FRANCE Post-Fukushima activities · FRANCE Post-Fukushima activities Norbert NICAISE ... Post-FKSH actions at French and European levels ... (Ultimate Diesel Generator,

FRANCE Post-Fukushima activities

Norbert NICAISE

IAEA

18th Meeting of the Technical Working Group

on Advanced Technologies for LWRs Vienna 18-20 June 2013

IAEA 18th Meeting of the Technical Working Group on Advanced Technologies for LWRs - Vienna 18-20 June 2013 2

Post-FKSH actions at French and European levels

May 2011 ASN resolutions : ● Licensees to perform Stress Tests according to detailed stress specifications (WENRA basis)

consistent with EU ones

Jan 2012 ASN national evaluation report : ● ASN formal report and ASN opinion about Stress Tests

Jan-April 2012 European peer review (organised by ENSREG - European Nuclear Safety Regulators) + TRICASTIN NPP inspection by international team

Sept 2011 EDF Stress Test reports ● 19 Complementary Safety Assessment (CSA) reports

Nov 2011 ASN Standing Committee review of the Stress Test reports (Advisory Expert Committee : “Groupe Permanent Réacteur”)

March,11 2011 FUKUSHIMA accident


Post-FKSH actions at French and European levels

June 2012 ASN technical prescriptions (License Conditions) :

● Legally binding prescriptions to EDF on improvements to be implemented - 19 site specific resolutions with around 40 requirements each - Compliance deadlines : from 2012 to 2018 -> Implementation of improvements expected as soon as possible, not waiting for the next Periodic Safety Reviews (EU peer review recommendation)

● Letter with 41 additional requests to EDF

Sept 2012 EDF Stress Test reports for the decommissioning sites

Dec 2012 Standing Committee review on determining the Hardened Safety Core (HSC) of the Stress Test requirements

Aug 2012 Extraordinary IAEA convention on Nuclear safety


Stress Tests

Immediately after the accident, ASN launched :

A campaign of targeted inspections

“Stress Tests” (“Complementary Safety Assessments” CSA)

Complementary approach to the continuous improvement process of safety pursuant to the law and overseen by ASN (Periodic Safety Reviews PSR, and integration of Operating Experience Feedback)

Cover all French nuclear installations (~ 120), including EPR reactor under construction, with priority given to the most important ones (NPPs, La Hague fuel reprocessing plant …)

Stress Tests aim at checking :

The robustness of plants to beyond-design FUKUSHIMA-related situations : extreme natural events, loss of safety systems (heat sink, electrical power), severe accident situations.

Organisational and Human factors.


ASN requirements (License Conditions)

ASN position (Jan 2012)

“ The facilities examined offer a safety level that is sufficient for ASN not to request the immediate shutdown of any of them […].

At the same time, ASN considers that continued operation of the facilities requires that their robustness to extreme situations be increased beyond the existing safety margins, as soon as possible.”

Improvements required

Need for a “Hardened Safety Core”

Technical and organizational measures which remain operational under conditions considered in the Stress Tests

Set up a “Nuclear rapid response force” for NPPs (FARN)

Specialist crew and equipment within 24h to the site

Reinforced measures to reduce the risk of dewatering of the spent fuel stored in pools.

Feasibility studies to protect the groundwater and surface waters in case of Severe Accident

Organisational & Human Factors are essential to nuclear safety


ASN License Conditions (June 2012)

Stress Tests (“Complementary Safety Assessments” CSA)

Hardened Safety Core Water & Electricity supplies Earthquake Emergency management Flooding

ECS 1 : Define the SSC of the “Hardened Safety Core”

ECS 4 : End of work relating to BLAYAIS NPP experience feedback (ext flooding)

ECS 5 : Conformity of the” protection volume”

ECS 6 : Reinforcement of protection against flooding

ECS 7 : Measures to cope with site isolation in the event of flooding (specific sites)

ECS 8 : Conformity of seismic instrumentation

ECS 9 : Reinforcement of the seismic interaction approach

ECS 10 : Reinforcement of team preparation in the event of an earthquake

ECS 11 : Robustness of the FESSENHEIM-NPP and TRICASTIN-NPP embankments

ECS 12 : Verification of the seismic design basis of the fire-fighting system

ECS 13 : Study of the implementation of automatic shutdown in the event of earthquake

ECS 14 : Integration of industrial risks in extreme situations (neighbouring industrial operators)

ECS 15 : Heat sink design review

ECS 16 : Emergency water supply resources, Emergency water makeup in open RCS

ECS 17 : Reinforcement to manage lasting situations of Total Loss of Heat Sink or Total Loss of Electrical Power Supplies

ECS 18 : reinforcement of battery autonomy, additional electrical power supply (Ultimate EDG)


ASN License Conditions (June 2012)

Stress Tests (“Complementary Safety Assessments” CSA)

