Written examination

The Exposure Device Operator written examination is used to determine whether a candidate has acquired, or a certified EDO has maintained, the knowledge, skills and abilities to operate an exposure device safely and securely.

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How to apply

The EDO written examination is administered by NRCan National Non-Destructive Testing Certification Body (NDTCB). Consult their website for information on how to apply and where to submit the application.

Guidance for candidates

The CNSC recommends candidates study extensively using the resources provided from their training programs, CSA PCP-09, Exposure Device Operator Personnel Certification Guide – Revision 1, and CNSC regulations prior to attempting the written examination. Simply using knowledge obtained completing the theoretical portion of the training course will not adequately prepare a candidate to succeed in the examination. Below are some general tips on how to succeed on multiple-choice examinations:

  1. When you begin your written examination, ensure you carefully read the examination instructions prior to reading and answering the questions.
  2. Before you answer a question, ensure you carefully read the stem (beginning portion) and each alternative answer in order to accurately understand the question.
  3. Remember, although more than 1 answer may appear to be correct or partially correct, only the best answer is the correct choice.
  4. If you have difficulty choosing an answer to a question, proceed by first eliminating the answers that you believe are incorrect, and then choose between the remaining answers.
  5. If you find you cannot answer a question, proceed to the next question(s), and then return to the unanswered ones before ending the examination. Do not spend too much time on difficult questions at the expense of completing the examination.

Content of the examination

The examination is based on 6 areas of study determined from detailed knowledge and skills requirements:

  1. Fundamentals of radiation and radioactivity: Understanding the differences between radiation and radioactivity will not only help certified EDOs understand some of the differences and physical aspects of electromagnetic and particle radiation, but also allow them to make risk-informed decisions on using different devices and the importance of personal exposure limitation. Certified EDOs are responsible for high-risk radioactive sources and must have an understanding of the hazards and effects of radiation (both acute and chronic) as well as some of the characteristics such as half-life, energy levels and scatter radiation for the types of sealed sources and shielding used in industrial radiography.
  2. Units of radiation detection and measurement: Accurate detection and measurement of radiation from normal background, as well as the sealed sources and devices used in industrial gamma radiography, are essential to ensure safe operations in the work environment. The certified EDO must understand and verify the calibration requirements and operational characteristics of all the radiation detection instruments needed for industrial gamma radiography.
  3. CNSC regulatory requirements: The CNSC regulates the certification and safe operation of exposure devices, as well as the certification of exposure device operators. The regulatory requirements are directed at the safety and security of the exposure devices and sealed sources as well as the operators, other workers, the public and the environment. The following information is available from the CNSC’s website:
  4. Security: The small size and easy portability of certified exposure devices make them very susceptible to loss, theft and damage. As a result, a certified EDO must adhere to all the required security measures for any exposure device in their possession. The CNSC regulatory document REGDOC-2.12.3, Security of Nuclear Substances: Sealed Sources and Category I, II and III Nuclear Material, sets out the minimum physical security measures that must be implemented to prevent the loss, sabotage, illegal use, illegal possession or illegal removal of Category 1, 2 and 3 (RS-G-1.9, Categorization of Radioactive Sources) radioactive sealed sources.
  5. Operational procedures: Certified EDOs must not only comply with CNSC regulations but must also follow the operational procedures established by the licensee. Developing a clear understanding of how to conduct the proper inspection, care and maintenance of all tools, equipment and instruments associated with the use of exposure devices is a powerful prevention tool. These procedures may be specific to a licensee’s work environment.
  6. Radiation protection: Radiation protection practices and a safety-based radiation protection program are invaluable to a certified EDO. Working in an environment with well-established safety and security cultures will significantly reduce the risk of unplanned events. Optimization of the licensee’s radiation protection program will assist in keeping radiation exposures to ALARA, with economic and social factors taken into account.
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