Implementation of
post-Fukushima
international
recommendations
Switzerland

Table of contents

1

Introduction

2

Implementation status in Switzerland of International Recommendations 5

3

2

2.1

Table 1: ENSREG recommendations

5

2.2

Table 2: CNS 2nd Extraordinary Meeting recommendations

15

2.3

Table 3: IAEA Action Plan recommendations for Members States

19

2.4

Table 4: List of checkpoints from the Swiss "Lessons Learned" report 25

2.5

Table 5: List of open points for Switzerland from the EU Stress Tests 29

List of abbreviations30

2 | I m p l e m e n t a t i o n o f p o s t - F u k u s h i m a i n t e r n a t i o n a l r e c o m m e n d a t i o n s | ENSI

1

Introduction

In the aftermath of the Fukushima Dai-ichi accident the international community has undertaken
several actions to foster exchange of information, cooperation and peer review in the field of nuclear
safety, thus facilitating the leverage and dissemination of the lessons learned from the accident.
In September 2011 the International Atomic Energy Agency (IAEA) issued the so-called Action Plan on
Nuclear Safety /1/ addressing issues that the international community as well as the single member
countries should pick up with the ultimate goal of strengthening nuclear safety worldwide. The IAEA
decided also to call for a (second) extraordinary meeting of the contracting parties to the Convention
on Nuclear Safety (CNS), which was held in August 2012 and resulted in a list of action-oriented
objectives compiled in the annex to the Final Summary Report of the meeting /2/.
In parallel, the European Council mandated the European Nuclear Safety Regulators Group (ENSREG)
to conduct a first-of-a-kind peer review exercise for nuclear power plants in Europe – the European
Stress Tests – addressing the targeted re-evaluation of safety margins in relation to the most relevant
Fukushima issues. The European Stress Tests were concluded in April 2012 /3/ and a follow-up waslaunched to monitor the advancement of post-Fukushima activities on the considered topics. In theframe of the follow-up activities ENSREG produced, among others, a compilation /4/ ofrecommendations and suggestions summarizing the results and best practices identified during thepeer review of the 17 country reports participating in the exercise (15 countries from the European
Union having nuclear power plants plus Switzerland and Ukraine).
ENSI, as regulatory authority for nuclear safety and security in Switzerland, has actively contributed tothe above-mentioned international efforts in the conviction that such efforts towards moretransparency and openness could benefit the internationally shared fundamental safety objective /5/ ofprotecting people and the environment from harmful effects of ionizing radiation. Thus ENSI submitted
several reports to international scrutiny and discussion, among which the Swiss National Report for theEuropean Stress Tests /6/ with the corresponding Peer Review report by ENSREG for Switzerland /7/,
the Swiss status report for 2012 within the frame of the European Stress Tests Follow-Up /8/ with thecorresponding Peer Review Summary report by ENSREG /9/. Along the lines of the IAEA Action Plan on
Nuclear Safety ENSI has published the following reports: Swiss National Report to the Second CNS
Extraordinary Meeting /10/ and the 6th National Report of Switzerland to the Convention on Nuclear
Safety /11/. Beyond that, ENSI hosted at the end of 2011 an Integrated Regulatory Review Service(IRRS) Mission of the IAEA, a peer review mission on the activities of the regulatory body, the results ofwhich were made publicly available /12/. At the same time, as recommended in the IAEA Action Plan,
the Mühleberg NPP invited an Operational Safety Review Team (OSART) led by the IAEA to conduct apeer review mission on its operational activities and disclosed the mission’s results /13/.
At the national level ENSI has conducted in 2011 an own event analysis aiming at extracting the lessons
learned in view of their applicability for the situation in Switzerland and derived from those a series of
so-called checkpoints which warranted further analysis /14/. Further open points were added to theissue list (see Tables 4 and 5 of the present report) on completion of the analyses for the European
Stress Tests. In order to keep track of the work conducted on the identified issues, ENSI publishes
regularly on a yearly basis an Action Plan Fukushima (/15/, /16/, /17/), the most recent update of whichdates February 2014.

ENSI | I m p l e m e n t a t i o n o f p o s t - F u k u s h i m a i n t e r n a t i o n a l r e c o m m e n d a t i o n s | 3

By means of critical reviews, frank discussions among experts and stakeholders, as well as open
communication of evaluation results and regulatory decisions ENSI has advanced its commitment totransparency and openness in Switzerland and abroad. The present report describes theimplementation status in Switzerland of the recommendations issued by ENSREG and the IAEA in theaftermath of the Fukushima Dai-ichi accident as of February 2014. Chapters 2.1 to 2.3 list one by one
the ENSREG and IAEA recommendations extracted from /1/, /2/ and /4/ in their original formulation andinclude a concise comment about how Switzerland, and in particular ENSI, has dealt with the issue.
Reference is also made to the own lessons learned, checkpoints and open points as listed in Chapters
2.4 and 2.5.

REFERENCES/1/

IAEA Action Plan on Nuclear Safety, September 2011
http://www.iaea.org/newscenter/focus/actionplan/reports/actionplanns130911.pdf/2/

IAEA, Final Summary Report from the 2nd Extraordinary Meeting of the Contracting Parties to
the Convention on Nuclear Safety, August 2012
http://www.iaea.org/Publications/Documents/Conventions/cns-summaryreport310812.pdf/3/

ENSREG, EU Stress Test Peer Review Final Report, April 2012
http://www.ensreg.eu/sites/default/files/EU%20Stress%20Test%20Peer%20Review%20Final%
20Report_0.pdf/4/

ENSREG, Compilation of recommendations and suggestions from the Review of the European
Stress Tests, July 2012
http://www.ensreg.eu/sites/default/files/Compilation%20of%20Recommendationsl_0.pdf/5/

IAEA, Fundamental Safety Principles, SF-1, November 2006
http://www-pub.iaea.org/MTCD/publications/PDF/Pub1273_web.pdf/6/

ENSI, EU Stress Tests: Swiss National Report, December 2011
http://static.ensi.ch/1326182677/swiss-national-report_eu-stress-test_20111231_final.pdf/7/

ENSREG, Peer Review report on EU Stress Tests for Switzerland, April 2012
http://www.ensreg.eu/sites/default/files/Country%20Report%20CH%20Final.pdf/8/

ENSI, EU Stress Test: Swiss National Action Plan, Follow-Up of the Peer Review, 2012 Year-End
Status Report, December 2012
http://static.ensi.ch/1357553310/ensi_swissap_eng_121231_final.pdf/9/

ENSREG National Action Plans Workshop, Summary Report, June 2013
http://www.ensreg.eu/sites/default/files/HLG_p(201324)_120%20Final%20NAcP%20Workshop%20Summary%20Report.pdf/10/

ENSI, Swiss National Report to the Second CNS Extraordinary Meeting, May 2012
http://static.ensi.ch/1336738953/swiss_national_report_to_the_second_cns_extraordinary_mee
ting.pdf/11/

ENSI, 6th National Report of Switzerland to the Convention on Nuclear Safety, August 2013
http://static.ensi.ch/1376900783/cns_6th_national_report_of_switzerland_web_v2.pdf

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/12/

IAEA, Integrated Regulatory Review Service (IRRS) Report to Switzerland , May 2012
http://static.ensi.ch/1336384223/irrs-mission-to-switzerland_2011_report_final.pdf/13/

IAEA, Report of the Operational Safety Review Team (OSART) Mission to the Mühleberg
Nuclear Power Plant (Switzerland), January 2013
http://static.ensi.ch/1359642780/osart-report-muhleberg_8-january-2013.pdf/14/

ENSI, Lessons Learned and Checkpoints based on the Nuclear Accidents at Fukushima, ENSIAN-8001, October 2011
http://static.ensi.ch/1344405641/ensi_lessons_eng_020712_web.pdf/15/

ENSI, Fukushima Action Plan 2012, ENSI-AN-7844, 28 February 2012
http://static.ensi.ch/1331720486/ensi_actionplan_2012_fukushima.pdf (in German)/16/

ENSI, Fukushima Action Plan 2013, ENSI-AN-8283, 28 February 2013
http://static.ensi.ch/1369139826/ensi_action_plan_fukushima_2013_eng.pdf/17/

ENSI, Fukushima Action Plan 2014, ENSI-AN-8711, 28 February 2014
http://static.ensi.ch/1393918895/ensi_2014_aktionsplan_fukushima_de.pdf (in German)

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2

Implementation status in Switzerland of International
Recommendations

2.1

Table 1: ENSREG recommendations

Reference

Description

StatusRelatedCheckpoint
or Open
Point

European Level Recommendations

ENSREG2.1.

The peer review Board recommends thatWENRA, involving the best available
expertise from Europe, develop guidanceon natural hazards assessments,
including earthquake, flooding andextreme weather conditions, as well as
corresponding guidance on theassessment of margins beyond thedesign basis and cliff-edge effects.

ENSREG2.2.

The peer review Board recommends that
ENSREG underline the importance of
periodic safety review. In particular,
ENSREG should highlight the necessity
to reevaluate natural hazards andrelevant plant provisions as often as
appropriate but at least every 10 years.

In compliance with the Swiss DETEC Ordinance on the Hazard
Assumptions and the Assessment of the Protection against
Accidents in Nuclear Installations, hazard assumptions are
updated to take into consideration findings from experience,research and methodical developments. In particular with the
PEGASOS Project and the PEGASOS Refinement Project,
Switzerland has performed a first-of-a-kind study in Europe for the
probabilistic assessment of seismic hazards on the sites of the
Swiss NPPs.
As regards most recent regulatory developments, ENSI is an active
contributor in the WENRA working group on natural hazards
assumptions. The updated WENRA safety reference levels will be
implemented by ENSI as soon as they are officially adopted by
WENRA (public consultation on the updates ended in February2014).
In Switzerland, Periodic Safety Reviews (PSRs) are mandatory. As
stated in the Article 34 of the Swiss Nuclear Energy Ordinance, thefollowing elements are part of a PSR:
•safety concept•operational management and performance•deterministic safety analysis•probabilistic safety analysis•overall safety assessment•organisation and personnel
The deterministic and probabilistic analyses must be based on upto-date hazard assumptions. The current seismic hazards are
based on the PEGASOS Refinement Project results.
The flooding hazards for the Swiss NPPs have been recently
updated. Further refinements of the analysis methods for flooding
are possible but should be supported by research results. In thisrespect, ENSI is participating with several federal agencies in a
research project on flooding hazard calculation for the Aare river
basin.
As regards extreme weather conditions the operators havesubmitted their updated hazards at the beginning of 2014, withthe corresponding safety cases expected by the end of 2014. ENSI
will subsequently review the safety cases in order to check theadequacy of the protection against extreme weather conditions.

PP1, OP4-1-

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Urgent implementation of therecognised measures to protect
containment integrity is a finding of thepeer review that national regulators
should consider.
The measures to be taken can varydepending on the design of the plants.
For water cooled reactors, they include
equipment, procedures and accident
management guidelines to:•depressurize the primary circuit in orderto prevent high-pressure core melt;•prevent hydrogen explosions•prevent containment overpressure.

ENSREG2.4.

