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IMPACT ON PEOPLE AND THE ENVIRONMENT
Release

CRITERIA FOR UNPLANNED AIRBORNE RELEASES OF ACTIVITY FROM RADIATION SOURCES

 
 

These are the two definitions related to releases fom radiation sources.

As mentioned before, there is no need to define criteria at Level 6 or 7 as it is physically impossible for an accident involving a radiation source to generate such a release.

Note that here the level definition is more precise as the source content is usually known.

Using D2 value for 131I, a level comparable to the definition for releases from facilities has been derived. The D2 value for 131I is 0.2, hence the Level 5 threshold of 500 TBq is equivalent to 2 500 D2. The lower level is based on a factor of 10 reduction.

 
 
 
 
 

Activity greater than 2 500 times the D2 value for the isotopes released

 

Activity greater than 250 times the D2 value for the isotopes released