IAEA 2nd Symposium on PLIM 15-18 October 2007 – Shanghai CHINA1 /16

GB ConsultingFRENCH NUCLEAR PLANT LIFE MANAGEMENT STRATEGY----------------------------------------------------------------

REACTOR PRESSURE VESSEL ASSESSMENTAND

STEAM GENERATORS LIFE MANAGEMENT STRATEGY

.

Georges BEZDIKIAN

CONTENT� REACTOR PRESSURE VESSEL PLIM � STEAM GENERATORS STRATEGY

SGpressurizer

SG

vessel head

elbows primary pump

confinement containment

SG

IAEA 2nd Symposium on PLIM 15-18 October 2007 – Shanghai CHINA2 /16

GB ConsultingNUCLEAR PLANTS LIFE MANAGEMENT

INTRODUCTIONNUCLEAR PLANTS LIFE MANAGEMENT

INTRODUCTION

The capability of nuclear electricity generation by French Utility’s (EDF Electricité de France) is 80% of global generation, 58 PWR units are in

operation, 34 units three-loop, 20 units four-loop (1300MWe) and 4 units four-loop (1450MWe).

� The Status of Nuclear Plants Life Management is depending of the following objectives :� To maintain current operating performances (safety, availability, costs, security,

environment) in the long term, and possibly improve on some aspects ;� wherever possible, to operate the units throughout their design lifetime, in other

words 40 years, and after 40 years ;� To consolidate Mormal and Exceptionnal Maintenance and long term

Prediction.The Nuclear Plants Life Management Policy will take intoaccount the category of the components and structure ; and strategic choices in relation with prediction of AgingManagement

IAEA 2nd Symposium on PLIM 15-18 October 2007 – Shanghai CHINA3 /16

GB Consulting

PWR in FRANCE.GRAVELINES

6 units NOGENT-sur-SEINE

2 unitsDAMPIERRE4 units

CHOOZ2 unitsCATTENOM4 units

FESSENHEIM2 unitsBELLEVILLE2 unitsLE BUGEY4 units

SAINT-ALBAN2 unitsCRUAS4 units

TRICASTIN4 units

1300 MW unit (20)900 MW unit (34) 1450 MW unit (2)

PENLY2 units

FLAMANVILLE2 units

PALUEL4 units

GOLFECH2 units

LE BLAYAIS4 units

CIVAUX2 units

CHINON4 units

SAINT-LAURENT2 units

REACTOR PRESSURE VESSEL LIFE MANAGEMENT AT FRENCH PWR PLANTS

.PARIS

(4)

IAEA 2nd Symposium on PLIM 15-18 October 2007 – Shanghai CHINA4 /16

GB ConsultingREACTOR PRESSURE VESSEL INTEGRITY ASSESSMENT

The lifetime of a nuclear power plant may be affected by three main factors :� normal wear of its components and systems - called aging - that depends

particularly on their age, operating conditions and maintenance conditions applied to them ;

� the safety level, that must consistently comply with the safety requirements applicable to the power stations at all times, and which could change as a function of new regulations ;

� competitiveness, which must remain satisfactory compared with the competitiveness of other production means.

The general strategy is based on the following two points :� the ten-year safety reassessment process for each ten years period PSR,� the implementation of two structured programmes in order to make sure that all

technical and industrial actions necessary to achieve a lifetime of at least 40 years are actually implemented .

IAEA 2nd Symposium on PLIM 15-18 October 2007 – Shanghai CHINA5 /16

GB Consulting

.

