Appendix CRF - Part 3 - Northamptonshire County Council

Radiological Assessment 0820-2
Version 2
CRn,soil(t) is the concentration of radionuclide Rn in the pasture and crop soil at
time t (Bq kg -1 ).
Ding is the dose coefficient for ingestion of radionuclide, Rn (Sv Bq -1 ).
Dose from external irradiation while living or working on contaminated soil is given
by:
Rn
OOsf C( t)
D
Dose irr,
soil out in
Rn,
soil irr,
slab
where: Oout
is the time spent outside exposed to the soil (years year –1 ).
Oin is the time spent inside (years year –1 ).
sf is the shielding factor from the ground when indoors (dimensionless).
CRn,soil(t) is the concentration of radionuclide in the soil at time t (Bq kg -1 ).
Dirr,slab is the dose conversion factor for irradiation from radionuclide Rn
(Sv year -1 Bq -1 kg), based on the receptor being 1 m from the ground
and assuming a semi-infinite slab of contamination.
Dose from inhaling dust derived from contaminated soil is given by:
Dose BO
C ( t)
dustload
D
inh,
soil
dust
Rn,
soil
where: Odust
is the time spent exposed to dust from the soil (years year –1 ).
B is the breathing rate (m 3 year -1 ).
CRn,soil(t) is the concentration of radionuclide in the soil at time t (Bq kg -1 ).
dustload is the dust concentration (kg m -3 of air).
Dinh is the dose coefficient for inhalation of radionuclide Rn (Sv Bq -1 ).
Parameter Description Value Units
Irrigrate rate of irrigation 0.3 m year -1
Intcrop effective interception factor 0.33 dimensionless
Fcrop fraction remaining after Grain 1.0
dimensionless
processing
Green veg 0.3
Yieldcrop
crop yield
Root veg 1.0
Pasture 1.7
Grain 0.4
Green veg 3.0
Root veg 3.5
Galson Sciences Limited 75 14 July 2009
Rn
inh
kg m -2
Table A.5 Parameter values used in calculations of doses arising from use of
contaminated groundwater for irrigation.
WS010001/ENRMF/CONSAPPCRF 625