Hardened Safety Core Water & Electricity supplies Earthquake Emergency management Flooding

ECS 19 : Redundancy of instrumentation for detecting RV melt-through and H2 in containment

ECS 20 : Reinforcement of Spent Fuel Pool instrumentation

ECS 22 : Reinforcement of the measures to prevent accidental rapid draining of the SFP

ECS 23 : Placing a Fuel Assembly in safe position during handling

ECS 24 : Thermo-hydraulic development of a pool accident

ECS 25 : Reinforcement of the provisions for managing a transfer tube leak

ECS 27 ; Study of the feasibility of installing a geotechnical containment (or system of same effect)

ECS 28 : Reinforcement of the provisions for managing the pressure in containment

ECS 29 : Reinforcement of the Containment venting-filtration system (“sand-bed filter”)

ECS 30 : Designing the emergency premises to withstand earthquakes and flooding

ECS 31 : Modifications to ensure facility management further to releases

ECS 32 : Multiple plant unit emergency organisation

ECS 35 : Feasibility of emergency management actions in extreme situations

ECS 36 : The Nuclear Rapid Response Force (FARN)


EDF “Complementary Safety Assessment” (Stress Tests)

EDF assessment of its 58 NPPs, in accordance with the ASN specifications

Re-assessment of the safety margins :

Consideration of extreme natural events :

Earthquake, flooding, others…

Consecutive loss of safety functions, regardless the probability or cause of the function loss :

Loss of electrical power (incl. SBO)

Loss of Ultimate Heat Sink (LUHS)

Combination of both

Management of Severe Accidents

Work of more than 3000 engineers, during 4 months

19 reports issued (1 per site) submitted to ASN (about 7000 pages)


EDF Stress Tests

6 fields assessed :

Earthquake

Flooding

Loss of Heat Sink (LHS)

Loss of electrical supply (SBO)

Severe accident management

Sub-contracting

Earthquake

Probabilistic methods recommended by ENSREG (Seismic Margin Assessment)

Beyond-Design hypothesis :

1.5 Safe Shutdown Earthquake

Flooding

Beyond-Design hypotheses :

1.3 design flood levels (river side), tide level +1m (sea side), rainfall intensity x2

Others :

Tornado (F4), hail (50mm, 32m/s), lightning (300 kA) …


EDF results / actions to be implemented

Main conclusions of EDF Stress Tests

1. Reinforce protections against hazards

2. Reinforce electricity and water supplies

3. Limit releases in Severe Accident conditions

4. Reinforce Crisis Management on site and at national level

Main Actions to be implemented

1. Water-proof perimeter Reinforcement or raising of dams/dikes, of supports/anchorages, of flood protection for electrical switchyards, of electrical equipment robustness

2. Additional Diesel Generator (protected), one per unit

- to supply the minimum required I&C / injection pump to SG/RCS/SFP

Additional water supply (protected) - from groundwater or other water sources (basins…)

3. Reinforce Containment function and pressure control

4. Reinforce Crisis Management

- Implement an appropriate Crisis Management Center, adequately equipped to manage the crisis on a long term basis

- Implement the National Nuclear Rapid-Response Force (FARN)


General approach

Modifications implemented acc. to following schedule

Phase 1 : Short Term (2012-2015) Preliminary additional means

(Temporary EDG, mobile injection pump, Spent Fuel Pool, Batteries …)

Crisis means [Nuclear Rapid-Response Force (FARN)]

“Hardened Safety Core” first means

Phase 2 : Medium Term (2015-2019)

Permanent additional means (Ultimate Diesel Generator, Water Supply, Emergency Crisis Center …)

“Hardened Safety Core” first means

Phase 3 : Long Term (> 2019)

“Hardened Safety Core” completed

EDF General implementation schedule

Design Basis Beyond Design Basis Extreme hazards severity

Additional means +

Crisis means (FARN) “Hardened Safety Core”

No large off-site releases

with long term contamination

Cliff-edge

effects ?

Design

criteria Safety Reassessments :

- Periodic Safety Reviews

- Experience Feedback …


EDF General implementation schedule

- - - 2018 - - - 2025 2012 2013 2014 2015

Temporary Diesel Generator

Mobile injection pump

Current ECC seismic improvement

Spent Fuel Pool level meast available in

SBO Spent Fuel Pool modifications to avoid rapid drain-out

Improvement of batteries autonomy

FARN (1 team)

FARN (4 reactors)

FARN (6 reactors)

Ultimate Diesel Generator

Ultimate water supply

Emergency Crisis Center

Other modifications …

Modifications &

upgrading actions

phase 2 instruction

PH

AS

E 1

Modifications Studies

PHASE 2

To be defined … Modifications & upgrading actions

phase 3 instruction

Modifications Studies

PHASE 3


EDF “Hardened Safety Core”

