CNSC radiation protection regulations

Earlier lessons quoted pieces of the Radiation Protection Regulations as they arose. This lesson puts them in order. The class's assignment is practical: Marcel gives them a short incident report from a contractor's radiography job at a pipe fabrication shop near Oshawa and asks them to find every regulatory obligation it triggered, who was responsible, and what the licensee had to report. To do that, they need to know how the Canadian framework fits together.

The legal framework

Nuclear energy in Canada is under federal jurisdiction. The Nuclear Safety and Control Act, in force since 2000, created the Canadian Nuclear Safety Commission (CNSC) and gives it authority to regulate the development, production and use of nuclear energy and nuclear substances, and the equipment and information associated with them, to protect health, safety, security and the environment. Under the Act sit regulations made by the Commission, and under them licences issued to each facility or user, each with a licence conditions handbook.

Not every source of radiation is federal. X-ray machines used in medicine, dentistry and industry are regulated by the provinces; in Ontario, for example, under occupational health and safety and healing arts legislation. Naturally occurring radioactive material outside the nuclear fuel cycle is managed by provinces and territories using the Canadian NORM Guidelines. Health Canada sets guidelines for radon and drinking water and maintains the National Dose Registry.

The Radiation Protection Regulations, section by section

The 2020 amendments, in force from 2021, lowered the lens of the eye limit for NEWs from 150 to 50 mSv, added the obligation to accommodate breastfeeding workers, clarified the requirements for selecting and using radiation instruments, and added an explicit duty to inform workers of their duties and risks in emergencies.

# Compliance check under the Radiation Protection Regulations (doses in mSv).
history = {2021: 8.5, 2022: 12.0, 2023: 21.0, 2024: 9.0, 2025: 6.0}   # one five-year dosimetry period, 2021 to 2025
ANNUAL, FIVE_YEAR = 50.0, 100.0
ACTION_LEVEL = 10.0          # illustrative licence action level per year

total = 0.0
for year, d in sorted(history.items()):
    total += d
    flags = []
    if d > ANNUAL: flags.append('exceeds annual limit')
    if d >= ACTION_LEVEL: flags.append('action level reached: investigate and notify')
    print(f"{year}: {d:5.1f} mSv  running five-year total {total:5.1f}  {'; '.join(flags) or 'ok'}")
print(f"five-year dosimetry period total {total:.1f} of {FIVE_YEAR:.0f} mSv; "
      f"remaining {FIVE_YEAR - total:.1f} mSv")

# Radiography incident: who is affected?
for who, nev, dose in (('radiographer', True, 6.0), ('assistant', False, 0.4)):
    limit = ANNUAL if nev else 1.0
    print(f"{who:12s} NEW={nev!s:5s} dose {dose:4.1f} mSv of {limit:4.1f} mSv limit "
          f"({100*dose/limit:4.0f} % of limit)")

2021:   8.5 mSv  running five-year total   8.5  ok
2022:  12.0 mSv  running five-year total  20.5  action level reached: investigate and notify
2023:  21.0 mSv  running five-year total  41.5  action level reached: investigate and notify
2024:   9.0 mSv  running five-year total  50.5  ok
2025:   6.0 mSv  running five-year total  56.5  ok
five-year dosimetry period total 56.5 of 100 mSv; remaining 43.5 mSv
radiographer NEW=True  dose  6.0 mSv of 50.0 mSv limit (  12 % of limit)
assistant    NEW=False dose  0.4 mSv of  1.0 mSv limit (  40 % of limit)

Regulatory documents and expectations

Regulations state requirements in general terms; regulatory documents add detail. REGDOC-2.7.1 describes expectations for the radiation protection program: application of ALARA, worker dose control, radiation protection training, monitoring of the workplace, and estimation of public dose. REGDOC-2.7.2 covers dosimetry, including the ascertainment and recording of doses and requirements for dosimetry services. REGDOC-2.10.1 covers nuclear emergency preparedness and response, the subject of lesson 11. Licensees state in their licence application how they meet each relevant document, and the CNSC inspects against those commitments.

Compliance and enforcement

The CNSC verifies compliance through inspections, desktop reviews of reports, and event follow-up. Its tools range from requests for information and orders to administrative monetary penalties, licence amendments and prosecution. For nuclear power plants it publishes an annual regulatory oversight report rating each station in its safety and control areas, including radiation protection. Workers also have obligations under the General Nuclear Safety and Control Regulations: to follow procedures, use protective equipment and report hazards and events.

Obligations of workers

The General Nuclear Safety and Control Regulations place obligations on workers as well as licensees. Every worker must use equipment, devices, clothing and procedures as required by the licence, comply with measures established by the licensee to protect the environment and the health and safety of persons, promptly report to the licensee or a supervisor any situation that could lead to an increase in radiation levels or an unauthorized release, any failure of equipment that may impair safety, and any act of sabotage, theft or loss, and not tamper with or render ineffective any safety device. Workers who see a problem have both the right and the duty to report it.

Exceeding a dose limit

If a dose limit may have been exceeded, sections 16 and 17 of the Radiation Protection Regulations set out what happens. The licensee must immediately notify the person concerned and the Commission, investigate to determine the magnitude of the dose and the causes, identify and take any action needed to prevent a recurrence, and remove the person from any work likely to add to the dose until the Commission authorizes a return. A worker whose dose has exceeded a limit can return to work only with that authorization and with any conditions the Commission sets, such as a reduced dose allowance for the rest of the dosimetry period.

Transport and sealed sources

Radiation protection obligations follow radioactive material when it leaves a facility. The Packaging and Transport of Nuclear Substances Regulations, 2015, adopt the IAEA transport regulations and require packages to be labelled with their category and transport index, and carriers to have a radiation protection program when doses to transport workers could exceed set levels. Sealed sources, such as radiography and calibration sources, are licensed under the Nuclear Substances and Radiation Devices Regulations, which require inventories, leak testing at set intervals and secure storage, and the CNSC maintains a national sealed source registry for high-activity sources.

Reading a licence

A station's operating licence is short; its licence conditions handbook is long. For radiation protection the handbook lists the compliance verification criteria: which REGDOCs and CSA standards apply and in which versions, the action levels and their values, the reporting requirements and their timelines, and the documents in which the licensee describes its program. An engineer joining a licensee should read the radiation protection section of the handbook early, because it is the practical definition of what the company has promised the regulator.

Marcel's radiography case ends with one more lesson: the contractor's licence required an action level for any unplanned exposure of a radiographer above 1 mSv in a single event. The company had reported the equipment failure but not the action level, an omission the CNSC treated as a separate non-compliance. Knowing the licence matters as much as knowing the regulations.

Federal and provincial overlap in practice

Occupational health and safety at a nuclear power plant is itself split. The CNSC regulates radiation protection and nuclear safety, while conventional hazards such as falls, electrical safety and confined spaces are under provincial occupational health and safety law for most provincially regulated employers, including Ontario Power Generation. Station procedures combine both sets of requirements, and joint inspections or memoranda of understanding between regulators help avoid gaps. A confined space entry into a contaminated tank, for example, must satisfy the provincial confined space rules and the CNSC-licensed radiation protection program at the same time.