Necessary implementation of measures
allowing prevention of accidents andlimitation of their consequences in caseof extreme natural hazards is a finding of
the peer review that national regulators
should consider.

In Switzerland, the recommendation ENSREG2.3. has alreadybeen analysed and technical measures have been implemented toprotect the third barrier. Regarding hydrogen hazard, extensive
studies were performed which served as basis for the probabilistic
safety analysis. ENSI ordered nevertheless a new re-assessment of
this topic also taking into account the state-of-the-art inbackfitting technology. As listed in the Action Plan Fukushima
2013 (http://www.ensi.ch/en/2013/05/21/action-plan-fukushima2013/), the following plant-specific points need to be addressed:• review of robustness and scope of the measurement equipment
in connection with the assessment of the hydrogen hazard;• update of the hydrogen hazard analyses as well as investigationof hydrogen dispersion from the containment to other buildings;• review of existing provisions and procedures for protection
against the hydrogen hazard;• review of the containment venting path with regard to thehydrogen hazard.
The restoration of the containment integrity in case of a total SBO
during shutdown (see OP6-2) has also been identified as an open
point by ENSI at the end of the EU stress tests. This issue will be
addressed in the course of 2014 (see ENSI Fukushima Action Plan
2014).
The results of ENSI's reviews performed after Fukushima
confirmed that the Swiss nuclear power plants display high levelsof protection against the impacts of earthquakes, flooding andcombinations thereof, and that appropriate precautions have been
put in place to cope with a loss of power supply and of the ultimate
heat sink. For such events, the legal requirements are met, taking
into account the latest hazard assumptions and the NPPs are
therefore in compliance with the safety objectives.
Beyond that, with regard to reactivity control, fuel cooling andconfinement of radioactive substances, safety margins areavailable. During the evaluation of the safety margins, theimportance of the bunkered special emergency safety systems inplace in the Swiss NPPs was confirmed.
As described in ENSI Fukushima Action Plan 2013(http://www.ensi.ch/en/2013/05/21/action-plan-fukushima-2013/),a project was started in 2013 with the aim of increasing the safetymargins. Based on the results of the deterministic and probabilistic
analyses, areas for possible significant risk reduction wereidentified. For these areas (namely earthquakes and external
flooding) the operators will submit to ENSI’s review their relevant
studies in 2014.

PP5, PP7,
PP8, OP6-2

All PPs
OPs and
PRTs

Topic I: Natural Hazards

ENSREG3.1.1.

To consider the use of a return frequencyof 1E-4 per annum (0.1g minimum peakground acceleration for earthquakes) for
plant reviews/back-fitting with respect toexternal hazards safety cases.

ENSREG3.1.2.

To consider the possible secondary
effects of seismic events, such as flood orfire arising as a result of the event, in
future assessments.

2011: ENSI ordered the seismic safety of the Swiss NPPs to bereassessed.
In the analysis, the operators had to consider the intermediate
results of the PEGASOS Refinement Project (PRP) for the sitespecific seismic hazard.
2012: The analyses showed that margins exist and that only
moderate, non-relevant building damage is to be expected.
The Swiss NPPs are designed to withstand natural hazards with areturn period of 1E-4 years, and have further margins beyond this.
2013: The PRP results are submitted to ENSI for final review
according to the SSHAC Level 4 procedure followed for theevaluation of the seismic hazard.
2014: ENSI is reviewing the submitted documents and willsubsequently set the updated site-specific seismic hazard curves.
In the Swiss legislative framework, the DETEC ordinance on the
Hazard Assumptions and the Assessment of the Protection against
Accidents in Nuclear Installations requires that secondary effectsof earthquakes be considered in the seismic safety cases.
2011: ENSI ordered the seismic safety of the Swiss NPPs to bereassessed.
2012: ENSI confirmed that the seismic safety cases of the Swiss
NPPs are compliant with the relevant requirements.
2013: The Mühleberg NPP started a project for reinforcing theLake Wohlen dam (some 2 Km upstream from the Mühleberg
NPP) against sliding, in order to further decrease the hazard ofseismically-induced flooding. Licensing authority for the project is

PP1

PP1

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Reference

Description

ENSREG3.1.3.

To consider the use of a protectedvolume approach to demonstrate flood
protection for identified rooms or spaces.

ENSREG3.1.4.

To consider the implementation ofadvanced warning systems fordeteriorating weather, as well as theprovision of appropriate procedures to befollowed by operators when warnings are
made.

ENSREG3.1.5.

To consider the installation of seismic
monitoring systems with related
procedures and training.

To consider the development ofstandards to address qualified plant
walkdowns with regard to earthquake,flooding and extreme weather – toprovide a more systematic search for
ENSREG3.1.6.
non-conformities and correct them (e.g.
appropriate storage of equipment,
particularly for temporary and mobile
plant and tools used to mitigate beyond
design basis (BDB) external events).
To consider the analysis of incrementally
increased flood levels beyond the design
ENSREG3.1.7.
basis and identification of potential
improvements, as required by the initial
ENSREG specification for the stress tests.
To consider, in conjunction withrecommendation 2.1 and 3.1.7, theformal assessment of margins for all
ENSREG3.1.8.
external hazards including, seismic,
flooding and severe weather, andidentification of potential improvements.
Topic II: Loss of safety systems

ENSREG3.2.1.

To consider the provision of alternativemeans of cooling including alternate heatsinks. Examples include steam generator(SG) gravity alternative feeding,alternate tanks or wells on the site, aircooled cooling towers or water sources inthe vicinity (reservoir, lakes, etc.) as anadditional way of enabling core cooling.

ENSREG3.2.2.

To consider the enhancement of the onsite and off-site power supplies.
Examples include adding layers of
emergency power, adding independentand dedicated backup sources, theenhancement of the grid throughagreements with the grid operator on
rapid restoration of off-site power,
additional and/or reinforced off-site
power connections, arrangements for

Statusthe Federal Office of Energy (supervision of dams).
The reactor buildings and the buildings with the bunkered safetysystems of all Swiss NPPs are protected against flooding.
2011-2012: The flood protection of other safety-relevant buildings
was enhanced with mobile flood barriers.
Warning systems are already in place for dams and similar facilities
with the potential to cause flooding at NPP sites in case of large
releases of water. Corresponding procedures exist on the NPP
operator's side.
2012: ENSI requested the safety cases for extreme weather
conditions to be updated by the operators.
2014: The updated hazards were submitted at the beginning of theyear and safety cases will be submitted to ENSI by the end of theyear. Change in the procedures, if necessary, will be part of theevaluation.
At all four Swiss NPP sites, seismic monitoring systems were
installed many years before the Fukushima accident. Operatingprocedures include rules for the operators on how to respond after
certain pre-defined seismic thresholds are reached (e.g., OBE,
SSE).
2014: ENSI is analysing the advantages and disadvantages of an
automatic shutdown of the plants triggered by the seismic
instrumentation.

Guideline ENSI-A05 requires systematic and comprehensive
walkdowns in the context of the development and update of a PSA
based on recognised standards, e.g. for seismic walkdowns EPRINP-6041-SL.
All the NPPs have developed seismic housekeeping concepts
which are regularly inspected by ENSI.

2011: The external flooding analyses were redone for flood levels
with an exceedance frequency of 1E-4 per annum. It could beshown that all Swiss NPPs fulfil the regulatory requirements.
2012: A research project was initiated in Switzerland to develop
the scientific data necessary to further refine the flood hazard
assessment.
2013: ENSI started a project with the aim of increasing the safetymargins in case of accidents beyond the design basis (including
seismic and flooding events).
2014: The operators' reports on increasing the safety margins will
be submitted to ENSI.
All Swiss NPPs with the exception of Mühleberg NPP haveredundant, diverse ultimate heat sinks.
2011: At ENSI's request the Mühleberg NPP started a project tobackfit an additional, diverse ultimate heat sink.
2012: ENSI approved the Mühleberg NPP's submittal issuing theso-called permit of concept.
2013: The Mühleberg NPP decided to permanently shutdown theplant in 2019 and informed ENSI about its intention of deviatingfrom the permit of concept.
2014: The Mühleberg NPP will submit a request for alternative
measures for a diverse ultimate heat sink taking into account thelimited additional operating lifetime.
The design of power supply of the Swiss NPPs is based on multiple
layers of defence. The first layer consists of the external main grid;
the second layer consists of the island mode of the plant after load
rejection (failure of the main grid). The external reserve grid acts
as third layer. The emergency electrical power supply (either froman emergency DG or a direct feed from a hydroelectric power
plant) is the 4th layer. In the fifth layer the special emergency
electrical power supply from bunkered emergency DGs is activatedupon loss of external feed. A sixth layer consists of accident
management equipment.

RelatedCheckpoint
or Open
Point

PP4

PP1, OP4-1

PP1, PP5,
OP2-1

PP4

PP1, PP4

PP1, OP2-2,
PRT-1

PP3, PP12,
PP13, PP14

PP2, PP13

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Reference

ENSREG3.2.3.

Description

Statusblack start of co-located or nearby gas orhydro plants, replacing standard ceramic
based items with plastic or other material
that are more resistant to a seismic
event. Another example is the possible
utilization of generator load shedding
and house load operation for increased
robustness, however, before introducing
such arrangements the risks need to beproperly understood.
To consider the enhancement of the DC
power supply. Examples include
improving the battery discharge time by
upgrading the existing battery,changing/diversifying battery type(increasing resistance to common-mode
failures), providing spare/replacement
batteries, implementing well-preparedload shedding/ staggering strategies,
performing real load testing and on-line
monitoring of the status of the batteries
and preparing dedicated recharging
options (e. g. using portable generators).

Since the Fukushima event, the sixth layer has been reinforced anda seventh layer with off-site accident management equipment has
been newly added (see ENSREG3.3.14).

ENSREG3.2.4.

To consider the implementation ofoperational or preparatory actions withrespect to the availability of operational
consumables.
Examples include, ensuring the supply of
consumables such as fuel, lubrication oil,
and water and ensuring adequate
equipment, procedures, surveillance,
drills and arrangements for the resupply
from off-site are in place.

ENSREG3.2.5.

To consider the enhancement of
instrumentation and monitoring.
Examples include separate
instrumentation and/or power sources toenable monitoring of essential
parameters under any circumstances for
accident management and the ability tomeasure specific important parameters
based on passive and simple principles.

ENSREG3.2.6.

To consider the enhancement of safety in
shutdown states and mid-loop operation.
Examples of improvements include,
reducing or prohibiting mid-loop
operation, adding dedicated hardware,
procedures and drills, the use of otheravailable water sources (e. g. fromhydroaccumulators), requiring theavailability of SGs during shutdown
operations and the availability of
feedwater in all modes.

ENSREG3.2.7.

To consider the use of temperatureresistant (leak-proof) primary pumpseals.

ENSREG3.2.8.

To consider the enhancement ofventilation capacity during SBO to ensure
equipment operability.

