COMMISSION STAFF WORKING DOCUMENT Technical summary on the implementation of comprehensive risk and safety assessments of nuclear power plants in the European Union Accompanying the document COMMUNICATION FROM THE COMMISSION TO THE COUNCIL AND THE EUROPEAN PARLIAMENT on the comprehensive risk and safety assessments ("stress tests") of nuclear power plants in the European Union and related activities
Date: 2012-10-04
Institutions: European Commission
Subjects: nuclear law, nuclear power station, nuclear safety













EUR-Lex - 52012SC0287R(01) - EN











|



52012SC0287R(01)

COMMISSION STAFF WORKING DOCUMENT Technical summary on the implementation of comprehensive risk and safety assessments of nuclear power plants in the European Union Accompanying the document COMMUNICATION FROM THE COMMISSION TO THE COUNCIL AND THE EUROPEAN PARLIAMENT on the comprehensive risk and safety assessments ("stress tests") of nuclear power plants in the European Union and related activities /* SWD/2012/0287 final/2 */









TABLE OF CONTENTS
1........... The EU nuclear stress
tests: Approach and Methodology.. 4
1.1........ The peer
review process. 4
2........... Key recommendations from
the safety assessments. 5
2.1........ Specific
recommendations on external hazards. 5
2.2........ Specific
recommendations on loss of safety functions. 6
2.3........ Specific
recommendations on severe accident management 6
2.4........ Aircraft
crashes. 6
3........... Key recommendations from
the security assessments. 7
4........... More detailed
transversal and generic
results of the safety assessments  7
4.1........ Initiating
events. 7
4.2........ Loss of safety
functions. 10
4.3........ Severe
Accident Management 12
5........... Summaries of Member
State Stress Test Peer Review results. 16
5.1........ BELGIUM... 16
5.2........ BULGARIA.. 18
5.3........ CZECH REPUBLIC.. 19
5.4........ FINLAND.. 21
5.5........ FRANCE.. 23
5.6........ GERMANY.. 25
5.7........ HUNGARY.. 26
5.8........ LITHUANIA.. 28
5.9........ THE
NETHERLANDS. 29
5.10...... ROMANIA.. 31
5.11...... SLOVAKIA.. 33
5.12...... SLOVENIA.. 34
5.13...... SPAIN.. 36
5.14...... SWEDEN.. 38
5.15...... UNITED KINGDOM... 39
6........... Summaries of
Neighbouring Countries' Peer Reviews. 42
6.1........ SWITZERLAND.. 42
6.2........ UKRAINE.. 44
GLOSSARY.. 47
Annex 1: Summary Table. 49
1.                      
The EU nuclear stress tests: Approach and Methodology
The stress tests were conducted according to a
common methodology[1]
along two parallel tracks:
·              
A Safety Track to assess how individual nuclear
power plants can withstand the consequences of various unexpected events,
ranging from natural disasters to human error or technical failure and other
accidental impacts. 
·              
A Security Track to analyse security threats and
a methodology for the prevention of, and response to, incidents due to
malevolent or terrorist acts. For the assessments under this second track, the
Council set up the Ad-hoc Group on Nuclear Security (AHGNS). 
Specifications on the safety track of the
stress tests defined three main areas to be assessed: extreme natural events
(earthquake, flooding, extreme weather conditions), response of the plants to
prolonged loss of electric power and/or loss of the ultimate heat sink (irrespective
of the initiating cause) and severe accident management. 
·              
The safety assessments were organised in three
phases:
·              
Self assessments by nuclear operators. Nuclear
licensees were asked to produce reports to national regulators by 31 October
2011;
·              
Review of the self assessments by national
regulators. National regulators reviewed the information supplied by licensees
and prepared national reports by 31 December 2011;
·              
Peer reviews of the national reports, conducted
in the period January – April 2012.
All national reports were submitted to the
Commission within the agreed deadline. 
1.1.                
The
peer review process
In order to provide
an objective assessment of the work done at national level and to maximise
coherence and comparability, the national reports were subjected to a peer
review process, organised in three phases:
–              
A desktop review phase where the 17 national
reports were analysed by all the peer reviewers[2], who posed more than
2 000 written questions on the reports. The EU Stress Test secretariat run
by the Joint Research Centre of the Commission opened a dedicated website to
gather questions from the public for the peer reviews.
–              
A peer review related to
horizontal topics, comparing the consistency of the national approaches and
findings in three key areas: extreme natural events, loss of safety functions
and severe accident management. The topical review meetings were organised at
the Commission premises in February 2012, and involved around 90 experts.
National teams were called in and asked to answer the questions posed in the
desktop review phase. The result is summarised in 3 topical reports and 17
country reports for each participating country, with a list of remaining open
questions for the ensuing country peer reviews. 
–              
A vertical, individual
review of each of the 17 country reports. The country peer reviews took place
in March 2012 and included one NPP site visit in each country. As a result, the
country reports were finalised, providing the basis – together with the topical
reports – for the overall peer review Board report to ENSREG, which endorsed it
on 26 April 2012[3].
The peer review teams were
composed of nuclear safety experts from EU Member States, Switzerland, Ukraine and from the Commission, with observers from third countries (Croatia, USA, Japan) and the IAEA[4].
–              
A considerable effort was
made, in terms of human resources, to analyse the safety of all NPPs and spent
fuel storage facilities of all 17 countries in a short time. In each of the 17
countries the review team has conducted a NPP visit. The total number of
reactor units on the sites visited during the originally scheduled visits in
March 2012 was 43 (approximately 30% of all the units in operation). The plant
visits confirmed the prior analyses and in some cases have led to additional recommendations.
Additional visits were
performed to eight reactor sites by the peer review teams in September 2012, in
order to gain additional insight on different reactor types, to discuss
implementation of the identified improvements and in order to alleviate
concerns relating to installations in areas bordering other Member States.
Thus, all operating reactor types in Europe have been visited by peer
reviewers.
All reports, including the
licensee reports have been made available on the ENSREG website.
2.                      
Key
recommendations from the safety assessments
The key considerations for each topic are
summarised in the following sections.
2.1.                
Specific
recommendations on external hazards
·              
The technical design and operation of plant must
be able to deal with unforeseen external hazards (e.g. earthquake, flooding,
extreme weather and accidents) and external events, unexpected events which
were not planned for in the original design (beyond design margins).  
·              
On-site seismic instrumentation should be in
operation at each NPP. 
·              
As a good practice, the use of a ‘hardened core’
of safety-related systems, structures and components capable of withstanding
earthquakes and flooding significantly beyond design basis should be
considered. 
2.2.                
Specific
recommendations on loss of safety functions
This depends on the
specific reactor design, but in terms of safety margins, Station Black-Out (SBO, i.e. total loss of AC power), which can lead to
core heat-up within 30-40 minutes, depending on the reactor design, is the key
risk. Therefore, the following should be readily available under even the most
extreme conditions:
·              
a variety of mobile devices (such as mobile
generators, mobile pumps, mobile battery chargers or mobile DC power sources,
fire-fighting equipment, emergency lighting, etc.). 
·              
the availability of alternative means of
cooling; 
·              
specialised equipment and fully trained staff to
deal effectively with events affecting all the units on one site. 
2.3.                
Specific
recommendations on severe accident management
·              
Recognised measures to protect containment
integrity should be urgently implemented.
·              
Comprehensive Severe Accident Management
Guidelines (SAMG's) should be developed. Periodic validation of SAMG's is
essential for ensuring their practicability, robustness and reliability.
·              
SAM arrangements need to be enhanced, including
the methods and tools for SAM training, and exercises should include the
suitability of equipment, instrumentation and communication means. 
·              
On-site emergency centres should be available
and designed against impacts from extreme natural.
·              
Radiation protection of all staff involved in
severe accident management and emergency response must be ensured. 
·              
Where emergency equipment is stored centrally,
it must be stored in locations that are safe even in the event of general
devastation, and where it can be quickly supplied to the relevant NPP site.
2.4.                
Aircraft
crashes
Aircraft crashes have
not been considered explicitly as an initiating event in the safety
assessments. However, the stress tests have to a considerable extent covered
the indirect effects of airplane crashes through the thorough work undertaken
on station blackout and loss of plant cooling. 
The national reports of Belgium, Germany, Slovenia and the Netherlands mention that the scope of the stress test has been
extended to aircraft crashes. Further information on these countries is
presented in the corresponding country sections.
3.                      
Key recommendations from the security assessments[5]
The final report of the
Ad Hoc Group on Nuclear Security[6] presents
conclusions on the five themes discussed, namely physical protection,
malevolent aircraft crashes, cyber-attacks, nuclear emergency planning, and
exercises and training. It also contains several recommendations to the Member
States in order to strengthen nuclear security in the EU. It highlights in
particular:
·              
the importance for the Member States which have
not yet done so to complete the ratification of the amended Convention on
Physical Protection of Nuclear Materials;
·              
the added value of IAEA's guidance and services,
including IPPAS[7]
missions on a regular basis in all Member States having nuclear power plants;
·              
the importance of a regular and close
cooperation between Member States and with neighbouring countries and
·              
the necessity to define modalities and fora for
the continuation of EU work on nuclear security.
4.                      
More detailed transversal and generic results of the
safety assessments
The following
transversal and generic issues can be highlighted. A comprehensive description
of the situation can be found in the final peer review report, national reports
and the peer review reports. 
4.1.                
Initiating
events
Stress test results
clearly indicate that particular attention needs to be paid to periodic safety
reviews as a powerful tool to regularly reassess plant safety. The stress tests
have confirmed that all the 17 participating countries perform periodic safety
reviews at least every 10 years, including a reassessment of the external
hazards (currently unless it can be demonstrated that there was no significant
hazard evolution since the last reassessment). External hazards (e.g.
earthquake, flooding and extreme weather) and robustness of the plants against
them should be reassessed as often as appropriate but at least every 10 years. 
Generally the approach
to demonstrate an appropriate design basis is sound. All plants need to be
reviewed with respect to external hazard safety cases corresponding to an
exceedance probability of 10-4 / year (with a minimum peak ground
acceleration of 0.1 g for the seismic hazard).  Setting up an international
benchmark exercise to evaluate the relative strengths and weaknesses of
probabilistic and deterministic hazard assessment methods for external events
is recommended.
Almost all countries
consider for Design Basis Earthquakes an earthquake with an exceedance probability
of 10-4 / year as a minimum. The Stress tests results point out
nevertheless specific cases:
–              
In France, no probabilistic seismic hazard
assessment (PSHA) is used except for 3 plants (Saint-Alban, Flamanville and
Civaux). The peer-review recommended to the regulator to introduce
Probabilistic Seismic Hazard Analysis in France for the design basis of new
reactors and for future revisions of the seismic design basis of existing
reactors in order to provide information on event probability (annual frequency
of occurrence) and to establish a more robust basis for DBE specifications.
–              
In Romania, analyses showed that the exceedance
probability associated to the DBE was 10-3 / year. The Design Basis
is considered to be consistent with the minimum levels in international
standards but not with current practices in Europe. Margins have however been
demonstrated beyond the Design Basis, using a review level earthquake (RLE)
with a PGA of 0,33 g and upgrading this by a screening level of 0.4 g
(corresponding to an exceedance probability of 5.10-5/year) for
safety relevant Structures, Systems and Components on the safe shut down path. 
Almost all countries
consider for Design Basis Flood a flood with an exceedance probability of 10-4
/ year as a minimum. The Stress tests results point out nevertheless specific
cases:
–              
In Belgium, the Tihange site is currently
protected by its design against a reference flood with a statistical return
period up to 400 years. However, the reference flood with a statistical return
period up to 10,000 years will be implemented as a new DBF and associated
protection measures are foreseen.
–              
In France, the design basis flood is defined
considering statistical extrapolations limited to 10-3 / year
supplemented by a margin or a conventional combination. France stated that the current state of the art in flood level calculations does not allow
calculating, with a sufficient confidence, 10-4 / year levels,
except in some specific conditions such as "small catchments areas - up to
some 1000 km2". The Peer-review therefore recommended
performing a comparative evaluation with the methodologies used in other
European countries.
–              
In the Netherlands, the Borssele site is
protected against flooding by the network of dykes in Zeeland. This network
will be improved to comply with the legal requirements of 4000 year return
period. The reinforcements will include margins in order to guarantee the legal
safety standard also in the future. Therefore, the protection provided by the
levee after the reinforcement should be higher (against events with a return
period of 10,000 years).  However, the Peer-Review recommended examining
thoroughly the consistency of this approach with the new IAEA guidance
(SSG-18).
Almost all countries
consider 0.1 g as the minimal level of PGA to be considered for the Design
Basis Earthquake, except Germany, Lithuania and the Netherlands. It should be
mentioned however that the nuclear reactors have been shut down in Lithuania and that the existing and new spent fuel store facilities are designed to be
capable of withstanding this recommended level of seismic event. Moreover, as
for the Netherlands, the new seismic analysis to be conducted within the PSR of
Borssele in 2012 will consider a PGA value of 0.1g at free field for the DBE,
as per IAEA guidance.
The evaluation of beyond
design basis margins for earthquakes and flooding is not consistent in
participating countries. A few countries have quantified the inherent
robustness of the plants' beyond the design basis up to cliff edge effects, whereas
the majority have made only a general claim that sufficient safety margins
exist and therefore there is no verifiable information on the basis of which to
consider effective potential improvements. 
A number of possible
means to increase the robustness of NPPs against external hazards has been
identified during the stress tests. Among these, the following can be
mentioned:
–              
the protected volume approach (flood protection
of building containing safety significant systems and components), used at
least to some extent in CH, FR and NL.
–              
the use of a bunkered or ‘hardened core’ of
safety-related systems, structures and components capable of withstanding
earthquakes and flooding significantly beyond design basis can be mentioned.
This is currently used namely in BE, CH, Finland (only for Loviisa) and DE,
planned to some extent in SI and requested to be implemented in FR. 
Additional guidance on
natural hazards assessments, including earthquake, flooding and extreme weather
conditions should be developed, as well as corresponding guidance on the
assessment of margins beyond the design basis and cliff-edge effects. 
Regulators and operators
should consider developing standards to address qualified plant walk-downs with
regards to earthquake, flooding and extreme weather to provide a more
systematic search for non-conformities and correct them (e.g. appropriate
storage of equipment, particularly for temporary and mobile plant and tools
used to mitigate BDB external events).
The design for storage
of mobile equipment to perform necessary safety functions should take account
of external events at the design and beyond design levels, to ensure
appropriate availability in the event of being required following a significant
external event.
The Peer-Review observed
namely that mobile diesel generators should be adequately protected for beyond
design basis earthquake in Kozloduy (BG). Similar observations were made in the
 Czech Republic and in Slovakia where the fire brigade buildings should be
reinforced to withstand BDBE. Moreover, it was noted in the Netherlands that
storage facilities for portable equipment, tools and materials needed by the
alarm response organization that are accessible after all foreseeable hazards
would enlarge the possibilities of the alarm response organization.
Seismic monitoring
systems should be installed and associated procedures and training developed
for those NPPs that currently do not have such systems. On-site seismic
instrumentation should be in operation at each NPP. Currently, there is no on-site
seismic instrumentation yet in Dukovany NPP (CZ), Brokdorf, Brunsbüttel
(permanent shutdown) and Krümmel (permanent shutdown) NPPs (D), Borssele NPP
(NL) and in all Ukrainian NPPs. The installation of on-site seismic monitoring
is planned in each of these sites. A study to investigate the overall
cost-benefit and usefulness of automatic reactor shutdown induced by seismic
instrumentation is recommended.
Advance warning of
deteriorating weather is often available in sufficient time to provide the
operators with useful advice and national regulators should ensure that
appropriate communications and procedures are developed by all operators. In
Sweden in particular, the Peer Review recommended that early warning systems,
as well as relevant operating procedures in case of extreme weather conditions,
should be implemented at all sites.
4.2.                