NeutronCore zone

PTS Integrity Analysis Calculation Safety Injection Fluid

Reactor coolant fluid

Defect

Cladding

Defect postulatedCore zoneInspected

Neutron Action on Vessel Walland Degradation mode underirradiation

IAEA 2nd Symposium on PLIM 15-18 October 2007 – Shanghai CHINA6 /16

GB ConsultingEVALUATION APPROACHES CARRIED OUT

SPECIFIC VESSEL by VESSEL EVALUATION

Initial RTNDT

RTNDTvalues comparison

Margins ofcode criteria forin operation units

Chemical compositionparameters for each vessel

Thermal-hydraulic & Mechanical Analysis

Fluence reduce -15 %irradiation during operating lifetime

RTNDT ofeach vessel

RTNDT 30 years40 years50 years

Size of defect postulated at themaximum fluence situation

or Results of in service inspection

Results of transients analysesand most severe transient

A

B

+

Results of irradiationsurveillance program

∆ RTNDT during operating lifetime

prediction Formula

.

IAEA 2nd Symposium on PLIM 15-18 October 2007 – Shanghai CHINA7 /16

GB Consulting

Fluence initial properties of steel

T(x,t) and σ (x,t) distribution

Stress intensity factor KCP -computation at crack tipsToughness K1C -computation at crack tips

Margin factor KCP / K Ic

BRITTLE DUCTILEToughness

Initialtransition temperature

Temperature of the vessel steel

Defect

Cladding

Defect0

100

200

300

400

0 500 1500 2000timeflu

id tem

perat

ure

Transient

Assessment of RPV integrity : fluence calculations at EDF

Level A = 2nd category of situation => Sc =2level C = 3rd category of situation => Sc = 1.6Level D = 4th category of situation => Sc = 1.2

KCP = KI plastic correction

IAEA 2nd Symposium on PLIM 15-18 October 2007 – Shanghai CHINA8 /16

GB Consulting2 - FLUENCE

.

FIGURE 3 : PROJECTIONS DE FLUENCE A 40 ANS

0

1

2

3

4

5

6

7

8

0 5 10 15 20 25 30 35 40années

Flue

nce

en 1

019 n/

cm2

fluence deconception

fluenceréactualisée à15 ansprojection defluence - 20 %

projection defluence - 40 %

projection defluence -15%

Fluence –Basic Design

Fluence –updated 15 years

Years

Years

The actual fluence for 40 years lifetime (considering the reduction of fluence) is :• 3 loop Reactors : 6.5 x 1019 n/cm2• 4 - Loop RPV (1300 MWe) fluence at 40 years lifetime : 4.65 x 1019 n/cm2

of

of

of

IAEA 2nd Symposium on PLIM 15-18 October 2007 – Shanghai CHINA9 /16

GB Consulting.

Capsule V

Capsule Y

CP1 – CP2 Series Plants

Capsule Z

Capsule U

Capsule W

Capsule X

Capsule Capsule Capsule Capsule1 (u) 2 (V) 3 (Z) 4 (Y)

4 7 9 14

11.2 19.5 28.0 40

Extension of the RPV irradiation surveillance : introduction ofreserve irradiation capsules in theFrench plants since 1999 for allreactors.Two reserve capsules W and X in place of capsules U and Z afterremoving from reactor thesecapsules U and Z.

Time ofDurationin vessel(years)

Equivalenttime ofirradiation of Vessel(Years)

RTNDT VALUES - RPV SURVEILLANCE PROGRAMME RTNDT VALUES - RPV SURVEILLANCE PROGRAMME

RTNDT = 82 °C ->CP0 unitsRTNDT = 73°C -> CP1/CP 2 units.RTNDT = 82 °C ->CP0 unitsRTNDT = 73°C -> CP1/CP 2 units.

IAEA 2nd Symposium on PLIM 15-18 October 2007 – Shanghai CHINA10/16

GB Consulting

.