3 objectives for extreme situations considered in the Stress Tests

1) Prevent a Severe Accident with Fuel Melt, or limit its development

2) Limit large-scale radioactive releases

3) Enable the Operator to manage the emergency situation

Limited number of strengthened equipment, including

An additional Ultimate Electricity Generating set, for each reactor

A diverse Emergency cooldown water supply, for each reactor

New emergency management premises, offering greater resistance to hazards and remaining accessible and habitable at all times and during long-duration emergencies

Mobile devices and means of communication essential to emergency management

Technical and environmental instrumentation


EDF “Hardened Safety Core”

Perimeter = limited key functions

Electrical supplies and I&C : Ultimate Diesel Generator Batteries, electrical connections Instrumentation

Water make-up to : Steam Generators, Reactor Coolant System, Reactor Building, Spent Fuel Pool

RCS depressurization Containment isolation

Crisis management premises Mobile devices Essential means of communication

Ultimate water source

Piscine BK = Spent Fuel Pool

ASG = Emergency Feedwater Tank

PTR = Refueling Water Storage Tank


Proposed by EDF in April 2011, required by ASN in June 2012

National response system, including specialists crew and equipment, able to take-over from the personnel of a site affected by an accident, and deploy additional response resources in less than 24h.

3 steps of intervention

In less than 12h :

Bring skilled operators on site, in order to help the local shift, and possibly take-over

Assistance to NPP using local means (fixed or mobile), up to 24h

After 24 h :

Bring its own mobile equipment and other resources

Guarantee site autonomy, up to 72h

After 72h :

Additional resources from EDF group, or shared between Nuclear Operators

Guarantee durable safe situation

EDF “Nuclear Rapid Response Force” (FARN)


EDF “Nuclear Rapid Response Force” (FARN)


EDF “Emergency Crisis Response”

Telecommunication tools reinforcement

June 2012 : installation of an autonomous satellite GSM on each unit (to launch the alert in case of complete unavailability of all other communication means)

Oct 2011 to Dec 2015 : Installation of a satellite communication tool on each site

Emergency Crisis Organization improvement

Step 1 : On-going Crisis Management

Initiated in 2008, before FUKUSHIMA, based on operational feedback

Management of multi-units events, based on the current referential, end 2012

Step 2 : Multi-units events management in extreme conditions (FKSH-like)

Progressive implementation till 2015/2017 in several stages

On-site first 24h response - human resources recruitment/training,

- local mobile crisis equipment installation,

- additional communication means,

- associated procedures and organization

EDF HQ

Paris

EDF Crisis

Center Paris ASN

IRSN

Administration

NPP

AREVA… Crisis

Center Paris


EDF “Emergency Control Center” (Design principles)

Main Technical Specifications

Ground surface : 1000 m2, 3 floors, total usable surface : 3000 m2

100 people capacity

Same building for all sites

Foundations on shock absorbers (acc. to seismic level)

Resistance to extreme natural hazards (seism, flooding, tornadoes, hail, lightning …)


EPR reactor design

The EPR design is the only GEN III+ reactor submitted to the European “Stress Tests” after the FUKUSHIMA event

Protection against Earthquakes and Flooding are included in the design to ensure safety functions to a high level of confidence

MDEP EPR-Working Group meeting hold in Jan,24 2013

“EPR-family” common approach presented to MDEP members (Finland, France, China, US, UK, India)

2-step approach

Step-1 : Evaluate the robustness of the design against a range of FKSH-like rare and severe external hazards resulting in LOOP + LUHS.

Step-2 : Identify additional measures to cope with more severe situations due to additional failures on the mitigation means (with respect to Step-1), should they be deterministically imposed.

Design adaptations limited : increased fuel autonomy, introduction of mobile-connections, local reinforcement …


EPR reactor design

Double wall, up to 1.8m thick

Large commercial airplane crash

resistant:

External reinforced concrete containment

protecting critical buildings

High earthquake resistance

(up to 0.5-0.6g)

Doors able to withstand explosions

and flooding

Ability to withstand extreme external events

Common raft for

nuclear island

Airplane Crash

resistance shell

Diesel building door


EPR reactor design

4 protected redundant

Emergency Diesel Generators

+ 2 diversified

smaller Diesel Generators

4 independent cooling trains

installed in 4 separated divisions

+ 2 diversified cooling trains

Large protected site water reserves

More than 7 days of autonomy in case of loss of grid and

loss of access to the heat sink

1: EFWS Emergency Feed Water System

2: IRWST In Containment Refueling Water Storage Tank

IRWST2 (1800 m3)

EFWS1 tanks

(4x400 m3)

Fire fighting

tank

(2600 m3)

Robustness of cooling functions


Documents

FRANCE Post-Fukushima activities · FRANCE Post-Fukushima activities Norbert NICAISE ... Post-FKSH actions at French and European levels ... (Ultimate Diesel Generator,