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DEFENCE IN DEPTH
Defence in depth

Factor: how close?

 

The INES approach is fairly simple and is illustrated here.

If an event of the maximum potential consequences, should all the provisions fail, could reach Level 5 or above, a near miss should be rated Level 3 on INES. Click here.

However, if an event of the maximum potential consequences, should all the provision fail, could only reach Level 3 or 4, a near miss should be rated Level 2 on INES. Click here.

Similarly, if an event of the maximum potential consequences, should all the provisions fail, could not even reach Level 3, a near miss should be rated Level 1 on INES. Click here.

POTENTIAL ACCIDENTS
NEAR MISS ACCIDENTS
This shows the rating for a near miss based on the rating for the worst possible accident should all provisions fail.