Dosimetry

As high levels of ionizing radiation represent a health risk, it is important to track radiation exposure for those working with nuclear substances or devices.

Radiation doses to the body are measured in Sieverts (Sv), or miliSieverts (mSv). The measurement of such doses is known as dosimetry, and devices for measuring radiation doses are called dosimeters.

The limit for nuclear energy workers is 50 mSv per year, or 100 mSv in a five-year period.

The Canadian Nuclear Safety Commission (CNSC) Radiation Protection Regulations state that licencees must use a licensed dosimetry service to measure the doses to all employees with a reasonable probability of receiving an effective dose of 5 mSv or greater in a year.

Dosimetry service providers maintain records of doses measured on personal dosimeters, and are required to report such records to the National Dose Registry of Health Canada to help ensure that workers are not exceeding maximum dose limits.

There are two categories of dosimetry service providers:

• Commercial service providers: dosimetry service suppliers for external clients
• In-house service providers: nuclear licensees with the capability of providing dosimetry services for their own employees and visitors

Each dosimetry service provider must meet the technical and quality assurance requirements outlined in CNSC's Technical and Quality Assurance Standards for Dosimetry Services (S-106 rev 1) .

Read more about dosimetry - Introduction to Dosimetry (INFO-0827) (PDF).

For a list of licensed dosimetry service providers, please contact CNSC.