Loss
of safety functions
All the countries
estimated the cliff-edge effects related to various combinations of losses of
electrical power and/or cooling water, and the time available before safety
functions need to be restored. In terms of safety margins, Station Black-Out
(SBO, i.e. total loss of AC power) is the limiting case for most reactors. For
most reactor designs, SBO would typically lead to core heat-up after around
1-10 hours if no countermeasures were implemented. For ASEA/ABB Boiling Water
Reactor (BWR) designs without steam driven systems or emergency/isolation
condenser, SBO leads to core heat-up within 30-40 minutes (using conservative
assumptions). These reactors are Olkiluoto 1 & 2 (FI) and Forsmark 1 &
2 (SE), which have their core cooling systems electrical driven. According to
the Swedish regulator, this weakness was, however, identified in the original
design and redundant emergency power supply trains were consequently introduced
via four emergency diesel generators or a combination of two emergency diesel
generators and gas turbines. Numerous improvements related to hardware and
procedures have been identified; some have been implemented and others are
still at the planning stage. It is recommended to ensure in all plants that the
time available is sufficient to allow safety function restoration, with
adequate margin and not relying on organisational measures only. 
The loss of Ultimate
Heat Sink (UHS) and alternate heat sink was not identified as a cliff edge
effect at any plant design in EU, CH and UA. NPPs typically have several
redundant and diverse cooling options to ensure a minimum heat sink for 72
hours, provided that electrical power supply is available. The volume of
cooling water available on site that ensures heat removal from essential
consumers is not less than 6-8 days.
To increase the
robustness of the ultimate heat sink function, it is strongly recommended to
identify and implement also alternative means of cooling. The term “alternate
UHS” was interpreted differently in several countries. Most countries
considered a diverse source of cooling medium (water from ponds, wells, water
table, etc.) as an alternate UHS, but some countries also considered secondary
or primary feed-and-bleed into (ultimately) the atmosphere. To cope with losses
of the main ultimate heat sink, all plants have a variety of design features
that can be used to some extent; this includes multiple (and large) reserves of
water on site e.g. dedicated tanks (seismic proof), large capacity pools (e.g.
with spray-based heat removal from essential service water system), dedicated
wells (with own, independently powered pumps) as well as arrangements to obtain
water from rivers, nearby lakes or the sea (using tank trucks or fire hoses).
For multi-unit sites,
robustness could be enhanced if additional equipment and trained staff are
available to effectively deal with events affecting all the units on one site.
At most multi-unit sites, an accident simultaneously occurring at several units
was not considered in the original design. For multi-unit sites, robustness
could be enhanced if additional (to the existing) equipment and trained staff
are available to effectively deal with events affecting all the units on one
site. This recommendation is currently analysed and measures will be
implemented at all NPP sites in EU, CH and UA.
All plants confirmed
that they already possess or are in advanced process of acquiring a variety of
mobile devices including skid/trailer based diesel generators and diesel-driven
pumps, dedicated fire trucks, etc. including the connection points and
procedures on how to engage mobile units. Nevertheless, a systematic selection
of and acquisition of the equipment that would provide a variety of power and
pressure levels and that is safely stored on-site and/or offsite still needs to
be done. The transport, simple and fast connection of the mobile equipment
including its proper functioning (considering fuel supply, independence but
also organization and procedures) shall be assured by appropriate, plant and
site centric design and regular testing after installation. Mobile battery
chargers or mobile DC power sources are already installed at Cernavoda NPP (RO)
and Kozloduy NPP (BG) and ensure DC power for SBO consumers by recharging
station batteries via small diesel generators, or even back-up station
batteries have been installed at Paks NPP (HU) which allow extended use of
instrumentation and controls. Fire-fighting equipment, including fire trucks,
diesel pumps, generators, emergency lighting, etc. is normally readily
available at the plants.
Operational or
preparatory actions such as ensuring the supply of fuel and lubrication oil,
battery load-shedding to extend battery life are examples of measures that are
small (in many cases procedural) but that could make a considerable difference
in response to initiators. All in all, most of the plants have already
considered these measures and might be adding to them in the future.
Within the stress tests
evaluation the bunkered system, qualified to anticipated external events, are
equipped with independent diesel driven pumps and water storage to ensure heat
sink, and electrical power supply to vital consumers via stand-by small
emergency diesel generators, batteries, and diesel-driven pumps for at least 24
hours. Bunkered systems are already installed as a standard design feature at
German pre-Konvoi and Konvoi NPP design (i.e. in all plants operating these
reactor design in DE, NL, and ES), as well as in all NPPs in CH and with some
degree also at NPPs in BE. Bunkered system proved its worth in ensuring an
additional level of protection after the external events, able to cope with a
variety of initiators, including those beyond the design basis. It provides
back up to ordinary stand by systems (e.g. emergency diesel generators) to
ensure fulfilment of safety functions even if all stand by safety related
equipment is lost. The concept is taken even further in the form of the
"hardened core" where in addition to equipment, trained staff and
procedures designed to cope with a wide variety of extreme events will be
available.
4.3.                
Severe
Accident Management
PSR should continue to
be maintained as a powerful regulatory instrument for the continuous
enhancement of defence-in-depth in general, and the provisions of SAM in
particular. The lessons learned from the Fukushima accident and from the stress
tests should be reflected in the scope of future PSRs.
In response to their
previous commitments, regulators should incorporate the WENRA reference levels
related to SAM into their national legal frameworks, and ensure their
implementation as soon as possible. Regarding Emergency Operating Procedures
(EOPs) and Severe Accident Management Guidelines (SAMGs), utilities from only a
few countries have developed these procedures/guidelines for all power
conditions (Belgium, Slovenia, Sweden, the Netherlands, France for the 900 MWe reactor series, and Switzerland). In Hungary, EOPs and SAMGs are developed
for all plant states but the associated hardware modifications are still needed
in units 2 to 4 to complete implementation. In most of the other countries,
utilities have developed EOPs for power and shutdown states but SAMGs cover
only power state (e.g. in Bulgaria and Czech Republic). In a few countries like
 Germany or Spain the development of a more comprehensive and systematic set of
SAMGs is still on-going for some Plants. Ukraine has only EOPs for power states
available at the moment but is engaged in a program to complete EOPs for
shutdown states and to develop SAMGs for all power states. In the UK, it appears that EOPs and SAMGs need further development to be in line with
international Standards. 
Effective implementation
of SAM requires that adequate hardware provisions are in place to perform the
selected strategies. 
On top of RCS
depressurisation systems, Passive Autocatalytic Recombiners (PARs) and
containment Filtered Venting System discussed separately, several other
hardware provisions are already installed or will be installed in the different
NPPs concerned by this review. The main ones are listed below:
–              
Additional Diesel Generators (or Combustion
Turbines) physically separated from the normal DGs and devoted to cope with
SBO, external events or severe accident situations are already installed on the
different NPPs in Germany, the Netherlands, Belgium, Finland, Hungary, Romania, Spain, UK, France, Sweden and Switzerland. 
–              
Mobile equipment especially Diesels Generators
are already available on the different NPPs in many countries, such as Belgium, Lithuania, The Netherlands, Romania, Bulgaria, Slovenia, Hungary, and Sweden or are under
implementation in many others such as Slovakia, and Czech Republic. 
–              
In some countries, centralised storage of
emergency equipment has been set-up, shared among several NPP sites. This is
for example the case in the UK, DE and CH. And this will be implemented in Spain and in France (as part of the Rapid Action Force which will be put in place). The regulatory
Body from Czech Republic has also proposed to establish common (regional)
emergency response arrangements for neighbour countries operating similar
reactors.
–              
In most of the countries the instrumentation and
communication means have been qualified for Design Basis Accidents but further
investigations are needed to ensure the availability of these equipment during
a Severe Accident especially concerning power supply and survivability under
external events and harsh conditions.
The means for
maintaining containment integrity should in particular include depressurization
of the reactor coolant system, prevention of damaging hydrogen explosions, and
means of addressing long-term containment over-pressurization, and minimze
long-term off-site contamination, such as by means of filtered venting.
All plants foresee the
depressurization of the primary circuit with existing design features. For
example, Czech Republic, France, Finland and Sweden have implemented additional
measures for depressurization of the primary system, such as installation of
additional hardware (lines and specific valves). Slovakia is currently
implementing, and Slovenia has scheduled implementing similar measures. France has planned the reinforcement of the operability of existing equipment by fixed or
mobile supplies. 
Most of the plants have
measures to prevent hydrogen explosions in place. Older operating BWR plants in
 Switzerland (Mühleberg), Germany, Spain (Santa María de Garoña), Finland (Olkiluoto 1 and 2), and Sweden (Oskarshamn 1, 2 and 3, Forsmark 1, 2 and 3, and Ringhals
1), and Cernavoda 1 CANDU (Romania) have their containments inerted with
nitrogen. Newer, larger BWR plants like Leibstadt (Switzerland) and Cofrentes (Spain), and Cernavoda 2 CANDU (Romania) have ignitors. Of these, only the Gundremmingen B and C have
additionally Passive Autocatalytic Recombiners (PAR), although Santa María de
Garoña, Cofrentes and Cernavoda (both units) have plans to install them, and
Leibstadt is evaluating long term hydrogen management. Most of the non-inerted
light water reactor containments have reinforced the measures to prevent
hydrogen explosions during accidents by the installation of Passive Catalytic
Recombiners (PAR). The PARs installed in Bulgaria, Czech Republic, United
Kingdom (Sizewell B) and Ukraine (Rivne and Khmelnitsky) were designed for DBA,
and have not been proven to mitigate hydrogen explosion risks in severe
accidents. Slovenia has active hydrogen recombiners which will be replaced in
2013 by PARs designed for BDBA. Studies or plans to install additional PAR as
needed to cope with hydrogen risks in severe accidents are under way in these
countries. The countries that have not installed PAR in all their PWR plants: Spain, (PARs only in Trillo), and Ukraine, have also plans to install them. The rest of the PWR
plants have PAR capable of coping with the risk of hydrogen generation during
severe accidents. Although it has been recognized that the risk of hydrogen
explosions in the UK gas cooled reactors is not a sensitive issue, further
studies regarding generation of combustible gases are under way.  
Hungary, Slovakia and Ukraine do not have any plan or schedule with regard to implementing filtered venting
of the containment. Czech Republic, Spain and United Kingdom are in different
stages of the process of considering the implementation of containment filtered
venting, Belgium has included it in the long term operation project for its
older plants (Doel 1 and 2, and Tihange 1), and studying its installation in
the newer plants, while Romania has a schedule to implement it. The remaining
countries have already filtered venting infrastructure installed to avoid
pressure build-up in the containment and minimize long-term off-site
contamination.
A systematic review of
SAM provisions should be performed, focusing on the availability and
appropriate operation of plant equipment in the relevant circumstances, taking
account of accident initiating events, in particular extreme external hazards
and the potential harsh working environment. 
In the frame of this
Stress Tests exercise, a systematic review of SAM provisions (organization,
staffing, hardware, SAMGs, etc.) has been performed by the different
participants, focusing on the availability and appropriate operation of plant
equipment in the relevant circumstances, taking account of accident initiating
events, in particular extreme external hazards, potential harsh working
environment, need to work with a severely damaged infrastructure (i.e. in which
the usual means of communication and access, etc. are disabled), at plant
level, corporate-level and national-level aspects, and of long-duration
accidents affecting multiple units at the same time (on individual and nearby
sites as appropriate). These studies are still on-going in most of the
countries to finalize the most adequate SAM provisions to be put in place.
The assessment of SAM
provisions should take account of the need to work with a severely damaged
infrastructure (i.e. in which the usual means of communication and access, etc.
are disabled), of plant level, corporate-level and national-level aspects, and
of long-duration accidents affecting multiple units at the same time (on
individual and nearby sites as appropriate).
The SAMGs should be
comprehensively validated taking due account of the potential long duration of
the accident, the degraded plant and the surrounding conditions. All countries
that have developed SAMG have validated them in terms of feasibility of the
potential strategies, but it is not clear in all cases that the validation has
considered explicitly the potential long duration of the accident and the
existence of degraded conditions. In such cases, the countries have declared
their intention of extending the validation of the SAMG with the inclusion of
the potential long duration of the accident, and the presence of degraded
conditions (for example due to extreme external hazards). Pre-planned SAM
actions should be designed to function effectively and robustly for suitably
lengthy periods following the initiating event. In most cases, durations of at
least several days should be assumed for planning and assessment purposes.
Training and exercises
aimed at checking the adequacy of SAM procedures and organisational measures
should include testing of extended aspects such as the need for corporate and
national level coordinated arrangements and long-duration events. All countries
that have implemented the SAMG carry out periodic training and exercises to
check the adequacy of SAM procedures and the adequate co-ordination among the
involved organizations. The level of detail and scope of this training is
diverse among the participating countries, and all plan to enhance it to take
into consideration the improvements of the SAM strategies and of the Emergency
Organisations. It is worth mentioning as good practice the very complex
exercise organized by NL, which includes all involved emergency organizations,
with more than 1000 participants, and the real time SAM drills with simulator
carried out by Slovenia, which can take several days.
When developing SAM
action plans, conceptual solutions for post-accident fixing of contamination
and the treatment of potentially large volumes of contaminated water should be
addressed.
Radiation protection of
operators and all other staff involved in the SAM and emergency arrangements
should be assessed and then ensured by adequate monitoring, guaranteed
habitability of the facilities (hardened on-site emergency response facility
with radiation protection) needed for accident control, and suitable
availability of protective equipment and training.
On-site emergency
centres should be available and designed against impacts from extreme natural
and radiological hazards.
Main Control Rooms (MCR)
of the plants have been designed against Design Basis Accidents. In case the
Main Control Room becomes inhabitable as a consequence of the radiological
releases of a severe accident, of fire in the MCR or due to extreme external
hazards, all plants have a backup Emergency Control Room (ECR) except OL1&2
in Finland (where planning is underway to develop such a facility) and the AGRs
and Magnox reactors in UK (except Heysham 2 and Torness). The countries have
evaluated or are evaluating whether the MCR and ECR can withstand the
consequences of a severe accident (especially in case of accident affecting
several units at the same time) and extreme natural hazards. Most of the
countries have already proposed additional measures to improve MCR and ECR
habitability in case of severe accidents.
Additionally, some plants
have on-site emergency control centres from which the emergency response
activities can be co-ordinated in case of Severe Accident. As an example, the
emergency control centres of all the plants in Finland, Germany, Hungary, Sweden, Lithuania, Bulgaria and Ukraine are well prepared against radiological and
extreme natural hazards. The rest of the countries have found out that their
on-site emergency centres of facilities from which the emergency activities are
coordinated need to be improved to withstand extreme external hazards or
radiological conditions. All of these countries plan to reinforce their
existing on-site emergency centres, or to build new ones. As an example, the
Krško NPP's emergency control center is well designed against external hazards
and equipped for long-term habitability, but lacks the adequate radiological
protection in case of BDBA. A new emergency control center that will be
protected against BDBA and all external hazards will be built by the end of
2015. 
Although PSA is an essential
tool for screening and prioritizing improvements and for assessing the
completeness of SAM implementation, low numerical risk estimates should not be
used as the basis for excluding scenarios from consideration of SAM especially
if the consequences are very high.
5.                      
Summaries of Member State Stress Test Peer Review results
Note: a more comprehensive description of the
situation can be found in the national reports and the peer review reports.
5.1.                
BELGIUM 
Note: Stress tests in Belgium
cover also nuclear facilities other than operating NPPs (fuel fabrication
plant, waste treatment and storage facilities, radioisotope production
facility, research centres), and include man-made events (terrorist attacks,
aircraft crash, cyber-attack, toxic and explosive gases, blast waves) and
security related aspects. The assessment of these man-made events was
however developed in a separate national report which was not part of the peer
review exercise.
Recommendations: 
-       
It
is recommended that the regulator monitors the completion of the updated
probabilistic seismic hazard analysis (PSHA), the implementation of the
consequential measures and the updated assessment of safety margins. These
updates may benefit from a harmonization of the seismic hazard assessment on an
international level with neighbouring countries, in order to avoid
discrepancies for sites with comparable seismic activity.
-       
Taking
into account the relatively low safety margins with regards to flooding over a
period of 10 000 years and the reconsideration of design basis flood (DBF)
values at the Tihange site, it is recommended to focus on the implementation of
all safety improvements proposed by the licensee, as well as those prescribed
by the regulator. For the Doel site, it is recommended to the regulator to
monitor the implementation of the measures proposed in the licensee’s action
plan. 
-       
The
design parameters for extreme weather conditions are mainly based on historical
data, and therefore, on a return period in the order of 100 years. The
derivation of design basis parameters with 10,000 years return periods is
recommended to be considered.  Attention should be also paid to extreme
temperatures.
