Repères - N°48 / March 2021 - The IRSN magazine - 9

SAFETY

Based on feedback from the accident at
Fukushima Daiichi-loss of water supply,
loss of power, not enough manpower-the
aim of the hardened safety core is to " retain
control of the situation and, if necessary, be
able to contain severe accidents, no matter
the circumstances, " Lejuste explained.
The concept relies on two key measures:
the Emergency Diesel Generator (EDG)
and the Ultimate Heat Sink, designed,
respectively, to ensure electric power for
72 hours and makeup water (see p. 10 and
11). Technical dialogue with EDF1 has been
ongoing since 2012. ASN required EDGs
to be installed at all reactors by 2018. The
design of certain parts of the facilities has
also been under review; these must be made
more robust to withstand extreme weather
events: flooding (see p. 12), lightning, tornados, violent winds, etc.
To improve emergency response management, EDF proposed, within the framework
of the CSAs, building a Local emergency
center (CCL 2) on every site, designed to
withstand extreme hazards (see webmag).
The following year, again on its own initiative, EDF set up the FARN, the Nuclear
Rapid Response Force (see opposite).
All new equipment is designed with
extreme hazards in mind from the very
start. Full implementation of the hardened
safety core measures will be completed in
line with the ten-yearly reviews, with
expected completion set for 2038. n
1. Électricité de France/French national
power company.
2. Centre de crise local.

WEBMAGAZINE
READ
Local emergency
centers to stand
firm during
extreme
situations
irsn.fr/R48-EN

Have the ways in which
people can participate
changed?

What improvements
could be made?

MB: ASN's standing
groups are now open to
non-institutional experts.
YM: The amount of dialogue
We have gotten involved in
on technical issues has
a number of these committees,
increased. Local information
in particular those pertaining
committees (CLI) hold
to facility safety and waste
discussions with the experts
management.
at IRSN, the French Nuclear
YM: Such openness serves
Safety Authority (ASN) and the to enrich the assessment
operators on what are often very process. We often bring
controversial issues, such as
different views to the table.
the anomalies in the Flamanville On reactors, we stress the need
EPR (Manche department)
to stick to the safety margins,
reactor vessel. IRSN now
keep a close eye on whether
publishes more information.
the deadlines for implementing
It consults with citizens prior
ASN recommendations are met,
to conducting assessments
and so on.
instead of toward the end
of the process. A good example
of this is the project to create
a centralized spent fuel pool.

MB: Some information should
be made public, such as
monitoring implementation
of commitments made
by operators.
YM: We need to get to the point
where the concerns of civil
society have a real impact on
decisions.

What topics are not being
discussed?
YM: Security. It's only natural
that certain aspects, like
anti-terrorist surveillance,
should be classified for defense
purposes. But other subjects,
such as whether civil
engineering structures are
robust enough to withstand
an aircraft crash, or the ability
to maintain cooling after certain
types of attack, etc., should be
addressed through dialogue
with society.

4 questions for...
Manon Besnard
and Yves Marignac

© Coll. part ; © B. Runtz

72-hour autonomy vital on site

In what ways has the
accident at Fukushima
Daiichi changed relations
between key players
in the nuclear industry
and civil society?

Independent experts at the Institut négaWatt
Nuclear and Fossil Fuel Energies Unit
© EDF - Bruno Bony/Sipa

the required safety baselines relative to
natural hazards. IRSN proposed a new
concept, that of the hardened safety core.
Every facility has since been required to
have at its disposal the human and organizational resources and the " last resort "
equipment designed to withstand severe
hazards that go beyond the design-basis
scenarios set out in the safety reference
documentation in force.

The FARN is staffed by 300 trained employees.
Its fleet is composed of 52 all-terrain vehicles
as well as air and river transport craft.

FOCUS

Taking over to deliver a hardened
safety core within 24 hours

A

s an additional safety measure
that has been in place since 2013,
the FARN (for Force d'action
rapide nucléaire) provides human
resources and equipment in the event
of accident. In 2019, IRSN noted
in a notice that-for a given accident
scenario-the FARN must, without
fail, take action within 24 hours

(Notice 2019-00051 on the deployment
of ultimate cooling measures). The FARN
is tasked with maintaining reactor cooling
and ensuring supply of water, power
and compressed air.
It takes over to deploy the hardened
safety core measures to keep the situation
under control and prevent core melt or,
failing that, mitigate the consequences.
Page 9 - Repères No. 48 - March 2021
https://www.irsn.fr/R48-EN
Repères - N°48 / March 2021 - The IRSN magazine

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