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IMPACT ON PEOPLE AND THE ENVIRONMENT
Dose

WHAT DOES THE HIGHEST LEVEL LOOK LIKE?

 

As before, we’ll start with the highest level. For a single person, it corresponds to a high enough dose to result in a fatality.  Although this would be a serious event, it is clearly much less severe than the Chernobyl or Fukushima event.

INES was designed so that an event resulting in a single fatality from radiation would be rated at Level 4.

How exactly is this level defined? Click here or on Level 4 of the diagram above to find out.

This is the definition of Level 4 for a single exposed person:

 

The occurrence of a lethal deterministic effect

or

The likely occurrence  of a lethal deterministic effect as a result of whole body exposure leading to an absorbed dose of the order of a few Gy.

For such high doses, it may not be immediately clear if the exposure will
result in a fatality, and extensive medical treatment will probably be undertaken.

click here to reveal the estimated likelihood

The table shows the likelihood of a dose being fatal and if necessary, these numbers can be used to
judge whether the event should be rated at Level 4.