An accident which involves core damage and uncontrolled radioactive releases,
is absolutely unacceptable.
Nuclear operation maximum ideas are to operate or be safe and clean.
Although the sequence of events in Fukushima are improbable
to happen in the USA or in Europe, mainly due to the regulation.
But once again, their problem was to be overconfident
over possible accidents. Their main error was
not to adhere to a healthy safety culture.
And we cannot do the same mistake.
So, we can say that by applying the Defense-in-Depth philosophy,
using the definition of risk, we would provide
a stronger regulating frame, more logic, coherent, systematic
and more understandable.
This application would be strengthen
by adding new events beyond design basis accidents.
So, after clarifying the regulations frame,
achieving a balance between risk and Defense-in-Depth,
we can say that we have to reevaluate the design basis accidents,
especially against earthquakes and floods.
In Europe, the European Commission or the European Union
and the national regulators run stress tests to see
if their installations could withstand those beyond design basis accidents,
and all the required actions in order to improve safety.
To evaluate capability to prevent fires and floods provoked
specially by earthquakes in a devastating situation,
like Fukushima Daiichi surroundings that were destroyed
and the plant was isolated.
In Spain, for example, we created or it was established
the Emergency Support Center.
This is a common facility to all the nuclear power stations.
And can provide personnel and equipment to any facility
in less than 24 hours. Here we can include
all the equipment for fire extinction, water supply and others.
The power plants have to have landing places for helicopters.
As we have said, during Fukushima, all the roads were cut.
So, it was impossible to reach the plant by road.
So, in those cases, in Spain, we can use
helicopters from the Army in order to transport
all the equipment and personnel to the plant.
As we have said, in less than 24 hours.
Also, Ancillary Emergency Management Centers
were established in all the plants.
We have an example here.
They are independent, seismic class I
and radiologically protected buildings
where people involved in the emergency can go there to rest and eat.
Also, if we continue, we can say that
now, there are portable diesel generators,
which are able to plug into the plant to supply power to the safety systems.
That was one of the problems with the Defense-in-Depth in Fukushima.
When the tsunami destroyed all the diesel generators.
Also, there is pumping equipment to supply water
to the reactor vessel and the containment sprays.
So, not just in BWRs plants. In Spain, for example,
all plants are required to have Containment Filtered Vents,
which are passive systems.
And this means that they don't have any power supply.
They can produce a controlled depressurization
of the containment building in the case of a core melt,
and decrease the airborne radioactivity inside containment.
Following or continuing in this track,
we can control the hydrogen that is going to be produced
during a core melt using another passive system.
So, here now it's mandatory in many countries to have
Passive Autocatalytic Recombiners, also known as PARs.
Those PARs that you can see here, basically are going to reduce
that hydrogen that is produced during that core melting,
by combining oxygen with the hydrogen
and producing water vapor.
If we continue with the action summary,
we can see that also, it is necessary to have
ancillary water supply equipment, fixed and portable,
to supply water to the Spill Fuel Pool.
That was another problem in Fukushima.
And which can work without any power supply
to at least compensate the water evaporation.
Also, it was necessary to improve the Emergency Operating Procedures,
and new procedures were developed as well, which were called
Severe Accident Management Guidelines,
and also extended damage mitigation guidelines.
These guidelines are thought to be used when the accident scales
to a severe accident. Then you put apart the Emergency Procedures
and apply these Accident Management Guidelines
and extended damage mitigation guidelines.
Also, in the emergency plans it was considered
the extended Station Black Out
and multiple events in different units,
and decision making guides, radiation and radioactive airborne surveillances.
Also, new information ways for the public.
Now, it's possible to give information to all the general public
of the activities that are carried out during an emergency situation.
And the regulator should be more concerned
about the Defense-in-Depth systems.
After this, we are going to finish this unit,
comparing the Spanish measurements or the European measurements
regarding Defense-in-Depth
with actions taken by the nuclear regulator in Canada.
So, now please, enjoy the following video.