External irradiation and inhalation

For quantification of impacts consisting of external irradiation and exposure by inhalation inside the facilities SAFRAN, use the following procedure (see Table 4.1):

Dose from exposures during one hour via inhalation are calculated from the radionuclide concentrations in air, in the room linked to considered scenario, using equation 4.1. Since normal operation scenarios can be linked only to one activity, area or room, then the exposure are assessed for one activity, area or room at a time.

Equ41.png

where

DoseRateinhi is the inhalation dose rate for the i-th radionuclide Sv/h,

Concairi is the concentration in air of the i-th radionuclide Bq/m3,

InhRate is the inhalation rate m3/h,

DCCinhi is the inhalation dose coefficient of the i-th radionuclide Sv/Bq.

The radionuclide concentrations are extracted by SAFRAN from one of the tables of air concentrations in the room linked to the scenario, added by the user in the System Description Module. The inhalation rate (see Database tables) and the inhalation dose coefficients (see Database tables) are extracted by SAFRAN from the Internal Database.

The total dose rate from inhalation (DoseRateinh) is calculated with equation 4.2

Equ42.png

The total dose rate ( DoseRatetotal in equation 4.3) is the sum of the total dose rate from inhalation (equation 4.2) and the external dose rate (DoseRateext)in the area or room linked to the scenario.

Equ43.png

The external dose rate is extracted by SAFRAN from one of the tables of external dose rate in the room linked to the scenario, added by the user in the System Description Module.

Table 4.1. Quantification of impacts of the type external exposure and exposure via inhalation for normal operation scenarios

Table41.png

RN – radionuclide, HQ – Hazard Quotient, SDM – System Description Module, SDB – SAFRAN Internal Database, N/A – not applicable. The cell marked in read is used in the Analysis Module for comparison of hazards.

Definition of columns in Table 4.1:

  • Column 1. Short name of the radionuclides (RN).
  • Column 2. Radionuclide concentration in air.
  • Column 3. Dose rate from inhalation.
  • Column 4. Dose rate from external exposure.
  • Column 5. Total dose rate in the affected area.
  • Column 6. Screening dose rate for normal operation.
  • Column 7. Hazards Quotient.

Columns in Table 4.1 that can be modified by the user: The user can modify the following columns: column 5 for entering directly the Total Dose Rate, 6 – for entering own values of the Screening Dose Rate (no).