-       
In
case of design basis earthquake (DBE), the autonomy of the emergency diesel generators (EDGs) of
the 2nd level safety systems at the Tihange 1 is only 7.5 hours (the capacity
of their seismically qualified fuel tanks is the limiting factor). It is
recommended to take into consideration the benefits of increasing the autonomy
of these EDGs at Tihange 1 for events determined by DBE.
-       
The
preliminary study for the filtered venting system on each unit to be finished
in 2012 should consider sub-atmospheric pressures in the containment.
-       
Regardless
of the outcome of the assessment of the residual risk of hydrogen generation
and accumulation in the spent
fuel pool
(SFP) buildings, the installation of Passive Autocatalytic Recombiners (PARs)
in the SFP should be considered.
-       
The
additional measures to increase the consistency of the emergency training and
refresher training programs at the Tihange and Doel NPPs should be broadened to
the total concept of severe accident management (SAM) (hardware provisions,
procedures and guidelines) as much as possible.
Good practices:
-       
Multiple
external power supply links (two independent power supplies).
-       
Underground
cable 6.6 kV lines (after transformers) linking 150 kV on-site sub-stations
with the units at both sites.
-       
Two-level
redundant safety systems, including in particular: 1st and (bunkered) 2nd level
emergency diesel generators and power supply systems, seismically qualified for
all units at both sites (with the exception of the 1st level diesel generators
(DGs) in Doel 1/2, which will be completed by mid-2012).
-       
Auxiliary
feedwater turbo-pumps (in each unit).
-       
Emergency
steam-driven turbo-alternator (Tihange 1).
-       
Primary
and alternate ultimate
heat sink
(UHS) available at both sites.
-       
Diverse
other water sources (including unconventional) and inter-connection
possibilities available at the plant sites.
-       
Many
non-conventional means (NCMs - mobile/portable equipment) are available,
including mobile diesel-driven pumps and mobile diesel generators, and their
connections are already implemented (for electrical power and water supply).
-       
Long
autonomy of AC power sources and batteries.
-       
The
integration of the non-conventional means into the accident management
procedures and SAMG and benchmarking it with US NRC Extensive Damage Mitigation
Guidelines.
Safety improvements
implemented or planned (non-exhaustive list):
-       
Performing
more detailed seismic hazard studies.
-       
Enhancing
external power supply reliability in the Tihange NPP through a better
separation of  the high-voltage  (380 and 150 kV) lines.
-       
Increasing
the capacity of auxiliary feedwater tank and adding a motor-driven pump in
Tihange 1.
-       
Solving
the problem of refilling the primary circuit during mid-loop operation and with
primary system open in case of the total SBO in Tihange 3.
-       
Modifying
the spray system in order to achieve an alternative spraying flow with a mobile
spraying pump at Doel 3 & 4 units.
-       
Performing
seismic qualification of the refuelling water storage tanks at Doel 1/2.
-       
Enhancing
protection against external hazards (earthquake, flooding, weather conditions)
of the following areas: 
·              
At the Doel NPP, the construction of a new seismically
qualified building which is also protected against flooding, is planned; this
building will be used as a location for storage of NCM (including fire trucks)
that are expected to ensure the safety function in case of extreme external
hazards.
·              
Performing seismic upgrade of the AFW-turbo
pumps and their tanks at Doel 1/2.
·              
Assessment of strengthening the electrical
building of Tihange 1 unit
·              
Improving volumetric protection of the Tihange
site, and the reinforcement of the river embankment of the Doel site.
·              
Enhancement anti-flood protection measures at
Tihange, in particular its emergency power supply
systems, assuming the 10 000 year recurrence
frequency type of flooding (to prevent the loss of safety functions).
-       
Improving
the following power supplies:
·              
Alternative power supply (380V) for
non-conventional means or safety equipment 
·              
Alternative power supply (380V) for rectifiers;
this measure ensures the possibility to recharge the batteries before their
total depletion during an SBO event
·              
Introduction of a procedure for minimizing the
diesel generators fuel consumption 
·              
Purchase of a fuel tanker truck for the on-site
transportation of diesel fuel (Doel)
-       
Constructing
a new demineralized water production circuit at the Tihange site.
-       
Ensure
procedures take into account events such as loss of the primary UHS affecting
more than one unit, total SBO, and load shedding to increase the batteries
autonomy. Enhancing the organization and logistics of the internal emergency
plan to include “multi-unit” events.
-       
Implementing
continuous measurement of water level in SFPs in the Tihange NPP units where
this is not in place yet. 
-       
Improving
SAMG with decision support tools, long term monitoring and exit guidelines.
-       
Adapting
strategies for flooding reactor pit before reactor vessel rupture.
-       
Installing
additional instrumentation (e.g. pH sump, bottom reactor vessel) and
identifying effective means to control pH inside containment.
-       
Applying
specific provisions (maintenance, inspections, testing) to non-conventional
means credited in analyses.
5.2.                
BULGARIA
Recommendations: 
-       
Adequacy
of paleoseismological studies should be further analysed throughout the
periodic updates of the seismic PSA and in the PSR, on the basis of the
information available and verified, to evaluate the need of re-assessment of
the seismic hazard on site. 
-       
Implementation
of the complementary improvement measures for beyond design basis conditions
identified in the Action Plan (such as improvement of the leak tightness of
certain rooms below ground level) should be monitored.  
-       
A
combination of extreme weather conditions still needs to be considered. 
-       
Although
the batteries have 10 hours discharge time, a possibility of their recharging
from a mobile DG should be considered. 
-       
Concerning
SAM, there is still an open issue under which conditions is the implementation
of different SAM measures feasible, e.g. due to possible lacking some hardware
provisions for mitigation of severe accidents. It is recommended that
additional improvements for SAM covered by the “Program for Implementation of
Recommendations Following the Stress Tests Carried out on Nuclear Facilities at
Kozloduy NPP plc.” is pursued.
Good practices: 
-       
During
the country visit it was noticed that periodic and frequent walk downs on SAMGs
provisions are performed, this is considered as a good practice.
Safety improvements
implemented or planned (non-exhaustive list): 
Some examples of measures for improvement of
plant robustness related to the two operating units 5 & 6 at Kozloduy NPP
are, as follows:
-       
Studying
the possibilities for alterative options for Units 5 and 6 decay heat removal
using the existing SG emergency makeup system (EMS) of Units 3 and 4.
-       
Securing
the availability of at least one tank of the SG Emergency Feedwater System in
shutdown mode in order to provide for the use of the SG as an alternative for
the residual heat removal.
-       
Two
new mobile DGs will be delivered, and the existing one will be maintained in
standby conditions for the remaining structures at the NPP area; Power supply
from a mobile DG is provided for charging the accumulator batteries of the
safety systems.
-       
Implementation
of the symptom based EOPs for the shutdown states with open reactor, and
implementation of SAMGs.
-       
Development
of technical means for direct water supply to the steam generators, SFPs and
the containment using mobile fire equipment.
-       
Installation
of additional hydrogen recombiners in the containment.
-       
Installation
of instrumentation for monitoring of steam and oxygen concentrations in the
containment, and for monitoring the temperature in the reactor vessel
-       
Updating
on-site and off-site emergency plans, taking into account (a) difficulties in
accessing the emergency control rooms of Units 5+6; possible drying out of the
SFS basin compartments, with subsequent increase of dose rates; and (c)
providing alternative routes for evacuation, transport of fuels and materials
and access of staff.
-       
Construction
of a new Emergency Management Centre, outside the Kozloduy site.
5.3.                
CZECH REPUBLIC
Recommendations: 
-       
The
reviewers recommend the regulator to consider the implementation of diverse
ultimate heat sink at Dukovany NPP due to inadequate capability of the cooling
towers in regard to hard wind and seismic hazard.
-       
The
reviewers recommend the regulator to consider the qualification of equipment
and systems needed to manage SA, especially system ensuring power supply like
hydro power plant connection, diesel generators.
-       
The
reviewers recommend the regulator to consider modifications on emergency
procedures, staffing of emergency response organization and analysis's
regarding the usability of the shelter under flooding conditions.
-       
The
reviewers recommend the regulator to consider increasing the protection of
diesel fuel pumps against flooding effect at Temelin NPP.
-       
The
battery autonomy is currently an issue that needs to be addressed at all
operating NPP designs. The reviewers recommend the regulator to consider the
benefits of recharging the batteries before their complete depletion in case of
total SBO in addition to ensuring the depletion time / battery capacity
increase.
-       
The
reviewers recommend the regulator to consider studies of using a filtered
venting system to protect the containment against loss of integrity and to
reduce significantly the releases of radioactivity to the environment in case
of severe accidents, as the current system is not designed for severe accident
conditions. 
-       
The
reviewers recommend the regulator to consider studies on hydrogen management
considering reactor and SFP building and the installation of additional re-combiners
sufficient for severe accident conditions at Temelin and Dukovany NPPs.
-       
Mid-loop
operation at Temelin NPP is a critical issue in case of SBO. The licensee
announced that it eliminates the mid-loop mode of operation from the regular
outage schedule. The reviewers recommend the regulator to follow up the
announcement.
-       
The
reviewers recommend the regulator to consider increasing of the plant
robustness by implementation of alternative means for AC power supply for core
cooling and heat removal.
Good practices: 
-       
The
proposal by the regulator to establish common emergency response arrangements
for several neighbouring countries.
Safety improvements
implemented or planned (non-exhaustive list): 
-       
Finalization
of safety upgrading to the currently approved design Basis Earthquake by the
end of 2015 for Dukovany NPP.
-       
Upgrading
of fire brigade building for seismic resistance. 
-       
Discussions
of further hardware implementation to cover severe accident (primary circuit
depressurization, hydrogen management for severe accident, containment
isolation).
-       
Installation
of connection points for water supply from fire brigade pumps.
-       
Improvement
and finalization of EOPs and SAMGs including shutdown states, open reactor, SFP
and multi-unit accidents. Further analysis of the impact of damage of the
infrastructure.
-       
In
particular, the following measures indicated in the national report have to be
implemented:
·              
alternative containment sump water make up
(Temelin)
·              
selection and implementation of appropriate
solution for protecting containment from the overpressure loads
·              
providing mobile (portable) equipment for
ensuring feasibility of the SAM actions
·              
increase robustness of storage building
structures for mobile devices including fire trucks, or relocation of equipment
·              
implementation of ex-vessel cooling at Dukovany
NPP
·              
analysis of molten core cooling in Temelin NPP
·              
installation of additional re-combiners
sufficient for severe accident conditions at Temelin and Dukovany NPPs.
5.4.                
FINLAND
Recommendations: 
-       
Seismic
justification of structures, systems and components (SSC) is based on the
seismic PSA. The peer review recommends that STUK should consider additional
assessment of critical SSC with respect of PGA = 0.1g (as recommended in the
IAEA Safety Guide NS-G-3.3).
-       
The
peer review recommends that the assessment of the drainage system capacity in
case of high seawater level should be considered.     
-       
It
was noted that Olkiluoto 1 & 2 are vulnerable to SBO (short coping time),
particularly if it occurs at the time of reactor scram. It was also noted that
a heat sink completely independent of seawater does not currently exist at
Olkiluoto 1 & 2. The peer review recommends that corresponding planned
corrective measures should be implemented.
-       
General
suggestion is to perform special tests of several equipment, among them DC
batteries up to depletion, endurance tests of diesel generators, under extreme
conditions, training of some activities as for instance hoses installation etc.
-       
The
reassessment of the emergency preparedness should address events that occur at
all the units on site at same time. The peer review recommends that the scope
of EOPs/SAMG should also include all shut down states and that the availability
of dedicated systems and components to be used during severe accidents scenarios
should be verified.
Good practices: 
The detailed and strict legal basis regarding
the emergency preparedness and severe accidents management is a strong point.
Already implemented provisions enhancing robustness can be considered as
advantages when assessing the safety of Finish NPPs against hazards that
contributed the Fukushima accident. Several good practices were identified as
follows:
-       
At
Loviisa 1&2, independent air cooled SAM diesel generators (not depending on
EDGs), dedicated SAM valves for Reactor Coolant System (RCS) depressurization
measure providing external cooling of the vessel in case of a core meltdown
accident, hydrogen management, containment external spray (dedicated SAM
system), and operational by mobile equipment in case of loss of its own pumping
capability.
-       
At
Olkiluoto 1&2, means for flooding the lower drywell, depressurisation of
the RCS and diversification for keeping the valves open, modifications to
protect the drywell penetrations against pressure and thermal loads), filtered
venting system of the containment (a dedicated SAM system), and possibility to
fill the containment with fresh water.
Safety improvements
implemented or planned (non-exhaustive list): 
There is a long list of safety improvements that
were either implemented or are planned. Here are some examples:
-       
Continues
decreasing the seismic risk, which includes replacement of plant equipment with
new, seismically qualified equipment, (i.e. relays especially for eliminating
relay chatter, steel racks for batteries), and the study of seismic fragilities
of pool structures in reactor containment and pools in spent fuel storages.
-       
At
Loviisa, the licensee is studying modernization the bulkhead used to close the
cooling water discharge openings, etc. A water tightness and water pressure
tolerance of doors leading to the basement of the reactor building and
consequences of the eventual leakages will be investigated and improved if
needed. 
-       
At
Loviisa, evaluation of mobile devices to ensure boron injection into the RCS,
coolant inventory in the secondary circuit, water supply for the diesel driven
auxiliary emergency feed water pumps, electricity supply for instrumentation
needed in accidents, electricity supply for the RCS depressurisation valves,
containment heat removal during severe accidents, decay heat removal from the
spent fuel storage pools, control room lighting, and plant communication
systems.
-       
To
increase robustness of the UHS, two cooling towers per unit are under
consideration, one removing decay heat from the reactor and one the decay heat
removal from the in-containment spent fuel pool and the spent fuel storage
pools;
-       
At
Olkiluoto 1 & 2 possible renewal of all eight emergency diesel generators;
the new EDGs would have two diverse component cooling systems, allowing for air
cooling, improved water tightness of the rooms, and improved local control
room. Installation of a so called 9th EDG that could supply electric power to
either Olkiluoto 1 or 2. This EDG would be located in a new, separate diesel
building, qualified for flooding.
-       
Installation
of diverse and independent way of pumping water to the reactor pressure vessel
via fire fighting diesel driven pumps (Olkiluoto 1&2).
-       
STUK
requested the licensee to provide a plan and schedule to secure decay heat
removal from reactor core and containment in case of total loss of AC power
(Olkiluoto 1&2);
-       
At
Loviisa NPP, licensee has performed the following measures to enhance the
accident management capabilities:
·              
number of staff in the technical support
emergency organization was recently increased for better preparedness and
support against accident situations;
·              
improvements to guidance for accident management
(SAM Guidelines and SAM handbook) to ensure prevention of fuel uncovery are
under development for spent fuel pools and storages;
·              
reduction of bypass sequences frequencies will
continue in the future.
5.5.                
FRANCE
Recommendations: 
-       
The
DBE has been developed according to the French regulation, based on a
deterministic approach for seismic hazard assessment. IAEA recommends conducting
both deterministic and probabilistic approaches, as complementary strategies.
It is recommended that ASN consider introducing PSHA in France for the design basis of new reactors and for future revisions of the seismic design basis of
existing reactors, in order to provide information on event probability (annual
frequency of occurrence) and to establish a more robust basis for DBE
specifications.
-       
The
seismic margins for seismic events above the DBE have been roughly estimated by
the licensee. The reviewers recommend the regulator that a more systematic
evaluation will be used either by performing PSA or SMA as well as introducing
PSHA in France.
-       
The
reviewers recommend the regulator to improve the seismic instrumentation at the
plants.
-       
ASN
explained that the design basis flood is defined considering statistical
extrapolations limited to 10-3/y supplemented by a margin or a
conventional combination. ASN and IRSN stated that the current state of the art
in flood level calculations doesn't allow calculating, with a sufficient
confidence, 10-4/y levels, except in some specific conditions such
as "small catchments areas - up to some 1000 km2". It is
recommended to perform a comparative evaluation with the methodologies used in
other European countries.
-       
The
regulator asked the licensee to conduct the analyses of climatic phenomena
related to flooding. The reviewers recommend the regulator to consider
including also tornadoes, heavy rainfall, extreme temperatures and the relevant
combinations of extreme weather conditions in these complementary studies. 
-       
The
battery autonomy is currently an issue that needs to be addressed at all
operating NPP designs. The reviewers recommend the regulator to consider the
benefits of recharging the batteries before their complete depletion in case of
total SBO in addition to the foreseen battery capacity increase.
