R.1 Radiation protection considerations

R.1.1 General

Dose control procedures for ERAMG field teams are detailed in the ERAMG Response Plan, and the procedures therein should be considered when developing dose control procedures for other emergency workers.

Equipment must be available to measure and/or determine the dose received by field staff including (as required):

  1. Passive Dosimeter (e.g. TLD, OSLD) to all emergency workers
  2. Direct Reading Dosimeters (DRD) (e.g., electronic personal dosimeter (EPD)) for all emergency workers or a representative individual in all groups at risk
  3. radiation survey meters
  4. air sampling equipment and contamination meters.

R.1.2 Exposure control

Notwithstanding the permissible doses given (See Table R – 1), due diligence shall be exercised to maintain individual doses ALARA.

Table R – 1: Actions vs. Permissible Dose for Emergency Workers in the Urgent Response, Early Response, and Transition Phases
Action

Effective dose

(mSv)

Equivalent dose to the skin (mSv)
Permissible dose for participation in control of emergency50500
Permissible dose for actions taken to minimize dose consequences, for members of the public, associated with the release of radioactive material.1001 000
Permissible dose for actions taken to prevent health effects of radiation that are fatal or life-threatening, or that result in permanent injury.5005 000
Permissible dose for actions taken to prevent the development of conditions that could significantly affect people and the environment.5005 000

All personnel participating as emergency workers shall be provided training to perform required responsibilities during an actual emergency and informed of:

  1. The possible radiation hazards to which they might be exposed
  2. The applicable rules, regulations, orders, directives, plans and procedures
  3. The equipment, clothing, methods and measures required to reduce radiation doses
  4. Their responsibilities, obligations and rights including the individual’s responsibilities for personal and collective protection
  5. Their expected radiation dose levels
  6. The specified permissible dose and of the dose management control levels
  7. The potential effects of radiation during pregnancy, the rights and obligations of a pregnant woman
  8. That the designation shall only be effective during the nuclear emergency.

R.1.3 Turn-back dose rate

Turn-back dose rates are associated with Sector Safety Status, found in Table R – 2 , and form the basis for worker safety decision making at the EWC. If the values associated with the dose rate are exceeded, the member must leave the area when safe to do so, or move away from the radiation source until the dose rate has dropped below the dose rate set by the EWC. In order to use turn-back dose rates, personnel must have:

  1. A handheld dose rate meter may be carried by a representative individual in a group, which is to be closely monitored at all times when in an area of risk from radiation exposure; and/or
  2. A DRD worn when at risk of radiation exposure. The DRD will be configured with both a dose and dose rate alarm and may be used to indicate excessive radiation levels independent of the handheld meter or in tandem with the handheld meter.

The DRD measures both the accumulated dose and the dose rate the individual is receiving from the surrounding environment. However, the DRD and the dose rate meter measure the incident rate of radiation; thus, the specified limit applies only to situations where the individual is wearing suitable clothing and respiratory protection.

Table R – 2: Guidelines for Assigning Sector Safety and Stay Times
Sector StatusCriteria
Red

> 1 rem/h (10 mSv/h)

Recommended Stay Time – 1 hour

Orange

25 mrem/h (250 µSv/h)

to

< 1 rem/h (10 mSv/h)

Recommended Stay Time – 4 hours

Yellow

0.1 mrem/h (1 µSv/h)

to

< 25 mrem/h (250 µSv/h)

Recommended Stay Time – 4 hours

Green

< 0.1 mrem/h (1 µSv/h)

Recommended Stay Time – No Limit

Table R – 3 details some of the potential actions to be taken in the field after a release. Additional precautions are found in Table R – 4 .

R.1.4 Personal protective equipment

PPE will be supplied to members who are tasked with conducting survey and sampling operation in any sector that may be contaminated following a nuclear release. Specifics on the type, quantities, and capabilities of specific PPE are available in the Provincial Nuclear Facilities, Equipment and Maintenance Manual. In general, PPE shall provide an outer layer to protect the skin and respiratory protection. The PPE shall be sealable at the wrists, ankles, waist, neck, and around the face. Tape is acceptable to create the seal. More detailed PPE requirements are found in Table R – 5 .

