From the safety analysis point of view, we have to understand
how our work affects safety.
And specially how our work helps keeping the PSA hypothesis.
So, we have to be able to answer the six following questions:
The first one is:
Can I contribute to generate non predicted events?
Everybody can affect safety, just remember Three Mile Island.
There, the main control room operators were not able to solved the problem
just by themselves because there were actions made by local operators,
which caused the accident to happen in a way nobody predicted.
The second one is: Can I modify the frequency of an event?
Our work can lower or increase the frequency of a given event.
So, if we know our job's consequences for safety,
we can affect even the frequency for different events.
Third is: Can I contribute to change the initial conditions
in the safety analysis models?
It is important to remember that not complying
with those initial conditions can happen without any perceived effect.
Also: Can I affect the operability, availability
of structures or systems needed for safety?
The fifth one is:
Can I affect the probability of, sorry, active failures,
that are those that produce an event, or latent failures,
that are those that are visible just when an event occur?
And finally: Can I provoke an event
which is not considered in the safety analysis models?
After seeing those questions, we can say
that this is about questioning many things.
However, this doesn't mean to be questioning everything.
There is enough room to have different attitudes
between trying to understand every single thing
and following Tech Specs blindly.
If everybody moves in the right direction,
the sum of everybody’s actions would reduce the occurrence
of events with high severity.
Our goal is to know that our job contributes
in a way that the PSA fits adequately in our plant.
To do this, we can highlight the following questions
that help us to focus our job on one target, the global safety.
First, we can answer the question of what information does the PSA provide
that allows me to better understand the importance, for the risk,
of the structures, components and systems of the actions of the personnel, etc.?
So, basically, what information does the PSA provide
that helps me understanding better my job.
Second, we have to understand our job in order to see
if the PSA can be improved.
Or if the PSA can improve my nuclear performance.
And finally, we always have to have a questioning attitude,
trying to improve the PSA. If we identify any weakness in our PSA,
or if we think we can improve it,
it is a must to speak about it with the people in charge of this PSA.
A good example of this last question could be the safety culture.
We could use many resources to include safety culture in the PSA models.
Or we could ensure that I achieve a shared safety culture,
and thus, I would know that I was contributing
to decrease the actual risk and make it lower
than the PSA's expected risk.