-       
The
main improvements to be made in order to cope with severe accidents, possibly
affecting multiple units and caused by natural hazards have been pointed out by
ASN. One basic recommendation of the peer review process is to guarantee their
actual implementation. The reviewers consider the identified actions to be
adequate for a further improvement of safety features. The consideration and
implementation of these issues is important to be realized as soon as possible,
apart from the PSRs, which are usually the reference for introducing new safety
standards in France. 
Good
practices:

-       
Continuously safety
upgrading of the plants by regularly implementation of new safety features in
the framework of the period safety reviews 
-       
The
licensee announced the creation of specialized crews and equipment in order to
cope with accidents in 24 hours. These crews will be made up of the licensee's
employees at all plant sites and equipment will be stored in 4 regional
centres. 
Safety improvements
implemented or planned (non-exhaustive list): 
-       
The
regulator requires the licensee to define a certain "Hardened safety
core" of material and organizational measures. The hardened safety core
will be based mainly on new equipment diversified form the existing one to
prevent common cause failure. This hardened safety core should include:
·              
the emergency management rooms and equipment
(they must display high resistance to hazards and allow the management of a
long-duration emergency)
·              
the mobile devices vital for emergency
management;
·              
the active dosimetry equipment, the measuring
instruments for radiation protection and the personal and collective protection
equipment, which must be permanently available in sufficient quantity on the
sites
·              
the technical and environmental instrumentation
for diagnosing the state of the facility and assessing and predicting the
radiological impact on the workers and populations
·              
the communication means vital for emergency
management
·              
strengthened equipment including, for operating
NPPs: 
-       
mobile
electricity generating set
-       
diesel-driven
emergency cool down water supply for each reactor primary and secondary
circuits.
-       
ultimate
backup diesel generator (DUS) for electrical backup of control room ventilation
and instrumentation useful and necessary in SA
·              
qualification against external hazards of the
hydrogen re-combiners and the venting filters system
·              
improvement and updating of SAMGs including all
operation states, SFP and multi/unit events
-       
The licensee proposes
several improvements or studies to reinforce the management of accident or
severe accident situations on its sites including the provisions for multiple
unit events. These improvements target more particularly:
·              
appropriateness of the human and material
resources for the activities associated with deployment of the "hardened
safety core" equipment and the additional equipment proposed;
·              
reinforcement of the material resources and
communication means;
·              
conducting a study to improve the resistance and
habitability of the safety building;
·              
design of Local Emergency Centres, integrating
stringent habitability requirements and allowing more effective management of
the emergency. The design requirements taken into account shall be consistent
with those of the hardened safety core;
·              
reinforcement of the means of measurement and of
technical and environmental information transmission, including meteorological
information, necessary for emergency management;
·              
complementary measures to reduce the risk of
loss of water inventory in the SFPs.
5.6.                
GERMANY
Note: German stress tests
cover also several man-induced events, such as aircraft crash, blast wave,
toxic gases, terrorist and cyber-attacks. 
In
the safety review by the German Reactor Safety Commission (RSK), the assessment
criteria for a postulated aircraft crash differ in three Degrees of Protection.
A difference is made between the mechanical impact (impact of the aircraft) and
the thermal impact (kerosene fire). The Degree of Protection is considered
according to the crash of an aircraft comparable to a Starfighter (Degree of
Protection 1), the crash of a medium-size commercial aircraft (Degree of
Protection 2) and additionally of a large commercial aircraft (Degree of
Protection 3).
Recommendations:
-       
For
German NPP sites the PGA values are in some cases lower than 0.1g. As it
deviates from the approach recommended by the IAEA, and it is recommended that
the regulator should consider the safety impact of values below 0.1 g.
-       
It
is recommended to install seismic instrumentation at some NPPs in northern Germany where such instrumentation is not available yet, which is currently also required
by an updated KTA rule.
Good practices:
-       
SAM
measures including significant hardware modifications are in place for many
years (for PWRs: Secondary side Bleed & Feed including mobile pumps to feed
the SG; and primary side Bleed & Feed; for BWRs: diverse RPV
depressurization and injection systems, mobile pumps for RPV injection; for
both: PARs, Filtered Venting Systems…).
-       
Nuclear
intervention force exists since 1977.
-       
Main
control room habitability during accidents and the use of filtered venting is
ensured.
-       
Emergency
response organization could be housed in different buildings. Alternative
support centre is part of concept.
Safety improvements
implemented or planned (non-exhaustive list): 
-       
Only
4 of the NPPs have performed a seismic PSA. The next round of PSRs might be
used to review the seismic hazard and design for all plants on a probabilistic
basis, which remain in operation.
-       
At
Gundremmingen plant, feasibility studies to increase the AC power supply
robustness. The reviews of the external hazards are already part of the
deterministic part of the PSR. 
-       
Unterweser
NPP applied for license for measures aimed at using a fire water pump to
sustain low-pressure feed to the emergency feed water system or to the
emergency condition diesel system even under harsh ambient conditions.
-       
At
Isar-1 plant plans for installing two new emergency diesel generator buildings
and for replacing the water-cooled emergency diesel generator with new
air-cooled, diverse units.
-       
The
GRS information notice WLN 2012/02 contains 22 recommendations. It includes,
e.g., the following topics: SBO coverage for at least 10 hours, additional
emergency power generator available within 10 hours, diverse ultimate heat
sink, two feeding points for connection of mobile equipment to supply the
essential component cooling system.
-       
Systematic
inclusion of internal/external hazards into the AM Program (including operability
of mobile equipment).
-       
Development
of AM measures to protect the building structure surrounding the spent fuel
pool in a BWR, which is outside the containment, against hydrogen combustions
or to prevent them.
-       
SAMGs
for full power states exist for one NPP (GKN-1) and are being developed for all
operating NPPs. No low power or shutdown SAMGs exist (but there is some
guidance in operational manuals).
5.7.                
HUNGARY
Recommendations:
-       
Regarding
earthquake, it is recommended to the Regulator to monitor implementation of the
measures for further strengthening the level of protection of plant structures
against liquefaction effects and soil settlement, as well as for the completion
of seismic qualification of certain SSCs and a review of the database
containing the seismic safety classification of components.
-       
Concerning
flooding, it is suggested to the Regulator to monitor implementation of
specific measures for strengthening the level of protection of the essential
service water system.
-       
It
is suggested to the Regulator to monitor implementation of specific measures
for strengthening the level of protection of plant SSCs against extreme weather
conditions. Special attention should be paid to assessing vulnerability of the
rain drainage system in case of BDB of extreme precipitation and snowmelt.
-       
Concerning
loss of safety functions, the possibilities of interconnection of existing
equipment are beneficial. However this might also lead to loss of separation.
Such improvements or modifications should only be carried out after careful
investigation of separation issues.
-       
In
the area of SAM, to reduce radioactive release to the environment in case of
long term severe accident and to avoid over-pressurization a filtered
containment venting system or a specific containment cooling system should be
installed at all units, as the actual measures for long term internal
containment cooling are considered to be adequate only in the case of a
successful in vessel retention of the molten core.
-       
Water
supply to the SFP from an external source has to be made possible by pipeline
having adequate design against external hazards, with additional connection
from outside. Water with boron concentration has to be supplied through this
line to the SFP. The operating instructions have to be developed.
-       
Liquid
radioactive waste management procedures have to be developed for severe
accident situations
-       
The
management of on-site consequences, especially of multi-unit accidents, has to
be improved.
Good practices: 
-       
Regarding
earthquake, the reviewers acknowledge the measures undertaken to upgrade the
plant, which was originally not designed to withstand earthquakes, to its
current standard. 
-       
Concerning
flooding, a strong safety feature of the plant is its site ground elevation
above maximum possible water level in case of flooding caused by high flow
pattern of the Danube River or dam break.
-       
The
requirement of SAMG in the national regulatory framework and the decision of
the regulatory authority to require implementation of SAM measures as
pre-conditions for the life extension for all units are commendable.
-       
EOPs
and SAMGs have been developed for all operating modes (normal operating and
shutdown), for SFP accidents in all units.
-       
The
arrangements in place in the Protected Command Center (PCC) regarding power
supply, worker protection against external hazards (dose, contamination, etc.),
display of plant critical parameters during a severe accident are commendable.
Safety improvements
implemented or planned (non exhaustive list): 
-       
The
programme on development and implementation of hardware measures for severe
accident mitigation measures and of SAMGs was started before the Fukushima accident and is still on-going. As part of this programme, the installation
process of hydrogen recombiners was accelerated after Fukushima accident and is
now completed in all units.
-       
Several
measures have been envisaged to increase the robustness of the plants in case
of loss of electrical power, among others:
·              
The protection of 400 kV and 120 kV substations
and of the automatic switch to island mode will be evaluated against
earthquakes, and improved as appropriate.
·              
In addition to the existing severe accident
diesel generators supplying electrical power to I&C systems described in
accident management procedures, diverse diesel generator, which can supply
electrical power to safety consumers having role in severe accident prevention
and long term accident management is being considered. 
·              
The black start ability of the gas turbine
located in Litér will be assured by installing a diesel generator.
-       
To
enhance the resistance of the plant in the case of loss of UHS several
modifications are planned such as maximizing the inventory of the stored
demineralised water.
-       
Finally,
further studies on SAM are planned in the following topics:
·              
Hydrogen generation and distribution in the
reactor hall
·              
Long-progression with containment pressurization
during severe accidents
·              
Updating the Level 2 PSA studies
·              
Development of a software based severe accident
simulator.
5.8.                
LITHUANIA 
Recommendations: 
-       
To
perform a BDBE analysis for the new and operating spent fuel interim storages
by postulating cracks/collapse of walls of cask storage hall and hot cell (for
new spent fuel interim storage), cracks or collapse of the guarding concrete
fence (for operating spent fuel interim storage), turnover of casks during
transportation, loss of cask sealing as well as cask blockage by debris (for
the new and operating spent fuel interim storages). 
-       
To
perform a BDBE analysis of the accident management centre structure to confirm
their seismic capability.
-       
To
examine the possibility to use signals of seismic alarm and monitoring systems
to formulate emergency preparedness criteria (and include them in the relevant
procedures or guidelines).
-       
To
consider the need for a further PSR for reactor unit 2 and the SFPs if the
decommissioning phase is delayed.
-       
To
consider the benefits of qualifying the level and temperature instrumentation
in the SFPs for accident conditions and having these signals available in all
relevant locations.
Good practices: 
-       
A
strong feature is the 2 hydro plants that can provide electrical power when the
off-site power is lost. 
-       
Accessibility
of the SFPs under SA conditions has been considered and Ignalina NPP has
radiation protection provisions in case manual actions are required.
Safety improvements
implemented or planned (non-exhaustive list): 
-       
Development
of BDBA guidelines.
-       
To
install mobile DG connections to important to safety I&C, radiation
monitoring system, communication system, recharging point for the batteries of
flashlights, and temperature and level indicators of the SFP (and to install DG
connections to these last indicators), and to other consumers.
-       
To
use domestic potable water pumping system with own backup DG as diverse heat
sink cooling for the reactor and SFPs.
-       
Modifications
to supply Unit 1 systems by Unit 2 DGs.
5.9.                
THE
NETHERLANDS
Note: The
assessment by the Netherlands included also airplane crashes in its scope, and
the national regulator confirmed that a more extensive study of the impact on
the safety functions of different airplane crashes has to be performed as
proposed by licensee EPZ.
Recommendations: 
-       
The
seismic hazard assessment should be updated for Borssele NPP. It is understood
that a comprehensive and state-of-the-art seismic analysis will be performed as
part of the PSR of the Borssele NPP starting in 2012.
-       
This
analysis will then consider a PGA value of 0.1g at free field for the DBE, as
per IAEA guidance. The reviewers recommend to follow-up the mentioned analysis
for verifying its global scope and adequate performance, in particular
concerning the revision of the DBE level.
-       
The
combination of young unconsolidated sediments; grain size effects; and high
water tables are expected to make the site susceptible for liquefaction. It is
therefore recommended that the national regulator should consider assessing the
liquefaction problem in connection with the on-going seismic analyses.
-       
Considering
the very specific approach of the Netherlands for the flooding protection of
the site, which relies on the national dyke system, the reviewers recommend to
examine thoroughly the consistency of this approach with the new IAEA guidance
(SSG-18).
-       
Further
recommended topics that should be considered for additional studies are:
minimum depth of underground piping required for proper protection against
freezing, possibility to operate diesel generators at extremely low
temperatures and the potential effect of accumulation of wind transported snow
on roofs.
-       
The
capabilities to cope with SBO situations during mid-loop operation should be
developed and corresponding procedures should be prepared and validated. Due to
the short times available for manual intervention and the worsening
accessibility of the containment after the start of water boiling in the open
primary circuit, the possibility to use remotely controlled valves allowing for
primary system water make-up in case of SBO during mid-loop operation should
also be investigated.
-       
Possibilities
to increase the robustness of back-up power supply from mobile means, as well
as from small portable equipment, should be further investigated considering
external support.
-       
The
Dutch regulator’s suggestion for further analysis to establish the validity of
the assumptions made regarding the SSCs needed for SAM is supported and should
be pursued as a matter of priority.
-       
The
maintenance schedule for equipment related to accident management should be
reviewed by licensee.
-       
Unambiguous
tagging of keys of rooms (e.g. emergency control room) in the bunkered building
should be implemented.
-       
The
licensee should consider placing the SAM execution procedures at the location
where they are to be used.
Good practices: 
-       
Use
of risk monitor for planning maintenance during operation and outages.
-       
Explicit
incorporation of international standards (e.g. those of IAEA, WENRA) into the
license via the Nuclear Safety Rules (NVRs) approach.
-       
Borssele
has SAMGs for all operational states (including shutdown). The licensee has
been very proactive in this regard, implementing them far faster than in many
nations reviewed. Its SAMGs were considered state of the art in 2003.
-       
Borssele
has used a full scope Level 3 PSA for deriving its severe accident management
strategies and has been subject to IAEA IPSART missions.
-       
The
scale of emergency exercises at Borssele is unusually large by international
standards – one recent national exercise involved 1000 people.
-       
PARs
are already installed and are designed for severe accident conditions.
Safety improvements
implemented or planned (non-exhaustive list): 
-       
Storage
facilities for portable equipment, tools and materials that are accessible
after all foreseeable hazards would enlarge the possibilities of the alarm
response organization.
-       
Ensuring
the availability of fire annunciation and fixed fire suppression systems in
vital areas after seismic events would improve fire fighting capabilities and
accident management measures that require transport of water for
cooling/suppression.
-       
Ensuring
the availability of the containment venting system after seismic events would
increase the margin in case of seismic events.
-       
During
the next PSR, either a seismic PSA will be developed and/or a SMA will be
conducted and the measures will be investigated to further increase the safety
margins in case of earthquake.
-       
Modification
in process to install a seismic monitoring instrumentation in the plant.
-       
Improving
flood resistance of buildings containing emergency supply.
-       
Regulator
considers the impact of floods with long return period must be further
assessed. Additional study on extreme flooding with long term period including
dyke failure mechanisms is envisaged.
-       
Development
of an operating procedure for flooding has been initiated.
-       
The
sea dyke A of 9,4 m + NAP will be improved in 2012.
-       
Develop
check-lists for plant walk-downs and needed actions after various levels of the
foreseeable hazards.
-       
Improvement
of plant autonomy during and after an external flooding, for example by
establishing the ability to transfer diesel fuel from storage tanks of inactive
diesels towards active diesel generators would increase the margin in case of LOOP. Envisage potential actions to prevent running out of on-site diesel supply for fire
extinguishing system and the fire brigade. Increase the amount of lubrication
oil in stock. By increasing the autarky-time beyond 10 h the robustness of the
plant in a general sense would be increased.
-       
Reducing
connection time of the mobile Emergency Diesel Generator(s).
-       
Better
arrangements for emergency diesel generators, including improved means for
recharging batteries and strategies to conserve battery power.
-       
An
Emergency Response Centre facility that could give shelter to the alarm
response organization after flooding (and all foreseeable hazards) would
increase the options of the alarm response organisation. Establishing independent
voice and data communication under adverse conditions, both onsite and
off-site, would strengthen the emergency response organisation.
-       
Assessment
of the cooling possibilities in case of loss of the main Grid, Emergency Grids
1 and 2 and no secondary bleed and feed available.