All battery groups for safety-important electrical loads in an
emergency have been analysed with respect to the battery
discharge time and their locations in the buildings. The result
showed that, for safety equipment, battery life – before accident
management power supply for recharging the batteries isavailable – is sufficient in all cases, and for safety-importantequipment in most cases.
2014: The operator will submit their reports within the project
ENSI has started in 2013 on increasing the safety margins, which inturn can lead to additional improvements in the DC power supply(see ENSREG 3.1.7).
2011: creation of an external storage facility at Reitnau, containing
various accident management resources for emergencies
including DG fuel and other consumables.
Enhancement of the equipment on site was also conducted by theoperators.
2012: ENSI reviewed the operational concept of the Reitnau
external storage facility and inspected it.
2013: The procedures of the activation of the Reitnau external
storage facility and the provision of SAM equipment and its
transportation from the external storage facility to the plants havebeen tested. These tests have been carried out as part of an
unannounced alarm exercise in one NPP and a national emergency
drill.
Guideline ENSI-B12 on emergency preparedness sets therequirements for accident instrumentation and monitoring.
2011-2014: Upon ENSI's request the NPPs backfitted newtemperature and level measurements for the SFPs. The older
NPPs also started major backfitting projects for an additional
flooding and seismically robust SFP cooling system.
2014: new analysis on hydrogen management will be submitted by
the operators and reviewed by ENSI. Within the project related toincreasing the safety margins, a review of requirements for SAM
instrumentation will be performed. Additional actions aredescribed under ENSREG3.1.5..

The Swiss NPPs have sufficient procedures on the required
availability of core cooling capacity in shutdown states and midloop operation.

Gösgen NPP, Leibstadt NPP and Mühleberg NPP all have primary
pumps that are inherently leak-proof after shutdown.
2014: Beznau NPP will install an additional robust seal water
system as part of the bunkered emergency system.
Effects of the loss of ventilation at the special emergency control
rooms were tested. These tests showed that the operability of theequipment located in rooms of the special emergency bunkered
systems, including control panels, is assured for at least several
days.

RelatedCheckpoint
or Open
Point

PP2, OP5-1

PP2, PP12,
PP13

PP5

-

PP3

PP2

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Reference

Description

ENSREG3.2.9.

To consider the enhancement of themain control room (MCR), theemergency control room (ECR) andemergency control centre (ECC) toensure continued operability andadequate habitability conditions in theevent of a station black-out (SBO) and in
the event of the loss of DC (this also
applies to Topic 3 recommendations).

ENSREG3.2.10.

To consider the improvement of therobustness of the spent fuel pool (SFP).
Examples include
reassessment/upgrading SFP structural
integrity, installation of qualified andpower-independent monitoring,
provisions for redundant and diverse
sources of additional coolant resistant toexternal hazards (with procedures anddrills), design of pools that prevents
drainage, the use of racks made of
borated steel to enable cooling with fresh(unborated) water without having toworry about possible recriticality,
redundant and independent SFP coolingsystems, provision for additional heatexchangers (e. g. submerged in the SFP),
an external connection for refilling of the
SFP (to reduce the need for an approach
linked to high doses in the event of thewater falling to a very low level) and thepossibility of venting steam in a case ofboiling in the SFP.

ENSREG3.2.11.

To consider the enhancement of thefunctional separation and independenceof safety systems. Examples include theelimination of full dependence ofimportant safety functions on auxiliary
systems such as service water and theintroduction of an alternate source ofcooling.

ENSREG3.2.12.

To consider the verification of assured
flow paths and access under SBO

StatusDuring an extended SBO the necessary safety functions will be
carried out by means of accident management measures (AMM),
e.g. the use of fire water pumps or trucks, mobile diesel
generators, and other means that have a relatively small waste
heat production compared to the regular safety systems.
According to ENSI’s experience, conduction of AMM is possible
without extra ventilation of such equipment.
Since 1996 improvements of the ventilation of the main control
room (MCR) were implemented in order to ensure the habitabilityof the MCR in case of accidents with release of radioactive
material. The special emergency control room displays wereextended by adding neutron flux, important containment data,and stack release parameters to the existing displays. Further
enhancements were carried out regarding operational safety andavailability.
2012: The review of the emergency infrastructure at the nuclear
power plant site was initiated. The inspections that took placefocused on short term operability of the ECCs and their substituterooms: topics addressed encompass the operation strategy of the
ECCs and their substitute rooms as well as single aspects of theirhabitability under severe accident conditions. The operators havealso been required to submit reports on the long term operabilityof these rooms.
2013: Follow-up inspections were carried out, focusing on theradiation protection material to be used in case of an emergency.
2014: ENSI will review the submitted reports on the long term
operability of the ECCs and their substitute rooms.

2011: the protection of the Swiss NPPs and their spent fuel pools(SFP) against external events has been reassessed by theoperators and reviewed by ENSI.
ENSI ordered all licence holders to immediately implement two
physically separated lines/connections for feeding the SFPs fromoutside the buildings as an accident management measure, and to
backfit seismically robust SFP cooling systems in the older NPPs.
Correspondingly, backfitting projects are ongoing at the Beznau
and Mühleberg NPPs.
The Beznau NPP is furthermore required to improve theearthquake resistance of the SFP storage building, and has toimplement a venting duct to remove heat and pressure generated
by boiling SFP water in order to protect the building structure incase of beyond design basis accidents. A backfitting project was
launched in this respect and is foreseen to complete by 2014.

In the Swiss legal framework the Nuclear Energy Ordinancerequires physical separation and independence of safety systems.
The newer Swiss NPPs are designed from the beginning with thespecial emergency safety systems functionally separated andindependent from the classical safety systems. In the older Swiss
NPPs the special emergency safety systems were backfitted in the
90s.
During the periodic safety reviews which are performed every ten
years compliance of the NPPs with the regulatory requirements is
extensively checked. Appropriate improvements may result fromthe PSR reviews.
Additional analyses have been initiated especially within the frameof the EU stress tests. A redundant, diverse ultimate heat sinkneeds to be implemented in the Mühleberg NPP (seeENSREG3.2.1).
2012: ENSI inspection on the status of the provisions for copingwith a long lasting SBO.

RelatedCheckpoint
or Open
Point

PP10, PP11

PP6, PP14

PP3

PP2, PP11,
PP16, OP5-1

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Reference

ENSREG3.2.13.

ENSREG3.2.14.

ENSREG3.2.15.

ENSREG3.2.16.

ENSREG3.2.17.

Description

Statusconditions. Ensure that the state in whichisolation valves fail and remain, whenmotive and control power is lost, iscarefully considered to maximise safety.
Enhance and extend the availability of
DC power and instrument air (e. g. byinstalling additional or larger
accumulators on the valves). Ensure
access to critical equipment in all
circumstances, specifically whenelectrically operated turnstiles areinterlocked.

A verification of the robustness of the containment and primarycircuit isolation was submitted by the operators.
2013: ENSI reviewed the submitted document on containment andprimary circuit isolation and concluded that the equipment
employed is seismically robust enough to withstand loads
according to the newest seismic hazard assumptions available(PRP intermediate hazards). As a improvement measure, theGösgen NPP will increase the seismic resistance of theconventional emergency diesel generatos which are needed forcontainment isolation.
2014: The operators will submit their analyses on provisions to
restore containment integrity during outages in case of a total
SBO.

To consider the provision of mobile
pumps, power supplies and air
compressors with prepared quickconnections, procedures, and staff
training with drills. Mobile devices areintended to enable the use of existing
safety equipment, enable direct feedingof the primary or secondary side, allow
extended use of instrumentation andoperation of controls, allow effective firefighting, and ensure continued
emergency lighting. The equipment
should be stored in locations that are safe
and secure even in the event of generaldevastation caused by events
significantly beyond the design basis (thisalso applies to Topic 3
recommendations).
To consider the provision for a bunkered
or “hardened” system to provide an
additional level of protection with trained
staff and procedures designed to copewith a wide variety of extreme events
including those beyond the design basis(this also applies to Topic 3
recommendations).
To consider the enhancement of thecapability for addressing accidents
occurring simultaneously on all plants ofthe site. Examples include assuring
preparedness and sufficient supplies,
adding mobile devices and fire trucks andincreasing the number of trained andqualified staff (this also applies to Topic 3
recommendations).
To consider the establishment of regularprogrammes for inspections to ensurethat a variety of additional equipment
and mobile devices are properly installed
and maintained, particularly for
temporary and mobile equipment andtools used for mitigation of BDB external
events. Development of relevant staff
training programmes for deployment ofsuch devices.
To consider the performance of further
studies in areas where there areuncertainties. Uncertainties may exist in
the following areas:•The integrity of the SFP and its liner inthe event of boiling or external impact.
•The functionality of control equipment(feedwater control valves and SG relief
valves, main steam safety valves,2011: Creation of an external storage facility at Reitnau, containing
various operational resources that can readily be called up in caseof an emergency.
2013: Test of the severe accident equipment stored in Reitnau
during an emergency exercise (see ENSREG3.2.4).

Recommendation already implemented.
The Swiss NPPs already have bunkered systems containing thespecial emergency safety systems specially designed against
external hazards (including man-made threats).

RelatedCheckpoint
or Open
Point

PP12, PP13,
PP15, PP16,
OP5-1

PP18, PP19,
PP12

Only Beznau NPP has two units. In the year 2013, theorganizational aspect of this issue has been addressed in thecourse of the revision of the Emergency Regulation (NotfallReglement). Resource aspects (equipment, personnel) are treatedwithin the work on post-Fukushima checkpoint PP16.
Furthermore, this point has been addressed in the new draft of theregulatory guideline ENSI-A03 “Periodic Safety Review of NPPs”.

PP16, PP18,
PP12, PP19

2011: On the basis of the submitted documentation and inspection
results, ENSI concluded that the Reitnau external storage facility isa viable facility for the purposes of storing equipment and auxiliary
supplies in order to extend the emergency preparedness of the
Swiss NPPs in case of severe accidents.
2013: Equipment, procedures and organization of the Reitnau
external storage facility were tested during an alarm exercise andthe general emergency drill.

