epr-method (2003) - IAEA Publications - International Atomic Energy ...

involving this amount of radioactive material. However, a limited area, probably no more
than a small fraction of a square kilometre (i.e. a few soccer pitches), may be contaminated
to non-dangerous levels that may warrant long term control 147 or clean up 146 . The size of the
area to be cleaned up would depend on many factors (including the size and type of source,
whether and how it had been dispersed, and the weather). It would be virtually impossible
for this amount of radioactive material to contaminate a public water supply to dangerous
levels, even if the radioactive material were highly soluble in water.
A/D >10.0 -1000
A/D >1000
INDIVIDUAL SOURCES
Very dangerous to the person: This amount of radioactive material, if not managed safely
and kept securely, could cause the permanent injury of a person who handles it or is
otherwise in contact with it for a short time (minutes to hours). It could possibly be fatal to
be close to unshielded material for a period of hours to days.
DISPERSIBLE RADIOACTIVE MATERIAL
Very dangerous in the locality: Handling this amount of radioactive material could be
fatal. There would be little or no risk of permanent injuries beyond a hundred metres
downwind of a fire or explosion involving this amount of radioactive material. However, a
limited area, probably no more than one square kilometre, could be contaminated to nondangerous
levels that may warrant long term controls or clean up 146 . The size of the area to
be cleaned up would depend on many factors (including the size and type of the source,
whether and how it had been dispersed, and the weather).
It would be virtually impossible for this amount of radioactive material to contaminate a
public water supply to dangerous levels, even if the radioactive material were highly soluble
in water.
INDIVIDUAL SOURCES
Extremely dangerous to the person: This amount of radioactive material, if not managed
safely and kept securely, could cause the permanent injury of a person who handles it or is
otherwise in contact with it. It would probably be fatal to be close to unshielded material for
a period of minutes to an hour.
DISPERSIBLE RADIOACTIVE MATERIAL
Very dangerous in the locality: Handling this amount of radioactive material would likely
be fatal. There would be little or no risk of permanent injuries beyond a few hundred metres
downwind of a fire or explosion involving this amount of radioactive material. However, a
limited area, probably no more than a few square kilometres, could be contaminated to nondangerous
levels that may warrant long term controls or clean up. The size of the area to be
147 This only applies to radionuclides that have long half-lives and refers to levels of contamination that could result in doses
in excess of those warranting permanent resettlement in accordance with international guidance (1000 mSv over a lifetime)
[2, 3].
248