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IMPACT ON RADIOLOGICAL BARRIERS AND CONTROLS AT FACILITIES
Radiological barriers and controls

WHAT THE CRITERIA LOOK LIKE

 

Now we move on to criteria for similarly significant events at non-reactor facilities.

Criteria related to severe damage to radiological barriers.

At non-reactor facilities, criteria rely more on containment than cooling, hence the title of damage to radiological barriers.

 

To rate an event at Level 5 based on this criterion requires
a major release within the facility with a high probability of significant overexposure

major = comparable with a release from a core melt

high probability = similar to that of a release from reactor containment following a major accident

 

To rate an event at Level 4 based on this criterion requires a
total amount of activity released within the facility of a few thousand TBq with a high probability of significant exposure

The same definition of 'high probability' applies, although, high probability might be as low as 1%.

Note the definition for Level 4 is simply total activity—there is no assessment of radiological equivalence.