PP16, PP18,
PP12, PP19

After Fukushima, the issues related to SFP have been re-assessedby the Swiss operators and reviewed by ENSI. Backfitting werealso implemented (e.g. external hook-up points for water make-up
into the SFP; backfitting of level and temperature instrumentation
for the SFP). Further studies regarding hydrogen dispersion are
currently on-going (see ENSREG 3.3.10.).
For SBO please refer to the recommendations above.
Extensive infrastructure damage is the subject of studies
performed in the frame of the activities of the IDA-NOMEX

PP1, PP6,
PP14
PP2
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Reference

Description

isolation condenser flow path,containment isolation valves as well as
depressurisation valves) during the SBO
to ensure that cooling using natural
circulation would not be interrupted in a
SBO (this is partially addressed inrecommendation 3.2.10).
•The performance of additional studies
to assess operation in the event ofwidespread damage, for example, theneed different equipment (e.g.
bulldozers) to clear the route to the mostcritical locations or equipment. This
includes the logistics of the external
support and related arrangements(storage of equipment, use of national
defence resources, etc.).
Topic III: Severe accident management
To consider the incorporation of theWENRA reference levels related tosevere accident management (SAM) into
their national legal frameworks, andensure their implementation in the
installations as soon as possible. This
would include:•Hydrogen mitigation in the containment•Demonstration of the feasibility andimplementation of mitigation measures
to prevent massive explosions in case of
severe accidents.
•Hydrogen monitoring system Installation of qualified monitoring of thehydrogen concentration in order to avoid
dangerous actions when concentrations
that allow an explosion exist.
ENSREG3.3.1.
•Reliable depressurization of the reactor
coolant system – Hardware provisions
with sufficient capacity and reliability toallow reactor coolant systemdepressurization to prevent highpressure melt ejection and early
containment failure, as well as to allow
injection of coolant from low pressuresources.
•Containment overpressure protection Containment venting via the filters
designed for severe accident conditions.
•Molten corium stabilization - Analysis
and selection of feasible strategies andimplementation of provisions against
containment degradation by molten
corium.
To consider adequate hardware
provisions that will survive external
hazards (e.g. by means of qualification
against extreme external hazards,
storage in a safe location) and the severe
ENSREG3.3.2.
accident environment (e.g. engineering
substantiation and/or qualification
against high pressures, temperatures,radiation levels, etc.), in place, to performthe selected strategies.
To consider the systematic review of
SAM provisions focusing on the
ENSREG3.3.3.
availability and appropriate operation ofplant equipment in the relevant
circumstances, taking account of

StatusRelatedCheckpoint
or OpenPoint

working group (see IAEA-AP3.1, ENSREG 3.3.4. and 3.3.9.).
ENSI supports and coordinates safety research within its
regulatory powers. The results of that research directly influence
its Guidelines, regulatory decisions and resources. Research
projects serve training purposes and thereby maintaincompetence within ENSI and among its experts. ENSI’s research
programme contributes to international projects which
Switzerland would be unable to conduct on its own. International
exchange of expertise is thereby encouraged.

ENSI has committed to incorporate all WENRA reference levels in
its guidelines. The process is completed to a high percentage(more than 80%).
After Fukushima, WENRA created additional topical working
groups dedicated to tackle the issues of: Mutual assistance,
Natural Hazards, containment in severe accidents, Accident
management and Periodic safety reviews.
ENSI participates actively in all the topical working groups and will
implement the updated safety reference levels as soon as they are
officially issued (public consultation on the updated WENRA
reference levels was concluded in February 2014).

PP28

AM provisions are available on the Swiss NPPs sites and offsite.
After Fukushima these provisions were checked andimprovements implemented (e.g. additional onsite AM-DGs).
Beyond that, the Reitnau external storage facility was establishedin June 2011 (see ENSREG3.3.14).

PP1, PP15,
PP16, OP5-1

AM provisions are available on the Swiss NPPs sites and offsite.
After Fukushima these provisions were checked andimprovements implemented (e.g. additional onsite AM-DGs).
Beyond that the Reitnau external storage facility was establishedin June 2011 (see ENSREG3.3.14).

PP15, PP16,
OP5-1

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Reference

ENSREG3.3.4.

ENSREG3.3.5.

ENSREG3.3.6.

ENSREG3.3.7.

ENSREG3.3.8.

Description

Statusaccident initiating events, in particular
extreme external hazards and thepotential harsh working environment.
To consider, in conjunction with therecommendation 2.4 (among theEuropean level recommendations) , theenhancement of SAMGs taking into
account additional scenarios, including, asignificantly damaged infrastructure,including the disruption of plant level,
corporate-level and national-levelcommunication, long-duration accidents(several days) and accidents affecting
multiple units and nearby industrial
facilities at the same time.
To consider the validation of theenhanced SAMGs.

SAMGs of the Swiss NPPs are generally symptom-based and thus
not only focused on specific scenarios. Recently the use of mobile
accident management equipment in case of a SBO received
special attention, including focused inspections by ENSI.
At the Swiss national level (e.g. in case of accidents not involving
only the nuclear facilities) the IDA-NOMEX group has been tasked
by the Swiss government to review emergency preparedness
measures in case of extreme events in Switzerland (see IAEAAP3.1). A concept paper has identified 56 measures to be analysedand checked in detail. Work on the 56 measures is in progress.

To consider exercises aimed at checking
the adequacy of SAM procedures andorganizational measures, including
extended aspects such as the need forcorporate and nation level coordinatedarrangements and long-duration events.
To consider regular and realistic SAM
training exercises aimed at training staff.
Training exercises should include the useof equipment and the consideration ofmulti-unit accidents and long-duration
events. The use of the existing NPP
simulators is considered as being a useful
tool but needs to be enhanced to cover
all possible accident scenarios.
To consider the extension of existing
SAMGs to all plant states (full and lowpower, shutdown), including accidents
initiated in SFPs.

ENSREG3.3.9.

To consider the improvement ofcommunication systems, both internaland external, including transfer of severe
accident related plant parameters andradiological data to all emergency andtechnical support centre and regulatory
premises.

ENSREG3.3.10.

To consider the preparation for the
potential for migration of hydrogen, withadequate countermeasures, into spaces
beyond where it is produced in the
primary containment, as well ashydrogen production in SFPs.

ENSREG3.3.11.

To consider the conceptual preparationsof solutions for post-accident
contamination and the treatment ofpotentially large volumes ofcontaminated water.

In Switzerland, the adequacy of SAMGs is continuously reviewed
in PSR and emergency exercises.
2011: Start of the revision of Guideline ENSI-B11 (Emergency
exercises). The revised version includes regular emergency
exercises with the involvement of fire brigades and security forces.
Beyond that, the revised ENSI-B11 foresees the possibility of longlasting exercises. The communication among different
organisations and transboundary partners will be regularly
checked during the general emergency drills.

RelatedCheckpoint
or Open
Point

PP15, PP16,
OP5-1

PP15, PP16
OP5-1

PP15, PP16
OP5-1

The ENSI Guideline ENSI-B11 describes the requirements for
emergency exercises (see ENSREG 3.3.6).
2013: During the national emergency drill AM equipment wastested (also from the Reitnau external storage facility) as well asprocedures and organisational processes.

PP15, PP16,
OP5-1

SAMGs of the Swiss NPPs cover all plant states and include the
SFPs.

PP15, PP16
OP5-1

Effects of damage to infrastructure and communication systems
are addressed by IDA-NOMEX (see IAEA-AP3.1). The work on themeasures suggested by IDA-NOMEX is in progress.
2013: ENSI and the NPPs have introduced the so-called POLYCOM(radio-based communication network also used by the rescue
teams in Switzerland) as an alternative communication system.
2014: Currently the possibility of satellite-based communication isunder investigation.
2012: The licensees have submitted their investigations regarding
protection against hydrogen hazards in the area of the spent fuelpools. Based on its review of the submitted documentation, ENSI
has imposed specific additional requests for each plant to ensure
monitoring of the spent fuel pools, upgrading of the SFP coolingsystems and extension of the relevant on-site emergency
preparedness measures. These measures additionally reduce therisk of a severe accident in the area of the SFP.
2014: The licensees will submit their updated studies on hydrogen
management including migration to other building outside thecontainment. Based on the review of the submitted
documentation ENSI will decide on the necessity of additional
hardware provisions (e.g. PARs).
2013: ENSI issued a report on the situation in Switzerland in caseof a discharge of large quantities of radioactivity into the rivers
Aare and Rhine. It concluded that the measures to protect the
population are in principle adequate. Some improvements e.g. in
the alarming process and continuous radioactivity surveillance
have been identified and will be followed-up in 2014.
ENSI has required the licensees to examine those cases in whichlarge quantities of radioactively contaminated water can be
expected in their plant, the routes by which these quantities ofPP9, PP15,
PP17, PP20,
PP22, PP23

PP7, OP6-1,
PRT-2

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Reference

Description

ENSREG3.3.12.

To consider the provision for radiation
protection of operators and all other staff
involved in the SAM and emergency
arrangements.

ENSREG3.3.13.

To consider the provision of an on-site
emergency centre protected against
severe natural hazards and radioactive
releases, allowing operators to stayonsite to manage a severe accident.

ENSREG3.3.14.

To consider rescue teams and adequate
equipment to be quickly brought on sitein order to provide support to local
operators in case of a severe situation.

ENSREG3.3.15.

ENSREG3.3.16.

To consider a comprehensive Level 2 PSA
as a tool for the identification of plant
vulnerabilities, quantification of potential
releases, determination of candidate
high-level actions and their effects andprioritizing the order of proposed safety
improvements. Although PSA is an
essential tool for screening andprioritizing improvements and forassessing the completeness of SAM
implementation, low numerical risk
estimates should not be used as the basis
for excluding scenarios fromconsideration of SAM especially if theconsequences are very high.
To consider the performance of further
studies to improve SAMGs. Examples ofareas that could be improved with further
studies include:•The availability of safety functions
required for SAM under different
circumstances.
•Accident timing, including core melt,
reactor pressure vessel (RPV) failure,basemat melt-through, SFP fueluncovery, etc.
•PSA analysis, including all plant statesand external events for PSA levels 1 and
2.
•Radiological conditions on the site andassociated provisions necessary to ensure
MCR and ECR habitability as well as thefeasibility of AM measures in severe
accident conditions, multi-unit accidents,
containment venting, etc.
•Core cooling modes prior to RPV failure
and of re-criticality issues for partly

Statuswater can reach the surrounding area, and the methods that canbe used to retain and/or minimise them. Work on this topic is inprogress.
Within its regulatory oversight, ENSI routinely checks radiation
protection measures for severe accident situations in all Swiss
NPPs, including rescue teams. Additional radiation protection
equipment in case of an emergency is available at the Reitnau
external storage facility.
2012: ENSI requested the plants to submit a report on the longterm operability of the emergency control centre (ECC) andsubstituted ECC after a core damage accident with large releases.
ENSI carried out inspections in the ECC and substituted ECC at
NPP sites.
2013: The plants submitted these reports.
2014: The reports are currently under review.
2011: Creation of an external storage facility at Reitnau, containing
various operational resources for emergencies that can readily becalled up.Transport by road or air transportation by helicopter areplanned options. Beyond off-site equipment, it’s worth
mentioning that mobile accident management equipment stored
on-site has been significantly upgraded.
2013: Test of the procedures of the activation of the Reitnau
external storage facility and the provision of SAM equipment andits transportation from the external storage facility to the plant.
These tests have been carried out as part of an unannounced
alarm exercise and an emergency exercise in one plant.
Guideline ENSI-A05 (Probabilistic safety analysis: quality andscope) already requires all Swiss NPPs to develop and maintainlevel 2 PSAs covering all relevant accidents due to internal orexternal events in all plant states. The Swiss NPPs have developed
their level 2 PSAs accordingly.
SAMGs of the Swiss NPPs are generally symptom based and thus
not only focused on specific scenarios. PSA is not used to reduce
the scope of SAMG but applied to check the completeness ofconsidered measures in the SAMGs and to support the technicalbasis.