-       
Updated
and extended analysis of hydrogen management within containment, including for
the SFP.
-       
Potential
improvements to SFP cooling arrangements so that this does not require a
containment entry.
-       
Strategies
for corium stabilisation within containment.
-       
Revisiting
previous analyses of ex-vessel Reactor Pressure Vessel cooling.
-       
Analysing
the possibility of detonation / deflagrations in the containment filtered
venting stack.
-       
Analysis
of potential doses to workers during severe accident management activities,
including assessments of how dose levels increase with reducing Spent Fuel Pool
level and habitability of the Main Control Room and ECR.
5.10.            
ROMANIA
Recommendations: 
-       
The
absence of a seismic level comparable to the SL-1 of IAEA leading to plant
shutdown and inspection is regarded a critical issue at the background that the
probability of large earthquakes occurring during the lifetime of the plant is
extremely high (recurrence intervals for the Vrancea seismic zone: 50y for Mw>7.4).
It is suggested to the regulator to consider implementing adequate regulations.
-       
There
is only little information about margins to cliff edges, weak points and no
evidences that further improvements in the seismic upgrading have been
considered. Further work is proposed in this area and it is recommended that
the CNCAN obtains good quality programmes from the licensees and ensures that
the work is appropriately followed up.
-       
It
is suggested to consider improving the volumetric protection of the buildings
containing safety related equipment located in rooms below plant platform
level. It is also suggested to the regulator to consider routine inspections of
the flood protection design features.
-       
The
habitability of the MCR and SCA was assessed for various types of accidents but
not in the case of a total core melt accident associated to a containment
failure (or voluntary venting). MCR habitability analysis to be continued (e.g.
implementation of a close ventilation circuit with oxygen supply).
-       
Further
SAM study is required for shutdown states. 
Good practices: 
-       
The
plant units have a high level of defence against the loss of power and its
consequences. The robustness of the electrical power supply is provided by four
levels of defence in depth.
-       
The
dousing tank of the CANDU design allows gravity feed into the Steam Generators.
-       
The
primary and alternative heat sinks provide a good level of redundancy and
diversity.
-       
Possibility
to use diverse methods to open the Main Steam Safety Valves if the normal power
supplies are lost.
-       
The
robustness of the CANDU design to SA progression (slow accident progression due
to the quantity of water available in the vessel and calandria vault, which
increases the chances to stabilize a degraded situation and limit the
possibility of large early release (except for hydrogen combustion),
-       
The
large spreading area in case of MCCI which contributes to the possibility of
corium cooling in the late phase of an accident.
Safety improvements
implemented or planned (non-exhaustive list):
-       
Two
new mobile diesel generators for electrical power supply and two pumps that can
provide water in the domestic water system from the deep wells. In order to
further decrease the time to connect the mobile DGs, the plant has initiated a
modification to install special connection panels to the loads which may be
supplied from these DGs.  
-       
Design
modification for water make-up to the calandria vessel and the calandria vault
(completed for unit 2).
-       
Improving
the seismic robustness of the existing Class I and II batteries. The option of
charging the batteries or the installation of a supplementary uninterruptible
power supply for the SCA is being considered.
-       
Implementation
of a hydrogen monitoring system (proposed by the utility and considered by the Romania safety authority to be reliable). PARs on unit 1 and 2 for hydrogen management.
-       
Additional
instrumentation for SAM (e.g. hydrogen concentration monitoring in different
areas of the reactor building).
-       
Dedicated
emergency containment Filtered Venting System (FVS) for each unit will be
installed.
-       
Improving
the reliability of existing instrumentation by qualification to SA conditions
and extension of the measurement domain (e.g. 30 days resistance for cables and
connectors).
-       
Spent
Fuel pool: Use of a new, seismically qualified, fire water pipe to allow water
make-up without entering in the SFP area. Connections are provided outside the
SFP building,
-       
Reinforced
water height level instrumentation in the SFP and the reception bay.
-       
Cernavoda
NPP will establish a new seismically qualified building to host the on-site
Emergency Control Centre fire fighter’s facility and main intervention
equipment.
-       
Cernavoda
NPP will increase the reliability of the communication systems and the
robustness of the on-site emergency control centre. The set-up of an
Alternative Off-site Emergency Control Centre is in progress. 
5.11.            
SLOVAKIA
Recommendations: 
-       
It
is recommended to consider monitoring the implementation of measures for
quantification of seismic margins, and measures for strengthening of the level
of protection of the plants against flooding and extreme weather conditions. 
-       
In
order to assure a timely completion of the measures for seismic resistance of
the relevant SSCs of Mochovce NPP 1&2 for the newly defined Review Level
Earthquake (PGA of 0.15g), it is recommended to consider prioritization of the
seismic upgrading measures, e.g. in respect to the fire brigade building, and
to re-evaluate cases where components of no primary safety feature potentially
may have indirect influence on safety functions.
-       
It
is important that the SAM modification will be implemented according to the
proposed schedule. It is suggested to consider locating the special equipment
for SAM in dedicated locations qualified against external hazards. The
verification of tightness of all containment penetrations in SA conditions
should be further examined (resistance of seals in particular).
-       
The
strategy of long term management of containment pressure without any
containment venting system should lead to further verification to check the
real feasibility of long term containment heat removal in severe accident
conditions.
Good practices: 
-       
The
robustness of the plants against earthquakes has been significantly increased.
-       
Measures
to improve the safety of the plants regarding LOOP, SBO and loss of UHS have
been planned and prioritised. Good practices include: large capacity of
batteries and availability of several batteries trays; battery status
monitoring system; equipment configuration management system dedicated for assessment
of situation during extreme events and combinations of events; availability of
EOP for usage of water from bubble condenser tower for SFP cooling, filling up
reactor vessel, cavity and pit; availability of EOP to remove the decay heat by
steam generator when reactor is opened.
-       
Specific
tests were performed to validate emergency measures (e.g. test of feeding steam
generators using the fire truck high pressure pump, test of water supply to SFP
from bubble condenser trays).
-       
Most
of SAM measures are not yet implemented, but regarding the future situation the
following points can be highlighted as good practices: the SAM measures to
avoid large early releases and with long term management of the damaged plant;
the application of EUR safety objectives for the new units; the continuous
improvement of containment tightness of all plants; the new concept for the
emergency control centres with remote control of SA equipment.
Safety improvements
implemented or planned (non-exhaustive list): 
-       
Some
additional safety upgrading measures are envisaged to increase seismic
resistance.
-       
Some
protective measures against flooding were promptly implemented during the
period of stress tests (e.g. temporary passive protection of the reactor
building and DG station). An action plan for implementation of short term and
long term corrective measures to increase plant robustness against flooding
with defined deadlines for implementation has been developed and agreed by the
regulator.
-       
Further
work is defined to better document the resistance to beyond design weather
conditions.
-       
The
measures to increase robustness against LOOP, SBO and loss of UHS include the
following: a 6kV air cooled diesel generator for SAM; a 0.4 kV mobile diesel
generator for each unit for charging batteries and supplying selected consumers
during SBO; modifications of the power supply of the high-pressure boron system
pumps enabling their use during SBO; provision of a mobile high-pressure
feedwater pump for each unit for injection into steam generators (available
during SBO).
-       
An
extensive project for the implementation of the plant modifications and the
development of the SAM was confirmed for 2013 for Bohunice (including new
improvements) and was accelerated from 2018 to 2015 for Mochovce NPPs. It
includes reactor cavity flooding, an additional line for RCS depressurization,
containment hydrogen management, and containment vacuum breaker.
5.12.            
SLOVENIA
Note: The Krško NPP has also prepared an analysis of
the impacts of aircraft crashes on the plant. While this report is confidential
and was not part of the peer review process, the national regulator states that
the plant is well prepared even for such events.
Recommendations: 
-       
The
new updated seismic hazard assessment resulted in a decrease in seismic
margins. It is recommended that the regulator consider requesting the update of
the seismic design basis for future design modifications and consequently the
associated PSA model. 
-       
Additional
systems and equipment that can ensure the main safety functions during LOOP and loss of UHS are planned to be deployed. It is recommended to complete these
changes in a timely manner.
-       
Several
provisions are already in place to support SAM with the use of mobile
equipment, and additional upgrading measures (e.g., installation of PARs,
filtered venting, new emergency control room, third engineered safety features
train) are being implemented. It is recommended to complete these improvements
as soon as possible.
Good practices:
-       
During
the winter, warm water can be diverted from the essential service water to the
inlet of the intake structure for de-icing purposes. 
-       
At
extremely low temperatures, daily plant surveillance is performed for all open
air isolated lines. The plant has in place several heaters which can be used to
heat safety related SSCs even during a SBO.
-       
Sufficient
mobile and portable power generation sources are available on-site.
-       
Turbine-driven
auxiliary feedwater pump is available for reactor cooling (provided the SGs are
available).
-       
Possibility
of independent water injection into the reactor vessel.
-       
SAMGs
are validated by exercises on the full scope simulator and have been reviewed
by IAEA RAMP mission in 2001. 
-       
Full
scope simulator used during drills provides real time response. Simulation goes
up to containment failure and beyond. Longest exercise lasted 2.5 days.
-       
SAMGs
are in place for the reactor as well as for SFP and are independent of the
reactor operating state.
-       
Consideration
of extensive damage due to aircraft crash and implementation of mitigation
measures.
Safety improvements
implemented or planned (non-exhaustive list): 
-       
Several
alternative cooling means are available or planned, in case of loss of primary
UHS.
-       
Alternative
means to provide suction to Auxiliary Feedwater System (AFW) pumps or to
provide water to Steam Generators (SGs) directly.
-       
Alternative
means for power supply to Chemical and Volume Control System in order to
preserve reactor coolant system inventory and the integrity of reactor coolant
pumps seals in induced SBO or Loss of essential service water system /
component cooling system conditions.
-       
Alternative
means for power supply to selected Motor Operated Valves.
-       
Alternative
means for providing water from the external sources to the containment.
-       
Procedures
for local operation of AFW turbine driven pump and for local steam generators
power depressurization without need of DC or instrument power.
-       
Third
independent diesel generator 6.3 kV (in a separate building with the third
safety bus which could be connected to either one of the existing two safety
buses).
-       
Provision
to connect mobile diesel generator of capacity 2000 kVA to switch gear of the
third diesel generator.
-       
Two
engine driven 125 V aggregates will be available to provide the power to DC
system panels in case of loss of DC main distribution panels.
-       
Acquiring
onsite additional pumping station to assure additional high capacity “portable
water ring” around the plant.
-       
Acquiring
two additional high pressure mobile fire protection pumps (to remove decay heat
in early stage after reactor shutdown and depressurizing SGs).
-       
Installation
of additional quick connection points for mobile equipment.
-       
Alternative
means for makeup of Spent Fuel Pool water inventory.
-       
An
alternative system with skid mounted pump and heat exchanger to cool the SFP.
-       
Installation
of a special emergency control room in the already constructed building
protected against external events.
-       
Filtered
containment venting.
-       
PAR
for hydrogen control in the containment.
-       
A
new Technical Support Centre with enhanced habitability requirements.
-       
Improving
existing flood protection by increasing the heights of dikes upstream the
plant, in order to keep the left Sava river bank dry even for flows beyond the
PMF flood flow. 
5.13.            
SPAIN
Recommendations:
-       
Within
the framework of the on-going analyses on the effects of pipe rupture
(non-seismic and seismic), it is suggested to consider in particular verifying
that there are no common cause failure issues.
-       
Within
the framework the seismic hazard update, it is suggested that the updated
Seismic Hazard Assessment should use the available geological and
paleoseismological data characterizing the active faults of the Iberian Peninsula.
-       
Adopting
a consistent approach for the return periods associated to heavy rain and
extreme temperatures scenarios at the different sites.
-       
Improving
the external flood volumetric protection of buildings containing safety related
SSCs.
-       
Completing
the establishment of a comprehensive set of requirements for accident
management integrated within the Spanish legal framework.
-       
It
is suggested to consider containment filtered venting system in the NPPs.
-       
To
explicitly include accident management as a topic in CSN’s safety guide on
"the content of periodic safety reviews” and to include External events in
the scope of PSA.
-       
Reviewing
the approach linked in calculating the time margins for the control or
mitigation of severe accidents.
-       
Trillo:
development of symptom-based SAMG for mitigation of the consequences of severe
accidents and maintenance of containment integrity.
-       
Considering
passive autocatalytic hydrogen re-combiners (NPP Cofrentes and Westinghouse
NPPs) and a clear commitment for SAMGs for hydrogen mitigation in SFP
accidents.
-       
Developing
severe accident management guidance for accidents initiated during shutdown
operation and accelerating plans to include SAMGs addressing mitigating aspects
for SFP.
Good practices:
-       
A
comprehensive analysis of indirect effects induced by earthquake (explosions
and fires, internal flooding caused by pipe breaks, damage on nearby
infrastructure, sloshing in the SFPs, effects of earthquakes on industries in
the vicinity of their sites).
-       
Organisational
and technical measures to restore power supply directly from hydropower
stations.
-       
Possibility
to use turbine-driven pumps and atmospheric discharge valves to cool reactor
core and possibility to operate such equipment manually (without any AC/DC
power).
-       
The
setting-up of a working group to analyse important factors like accessibility,
human resources and times available.
-       
Verification
and validation of SAMGs by supporting calculation, analysis and exercises.
-       
Permanent
connection allowing alternate SFP makeup without entering the SFP area
(Trillo).
-       
Provision
for containment cooling from the outside by the annulus building ventilation
(Trillo).
Safety improvements
implemented or planned (non-exhaustive list):
-       
Update
site seismic hazard characterization following the most recent IAEA standards.
-       
Analyses
on-going for different improvements: increasing capacity of downstream dams
spillways, reinforcing of water leak-tightness of building gates, increasing
the evacuation capacity in the drainage networks, improvements to galleries
with potentiality to induce in-leaks, improving the hydrostatic resistance of
seals in galleries connecting to buildings containing safety-related equipment.
-       
A
specific study on occurrence of tornados in the areas surrounding nuclear
facilities
-       
Availability
on site of autonomous electricity generating groups.
-       
Additional
portable instrumentation in the event of complete loss of the batteries.
-       
Improvements
to the communications systems (on- and off-site) in situations with loss of the
electrical feed systems; improvements to the lighting for prolonged scenarios.
-       
Design
modifications required to make available connection points for autonomous
electrical and mechanical equipment.
-       
 Preparation
of relevant procedures and training of personnel according to these procedures.
-       
The
setting-up of new on-site Alternative Emergency Management Centres (AEMC),
seismically and flood-resistant at each plant.
-       
the
setting-up of an Emergency Support Centre (ESC), common to all the plants, with
back-up equipment located at a central storage and available to be deployed and
operated by an Intervention Unit ready to act at the sites in 24 hours.
-       
Installing
passive autocatalytic re-combiners (PARs) at those plants that do not have them
yet.
-       
Installing
a filtered venting system.
-       
Applying
measures to prevent core damage sequences with high pressure in the reactor and
improving the ability to implement containment flooding strategies. 
-       
Reinforcement
of the electrical power supply to the Main Control Room ventilation system.
-       
Spent
Fuel pools: develop specific procedures to allow taking preventive measures to
assure cooling or water replenishment.
-       
Defining
reference dose levels for the personnel intervening in an emergency for all
onsite intervening personnel during an emergency. 
5.14.            
SWEDEN
Recommendations:
-       
To
consider carrying out more detailed flooding risk analysis including cliff edge
analysis. To assess plant vulnerability against flooding, implementation of a
refined external flooding PSA could be suggested.
-       
For
the Forsmark and the Ringhals sites, to consider studying the combination of
high sea water level and other external phenomena such as swell, strong wind
and organic materials.
-       
To
implement early warning systems and relevant operating procedures in case of
extreme weather conditions (which are not in place for all sites).
-       
Reducing
risks of common cause failures in Emergency Diesels Generators.
-       
Enhancing
the reliability of electric power supply (analysis of robustness of gas
turbines as alternate AC power, improving possibilities to refill the diesel
tanks at diesel units, availability of lube oil, use of diesel generators used
for physical protection, increasing the number of mobile diesel generators at
site, load shedding, etc.
-       
The
alternate cooling system for EDGs that is in place in Ringhals might be an
alternative at other units.
-       
Maintaining
the level in available water storage tanks close to maximal.
-       
Installation
of pipelines to provide fire water to spent fuel pools.
-       
Qualification
of mobile equipment (and its storage) against DBE and other external hazards. 
