of device at all times throughout operations
- *that when not in use, the device was locked and secured inside 2 levels of locked enclosure and that there is immediate response to an alarm in the event of an attempted intrusion
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