SAMGs of the Swiss NPPs are generally symptom-based and thus
suitable to cover a comprehensive set of scenarios. Recently theuse of mobile or accident management equipment to cope with an
SBO received special attention, including focused inspections by
ENSI.
SAMGs of the Swiss NPPs cover all plant states and include the
SFPs.
Studies with relevance to the SAMGs are continuously being
performed.
ENSI and the operators independently cooperate with domestic
and foreign research institutions to increase knowledge on severe
accident behaviour.

RelatedCheckpoint
or Open
Point

PP18, PP31

PP10, PP11

PP18, PP19,
PP31

-

PP16

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Reference

Description
damaged cores, with un-borated watersupply.
•Phenomena associated with cavity
flooding and related steam explosion
risks.
•Engineered solutions regarding molten
corium cooling and prevention of
basemat melt-through.
•Severe accident simulators appropriate
for NPP staff training.

StatusRelatedCheckpoint
or OpenPointENSI | I m p l e m e n t a t i o n o f p o s t - F u k u s h i m a i n t e r n a t i o n a l r e c o m m e n d a t i o n s | 15

2.2
Reference

Table 2: CNS 2nd Extraordinary Meeting recommendations
Description

CNS-EOM1

Take the IAEA Safety Standards into
account in enhancing nuclear safety.

CNS-EOM2

Include information in its report under theConvention on Nuclear Safety (National
Report) about how it has taken or intends
to take the IAEA Safety Standards(including, in particular, the Safety
Fundamentals and Requirements) into
account in implementing its obligations
under the Convention on Nuclear Safety.

CNS-EOM3

CNS-EOM4

Ensure that its regulatory body iseffectively independent in making
regulatory judgments based on scientificand technological grounds and taking
enforcement actions and that it has
functional separation from entities having
responsibilities or interests, such as thepromotion or utilisation of nuclear energy(including electricity production), that
could conflict with safety or otherimportant regulatory objectives orotherwise unduly influence the decision
making of the regulatory body.
Ensure the effectiveness of its regulatory
body by providing for adequate legal
authority, sufficient human and financial
resources, staff competence, access tonecessary external expertise for its
decision-making based on adequate
scientific and technical knowledge, accessto international cooperation, and othermatters needed for fulfilling its
responsibilities for the safety of nuclear
installations.

CNS-EOM5

Ensure that its regulatory body requires alicensee for a nuclear installation to haveadequate expertise and resources to fulfill
its responsibility for the safe operation of
the nuclear installation, including
effective response to any accident andmitigation of its consequences.

CNS-EOM6

Ensure that its regulatory body operates
in a transparent and open manner, taking
into account legitimate concerns oversecurity and other sensitive interests thatmight be adversely affected by the public
disclosure of particular information.

StatusENSI was peer-reviewed by an IRRS mission in 2011 which also
checked for compliance with the IAEA safety standards (see IAEA
AP4.1)The explanatory reports (mandatory reports accompanying ENSI
guidelines) contain an updated list of all relevant IAEA
requirements and guides and WENRA reference levels which arecovered by each guideline.
ENSI was peer-reviewed by an IRRS mission in 2011 which also
checked for compliance with the IAEA safety standards (see IAEA
AP4.1).
In its 6th national CNS report Switzerland promotes the idea thatthe use of IAEA Safety Standards should be strengthened in regularpeer review missions on the assessment of the regulatory
framework and activities, on NPP design and on NPP operation. In
fact Switzerland proposed an amendment to the Convention
aiming at setting safety goals for new plants as well as existing
reactors.
The Nuclear Energy Act requires the supervisory authorities to be
independent of technical directives and formally independent of
the licensing authorities. It also clarifies and expands the position,
duties and responsibilities of ENSI as the supervisory authority for
nuclear safety in terms of the development of safety criteria andthe maintenance of nuclear safety.
Since the beginning of 2009, ENSI is an independent body
constituted under public law. It reports direct to the Government
but is completely separate from the Swiss Federal Office of Energy.
In other words, the regulatory body is now legally, institutionally,
politically and financially independent.
Costs incurred by the safety authorities (with the exception of theregulatory framework and informations to the public), totallingsome 60 million Swiss francs per year, are mainly covered by feesfrom licensees.
Knowledge management and training measures are an integral
part of ENSI's Management System. The process includes anannually updated systematic compilation of the skill andknowledge requirements for each organisational unit. Staff training
is based on this compilation (see also the 6th National Report of
Switzerland to the Convention on Nuclear Safety).
Swiss nuclear legislation stipulates that nuclear installations must
be kept in good condition and that the licensee must provide
persons responsible for the safe operation of a nuclear installation
with the necessary resources.
Under the Swiss Nuclear Energy Act, there must be a sufficientnumber of qualified staff with the expertise required to manage
and control a nuclear installation during all phases of its life cycle. A
minimum level of staffing with qualified personnel is stipulated forthe plants on a 24-hour basis. This ensures that adequate staff ispresent in the plant at all times under normal conditions, to initiate
alarms and to undertake the first measures required in case of an
emergency.
Moreover, all employees of Swiss NPPs are members of therespective Emergency Response Organisation (ERO), so the plants
can always draw on a sufficient large pool of specialists for their
ERO.
Under the Nuclear Energy Act (Article 74), ENSI “shall regularly
inform the general public about the condition of nuclear
installations and any matters pertaining to nuclear goods andradioactive waste” and “shall inform the general public of any
special occurrences”. In addition to that, ENSI is obliged to respondto questions from the parliament on nuclear safety and the work of
the regulatory body. As a federal authority, ENSI is subject to theRelatedCheckpoint orOpen Point

PP29

PP29

PP30

PP29, PP30

PP29, PP31,
PP36, PP37

PP29, PP30

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Reference

Description

CNS-EOM7

Include information in its National Reporton its efforts to ensure the independence,
effectiveness and transparency of its
regulatory body.

CNS-EOM8

Host, as appropriate, an international
peer review mission of its regulatory
framework governing the safety of
nuclear installations, if the Contracting
Party has an operating nuclear
installation.

CNS-EOM9

CNS-EOM10

CNS-EOM11

CNS-EOM12

CNS-EOM13

Host regularly, as appropriate for the size
and number of the nuclear installations
within that Contracting Party,
international peer review missions of theoperational safety of its nuclear
installations, if the Contracting Party has
an operating nuclear installation.
Host international peer review missions
on integrated nuclear infrastructure andother relevant matters, including site anddesign safety reviews prior tocommissioning its first nuclear
installation,
Include information in its National Reporton any international peer review missions
under paragraph 1, 2 or 3 of this sectionthat the Contracting Party has hosted in
the period between two review meetingsof the Contracting Parties including asummary of the findings,
recommendations and other results ofthe missions, actions taken to addressthese results, and plans for follow-up
missions.
Make its National Report and any written
questions and responses relating to thatreport publicly available, with the
exception of any particular item of
information that would adversely affectsecurity or other sensitive interests if
publicly disclosed and request the IAEA tomaintain this information, other than any
information covered by the above
exception, on a website open to the
public.
Make any international peer review
mission reports, any follow-up reports or
any national responses to such reports
publicly available, with the exception of
any particular items of information thatwould adversely affect security or othersensitive interests if publicly disclosed
and request the IAEA to maintain thisinformation, other than any information
covered by the above exception, on a

StatusFederal Act on Freedom of Information in the Swiss administration.
According to this law, all ENSI documents are public with a few
exceptions, such as security-related information, personal data or
trade secrets.
The communication services of ENSI comply well with these legal
requirements. They regularly provide direct information to the
public. ENSI’s website www.ensi.ch is an important information
tool covering all aspects of nuclear safety in Switzerland in thenational languages of German and French as well as some aspects
in Italian and English. It is accompanied by activities on social media– e.g. Twitter, Facebook, YouTube, etc.
All this information is listed in chapter 8 "regulatory body" of the
6th National Report of Switzerland for the CNS (see also CNSEOM3).
From the very beginning Switzerland, and in particular its nuclear
regulatory body ENSI, committed to international peer review
missions. Switzerland had already hosted an IRRT mission in 1998
and a follow-up in 2003 and has provided experts to participate invarious IRRT and IRRS missions in the past. According to the law(ENSI ordinance) ENSI has to periodically host IRRS missions.
The last IRRS mission took place in 2011 and a follow-up isscheduled for 2015 (see IAEA AP2.1).

RelatedCheckpoint orOpen Point

PP29

PP29

All Swiss plants regularly undergo WANO missions. From 1994 to2000 the plants hosted OSART missions as well.
In order to comply with IAEA AP5.2 recommendation ENSI plans tohave all the NPPs carry out new OSART missions. This new series
started with an OSART mission in Mühleberg NPP in 2012. The
follow-up will take place in 2014.

PP29

Recommendation not applicable.
Switzerland started its nuclear programme more than 50 years ago.

-

Switzerland’s 6th National Report to the CNS presents the resultsof both the IRRS Mission from 2011 and the OSART Mission to
Mühleberg NPP from 2012 (see 6th National Report of Switzerland
for the CNS pages 61 and 146).

PP29

Switzerland’s 6th National Report to the CNS is available on ENSI
website on the following webpage (see CNS-EOM15)
http://www.ensi.ch/en/2013/08/16/6th-national-report-ofswitzerland-to-the-convention-on-nuclear-safety/

All related documents to the IRRS mission from 2011 (the latest to
take place in Switzerland) are available on ENSI website
http://www.ensi.ch/en/dossiers-3/irrs-mission-2011/ .
The final report of the IAEA to the OSART mission in Mühleberg isavailable under http://static.ensi.ch/1359642780/osart-reportmuhleberg_8-january-2013.pdf .
Switzerland’s 6th National Report to the CNS presents the results ofboth IRRS Mission from 2011 and the OSART Mission to Mühleberg
NPP from 2012.

PP29

PP29

ENSI | I m p l e m e n t a t i o n o f p o s t - F u k u s h i m a i n t e r n a t i o n a l r e c o m m e n d a t i o n s | 17

Reference

Description

StatusRelatedCheckpoint orOpen Point

website open to the public.

CNS-EOM14

CNS-EOM15

Include information in its National Reporton its efforts to enhance openness andtransparency in the implementation of its
obligations under the Convention on
Nuclear Safety.

Enhance the robustness of the peer
review of national reports submitted
under the CNS through the preparationand submission of thorough reports that
present successes and challenges and thefrank discussion of these reports.