CORE ZONE INSPECTION

VPM

IAEA 2nd Symposium on PLIM 15-18 October 2007 – Shanghai CHINA11/16

GB ConsultingSTEAM GENERATOR REPLACEMENT PROGRAMME and STRATEGY

The global Life Management strategy and Maintenance Program of Steam Generators are in relation with:

� The importance of the inspection Programme� The on-going actions during NPPs time in operation normal and current

Maintenance � To anticipate the exceptional maintenance � To anticipate to order the strategic components

Classification of plants with SG Replacement strategyPERIODIC INSPECTIONS OF STEAM GENERATOR

– Technical SG End of Life – SG Plugging Rate max: 12,5 or 15%– Planning schedule in function of intervention on Plants (industrial

capability, Availability of reserve of SG spare parts) – Connection with SGR and 10-years outages

IAEA 2nd Symposium on PLIM 15-18 October 2007 – Shanghai CHINA12/16

GB ConsultingClassification of PWR plants in relation with SR Replacement strategy

� Group 1Units with SG affected by dégradations and SGR is will be carry out in futur (date of SGR estimated)

� Group 2Units with SG lifetime evaluation iswith incertainties (evolution of dégradations is unknown, treat onSGR Planed with 3rd 10-years outage

� Group 3Units with SG Lifetime = Plant lifetime

GROUP 1DAMPIERRE 2, DAMPIERRE 4GRAVELINES 3BUGEY 2, BUGEY 3, BUGEY 4FESSENHEIM 2BLAYAIS 1

GROUP 2CHINON B1, CHINON B2BLAYAIS 2, BLAYAIS 3, BLAYAIS 4

GROUP 3 900 Mwe : 21 unitsCRUAS 1-2-3-4GRAVELINES 5 – 6CHINON B3 – B4

• Units with SG replaced in past• 1300 MWe: all 20 units• 1450 MWe : all 4 units

IAEA 2nd Symposium on PLIM 15-18 October 2007 – Shanghai CHINA13/16

GB ConsultingSYNTHESIS of DURATION FRENCH SGR

DAM10

50

100

150

200

250

BUG5

DURÉ

ES en

JOUR

S

GRA1 SLB1 DAM3 GRA2 TRI2 TRI1 GRA4

Heures en zone

Durée de l'arrêt (jours)

Durée du RGV (jours)TRI3 FES1

140000

120000

100000

80000

60000

40000

20000

HEUR

ES en

ZONE

0

176600dont environ 10000 de RCVSG In 2 Parts

SG In 2 Parts

RPV Inspection Core Zone VPM

SGR Duration

Outage total Duration

Total hours in controled zone

10 000 hours on CVCSTOTAL

D U R A T I O NI N Z O N E

DURATION

IN

DAYS

IAEA 2nd Symposium on PLIM 15-18 October 2007 – Shanghai CHINA14/16

GB ConsultingPLANNING OF SG REPLACEMENT

GRA4TRI1TRI2

GRA2

SLB1DA3

GRA1BUG5

DAM1

1990199119921993199419951996199719981999200020012002Réalisées

TRI3FES1

DAM2BUG4

SLB2

2003200420052006200720082009DAM4, GRA3, ... ?

TRI4

A venir

SGR Carried out

2003 2004 2005

SLB2TRI4

DAM2

Futur SGR 2007 2008 2009 2010 20112006 2012

BUG 4CHB1, DAM4, BLA1,

IAEA 2nd Symposium on PLIM 15-18 October 2007 – Shanghai CHINA15/16

GB Consulting

.

~ 20 m

320 tons in weight

Example SGR One Piece Monobloc

IAEA 2nd Symposium on PLIM 15-18 October 2007 – Shanghai CHINA16/16

GB Consulting

CONCLUSION

The importance of Criteria combined with periodic inspection and in relation with:� The global Maintenance program and strategy

Specific Maintenance and Inspection for RPV and for Steam Generator

� The monitoring to enrich the feedback experience and database collectedon Steam Generator and RPV

� To anticipate the exceptional maintenance Mainly for SGR

� To anticipate to order the strategic componentsare very important for Plant Life Mnagement Strategy

All of actions engaged and applied on 58 NPPs taking into account thelarge informations capitalised in database from the feedback experienceinformations , current Maintenance and exceptionnal maintenance give to the french utility the good approaches to the long term life

Management