Now we can remember some of the most important concepts
in order to do a summary.
First, remember that nuclear safety is not an intrinsic feature of the system.
It's the result of the different parts interactions analysis.
This means that without deep knowledge of the whole system,
it's going to be difficult to achieve a high level of safety.
Before doing any activity, like a Safety Analysis,
we have to know what we have in our hands.
Also, the Safety Analysis, the deterministic or the probabilistic,
is a key tool to achieve a high degree of response
to accidents and incidents that are forecasted in the design.
That means that, going to a step higher,
with that deep knowledge that we have, then, we can do the Safety Analysis.
And that Safety Analysis is there in order to help us
see what to do when an event happens.
As a nuclear workers, or for nuclear workers,
it is a must to know and understand the basis of that Safety Analysis
that can improve my job or your job in order to preserve
the hypothesis from that analysis.
And finally, a new key is that Safety II can improve the Safety Analysis
by analyzing small different events, but that are frequent,
and also by paying attention to the work-as-done.
From this, we can learn and anticipate, and we can improve the Safety Analysis
and our knowledge of safety.
And with this, we can see now how the Defense-in-Depth concept
has evolve, especially after Fukushima.
But that is for the next Unit.
I hope you have enjoyed this unit.
And after this, we can continue with Unit 5.