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In case the radiation source module is not attached to the base plate of the
lexsyg
the
source module’s bottom side shall be completely covered by a 4 mm thick aluminium
transport safety plate. Hence, the radiation source module can be used for safely storing and
shipping of the built-in radiation source.
2
Occupational dose assessment
2.1
Dose rates relevant for exposure assessment
Ambient dose equivalent rate H*(10) was determined at various distances from the radiation
source module. A prototype source having an activity of 1.5 GBq was utilized, and the results
were extrapolated according to a maximum source activity of 2.0 GBq.
Conditions were as follows:
-
Radiation source (Sr-90)
-
Radiation source module with 5 mm lead-lined housing installed in
lexsyg
(prototype unit)
-
Radiation source shutter open (sample irradiation)
Table 2
Ambient dose equivalent dose rate at various distances to the surface of the
radiation source module (source activity 2.0 GBq)
distance to source
cm
position
equivalent dose
rate H*(10) / µSv/h
5
Position of operator’s hand during installation of the
source module in device
270
10
Position of operator’s hand during adjustment and
calibration activities
160
20
Position of operator’s hand during cleaning of
sample holder
27
30
Position of operator’s eyes during adjustment and
calibration activities
40
50
Position of operator’s hand during loading the
sample holder
2,7
70
Position of operator’s body during loading the
2,0