-       
Consideration
of multiple unit events including long term effects, particularly during
extreme situations.
-       
Ensuring
long term performance of the filtered venting system (> 24 hours).
-       
Consideration
of natural disasters leading to loss of infrastructure in the SAM.
-       
Concepts
to manage large volumes of contaminated water.
-       
Accumulation
of hydrogen in rooms or buildings outside the containment.
-       
Qualification
of instrumentation (water level, temperature in the Spent Fuel Pool) for severe
accident as well as qualification of the equipment against harsh conditions.
-       
Enhancement
of the accident management programmes (SAMGs, EOPs) for all plant states
(including spent fuel pools and multi-units events).
-       
EOP
training and drills for extended scope of the accident management (multiunit
accidents under conditions of infrastructure degradation).
Good practices:
-       
After
the Three Mile Island accident, the Swedish government decided that all Swedish
NPPs should be capable of withstanding a core melt accident without any
casualties or ground contamination of importance to the population. This
resulted in an extensive backfitting for all Swedish NPPs, including:
·              
Filtered containment venting through an inerted
MVSS with a decontamination factor of at least 500.
·              
Independent containment spray water supply
(mobile units and/or firefighting system).
·              
Passive Autocatalytic hydrogen recombiners
(PWR).
·              
Flooded lower drywell in BWR aiming to stabilize
ex vessel molten corium.
-       
All
Swedish BWR containments are inerted with nitrogen since their original design
to avoid hydrogen risks.
-       
For
the most part, the SAM systems and procedures currently in place were developed
during the 1980s and are part of the design bases of the plants. 
-       
The
communication solution RAKEL.
-       
Capability
to withstand loss of UHS scenario for long time periods if water volumes in
various tanks are close to maximal.
Safety improvements
implemented or planned (non-exhaustive list): 
-       
More
detailed studies for potential improvements regarding mitigation strategies for
long term severe accident conditions, capability to handle more than one
affected unit, analysis of destruction of infrastructure, and damage to safety
systems and barriers. 
-       
Additional
assessment of the containment integrity in the event of a severe accident,
including measures if necessary (all reactors: 2012).
-       
Strategy
for long term cooling of a severely damaged core, including physical measures
if necessary (all reactors: 2012, some measures before 2012).
-       
Independent
emergency core cooling system. (All reactors, studies ongoing).
-       
Change
to two phase flow relief valves (Ringhals 1: 2011, Oskarshamn 2: 2013).
-       
Measures
to vent incondensable gases from the reactor vessel (Ringhals 1: 2012).
-       
Analysis
of the adequacy of emergency control, including upgrade measures, if necessary
(Oskarshamn 3: 2012, Ringhals 3 & 4: 2012).
-       
Installation
of a new emergency control (Forsmark 1: 2011, Forsmark 2: 2012, Oskarshamn 2:
2013).
5.15.            
UNITED KINGDOM 
Recommendations: 
-       
Several
uncertainties exist with regard to the Design Basis Earthquake, which were
established by different methodologies for different sites during the 1980s and
1990s. This leads to ONR’s “Stress Test Finding” that: “The nuclear industry
should establish a programme to review the Seismic Hazard Working Party
methodology against the latest approaches”.
-       
The
currently available Design Basis Flooding (DBF) assessments have not accounted
for some recent tsunami research work, although ONR are content that such work
is unlikely to significantly affect previous work on maximum credible tsunami
heights.
-       
For
flooding, there is no satisfactory evidence of capability of the plants beyond
the design basis. It is recommended that the UK regulator considers providing a
specific programme for additional review regarding the design basis approach
and an adequate response regarding margin assessment and identifies specific
potential plant improvements is recommended. ONR has raised this as findings in
the UK report. 
-       
For
earthquake and some specific external hazards, beyond design basis capability
are inferred but not quantified and no specific evidence is provided that
margins to cliff edge effects and potential specific improvements have been
considered systematically for all NPP. Additional review regarding the design
basis approach and an adequate response regarding margins assessment beyond the
design basis and identification of specific potential plant improvements. The
review team encourages the ONR to establish a strong regulatory oversight
programme on this matter.
-       
Although
the reviewers note that the UK Chief Inspector’s final report makes a
recommendation to review/revise site-specific flood analyses, ONR is urged to
ensure that common cause failure modes from flood hazard are comprehensively
taken into account for all the reactors of a site, in particular regarding the
need to share mitigation or mobile equipment.
-       
ONR
should clarify its technical requirement in the implementation of the defence
in depth principle regarding flooding, and consider requirements for warning
and prevention of flooding of the site, protection against flooding of rooms
and mitigation, for the whole site.
-       
For
AGRs/Magnox, the longer grace times should not be used as an argument for not
considering implementation of fixed hardware provisions. The following further
improvements are suggested:
·              
Inject water into the reactor core as an
ultimate means to provide residual heat removal from the core without use of
the boilers and identify the means/equipment that would be used, including
filtering for AGR/Magnox.
·              
Stocks of fuel and other consumables. for at
least 72h.
·              
Battery capacity is low
compared with other countries and therefore should be increased or recharged by
additional generators for most of the plants.
-       
In
accordance with the existing plans, the on-site emergency facilities should be
strengthened in order to be resistant against external hazards and provide for
working conditions in case of severe accident. A more comprehensive assessment
is also needed regarding the occurrence of severe accident at multiple units
and conditions of severely damaged infrastructures.
-       
The
need for a backup control room providing for shutdown and cooldown to safe
condition of the plants should be considered.
-       
Symptom
Based Emergency Response Guidelines (SBERGs) and SAGs should be further
developed to cover fully all spectrums of accident scenarios, including plant
shutdown conditions. Training and exercises for implementation of the
procedures should be improved.
-       
Radiation
conditions which may potentially develop on site in case of severe accident,
possibly at several units, should be more comprehensively analysed and
appropriate measures to address them implemented.
-       
The
existing plans to strengthen hardware provisions for SAM in all reactors, but
in particular in Sizewell B, are supported by the review team. It is advisable
to take into account the need for operability of newly installed equipment under
conditions of extreme external hazards and prolonged SBO. Provisions for
ensuring sufficient coolant inventory in the SFP should be further strengthened
by providing e.g. additional delivery of coolant from external sources.
Good practices:
-       
Accident
management for gas cooled reactors represent a special case due to their unique
design features, in particular absence of a separate containment building and
very large thermal inertia. This large inertia provides comfortable time
margins for performing recovery actions. Many severe accident challenges to
confinement integrity such as hydrogen explosion, high pressure melt ejection;
steam explosion and direct containment heating are not present.
-       
The
PSA that has been produced for Sizewell B is a full scope Level 3 PSA. The PSA
addresses all modes of operation of the plant (full power, low power and
shutdown modes), internal initiating events, and internal and external hazards.
-       
Strong
safety features for NPPs in the UK are the different independent and autonomous
systems and the diverse back-up AC power Diesel or Petrol Driven Generators and
pumps or steam driven pumps present on any site, the Gasturbines at Magnox
operating reactors and the four independent EDG’s at Sizewell B. At Sizewell B
the Reserve Ultimate Heat Sink system and the two steam-driven emergency feed
deserve also to be mentioned.
-       
Approximately
ten years ago the licensees established a number of beyond design basis
containers that contain a range of equipment and materials that could be
beneficial when responding to a beyond design basis accident. These containers
are located remotely offsite at a central UK location, available to be
transported to an affected site within a ten hour timeframe following
declaration of an off-site nuclear emergency. All containers and their contents
are maintained regularly, and their deployment has been exercised.
Safety improvements
implemented or planned (non-exhaustive list): 
-       
For
Sizewell B, it was confirmed during the country visit that the licensee will
install a filtered containment venting system and passive autocatalytic
hydrogen recombiners as part of SAM improvement measures. In addition, it will
consider a flexible means of injecting water into the containment using
portable external equipment. Some other specific enhancements are already being
considered, for example the provision of a hardened Emergency Control Centre at
Sizewell B.
-       
Finally,
further studies on SAM are planned in the following areas:
·              
How the pilot PSA studies (Level 2 PSA; Fire
PSA; Shutdown PSA) and the insights from them are taken forward across the AGRs
fleet.
·              
Further resilience enhancements to
communications equipment and associated critical supplies.
·              
Potential explosive hazard arising from the
production of Carbon monoxide (CO) for AGRs during a severe accident.
·              
AGR pressure vessel basemat melt through in
severe accident conditions.
6.                      
Summaries of Neighbouring Countries' Peer Reviews
6.1.                
SWITZERLAND 
Recommendations: 
-       
It
is recommended that the regulator assesses the opportunity of requiring more
reliance on passive systems for hydrogen management for severe accident
conditions. 
-       
It
is recommended that the regulator considers further studies on the hydrogen
management for the venting systems.
Good practices: 
-       
The
review team has recognized the significant efforts carried out to update in
depth the seismic hazard assessment in Switzerland, which would lead to
identification of possible safety improvements.  It is based on a probabilistic
seismic hazard analysis and is considered to be ’state of the art’ by the
Regulator. It includes a recently updated paleoseismological data-base and uses
a solid scientific basis. 
-       
The
peer review team recognises as good practice the recent creation of a
flooding-proof and earthquake-resistant external storage facility at Reitnau.
The storage facility houses various operational resources for emergencies,
which are readily available and can be supplied to the required location within
reasonably short time frames.
-       
The
safety train concept and a strong defence in depth contribute to the robustness
of the plant. There are 3 independent paths to bring and maintain the plant in
a safe shutdown state, one being fully autonomous for at least 10 hours. The
number of safety layers for power supply is significant and diverse options are
available. An external storage was set up in 2011 and can provide in a timely
manner additional diesel generators.
-       
Three
sites have an alternate cooling source consisting of specially protected
deep-water wells that would provide water in the event of the loss of the
primary ultimate heat sink.
-       
During
the peer review process, the following strong points have been identified:
·              
The ENSI issued a comprehensive report on
lessons learned after Fukushima. 
·              
SAM has been addressed in national regulations
and the main components of SAM were in place before the Fukushima accident, 
·              
SAMGs are available for both power and shutdown
states,
·              
Effective AM strategies are available in case of
prolonged SBO.
·              
Long-term scenarios are covered in procedural
guidance’s.
·              
SFPs outside the containments are addressed by
SAMGs.
·              
Multi-unit events (for Beznau NPP, the only site
with more than one unit) and arrangements have been tested repeatedly even
before the Fukushima accident.
·              
Filtered containment venting, with active and passive
activation. 
·              
Emergency Control Rooms are protected against
external events, including filtered air supplies. Manual actions can be
performed from radiologically protected areas.
·              
Re-criticality in the SFP is unlikely.
Possibility for injection of non-borated water, e.g. with fire pumps through
prepared connections. 6 tons of boron is available for SAM.
Safety improvements
implemented or planned (non-exhaustive list):
-       
Targeted
back-fitting measures to improve the seismic resistance of: the supporting structures
for cables and the control stations in the main control room (Gösgen NPP), the
SFP cooling at Beznau NPP and Mühleberg NPP, and the installation of a new set
of EDGs that are robust against earthquake at Beznau NPP.
-       
Back-fitting
of two physically separated connections for the external spent fuel pool supply
at all the NPPs (without the need to enter the SFP area).
-       
At
Beznau NPP, additional independent flood protected spent fuel pool cooling
system with coolant supply from the protected special emergency well and
additional injection means into the SFPs via an existing alternative pool
cooling system, and via a new flood protected pool cooling system.
-       
At
Gösgen NPP, building of a flood protection wall to prevent water ingress
through a breach in an embankment, and preparation of a shut-off bulkhead for
access via the power plant road. Mühleberg NPP plans to install a diverse flood
protected SFP cooling water system.
-       
For
Gösgen NPP the following improvements have been implemented: 
·              
Introduction of an automatic advance flooding
alarm.
·              
Additional sealing of building shells, air
inlets and doors, etc., of buildings with equipment used for the safe shutdown
of the plant.
·              
Preparation for the erection of dam bulkheads.
·              
Installation of ‘flood valves’ to seal ventilation
intakes.
-       
For
Mühleberg NPP the following improvements have been implemented: 
·              
Provision of mountable flood protection walls
for protection against flooding of the auxiliary cooling water pumps in the
pump building, and enhancement of the relevant operating instructions.
·              
Provision of mobile pumps to inject water into
the diversified heat sink intake structure.
·              
Implementation of an additional injection option
(intake shaft) into the diversified heat sink intake structure.
·              
Back-fitting of three special vertical pipes on
top of the diversified heat sink intake structure to ensure the cooling water
supply for the diversified heat sink.
-       
To
increase the number of options available for SFP cooling, all sites will also
have to back-fit a physically separated additional feed for the pools (used by
mobile means from outside the building).
-       
In
three plants, at least one medium-sized mobile AM emergency power unit (at
least 120 kW / 150 kVA) is available locally. Since the end of October 2011,
two large mobile units (approx. 890 kW) have been available at Beznau NPP.
6.2.                
UKRAINE
Recommendations: 
-       
The
seismic evaluations for some parts of the equipment, piping, buildings and
structures important to safety are not yet completed. Some additional seismic
safety upgrading measures are envisaged, but not implemented yet. The peer
review recommends monitoring in a systematic way the implementation of the
upgrading measures in order to assure timely completion as part of the
Comprehensive safety improvement programme. 
-       
A
special attention should be paid for defining vulnerability of the plant in
case of beyond design basis tornado (in terms of potential loss of essential
service water). Safety margins with respect to extreme wind and extreme snow
should be evaluated too. The peer review recommends considering monitoring the
fulfilment of additional analyses of the threat to the essential service water
system due to the tornado impact as well as the evaluation of emergency
arrangements with respect to the personnel access to sites in severe weather
conditions.
-       
The
improvement of makeup possibilities to primary circuit, to the SGs, and to the
spent fuel ponds in case of SBO and LUH events is being considered. The
deployment of mobile diesel and pumping (MDGPU) unit has to be further analysed
in detail. The peer review recommends that the regulator considers monitoring
resolution of these proposals. 
-       
Concerning
SAM the peer review recommends the following topics for consideration by the
Ukrainian regulator:
·              
Demonstration, with a high degree of confidence,
that the key functions needed for SAM can be achieved. In particular,
provisions against cliff-edge effects on accident progression should be
addressed in priority (hydrogen management, control, reliability of RCS
depressurization function in severe accident condition).
·              
A strategy and program for the qualification of
equipment needed in severe accident conditions should be implemented.
·              
The risk induced simultaneously by reactor and
SFP in case of a severe accident should be assessed.
·              
The analysis of SFP accident in various
configurations in order to underwrite EOP and SAMGs, the robustness of the
means to cool the SFP even after core melt should be improved. If SFP is inside
the containment, a means to cool the SFP should be ensured even if some
internal structures (pipes) in the containment have been damaged by hydrogen
combustion.
·              
Further investigation of the habitability of
MCRs and ECRs in case of a severe accident as well as enhanced seismic
capabilities for the building hosting the crisis centre should be assessed. The
schedule for hardware and procedures implementations should stay under strict
control of the regulator.
·              
For site with several units it should be
verified in details the feasibility of immediate actions required to avoid core
melt, prevent large release, and avoid site evacuation for a disaster affecting
more than one unit at a particular site.
Good practices: 
-       
High
level of redundancy of SSCs and power supply (DGs) which offers many
possibilities and flexibility for accident management; some extensive
additional safety upgrades to the original design are implemented to prevent
severe accidents. 
-       
The
risk of common mode failure is being addressed through additional mobile
equipment that should allow for quick connection and should be stored in a safe
area.
-       
Some
prompt actions already implemented: mobile DG for Chernobyl NPP (ChNPP), set of
targeted emergency exercises conducted at all NPPs, including ChNPP.
-       
In
addition, emergency exercises on long term SBO type of scenarios were conducted
at all Ukrainian NPPs. Upon their results, measures were identified to improve
on-site emergency response taking into account Fukushima-related phenomena.
Safety improvements
implemented or planned (non-exhaustive list): 
The following measures are envisaged in the
“Comprehensive (Integrated) Safety Improvement Program for Ukrainian NPPs”:
-       
Complete
equipment seismic qualification for 0.1g and additional seismic investigations
of NPP sites and assurance of robustness of equipment, piping, buildings and
structures important to safety to seismic impact >0.1g.
-       
Assurance
of operability of essential service water consumers under loss of water in
spray ponds of operating plants as a result of tornado.
