Page 35 - Nuclear Plant Journal Digital Edition: January - February 2013
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Nuclear Plant Journal, January-February 2013
35
(Continued on page 36)
Fukushima
Safety
Conference
This report includes excerpt of the
session chairperson’s closing remarks
at the three working sessions at, “The
Fukushima Ministerial Conference on
Nuclear Safety”, which was held in
Koriyama City, Fukushima Prefecture,
Japan from December 15 to December
17, 2012. The three working sessions
were:
1. Lessons learned from the accident
at TEPCO’s Fukushima Nuclear
Power Station, chaired by Mr.
Mike Weightman, Chief Inspector
of Nuclear Installations, Office
for Nuclear Regulation, United
Kingdom
2. The Strengthening of Nuclear Safety,
Including Emergency Preparedness
and Response, in light of the
accident at TEPCO’s Fukushima
Nuclear Power Station, chaired
by Mr. R. Jammal, Executive Vice
President and Chief Regulatory
Officer, Canadian Nuclear Safety
Commission, Canada
3. Protection of People and the
Environment from the Ionizing
Radiation, chaired by Ms. A. Dela
Rosa, Director, Philippine Nuclear
Research Institute, The Philippines .
The complete text of the summaries
may be accessed by going to: http://
/
PDFplus/2012/20120216/20120216_
CSummaries.pdf
Lessons Learned
1. It is particularly important and
reassuring that the process initiated by
Member States immediately after the
Fukushima Daiichi accident to review site
hazards and to complete complementary
safety assessments (through national
reviews or ‘stress tests’) has now been
largely completed. The results of these
assessments, undertaken to ensure plant
robustness to extreme events, have been
reported to national authorities and
international organizations, and where
Member States have identified the need for
improvements, these have been prioritized
and resourced. Such prioritization has
reflected the need to maintain continued
attention to the critical features of the
previous safety basis for plant operation.
It is reassuring to note that, despite the use
of different terminology and emphases,
the efforts have largely converged on
the same conclusions. In addition, the
similarities in actions provide confidence
that significant issues have not been
overlooked. The prior use of periodic
safety reviews has been shown to be
particularly advantageous.
2. The
Fukushima
Daiichi
accident reminds us of the imperative of
establishing an effective nuclear safety
regulatory framework, including an
independent (in law, practice and culture)
effective expert regulator that is credible,
trusted, competent and adequately
resourced. To achieve this objective, it
is vital to recognize the importance of
scientific and technical knowledge and
expertise in taking effective, optimized
regulatory decisions.
3. The Fukushima Daiichi accident
has reminded us of the importance of
paying careful attention to external events
such as floods, earthquakes and tsunamis.
It has served as the stimulus for a re-
examination of the design basis to ensure
that such external events are adequately
taken into account and for the introduction
of an additional layer of protection to
prevent or mitigate a beyond design basis
accident, regardless of the initiating event.
However, it was noted that more work
needs to be undertaken to explore what
constitutes a consistent design basis and
how much safety margin is reasonable for
establishing adequate beyond design basis
robustness. Probabilistic assessments can
add value in this respect.
4. Consideration needs to be
given to the potential performance of a
plant in response to beyond design basis
accidents; that is, the effectiveness of the
measures and safety features provided
for design basis accidents needs to be
evaluated to see whether these measures
and safety features can be enhanced to
provide protection against events that
had not previously been considered in
the design. These enhancements might be
introduced either through the provision
of additional equipment or by providing
protection against the effects of extreme
events.
5. Mitigation capabilities need
to be correspondingly enhanced;
alternatively, systems not normally relied
upon for mitigation may need to be re-
classified (e.g. installed fire systems
may take on part of the reactor and
spent fuel pool cooling safety function),
to adequately complement the accident
prevention features. This should include
updating and strengthening the severe
accident management guidelines and the
associated training, drills and exercise
programmes to improve the overall
response capability.
6. It should be emphasized that
any proposed additional measures to
mitigate the impact of severe accidents
should not be carried out at the expense
of the attention given to prevention of
accidents; both these aspects need to be
properly supported. The constant and full
compliance of nuclear power plants with
their licensing basis should continue to
provide assurance at all times that safety
margins are guaranteed to allow the
necessary time to respond to an initiating
event and to adequately mitigate and
properly manage accident progression,
when necessary.
7. Although the various safety
measures identified in response to the
Fukushima Daiichi accident will serve
to improve safety, the key will always
be constant vigilance, as there is no
room for complacency or anything less
than a total commitment to improving
safety. The establishment of a robust
and enduring safety culture is crucial.
Licensees and regulators need to be
constantly alert to any early sign of a
possible degradation of safety that could
directly or indirectly affect the public.
Other aspects of promoting a vibrant
safety culture were noted, in particular