In 2009, in connection with the search for sites for deep geologicalrepositories, the Swiss Federal Office of Energy set up theTechnical Forum on Safety, which is led by ENSI. The Technical
Forum on Safety discusses and answers technical and scientificquestions asked by the public, communities, siting regions,organisations, cantons and authorities in neighbouring states. The
forum comprises experts from the body leading the process (Swiss
Federal Office of Energy), from other bodies with supervisory or
supportive roles (ENSI, Swiss Federal Office of Topography[swisstopo]), from commissions (Federal Nuclear Safety
Commission [NSC], from the National Cooperative for the Disposalof Radioactive Waste [Nagra], from the cantons), and includes one
representative from each of the siting regions.
A similar panel (Technical Forum on NPPs) was created by ENSI in2012 for topics related to the safety of NPPs. All results of the work
conducted in the Technical Fora are publicly available (in German)on the ENSI website (http://www.ensi.ch/de/2012/09/03/ensiforum-fragen-und-antworten-zur-sicherheit-von-kernkraftwerken/
and http://www.ensi.ch/de/2013/09/25/technischen-forumkernkraftwerke-eingereichte-fragen/).
ENSI actively participated in the IAEA working group on
effectiveness and transparency to improve the CNS and its review
conferences.
Switzerland’s 6th National Report to the CNS is available on ENSI
website on the following webpage
http://www.ensi.ch/en/2013/08/16/6th-national-report-ofswitzerland-to-the-convention-on-nuclear-safety//

PP29

PP29

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2.3
Reference

Table 3: IAEA Action Plan recommendations for Members States
Description

Status

1. Safety assessment in the light of the accident at TEPCO's Fukushima Daiichi Nuclear Power Stations
In the scope of the EU stress test and as required by ENSI’s formal
orders issued shortly after Fukushima, the operators of the Swiss
nuclear power plants submitted their updated safety cases fornatural hazards (updated extreme weather hazards were submitted
but safety cases are still pending). The safety cases are based onsite-specific hazards which refer to a 1E-4 occurrence frequency per
year.
The results of ENSI’s review confirm that the Swiss NPPs display ahigh level of protection against the impacts of earthquakes, flooding
and other natural hazards, as well as loss of electrical power andultimate heat sink. For the performed analyses, the most updated
Member States to promptly undertake asite-specific hazard assumptions, e.g. PRP Intermediate Hazard fornational assessment of the design ofearthquakes, have been taken into account. The safety margins,
nuclear power plants against site specific
IAEA-AP1.1
which have been determined in the updated analyses, areextreme natural hazards and to
attributable to the robust design of the special emergency systems
implement the necessary correctiveat all Swiss NPPs (bunkered systems). The systems have a special
actions in a timely manner.
protection against external events, including an independent power
supply and a separate supply of cooling water.
Beyond that, improvements have been identified and corrective
actions have already been implemented except for major backfitting
projects which are still on going. In particular for the Mühleberg NPP
a redundant, diverse UHS has been requested (for implementation
status and more details see ENSREG3.2.1).
Provisions for handing accidents involving disrupted infrastructure
have also been taken off-site with the installation of an external
emergency storage facility for all Swiss NPPs in Reitnau (seeENSREG3.3.14).
2. IAEA Peer reviews
The IAEA Secretariat to strengthen
existing IAEA peer reviews by
incorporating lessons learned and by
ensuring that these reviews
IAEA-AP2.1
appropriately address regulatory
effectiveness, operational safety, design
Switzerland was the first Western country to request a mission by ansafety, and emergency preparedness
IAEA International Regulatory Review Team (IRRT). The mission
and response; Member States to provide
took place in 1998, the follow‐up mission in 2003. Swiss legislation
experts for peer review missions.
requires ENSI to regularly host IRRS missions.
The IAEA Secretariat, in order to
The last IRRS mission to Switzerland took place in November 2011,
enhance transparency, to provide
including issues dedicated to the lessons learned from thesummary information on where andFukushima event. The IRRS Follow-Up mission to Switzerland iswhen IAEA peer reviews have taken
scheduled for 2015. Furthermore, ENSI experts so far have
IAEA-AP2.2
place, and to make publicly available in aparticipated in sixteen IRRT and IRRS missions to other countries
timely manner the results of suchand chaired two of these missions.
reviews with the consent of the StateAt the international level, ENSI encourages the conduct ofconcerned.
international peer reviews having committed itself to transparencyof the regulatory performance (see CNS-EOM8 and CNS-EOM13).
Member States to be strongly
encouraged to voluntarily host IAEA
peer reviews, including follow-up
IAEA-AP2.3
reviews, on a regular basis; the IAEA
Secretariat to respond in a timely
manner to requests for such reviews.
3. Emergency prepardness and response
In May 2011, the Swiss Federal Council decided to appoint an
Member States to conduct a prompt
interdepartmental working group to review emergency protection
national review and thereafter regularmeasures in case of extreme events in Switzerland (IDA-NOMEX).
reviews of their emergency
The remit of this working group, in which ENSI was also represented,
preparedness and response
was to examine in the light of the Fukushima accident whether
IAEA-AP3.1
arrangements and capabilities, with thefurther action is required regarding emergency protection in case of
IAEA Secretariat providing support andextreme events in Switzerland, and whether any new statutory andassistance through Emergency
organisational emergency protection measures need to be taken. In
Preparedness Review (EPREV) missions,
July 2012, the Federal Council acknowledged the report of theas requested.
working group IDA-NOMEX and issued tasks for the elaboration oforganisational measures in the field of personnel and material for

RelatedCheckpoint
or Open
Point

PP1,
OP4-1,
PRT-1

PP29

-

PP29

PP15,
PP22, PP29

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Reference

Description

StatusRelatedCheckpoint
or OpenPoint

emergency management, improvement of the coordination andcooperation at national level and the clarification of responsibilities.
ENSI will mainly work on the reference scenarios and the emergency
planning zone concept, but will also be involved in several othermeasures.
The emergency preparedness of Switzerland and its response at theinternational level is regularly verified by its participation ininternational exercises conducted by the IAEA or ECURIE. The
OECD/NEA INEX exercises are another opportunity to verify certain
aspects of emergency management. Switzerland usuallyparticipates in these exercises. In November 2011, the IRRS mission
reviewed, amongst other things, the Swiss concept for emergency
preparedness and response.
Switzerland also participates in working groups of HERCA and
WENRA on emergency preparedness.
Finally, in order to improve the emergency response system at thenational and international level, members of ENSI and the National
Emergency Operations Centre actively support the activities of the
OECD/NEA working party on Nuclear Emergency Matters.
The IAEA Secretariat, Member States
and relevant international organizations
to review and strengthen theinternational emergency preparedness
and response framework, taking into
account recommendations given in the
final report of the International Action
IAEA-AP3.2
Plan for Strengthening the International
Preparedness and Response System for
Nuclear and Radiological Emergencies,and encouraging greater involvement of
the relevant international organizationsin the Joint Radiation Emergency
Management Plan of the International
Organizations.
The IAEA Secretariat, Member States
and relevant international organizations
to strengthen the assistancemechanisms to ensure that necessary
assistance is made available promptly.
IAEA-AP3.3.
Consideration to be given to enhancing
and fully utilizing the IAEA Response andAssistance Network (RANET), including
expanding its rapid response
capabilities.
Member States to consider, on a
voluntary basis, establishing national
IAEA-AP3.4
rapid response teams that could also bemade available internationally through
RANET.
4. National regulatory body
Member States to conduct a prompt
national review and thereafter regularreviews of their regulatory bodies,including an assessment of their
IAEA-AP4.1
effective independence, adequacy ofhuman and financial resources and theneed for appropriate technical andscientific support, to fulfil their
responsibilities.

IAEA-AP4.2

Each Member State with nuclear power
plants to voluntarily host, on a regularbasis, an IAEA IRRS mission to assess its
national regulatory framework. In
addition, a follow-up mission to be
conducted within three years of the main
IRRS mission.

As a consequence of the nuclear accident in Fukushima,
considerable effort has been deployed in Switzerland to strengthen
emergency preparedness and response at the national level with thework of the IDA-NOMEX group, see IAEA-AP3.1). Numerous tasks inthis respect are ongoing. Switzerland is committed to review andimplement IAEA’s recommendation to strengthen emergency
preparedness and response capabilities, in particular those identified
during an IRRS-mission in Switzerland in 2011.
Switzerland is further involved in international working groups
aiming at the harmonization of emergency preparedness andresponse in case of an emergency. Within the framework of RANET,
Switzerland will make available to other countries measurements
capacities and offer advisory services if needed. Switzerland ismember of the REMPAN network since 2013.

PP15,
PP22, PP29

PP22
In 2013 Switzerland joined the RANET and will make available toother countries measurements capacities and offer advisory
services.

PP22

A two-week IRRS mission took place in November 2011, ahead ofwhich a self-assessment was conducted by ENSI over a period ofalmost 2 years. The final report by the review mission contains 19
Good Practices, 12 Recommendations and 18 Suggestions. By theend of 2012, ENSI drafted an action plan on the measures needed tocope with the mission findings in view of the IRRS follow-up mission
which is scheduled for 2015.
Regarding the regulatory body, the IRRS team noted that “ENSI isinstitutionally, financially and politically independent”. A Good
Practice was given to the fact that the ENSI ordinance requires ENSI
to undergo an IRRS mission periodically. As a consequence of one
suggestion related to staffing, ENSI established a section fordecommissioning in August 2012 which will be further developed inaccordance with the advancement in the NPP decommissioning
projects (the Mühleberg NPP is due to permanently cease operationin 2019). In addition, a Human Capital Management concept wasdeveloped in 2012 by ENSI which will be implemented step by stepPP29, PP30

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Reference

Description

StatusRelatedCheckpoint
or OpenPoint

over the next three years.
5. Operator's organisations
Member States to ensure improvement,
as necessary, of management systems,
safety culture, human resourcesmanagement, and scientific and
IAEA-AP5.1
technical capacity in operatingorganizations; the IAEA Secretariat toprovide assistance to Member States
upon request.

IAEA-AP5.2

Each Member State with nuclear power
plants to voluntarily host at least one
IAEA Operational Safety Review Team(OSART) mission during the coming
three years, with the initial focus on
older nuclear power plants. Thereafter,
OSART missions to be voluntarily hosted
on a regular basis.

ENSI has started tackling the issue of management of safety by theoperators in the late 90s.
In 2013, ENSI published a report on its integrated oversightapproach. After the accident in Fukushima, safety culture was once
more identified as a key aspect. In this regard, safety culture was oneof the topics of the ENSI Fukushima action plan. As a result, a
position paper on safety culture was published in March 2014.

PP30, PP37

In the period from 1994 to 2000 all Swiss NPPs underwent OSART
missions, including follow-up missions, and all of them have
implemented the recommendations listed in the OSART reports.
Following the recommendation from the IAEA Action Plan on
Nuclear Safety, Switzerland requested a new OSART mission for the
Mühleberg NPP which reached 40 years of commercial operation in
2012. The OSART mission took place in October 2012 and thefollow-up mission is scheduled in 2014.
ENSI asked the NPPs to plan for regular OSART missions, possibly to
be alternated with the WANO missions.
All Swiss OSART reports are derestricted and available to the public,e.g. http://static.ensi.ch/1359642780/osart-report-muhleberg_8january-2013.pdf .

PP29

The Swiss legal framework governing the safe use of nuclear energy
is extensively based on the IAEA Safety Standards. When drafting
guidelines, the IAEA safety standards are systematically taken into
account. ENSI will continue its efforts to complete its regulatory
framework considering the current IAEA Safety Standards.
ENSI is actively involved in the IAEA’s committees for the drafting of
the IAEA Safety Standards and thereby contributes to theirstrengthening. ENSI is represented in the Nuclear Safety Standards
Committee (NUSSC), in the Radiation Safety Standards Committee(RASSC), in the Transport Safety Standards Committee (TRANSSC)
and in the Waste Safety Standards Committee (WASSC).