-       
Increase
the discharge time of batteries and restoration of power supply to stationary
makeup pumps from a Mobile Diesel Generator (MDG).
-       
Improve
the emergency makeup to SG, water injection into SG from fire trucks and MDGPU
(Mobile Diesel Generator and Pumping Units), as well as injection of borated
water into the primary circuit from MDGPU, restoration of power supply to
stationary makeup pumps from a MDG, and water injection into the SFP from
independent MDGPU or from the fire extinguishing system. 
-       
Development
and Implementation of SAMG at WWER 440 and 1000 Units.
-       
Preservation
of the containment integrity if there is interaction with corium (active core
melt) at the ex-vessel phase of severe accident including implementation of H2
concentration reduction measures for BDBA situations.
-       
Implementation
of the filtered containment venting system for all WWER-1000 and WWER-440
units.
GLOSSARY
AC                       Alternating
Current
AEFS                   Additional
Emergency Feedwater System
AEMC                 Alternative
Emergency Management Centres 
AGR                    Advanced
Gas Cooled Reactor
AFW                    Auxiliary
Feedwater
AM(P)                 Accident
Management (Programme)
APOP                  Abnormal
plant operating procedures
BDB(A)               Beyond
Design Basis (Accident)
BDBE                  Beyond
Design Basis Earthquake
BWR                    Boiling
Water Reactor
CANDU              Canada Deuterium Uranium (Pressurised Heavy Water) Reactor
CDF                     Core
Damage Frequency 
CNCAN              Romanian
National Commission for Nuclear Activities Control
CSN                    Nuclear
Safety Council (Consejo de Seguridad Nuclear), Spain
CVA                    Auxiliary
steam system
DBE                     Design
Basis Earthquake
DBF                     Design
Basis Flood
DC                       Direct
Current
DG                       Diesel
Generator
EC                       European
Commission
ECC                     Emergency
Control Centre
ECR                     Emergency
Control Room
EDF
NGL            EDF Energy Nuclear Generation Ltd
EDG                     Emergency
Diesel Generator
EDMG                 Extensive
Damage Mitigation Guidelines
EMC                    Emergency Management Center
EMS                    Emergency
Makeup System
ENSI                    Swiss
Federal Nuclear Safety Inspectorate
ENSREG             European
Nuclear Safety Regulators Group
EOP                     Emergency
Operating Procedure
EPR                     Evolutionary
Power Reactor
EPS
                     Emergency Power Supply
FANC                  Federaal
Agentschap voor Nucleaire Controle, BE
FARN                  Nuclear
Rapid Response Force
GRS                     The
Gesellschaft für Anlagen- und Reaktorsicherheit, DE
HCLPF                High
Confidence of Low Probability of Failure 
FANC                  Federal
Agency for Nuclear Control (in Belgium)
IAEA                   International
Atomic Energy Agency
I&C                     Instrumentation
and Control
LOOP                  Loss Of
Offsite Power
LUHS                  Loss
of Ultimate Heat Sink
MCCI                  Molten
Core-Concrete Interaction
MCE                    Maximum
Calculated Earthquake
MCR                    Main
Control Room
MSSV                  Main
Steam Safety Valves
MDGPU              Mobile Diesel and Pumping Unit
NCM                   Non-conventional
Means
NRC                    (United States) Nuclear Regulatory Commission
NPP                     Nuclear
Power Plant
NVR                    Nuclear
Safety Rule
ONR                    Office
for Nuclear Regulation, UK
PAR                     Passive
Autocatalytic Recombiner
PCC                     Protected
  Command Center
PGA                     Peak
Ground Acceleration
PMF                    Probable
Maximum Flood
PSHA                  Probabilistic
Seismic Hazard Analysis
PSA                     Probabilistic
Safety Analysis
PSR                     Periodic
Safety Review
PWR                    Pressurised
Water Reactor
RCIC                   Reactor
Core Isolation Cooling
RCP                     Reactor
Coolant Pump
RCS                     Reactor
Coolant System
RLE                     Review
Level Earthquake
RPV                     Reactor
Pressure Vessel
RWST                  Refuelling
Water Storage Tank
SAM                    Severe
Accident Management
SAMG                 Severe
Accident Management Guidelines
SBERG                Symptom
Based Emergency Response Guidelines
SBO                     Station
Blackout
SCA                     Secondary
Control area
SDG                     Stand-by
Diesel Generator
SG                       Steam
Generator
SGTR                   Steam
Generator Tube Rupture
SFP                      Spent
Fuel Pool / Pit
SFSF                   Spent
Fuel Storage Facility
SPSA                   Seismic
Probabilistic Safety Assessment
SSC                     Structures,
Systems and Components
STUK                  Radiation
and Nuclear Safety Authority (Finland)
SWHP                 Seismic
Hazard Working Party 
UHS                     Ultimate
Heat Sink
VVER                  (Russian)
Water Water Energetic Reactor
WANO                World
Association of Nuclear Operators
WENRA              Western
European Nuclear Regulators’ Association
Annex 1: Summary table
 
 Issue no. || Description (“X” in the table where these issues or good practices are applicable) 
 I1 || External hazard safety cases corresponding to an exceedance probability of less than once in 10 000 years should be used (I1a: for earthquakes; I1b: for flooding). 
 I2 || A DBE corresponding to a minimum peak ground acceleration of 0.1 g should be used. 
 I3 || Means needed to fight accidents should be stored in places adequately protected against external events. 
 I4 || On-site seismic instrumentation should be installed. 
 I5 || Time for restoration of the safety functions in case of loss of all electrical power and/or ultimate heat sink is less than 1 hour. 
 I6 || Emergency Operating Procedures not covering all plant states (full power to shutdown states) 
 I7 || Severe Accident Management Guidelines not covering all plant states (full power to shutdown states) 
 I8 || Passive measures to prevent hydrogen (or other combustible gasses) explosions in case of Severe Accident not in place (such as Passive Autocatalytic Recombiners or other relevant alternative) 
 I9 || Filtered Venting Systems not in place 
 I10 || A backup Emergency Control Room not available, in case the Main Control Room becomes inhabitable as a consequence of the radiological releases of a severe accident, of fire in the Main Control Room or due to extreme external hazards. 
 GP1 || Existence of alternative and fully independent ultimate heat sink (good practice). 
 GP2 || Additional layer of safety systems fully independent from the normal safety systems, located in areas well protected against external events (for instance bunkered systems or hardened core of safety systems) (good practice). 
 GP3 || Additional Diesel Generators (or Combustion Turbines) physically separated from the normal diesel generators and devoted to cope with Station Black-Out, external events or severe Accident situations already installed (good practice) 
 GP4 || Mobile equipment especially Diesels Generators devoted to cope with Station Black-Out, external events or severe accident situations are already available (good practice) 
 GP5 || Additional on-site emergency control centre, from which the emergency response activities can be coordinated, should available and adequately protected against radiological and extreme natural hazards (good practice). 
 Other issues || Site / unit specific issue referred in the text of the Staff Working Document. 
The legend above
summarises the recommendations made by the peer reviews to the national
regulators for consideration to improve the safety of nuclear power plants as
well as good practises identified. The table below connects those
recommendations as well as the good practices directly to each reactor of each
NPP in the EU. In order to assess the full applicability of each recommendation
a backward reference should be made to the relevant chapter of this working
document, as well as the national reports and the individual facility reports
available on www.ensreg.eu. 
 country || Site || Type || Unit || Start of commercial operation || Current years of operation || Current net capacity [Mwe] || Site visited? || I1a || I1b || I2 || I3 || I4 || I5 || I6 || I7 || I8 || I9 || I10 || GP1 || GP2 || GP3 || GP4 || GP5 || Other issues? 
 BE || Doel || PWR || 1 || 15/02/1975 || 36 || 433 || X ||   ||   ||   ||   ||   ||   ||   ||   ||   || X ||   || X || X || X || X ||   ||   
   ||   || PWR || 2 || 01/12/1975 || 36 || 433 || X ||   ||   ||   ||   ||   ||   ||   ||   ||   || X ||   || X || X || X || X ||   ||   
   ||   || PWR || 3 || 01/10/1982 || 29 || 1006 || X ||   ||   ||   ||   ||   ||   ||   ||   ||   || X ||   || X || X || X || X ||   ||   
   ||   || PWR || 4 || 01/07/1985 || 26 || 1039 || X ||   ||   ||   ||   ||   ||   ||   ||   ||   || X ||   || X || X || X || X ||   ||   
   || Tihange || PWR || 1 || 01/10/1975 || 36 || 962 ||   ||   || X[8] ||   ||   ||   ||   ||   ||   ||   || X ||   || X || X || X || X ||   ||   
   ||   || PWR || 2 || 01/06/1983 || 28 || 1008 ||   ||   || X1 ||   ||   ||   ||   ||   ||   ||   || X ||   || X || X || X || X ||   ||   
   ||   || PWR || 3 || 01/09/1985 || 26 || 1046 ||   ||   || X1 ||   ||   ||   ||   ||   ||   ||   || X ||   || X || X || X || X ||   ||   
 BG || Kozloduy || PWR (VVER-1000/320) || 5 || 23/12/1988 || 23 || 953 || X ||   ||   ||   || X ||   ||   ||   || X || X ||   ||   ||   ||   ||   || X || X ||   
   ||   || PWR (VVER-1000/320) || 6 || 30/12/1993 || 18 || 953 || X ||   ||   ||   || X ||   ||   ||   || X || X ||   ||   ||   ||   ||   || X || X ||   
 CZ || Dukovany || PWR (VVER-440/213) || 1 || 03/05/1985 || 26 || 427 || X ||   ||   ||   || X1 || X1 ||   ||   || X1 || X || X ||   ||   ||   || X || 1 || X ||   
   ||   || PWR (VVER-440/213) || 2 || 21/03/1986 || 25 || 427 || X ||   ||   ||   || X1 || X1 ||   ||   || X1 || X || X ||   ||   ||   || X || 1 || X ||   
   ||   || PWR (VVER-440/213) || 3 || 20/12/1986 || 25 || 471 || X ||   ||   ||   || X1 || X1 ||   ||   || X1 || X || X ||   ||   ||   || X || 1 || X ||   
   ||   || PWR (VVER-440/213) || 4 || 19/07/1987 || 24 || 427 || X ||   ||   ||   || X1 || X1 ||   ||   || X1 || X || X ||   ||   ||   || X || 1 || X ||   
   || Temelin || PWR (VVER-1000/V320) || 1 || 10/06/2002 || 9 || 963 || X ||   ||   ||   || X1 ||   ||   ||   || X1 || X || X ||   ||   ||   || X || 1 || X ||   
   ||   || PWR (VVER-1000/V320) || 2 || 18/04/2003 || 8 || 963 || X ||   ||   ||   || X1 ||   ||   ||   || X1 || X || X ||   ||   ||   || X || 1 || X ||   
 FI || Loviisa || PWR || 1 || 09/05/1977 || 34 || 488 || X ||   ||   || X ||   ||   ||   || X ||   ||   || X ||   || 1 ||   || X ||   || X ||   
   ||   || PWR || 2 || 05/01/1981 || 30 || 488 || X ||   ||   || X ||   ||   ||   || X ||   ||   || X ||   || 1 ||   || X ||   || X ||   
   || Olkiluoto || BWR || 1 || 10/10/1979 || 32 || 885 ||   ||   ||   || X ||   ||   || X ||   ||   || X ||   || X1 || 1 ||   ||   ||   || X ||   
   ||   || BWR || 2 || 10/07/1982 || 29 || 860 ||   ||   ||   || X ||   ||   || X ||   ||   || X ||   || X1 || 1 ||   ||   ||   || X ||   
 FR || Belleville || PWR-1300 || 1 || 01/06/1988 || 24 || 1310 ||   || X || X ||   || X1 ||   ||   ||   || X1 ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-1300 || 2 || 01/01/1989 || 23 || 1310 ||   || X || X ||   || X1 ||   ||   ||   || X1 ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   || Blayais || PWR-900-CPY-CP1 || 1 || 01/12/1981 || 30 || 910 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPY-CP1 || 2 || 01/02/1983 || 29 || 910 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPY-CP1 || 3 || 14/11/1983 || 28 || 910 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPY-CP1 || 4 || 01/10/1983 || 28 || 910 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   || Bugey || PWR-900-CPO || 2 || 01/03/1979 || 33 || 910 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPO || 3 || 01/03/1979 || 33 || 910 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPO || 4 || 01/07/1979 || 33 || 880 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPO || 5 || 03/01/1980 || 32 || 880 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   || Cattenom || PWR-1300 || 1 || 01/04/1987 || 25 || 1300 || X || X || X ||   || X1 ||   ||   ||   || X1 ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-1300 || 2 || 01/02/1988 || 24 || 1300 || X || X || X ||   || X1 ||   ||   ||   || X1 ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-1300 || 3 || 01/02/1991 || 21 || 1300 || X || X || X ||   || X1 ||   ||   ||   || X1 ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-1300 || 4 || 01/01/1992 || 20 || 1300 || X || X || X ||   || X1 ||   ||   ||   || X1 ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   || Chinon || PWR-900-CPY-CP2 || B-1 || 01/02/1984 || 28 || 905 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPY-CP2 || B-2 || 01/08/1984 || 28 || 905 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPY-CP2 || B-3 || 04/03/1987 || 25 || 905 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPY-CP2 || B-4 || 01/04/1988 || 24 || 905 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   || Chooz || PWR-1500 N4 || B-1 || 15/05/2000 || 12 || 1500 || X || X || X ||   || X1 ||   ||   ||   || X1 ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-1500 N4 || B-2 || 29/09/2000 || 12 || 1500 || X || X || X ||   || X1 ||   ||   ||   || X1 ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   || Civaux || PWR-1500 N4 || 1 || 29/01/2002 || 10 || 1495 ||   ||   || X ||   || X1 ||   ||   ||   || X1 ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-1500 N4 || 2 || 23/04/2002 || 10 || 1495 ||   ||   || X ||   || X1 ||   ||   ||   || X1 ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   || Cruas || PWR-900-CPY-CP2 || 1 || 02/04/1984 || 28 || 915 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPY-CP2 || 2 || 01/04/1985 || 27 || 915 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPY-CP2 || 3 || 10/09/1984 || 28 || 915 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPY-CP2 || 4 || 11/02/1985 || 27 || 915 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   || Dampierre || PWR-900-CPY-CP1 || 1 || 10/09/1980 || 32 || 890 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPY-CP1 || 2 || 16/02/1981 || 31 || 890 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPY-CP1 || 3 || 27/05/1981 || 31 || 890 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPY-CP1 || 4 || 20/11/1981 || 30 || 890 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   || Fessenheim || PWR-900-CPO || 1 || 01/01/1978 || 34 || 880 || X || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPO || 2 || 01/04/1978 || 34 || 880 || X || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   || Flamanville || PWR-1300 || 1 || 01/12/1986 || 25 || 1330 ||   ||   || X ||   || X1 ||   ||   ||   || X1 ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-1300 || 2 || 09/03/1987 || 25 || 1330 ||   ||   || X ||   || X1 ||   ||   ||   || X1 ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   || Golfech || PWR-1300 || 1 || 01/02/1991 || 21 || 1310 ||   || X || X ||   || X1 ||   ||   ||   || X1 ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-1300 || 2 || 04/03/1994 || 18 || 1310 ||   || X || X ||   || X1 ||   ||   ||   || X1 ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   || Gravelines || PWR-900-CPY-CP1 || 1 || 25/11/1980 || 31 || 910 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPY-CP1 || 2 || 01/12/1980 || 31 || 910 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPY-CP1 || 3 || 01/06/1981 || 31 || 910 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPY-CP1 || 4 || 01/10/1981 || 30 || 910 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPY-CP1 || 5 || 15/01/1985 || 27 || 910 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPY-CP1 || 6 || 25/10/1985 || 26 || 910 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   || Nogent || PWR-1300 || 1 || 24/02/1988 || 24 || 1310 ||   || X || X ||   || X1 ||   ||   ||   || X1 ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-1300 || 2 || 01/05/1989 || 23 || 1310 ||   || X || X ||   || X1 ||   ||   ||   || X1 ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   || Paluel || PWR-1300 || 1 || 01/12/1985 || 26 || 1330 ||   || X || X ||   || X1 ||   ||   ||   || X1 ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-1300 || 2 || 01/12/1985 || 26 || 1330 ||   || X || X ||   || X1 ||   ||   ||   || X1 ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-1300 || 3 || 01/02/1986 || 26 || 1330 ||   || X || X ||   || X1 ||   ||   ||   || X1 ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-1300 || 4 || 01/06/1986 || 26 || 1330 ||   || X || X ||   || X1 ||   ||   ||   || X1 ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   || Penly || PWR-1300 || 1 || 01/12/1990 || 21 || 1330 ||   || X || X ||   || X1 ||   ||   ||   || X1 ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-1300 || 2 || 01/11/1992 || 19 || 1330 ||   || X || X ||   || X1 ||   ||   ||   || X1 ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   || St. Alban || PWR-1300 || 1 || 01/05/1986 || 26 || 1335 ||   ||   || X ||   || X1 ||   ||   ||   || X1 ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-1300 || 2 || 01/03/1987 || 25 || 1335 ||   ||   || X ||   || X1 ||   ||   ||   || X1 ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   || St. Laurent || PWR-900-CPY-CP2 || B-1 || 01/08/1983 || 29 || 915 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPY-CP2 || B-2 || 01/08/1983 || 29 || 915 ||   || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   || Tricastin || PWR-900-CPY-CP1 || 1 || 01/12/1980 || 31 || 915 || X || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPY-CP1 || 2 || 01/12/1980 || 31 || 915 || X || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPY-CP1 || 3 || 11/05/1981 || 31 || 915 || X || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
   ||   || PWR-900-CPY-CP1 || 4 || 01/11/1981 || 30 || 915 || X || X || X ||   || X1 ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X || 1 || 1 ||   
 DE || Biblis || PWR || A || 26/02/1975 || 37 || 1167 ||   ||   ||   ||   ||   ||   ||   ||   || X ||   ||   ||   || X || X ||   || X || X ||   
   ||   || PWR || B || 31/01/1977 || 35 || 1240 ||   ||   ||   ||   ||   ||   ||   ||   || X ||   ||   ||   || X || X ||   || X || X ||   
   || Brokdorf || PWR ||   || 22/12/1986 || 25 || 1410 ||   ||   ||   || X ||   || X ||   ||   || X1 ||   ||   ||   ||   || X || X || X || X ||   
   || Brunsbüttel || BWR ||   || 09/02/1977 || 35 || 771 ||   ||   ||   || X ||   || X ||   ||   || X ||   ||   ||   || X || X || X || X || X ||   
   || Emsland || PWR ||   || 20/06/1988 || 24 || 1329 ||   ||   ||   ||   ||   ||   ||   ||   || X1 ||   ||   ||   || X || X || X || X || X ||   
   || Grafenrheinfeld || PWR ||   || 17/06/1982 || 30 || 1275 || X ||   ||   || X ||   ||   ||   ||   || X1 ||   ||   ||   ||   || X || X || X || X ||   
   || Grohnde || PWR ||   || 01/02/1985 || 27 || 1360 ||   ||   ||   || X ||   ||   ||   ||   || X1 ||   ||   ||   ||   || X || X || X || X ||   
   || Gundremmingen || BWR || B || 19/07/1984 || 28 || 1284 || X ||   ||   ||   ||   ||   ||   ||   || X1 ||   ||   ||   || X || X || X || X || X ||   
   ||   || BWR || C || 18/01/1985 || 27 || 1288 || X ||   ||   ||   ||   ||   ||   ||   || X1 ||   ||   ||   || X || X || X || X || X ||   
   || Isar || BWR || 1 || 21/03/1979 || 33 || 878 ||   ||   ||   || X ||   ||   ||   ||   || X ||   ||   ||   ||   ||   ||   || X || X ||   
   ||   || PWR || 2 || 09/04/1988 || 24 || 1410 ||   ||   ||   || X ||   ||   ||   ||   || X1 ||   ||   ||   ||   || X || X || X || X ||   
   || Krümmel || BWR ||   || 28/03/1984 || 28 || 1346 ||   ||   ||   || X ||   || X ||   ||   || X ||   ||   ||   ||   || X ||   || X || X ||   
   || Neckarwestheim || PWR || 1 || 01/12/1976 || 35 || 785 ||   ||   ||   ||   ||   ||   ||   ||   || X ||   ||   ||   || X ||   || X || X || X ||   
   ||   || PWR || 2 || 15/04/1989 || 23 || 1310 ||   ||   ||   ||   ||   ||   ||   ||   || X1 ||   ||   ||   || X || X || X || X || X ||   
   || Philippsburg || BWR || 1 || 26/03/1980 || 32 || 890 ||   ||   ||   ||   ||   ||   ||   ||   || X ||   ||   ||   || X || X || X || X || X ||   
   ||   || PWR || 2 || 18/04/1985 || 27 || 1402 ||   ||   ||   ||   ||   ||   ||   ||   || X1 ||   ||   ||   || X || X || X || X || X ||   
   || Unterweser || PWR ||   || 06/09/1979 || 33 || 1345 ||   ||   ||   || X ||   ||   ||   ||   || X ||   ||   ||   ||   || X || X || X || X ||   
 HU || Paks || PWR (VVER-440/213) || 1 || 10/08/1983 || 28 || 470 || X ||   ||   ||   ||   ||   ||   ||   ||   ||   || X ||   ||   ||   || X || X || X ||   
   ||   || PWR (VVER-440/213) || 2 || 14/11/1984 || 27 || 473 || X ||   ||   ||   ||   ||   ||   ||   || 1 ||   || X ||   ||   ||   || X || X || X ||   
   ||   || PWR (VVER-440/213) || 3 || 01/12/1986 || 25 || 473 || X ||   ||   ||   ||   ||   ||   ||   || 1 ||   || X ||   ||   ||   || X || X || X ||   
   ||   || PWR (VVER-440/213) || 4 || 01/11/1987 || 24 || 473 || X ||   ||   ||   ||   ||   ||   ||   || 1 ||   || X ||   ||   ||   || X || X || X ||   
 LT || Ignalina || LWGR (RBMK 1500) Permanent shutdown || 1 || 31/12/1983 || - || - || X ||   ||   || X ||   ||   ||   ||   ||   ||   ||   ||   || 1 ||   ||   || X || X ||   
   ||   || LWGR (RBMK 1500) Permanent shutdown || 2 || 01/08/1987 || - || - || X ||   ||   ||   ||   ||   ||   ||   ||   ||   ||   ||   || 1 ||   ||   || X || X ||   
 NL || Borssele || PWR ||   || 26/10/1973 || 38 || 487 || X ||   || X1 || X1 || X1 || X1 ||   ||   ||   ||   ||   ||   || X || X || X || X || 1 || X 
 RO || Cernavoda || PHWR (CANDU-6) || 1 || 02/12/1996 || 15 || 650 || X || X ||   ||   ||  X1 ||   ||   ||   || X || X1 || X1 ||   || X ||   || X || X || X ||   
   ||   || PHWR (CANDU-6) || 2 || 31/10/2007 || 4 || 650 || X || X ||   ||   ||   ||   ||   || X || X || X1 || X1 ||   ||   ||   || X || X || X ||   
 SK || Bohunice || PWR (VVER-440/213) || 3 || 14/02/1985 || 27 || 505 ||   ||   ||   ||   ||   ||   ||   ||   || X1 || X1 || X ||   ||   ||   || 1 || 1 || X ||   
   ||   || PWR (VVER-440/213) || 4 || 18/12/1985 || 26 || 505 ||   ||   ||   ||   ||   ||   ||   ||   || X1 || X1 || X ||   ||   ||   || 1 || 1 || X ||   
   || Mochovce || PWR (VVER-440/213) || 1 || 29/10/1998 || 13 || 470 || X ||   ||   ||   || X ||   ||   ||   || X1 || X1 || X ||   ||   ||   || 1 || 1 || X ||   
   ||   || PWR (VVER-440/213) || 2 || 11/04/2000 || 12 || 470 || X ||   ||   ||   || X ||   ||   ||   || X1 || X1 || X ||   ||   ||   || 1 || 1 || X ||   
 SI || Krsko || PWR ||   || 01/01/1983 || 28 || 666 || X ||   ||   ||   ||   ||   ||   ||   ||   || X1 || X1 ||   ||   ||   ||   || X ||   ||   
 ES || Almaraz || PWR || 1 || 01/09/1983 || 28 || 1008 || X ||   ||   ||   ||   ||   ||   ||   || X1 || X1 || X1 ||   ||   ||   || X ||   || 1 ||   
   ||   || PWR || 2 || 01/07/1984 || 27 || 956 || X ||   ||   ||   ||   ||   ||   ||   || X1 || X1 || X1 ||   ||   ||   || X ||   || 1 ||   
   || Asco || PWR || 1 || 10/12/1984 || 27 || 996 ||   ||   ||   ||   ||   ||   ||   ||   || X1 || X1 || X1 ||   || X ||   || X ||   || 1 ||   
   ||   || PWR || 2 || 31/03/1986 || 25 || 992 ||   ||   ||   ||   ||   ||   ||   ||   || X1 || X1 || X1 ||   || X ||   || X ||   || 1 ||   
   || Cofrentes || BWR/6 MK-3 ||   || 11/03/1985 || 26 || 1064 ||   ||   ||   ||   ||   ||   ||   ||   || X1 || X1 || X ||   || X ||   ||   ||   || 1 ||   
   || S.Maria de Garona || BWR/4 MK-1 ||   || 11/05/1971 || 40 || 446 ||   ||   ||   ||   ||   ||   ||   ||   || X1 || X1 || X1 ||   || X ||   ||   ||   || 1 ||   
   || Trillo || PWR || 1 || 06/08/1988 || 23 || 1000 || X ||   ||   ||   ||   ||   ||   || X || X1 ||   || X1 ||   || X || X || X ||   || 1 ||   
   || Vandellos || PWR || 2 || 08/03/1988 || 23 || 1045 ||   ||   ||   ||   ||   ||   ||   ||   || X1 || X || X1 ||   || X ||   || X ||   || 1 ||   
 SE || Forsmark || BWR || 1 || 10/12/1980 || 31 || 978 || X ||   ||   ||   || X ||   || X ||   ||   || X ||   ||   ||   ||   ||   || 1 || X ||   
   ||   || BWR || 2 || 07/07/1981 || 30 || 990 || X ||   ||   ||   || X ||   || X ||   ||   || X ||   ||   ||   ||   ||   || 1 || X ||   
   ||   || BWR || 3 || 18/08/1985 || 26 || 1170 || X ||   ||   ||   || X ||   ||   ||   ||   || X ||   ||   ||   ||   ||   || 1 || X ||   
   || Oskarshamn || BWR || 1 || 06/02/1972 || 39 || 473 ||   ||   ||   ||   || X || X ||   ||   ||   || X ||   ||   ||   ||   ||   || 1 || X ||   
   ||   || BWR || 2 || 01/01/1975 || 36 || 638 ||   ||   ||   ||   || X || X ||   ||   ||   || X ||   ||   ||   ||   ||   || 1 || X ||   
   ||   || BWR || 3 || 15/08/1985 || 26 || 1400 ||   ||   ||   ||   || X || X ||   ||   ||   || X ||   ||   ||   ||   ||   || 1 || X ||   
   || Ringhals || BWR || 1 || 01/01/1976 || 35 || 855 || X ||   ||   ||   || X ||   ||   ||   ||   || X ||   ||   ||   ||   ||   || 1 || X ||   
   ||   || PWR || 2 || 01/05/1975 || 36 || 813 || X ||   ||   ||   || X ||   ||   ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X ||   
   ||   || PWR || 3 || 09/09/1981 || 30 || 1051 || X ||   ||   ||   || X ||   ||   ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X ||   
   ||   || PWR || 4 || 21/11/1983 || 28 || 935 || X ||   ||   ||   || X ||   ||   ||   ||   ||   ||   ||   ||   ||   ||   || 1 || X ||   
 UK || Dungeness B || AGR || 1 || 01/04/1985 || 26 || 520 ||   ||   ||   ||   ||   ||   ||   || X[9] || X2 || X ||   || X ||   ||   || X || X ||   ||   
   ||   || AGR || 2 || 01/04/1989 || 22 || 520 ||   ||   ||   ||   ||   ||   ||   || X2 || X2 || X ||   || X ||   ||   || X || X ||   ||   
   || Hartlepool || AGR || 1 || 01/04/1989 || 22 || 595 ||   ||   ||   ||   ||   ||   ||   || X2 || X2 || X ||   || X ||   ||   || X || X ||   ||   
   ||   || AGR || 2 || 01/04/1989 || 22 || 595 ||   ||   ||   ||   ||   ||   ||   || X2 || X2 || X ||   || X ||   ||   || X || X ||   ||   
   || Heysham 1 || AGR || 1 || 01/04/1989 || 22 || 585 ||   ||   ||   ||   ||   ||   ||   || X2 || X2 || X ||   || X ||   ||   || X || X ||   ||   
   ||   || AGR || 2 || 01/04/1989 || 22 || 575 ||   ||   ||   ||   ||   ||   ||   || X2 || X2 || X ||   || X ||   ||   || X || X ||   ||   
   || Heysham 2 || AGR || 1 || 01/04/1989 || 22 || 620 || X ||   ||   ||   ||   ||   ||   || X2 || X2 || X ||   ||   ||   ||   || X || X ||   ||   
   ||   || AGR || 2 || 01/04/1989 || 22 || 620 || X ||   ||   ||   ||   ||   ||   || X2 || X2 || X ||   ||   ||   ||   || X || X ||   ||   
   || Hinkley Point B || AGR || 1 || 02/10/1978 || 33 || 410 ||   ||   ||   ||   ||   ||   ||   || X2 || X2 || X ||   || X ||   ||   || X || X ||   ||   
   ||   || AGR || 2 || 27/09/1976 || 35 || 430 ||   ||   ||   ||   ||   ||   ||   || X2 || X2 || X ||   || X ||   ||   || X || X ||   ||   
   || Hunterston B || AGR || 1 || 06/02/1976 || 35 || 430 ||   ||   ||   ||   ||   ||   ||   || X2 || X2 || X ||   || X ||   ||   || X || X ||   ||   
   ||   || AGR || 2 || 31/03/1977 || 34 || 430 ||   ||   ||   ||   ||   ||   ||   || X2 || X2 || X ||   || X ||   ||   || X || X ||   ||   
   || Oldbury || GCR || 1 || 31/12/1967 || 44 || 217 ||   ||   ||   ||   ||   ||   ||   || X2 || X2 || X ||   || X ||   ||   || X || X ||   ||   
   ||   || GCR || 2 || 30/09/1968 || 43 || 217 ||   ||   ||   ||   ||   ||   ||   || X2 || X2 || X ||   || X ||   ||   || X || X ||   ||   
   || Sizewell B || PWR || 1 || 22/09/1995 || 16 || 1188 || X ||   ||   ||   ||   ||   ||   ||   || X2 || X1 || X1 ||   ||   ||   || X ||   ||   ||   
   || Torness || AGR || 1 || 25/05/1988 || 23 || 600 ||   ||   ||   ||   ||   ||   ||   || X2 || X2 || X ||   ||   ||   ||   || X || X ||   ||   
   ||   || AGR || 2 || 03/02/1989 || 22 || 605 ||   ||   ||   ||   ||   ||   ||   || X2 || X2 || X ||   ||   ||   ||   || X || X ||   ||   
   || Wylfa || GCR || 1 || 01/11/1971 || 40 || 490 ||   ||   ||   ||   ||   ||   ||   || X2 || X2 || X ||   || X ||   ||   || X || X ||   ||   
   ||   || GCR || 2 || 03/01/1972 || 39 || 490 ||   ||   ||   ||   ||   ||   ||   || X2 || X2 || X ||   || X ||   ||   || X || X ||   ||   
 
[1]               ENSREG specifications agreed in May 2011, see www.ensreg.eu 
[2]               January 2012
[3]               http://www.ensreg.eu/sites/default/files/ENSREG%20Action%20plan.pdf

[4]               http://www.ensreg.eu/sites/default/files/Peer%20Review%20Topical%20Teams.pdf

http://ensreg.com/sites/default/files/Country%20Review%20Teams.pdf

[5]               This section is based on the Final Report of the
Council Ad-hoc Group on Nuclear Security (AHGNS).
[6]               http://register.consilium.europa.eu/pdf/en/12/st10/st10616.en12.pdf,
31.5.2012.
[7]               International
Physical Protection Advisory Service.
[8] Improvement planned.
[9] EOPs and SAMGs needs further development to be in line with
international standards – Improvement planned.