R.2 Safety sector status tables

Table R – 3: Precautions for Each Sector Safety Status

Safety Status		Precautionary Measures for Emergency Workers
GreenNo precautions necessary. No limit on stay period.
Yellow
  1. Report to the Emergency Worker Centre (EWC) before entering the sector.
  2. Carry personal monitoring devices and observe all precautions prescribed by the EWC.
  3. If duties permit, remain under shelter or inside a vehicle.
  4. If working outside, wear appropriate personal protective equipment (PPE) as prescribed by the EWC.
  5. Stay in the sector shall be limited to 4 hours, or the time prescribed by the EWC.
  6. Report again to the EWC on leaving the sector.
Orange
  1. Pregnant emergency workers shall not enter the sector.
  2. Report to the Emergency Worker Centre (EWC) before entering the sector.
  3. Carry personal monitoring devices and observe all precautions prescribed by the EWC.
  4. Dosimeters should be checked every hour. Exit from the sector if the reading reaches 40 mSv (4rem), or any lower personal limit prescribed by the EWC.
  5. If duties permit, remain under shelter or inside a vehicle.
  6. If working outside, wear appropriate personal protective equipment (PPE) as prescribed by the EWC.
  7. Stay in the sector shall be limited to 4 hours, or the time prescribed by the EWC.
  8. Report again to the EWC on leaving the sector.
Red
  1. Pregnant emergency workers shall not enter the sector.
  2. Report to the Emergency Worker Centre (EWC) before entering the sector.
  3. Enter the sector accompanied by a qualified escort provided by the reactor facility and carry alarming personal dosimeters. Observe any precautions prescribed by the EWC.
  4. Dosimeters should be checked every 30 minutes. Exit from the sector if the reading reaches 40 mSv (4 rem), or any lower personal limit prescribed by the EWC.
  5. If duties permit, remain under shelter or inside a vehicle. If working outside, wear an outer garment such as a plastic raincoat or any other personal protective equipment (PPE) prescribed by the EWC.
  6. Stay in the sector shall be limited to 1 hour, or the time prescribed by the EWC.
  7. Report again to the EWC on leaving the sector.
Table R – 4: Recommended Reference Levels
Band (acute or per year)Type of Situation
20-100 mSvEmergency situations, where events with uncertain consequences require urgent protective actions such a sheltering and evacuation to minimize the impacts of possible radiation exposures.
1–20 mSvExisting situations, where radioactivity is already present in the environment at the time actions are taken to reduce radiation exposures. If doses are optimized below this reference level it is safe to live in the contaminated area.

Note: From Reference levels for nuclear emergency response and post-accident recovery

Table R – 5: Recommended PPE Based on Sector Safety Status
Sector safety statusRecommended PPE (to be determined in the moment)
Red
  • Tyvek coveralls
  • Full-face piece air purifying respirator with a P-100 or high-efficiency particulate air (HEPA) filter
  • Rubber boot covers
  • Protective gloves
  • Electronic personal dosimeter (EPD)
  • Passive dosimeter
  • Hard hat, if required
  • Safety glasses, if required
  • Any other items as defined by the EWC supervisor 
Orange
  • Tyvek coveralls
  • N-100 mask or full-face piece air purifying respirator
  • Rubber boot covers
  • Protective gloves
  • Electronic personal dosimeter (EPD)
  • Passive dosimeter
  • Hard hat, if required
  • Safety glasses, if required 
Yellow
  • N-100 mask
  • Disposable (paper) boot covers
  • Electronic personal dosimeter (EPD)
  • Passive dosimeter
  • Hard hat, if required
  • Safety glasses, if required
  • Protective gloves, if required 
Green
  • Passive dosimeter
  • Hard hat, if required
  • N95, if required
  • Safety glasses or face shield, if required
  • Protective gloves, if required 
Table R – 6 : Conversion Tables for Radiological Units
From Curie to BecquerelFrom Becquerel to Curie
From Rem to SievertFrom Sievert to Rem
1 kilocurie (kCi) ≈ 37 terabecquerel (TBq)1 terabecquerel (TBq) ≈ 27 curie (Ci)
1 curie (Ci) ≈ 37 gigabecquerel (GBq)1 gigabecquerel (GBq) ≈ 27 millicurie (mCi)
1 millicurie (mCi) ≈ 37 megabecquerel (MBq)1 megabecquerel (MBq) ≈ 27 microcurie (μCi)
1 microcurie (µCi) ≈ 37 kilobecquerel (kBq)1 kilobecquerel (kBq) ≈ 27 nanocurie (nCi)
1 nanocurie (nCi) ≈ 37 becquerel (Bq)1 becquerel (Bq) ≈ 27 picocurie (pCi)
1 picocurie (pCi) ≈ 37 millibecquerel (mBq)/
1 kilorem (krem) = 10 sievert (Sv)1 sievert (Sv) = 100 rem (rem)
1 rem (rem) = 10 millisievert (mSv)1 millisievert (mSv) = 100 millirem (mrem)
1 millirem (mrem) = 10 microsievert (μSv)1 microsievert (μSv) = 100 microrem (μrem)
1 microrem (μrem) = 10 nanosievert (nSv)1 nanosievert (nSv) = 100 nanorem (nrem)
Table R – 7: Unit Prefixes
Large PrefixesSmall Prefixes
Tera (T) = x 10 12Pico (p) = x 10 – 12
Giga (G) = x 10 9Nano (n) = x 10 – 9
Mega (M) = x 10 6Micro (µ) = x 10 – 6
Kilo (k) = x 10 3Milli (m) = x 10 – 3