PP28

6. IAEA safety standards

IAEA-AP6.1

Member States to utilize as broadly andeffectively as possible the IAEA Safety
Standards in an open, timely andtransparent manner. The IAEA
Secretariat to continue providing
support and assistance in theimplementation of IAEA Safety
Standards.

7. International legal framework
States parties to explore mechanisms toenhance the effective implementation of
the Convention on Nuclear Safety, theJoint Convention on the Safety of Spent
Fuel Management and the Safety ofRadioactive Waste Management, theConvention on the Early Notification of a
IAEA-AP7.1
Nuclear Accident and the Convention on
Assistance in the Case of a Nuclear
Accident or Radiological Emergency,
and to consider proposals made toamend the Convention on Nuclear
Safety and the Convention on the Early
Notification of a Nuclear Accident.
IAEA-AP7.2

Member States to be encouraged to join
and effectively implement these
Conventions.

IAEA-AP7.3

Member States to work towards
establishing a global nuclear liability
regime that addresses the concerns of all
States that might be affected by anuclear accident with a view to providing
appropriate compensation for nuclear
damage. The IAEA International Expert
Group on Nuclear Liability (INLEX) to
recommend actions to facilitateachievement of such a global regime.

Switzerland is signatory party to the listed conventions.
Switzerland supports efforts to strengthen the global system fornuclear safety.
Switzerland aims for more transparency in the reporting on the CNS
meetings and the peer review missions by calling for mandatory
publication of the review results. The IAEA Action Plan on Nuclear
Safety includes these elements on a non-mandatory basis and isconsidered to be a necessary step towards the effective
strengthening of the global nuclear safety regime.
At the Second Extraordinary Meeting of the Convention on Nuclear
Safety held in August 2012, Switzerland proposed various
amendments to the Convention. To accommodate those, a working
group entrusted with the task of strengthening the Convention wasestablished. Switzerland is actively participating in this working
group. Switzerland also contributes in the Working Group on
Practices in the Management of the Review Process under theConvention on Nuclear Safety and the Joint Convention. ENSI
reaffirmed this position during the Fukushima Ministerial
Conference on Nuclear Safety in December 2012.
Nuclear liability is governed by the Act on Nuclear Third Party
Liability of 18 March 1983. This act reflects internationally accepted
principles such as strict liability and channelling of liability to theoperator of a nuclear facility. The act does not foresee any limitationof third party liability and provides for a minimum amount ofcoverage (1 million Swiss francs). On 13 June 2008, Switzerland
approved the revised Nuclear Third Party Liability Act and also
ratified the international Paris and Brussels Conventions. The total
revision of the Nuclear Third Party Liability Act increases the level ofcompulsory insurance coverage for nuclear accidents. It also greatly

PP28

PP28

-

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Reference

Description

Member States to give due
consideration to the possibility of joining
the international nuclear liability
instruments as a step toward achieving
such a global regime.
8. Capacity building

IAEA-AP8.1

Member States with nuclear power
programmes and those planning toembark on such a programme tostrengthen, develop, maintain andimplement their capacity building
programs, including education, training
and exercises at the national, regional
and international levels; to continuously
ensure sufficient and competent humanresources necessary to assume their
responsibility for safe, responsible andsustainable use of nuclear technologies;
the IAEA Secretariat to assist as
requested. Such programmes to cover all
the nuclear safety related areas,
including safe operation, emergency
preparedness and response andregulatory effectiveness and to build
upon existing capacity building
infrastructures.

StatusRelatedCheckpoint
or OpenPoint

simplifies the claims procedure and so better protects victims'
interests. The revised Liability Act can only enter into force when therevision protocol to the Paris Convention is ratified by at least twothirds of the 16 signatory states.

Switzerland has a well-defined legislative and regulatory framework
for the peaceful use of nuclear energy and the protection against
ionizing radiation. The policy and strategy are codified in major
statutes which establish the regulatory framework for the safety offacilities and sources, radiation protection, safe transport ofradioactive material, safe management of waste, decommissioning
and emergency planning. Regarding capacity building programs,
ENSI concluded in the 6th CNS national report that the existing
nuclear installations have adequate financial resources to support
the safety of each nuclear installation. They also have sufficientqualified staff with appropriate education and training for all safetyrelated activities together with adequate retraining opportunities.
On the regulatory side, knowledge management and training
measures are an integral part of ENSI's Management System (seeCNS-EOM4).

After the accident in Japan’s Fukushima Dai‐ichi NPP on 11 March
2011, an interdisciplinary team of experts from ENSI reconstructed
the events of the accident and subjected them to in‐depth analysis.
The results were presented to the public in two reports at the end ofMember States with nuclear power
August 2011. The third report on the Fukushima accident (Lessons
programmes and those planning tolearned) outlines how Switzerland can continue to optimise theembark on such a programme, tosafety of its NPPs on the basis of experience gained in Japan. Based
IAEA-AP8.2
incorporate lessons learned from theon the lessons learned (together with input from several
accident into their nuclear powerinternational sources) ENSI issued an “Action Plan Fukushima”. The
programme infrastructure; the IAEA
“Action Plan Fukushima” is effective from 2012 onwards andSecretariat to assist as requested.
updated annually with reports on the current status of on-goinganalyses and safety upgrades. It is expected that the issues listed in
the “Action Plan Fukushima” will be closed by 2015 with major
backfittings possibly taking two additional years to complete.
9. Protection of the people and the environment from ionizing radiation
Member States, the IAEA Secretariat
and other relevant stakeholders to
Switzerland has at its disposal a comprehensive sampling andfacilitate the use of available
measurement organization, which is continuously reviewed andinformation, expertise and techniques
enhanced. It comprises automatic, stationary and mobile means offor monitoring, decontamination and
IAEA-AP9.1
measurement and accredited laboratories. Within the framework of
remediation both on and off nuclear
RANET, Switzerland will make available to other countries
sites and the IAEA Secretariat tomeasurement capacities and offer advisory services.
consider strategies and programmes toimprove knowledge and strengthen
capabilities in these areas.
Member States, the IAEA Secretariat
and other relevant stakeholders to
After the accident on the prototype nuclear power plant Lucens
facilitate the use of available(Switzerland) in 1969, the plant was permanently shut down. During
information, expertise and techniques
IAEA-AP9.2
the decommissioning the molten core was removed and there is
regarding the removal of damaged
currently no more fuel on site.
nuclear fuel and the management anddisposal of radioactive waste resulting
from a nuclear emergency.
An automatic and continuous dose rate monitoring and emergency
Member States, the IAEA Secretariat
response data system (MADUK/ANPA) has been installed in theand other relevant stakeholders to sharevicinity of all NPPs in Switzerland. The data is transmitted to ENSI,
IAEA-AP9.3
information regarding the assessment of to the National Emergency Operations Centre, to the Badenradiation doses and any associated
Württemberg (Germany) and to the European Platform EURDEP.
impacts on people and the environment.
ENSI has set up an automated system for radiological dose forecast.
The results of these calculations are also made available to thePP29, PP30

All PPs
OPs and
PRTs

PP9, PP32

PP34, PP35

PP9, PP17,
PP20,
PP22, PP30ENSI | I m p l e m e n t a t i o n o f p o s t - F u k u s h i m a i n t e r n a t i o n a l r e c o m m e n d a t i o n s | 23

Reference

Description

StatusRelatedCheckpoint
or Open
Point

National Emergency Operations Centre and the responsible
authorities in Germany. In 2011 a new project was launched, aiming
to implement a new and modernised system for dispersion
calculations.
NPPs are responsible for detecting and assessing an accident, for
implementing on-site countermeasures and for disseminating
information immediately and continuously to the relevant off-site
authorities. According to the Emergency Preparedness Ordinanceand Guideline ENSI-A08, the NPPs are further responsible for thetimely determination of the source term and its transmission to
ENSI.
10. Communication and information dissemination

IAEA-AP10.1

Member States, with the assistance of
the IAEA Secretariat, to strengthen theemergency notification system, andreporting and information sharing
arrangements and capabilities.

Member States, with the assistance of
the IAEA Secretariat, to enhance thetransparency and effectiveness ofcommunication among operators,
regulators and various international
IAEA-AP10.2
organizations, and strengthen the IAEA’s
coordinating role in this regard,underlining that the freest possible flow
and wide dissemination of safety related
technical and technological information
enhances nuclear safety.
The IAEA Secretariat and Member
States, in consultation with the
OECD/NEA and the IAEA International
IAEA-AP10.3
Nuclear and Radiological Event Scale(INES) Advisory Committee to review
the application of the INES scale as acommunication tool.
11. Research and development

IAEA-AP11.1

IAEA-AP11.2

Relevant stakeholders, with assistanceprovided by the IAEA Secretariat as
appropriate, to conduct necessary
research and development in nuclear
safety, technology and engineering,
including that related to existing andnew design-specific aspects.
Relevant stakeholders and the IAEA
Secretariat to utilize the results ofresearch and development and to sharethem, as appropriate, to the benefit of
all Member States.

As a result of the IRRS mission in Switzerland in 2011, an emergency
classification system compatible with IAEA requirements will be
implemented. The use of IAEA reporting forms (GENF and SRF) is
being trained in general emergency exercises. Reporting and sharing
of information in case of an emergency and ways of improvement
are also being addressed in international working groups set up by
HERCA.

PP28, PP29

As a federal authority, ENSI is subject to the Federal Act on Freedomof Information in the Administration. According to this law, all ENSI
documents are public with defined exceptions, for instance security‐
related information, personal data, or trade secrets.
ENSI regularly informs the public about its activities (see CNSEOM14). In these technical fora meetings, all aspects of safety,
including emergency preparedness and response are addressed.
Within the WG on effectiveness and transparency ENSI supported
IAEA's coordinating role and peer review instruments (see CNSEOM15).

PP22,
PP27, PP29ENSI is an active member of the INES community and supports therelevant efforts for strengthening and improving the INES scale as acommunication tool.

PP22, PP27ENSI supports and coordinates safety research within its regulatory
powers.
The results of that research directly influence its Guidelines,
regulatory decisions and resources. Research projects serve training
purposes and thereby maintain competence within ENSI and its
experts. ENSI’s research programme contributes to international
projects which Switzerland would be unable to conduct on its own.
International exchange of expertise is thereby encouraged.

--

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2.4

Table 4: List of checkpoints from the Swiss "Lessons Learned" report
No

Point
designation

Description

1

PP1

The hazard assumptions for earthquake and external flooding, and also for
extreme weather conditions, must be re-evaluated to take account of the latest
knowledge.

2

PP2

The control strategies for a long-lasting total power failure must be re-evaluatedon the basis of knowledge gained from Fukushima.

3

PP3

A review must be carried out to determine whether the coolant supply for thesafety systems and the associated auxiliary systems is guaranteed from a diverse
source which is safe against earthquakes, flooding and contamination.

4

PP4

A review must be carried out to determine whether the requisite tightness ofbuildings containing important safety equipment is guaranteed in case of floodingof the site.

5PP5On the basis of experience gained from the Fukushima accident, another review
must be undertaken to determine whether the availability of the instrumentation
required to assess the condition of the plants is guaranteed adequately even in
extreme situations.

6

PP6

A review must be carried out to determine whether control of leaks and long-termcooling of the spent fuel pools are guaranteed in case of severe accidents.

7

PP7

A review must be carried out to determine whether tests and inspections regarding
the prevention of hydrogen explosions should be extended to additional areas ofthe plants beyond the primary containment.

8

PP8The design and operation of the systems for filtered venting of the containment
must be reviewed again.

9

PP9

It is necessary to carry out a new review of the earthquake and flood design of themonitoring network for automatic dose rate measurement in the vicinity of nuclear
power plants (MADUK), in relation to experience gained from the Fukushima
accident.

10

PP10

A review must be carried out to determine whether the emergency rooms (ER) andthe substitute emergency rooms (SER) at the Swiss nuclear power plants still meetthe requirements, based on the experience gained from the Fukushima accident.

11

PP11

The access control system for nuclear power plants and the associatedarrangements must be reviewed to determine the accessibility of rooms whereintervention is required in case of severe accidents, while maintaining appropriate
plant safety and security. Monitoring of radiation protection must continue to beguaranteed in this context.

12

PP12

The emergency measures for heat dissipation in case of a complete failure of thecooling water supply must be reviewed and verified under conditions resulting
from the disruption of the infrastructure and the power supply.

13

PP13

It is necessary to review how the alternative supply of water and power for
emergencies is ensured.

14

PP14

It is necessary to examine the water resources that can be made available to supply
the reactor pressure vessel, the spent fuel pools and the containment.

15

PP15

Emergency management must be reviewed to determine further potential for
improvement.

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No

Point
designation

Description
ENSI has identified the following issues as checkpoints for improving emergency
planning and emergency exercises:
a The decision-making aids for emergency management in case of severe
accidents (SAMG) at nuclear power plants, including the newly planned
checkpoints to deal with severe accidents, must be reviewed on the basis ofknowledge gained from the Fukushima accident. In this regard, it is particularly
necessary to check:16-

whether adequate consideration is given to a Station Blackout (SBO) of long
duration and the simultaneous occurrence of events in multiple-unit plants-

whether there is any need for measures, auxiliary resources and equipmentthat must be available to ensure that critical levels are not attained over thelong term in case of severe accidents.

PP16

b Consideration given to incidents involving an SBO of long duration in theplanning of emergency exercises.
c Examination of whether the procedures are trained often enough during
emergency exercises. Particular attention should be focused here on afunctioning inter-organisation chain of communication across the variousorganisations.
17

PP17

A review must determine whether and to what extent the communication facilities
are designed with adequate redundancy and diversity.

18

PP18

It must be ensured that adequate staff is available at all times to accomplish allnecessary emergency management activities.

19

PP19

Measures that increase the organisation's ability to react to unexpected events
must be reviewed again on the basis of experience gained from Fukushima.

20

PP20

Transmission of plant parameter data must be re-evaluated with respect to analternative, independent means of data transmission.

21

PP21

The evacuation concepts must be reviewed, taking account of knowledge gained
from the Fukushima accident.

22

PP22

Coordination with other international partners is required to determine whether
and how an international network for central international emergency support canbe set up.

23

PP23

A review must be carried out to determine whether the necessary information
regarding forecasts of releases and radiation exposure is provided in a timely andcontinuous manner in case of damage.

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No

Point
designation

Description
The following improvement measures were identified regarding information
provided to the general public:

24

PP24

a It must be ensured not only that the requisite infrastructure and the necessary
individuals and/or organisations and equipment are available for crisis
communication, but also that the necessary means of communication are inplace. The relevant precautions must be taken. Regular training must be
provided on the associated procedures. This point also includes a functioning
network of experts who are available to the media to supply neutral andobjective information.
b Review to determine whether the organisational responsibilities for informing
the public as well as the local authorities and support staff are clearlystipulated, and are uniformly understood by all involved parties.
c A review should be carried out to determine whether the timely communicationof radiological effects, including calculated forecasts, is also ensured beyond
Switzerland's borders.

25

PP25

It is necessary to examine the extent to which the release of non-nuclear
hazardous substances in case of events beyond the design basis could exert an
additional influence on the events related to an accident, and which countermeasures are required.

26

PP26

The process of evaluating and examining the applicability of national andinternational operating experience must be optimised on the basis of knowledge
gained from the Fukushima accident.

27

PP27

It must be guaranteed that the knowledge gained from national and international
operating experience (the procedure for processing events) in the licensees'organisations reaches all the relevant individuals and units (including those atgroup level).

28

PP28

It must be ensured that internationally harmonised assessment scales for nuclear
safety are established at the highest level of safety.

29

PP29

Greater importance should also be accorded in the international sphere to therecommendations resulting from international reviews (IRRS, OSART (Operational
Safety Review Team)) and from the regular Periodic Safety Reviews (PSR). The
transparency of ENSI's supervision and of the operators' safety-related activities
must be increased.

30

PP30

ENSI is reviewing the significance of the lessons learned from the Fukushima
accident for its supervisory activities.

31

PP31

Additional operational resources must be kept in readiness for radiation protection
in case of severe accidents.

32

PP32

It is necessary to examine whether the emission and immission measurements inplace on the power plant sites in order to determine the activity releases areguaranteed in case of loss of offsite power (LOOP) or in case of an emergency.

33

PP33

It is necessary to examine the extent to which the availability of the meteorological
data required for dispersion calculations is guaranteed in case of extreme natural
events.

34

PP34

It is necessary to stipulate arrangements for dealing with contamination in the areasurrounding nuclear plants following severe accidents.

35

PP35

It is necessary to examine how to deal with large volumes of contaminated water,
radioactive waste or environmentally hazardous substances in case of severe

28 | I m p l e m e n t a t i o n o f p o s t - F u k u s h i m a i n t e r n a t i o n a l r e c o m m e n d a t i o n s | ENSI

No

Point
designation

Description
accidents.

36

PP36

As part of the emergency planning for severe accidents, it must be ensured thatsufficient radiation protection staff is available on site.

37

PP37

The knowledge gained from the Fukushima accident must be taken into account in
the programmes to foster and develop the safety culture in Swiss nuclear power
plants.

ENSI | I m p l e m e n t a t i o n o f p o s t - F u k u s h i m a i n t e r n a t i o n a l r e c o m m e n d a t i o n s | 29

2.5

Table 5: List of open points for Switzerland from the EU Stress Tests
No

Point
designation

Description

38

OP2-1

ENSI will follow up the question as to whether automatic scrams in the Swiss NPPs
should be triggered upstream by the seismic instrumentation.

39

OP2-2

With respect to the seismic proof that has still to be supplied, ENSI will follow up,
for all Swiss nuclear NPPs, with a more detailed examination of the seismicrobustness of the isolation of the containment and the primary circuit.

40

OP2-3

For Gösgen and Leibstadt NPPs, ENSI will continue to follow up measures toimprove the seismic resistance of systems for containment venting in case of
events beyond the design basis.

41

OP3-1

ENSI will follow up on the impacts of a total debris blockage of hydraulicengineering installations at Gösgen and Mühleberg NPPs.

42

OP4-1

ENSI will follow up on more detailed proof of protection against extreme weather
conditions, including combinations thereof.

43

OP5-1

ENSI will follow up on the development of a comprehensive strategy for thetargeted deployment of the mobile accident management emergency diesels inorder to secure selected direct current or alternating current consumers in the longterm under total SBO (or SBO) conditions.

44

OP6-1

For the purpose of risk minimisation, ENSI will follow up on the extent to which thecurrent deployment strategies for the containment venting systems in severe
accidents should be retained.

45

OP6-2

ENSI will follow up on whether restoring containment integrity during shutdown inthe case of a total SBO represents a time‐critical measure.

46

PRT-1

The peer review team recommends considering the assessment of margins withrespect to extreme weather conditions exceeding the design bases, e.g. byextending the scope of future PSRs.

PRT-2

It is recommended that the regulator assesses the opportunity of requiring morereliance on passive systems for hydrogen management for severe accident
conditions. It is also recommended that the regulator considers further studies onhydrogen management for the venting systems.

47

30 | I m p l e m e n t a t i o n o f p o s t - F u k u s h i m a i n t e r n a t i o n a l r e c o m m e n d a t i o n s | ENSI

3

List of abbreviations

AM
BDB
CNS
DC
DG
DETEC
ECC
ECR
ECURIEENSIENSREG
EPRI
ER
ERO
EU
HERCA
IAEA
IDA-NOMEX
IRRS
IRRT
LOOP
MADUK
MCR
NEA
NPP
NSC
NUSSC
OBE
OECD
OP
OSART
PAR
PP
PRP
PSA
PSR
RANET
RASSC
REMPAN
RPV
SAM

Accident Management
Beyond Design Basis
Convention on Nuclear Safety
Direct Current
Diesel Generator
Department of Environment, Transport, Energy and Communication
Emergency Control Center
Emergency Control RoomEuropean Community Urgent Radiological Information Exchange
Swiss Federal Nuclear Safety Inspectorate
European Nuclear Safety Regulators GroupElectric Power Research Institute
Emergency Room
Emergency Response Organisation
European Union
Heads of European Radiological protection Competent Authorities
International Atomic Energy Agency
Interdepartmental working group to review emergency protection measures in caseof extreme events in Switzerland
Integrated Regulatory Review Service
International Regulatory Review Team
Loss Of Offsite Power
Monitoring network for automatic dose rate measurement in the vicinity of nuclear
power plants
Main Control Room
Nuclear Energy Agency of the OECD
Nuclear Power Plant
Nuclear Safety Commission
Nuclear Safety Standards Committee
Operating Basis Earthquake
Organisation for Economic Cooperation and Development
Open Point
Operational Safety Review Team
Passive Autocatalytic Recombiner
Checkpoint
PEGASOS Refinement Project
Probabilistic Safety Analysis
Periodic Safety Reviews
OAEA Response and Assistance Network
Radiation Safety Standards Committee
WHO Radiation Emergency Medical Preparedness and Assistance Network
Reactor Pressure Vessel
Severe Accident Management

ENSI | I m p l e m e n t a t i o n o f p o s t - F u k u s h i m a i n t e r n a t i o n a l r e c o m m e n d a t i o n s | 31

SAMG
SBO
SER
SFP
SG
SSE
SSHAC
TRANSSC
UHS
WANO
WASSC
WENRA
WHO

Severe Accident Management Guidelines
Station Black-Out
Substitute Emergency Room
Spent Fuel Pool
Steam Generator
Safe Shutdown Earthquake
Senior Seismic Hazard Analysis Committee
Transport Safety Standards Committee
Ultimate Heat Sink
World Association of Nuclear Operators
Waste Safety Standards Committee
Western European Nuclear Regulators’ Association
World Health Organisation

Issued by
Swiss Federal Nuclear Safety Inspectorate ENSI
Industriestrasse 19
CH-5200 Brugg
Phone +41 (0)56 460 84 00
Fax+41 (0)56 460 84 99
info@ensi.ch
www.ensi.ch
ENSI-AN-8801
Published 19.05.2014