from lto assessment to living ageing management · •kfd-review •iaea salto peer reviews •grs:...
TRANSCRIPT
Fourth International Conference on Nuclear Power Plant Life Management, Lyon 23–27 October 2017
Naam:
Functie:
Datum: datum maand jaartal
Volledige naam
Functietitel
From LTO assessment to
living ageing management
André de Jong
Rob Bollen
NPP Borssele
The Netherlands
2
Topics
Introduction of NPP Borssele
Changing LTO Horizon
LTO requirements overview
License Renewal Process
• LTO assessment project
From a static assessment to living ageing management
3
NPP Borssele
Siemens/KWU 2-loop
PWR
515 MWe (485 MWe net)
Original design lifetime:
40 years
Long Term Operation: 60
years
Every 10 years a PSR
3707 GWh production
(2012)
4
PWRs in Europe (connected before 1980)
Facility Process Mwe net Current status Start Year Owner Location
Beznau-1 PWR 365 Operating 1969 Nordostschweizerische Kraftwerke (NOK)
Switzerland
Beznau-2 PWR 365 Operating 1971 Nordostschweizerische Kraftwerke (NOK)
Switzerland
Borssele PWR 452 Operating 1973 N.V. Elektriciteits-Produktiemaatschappij Zuid-Nederland (EPZ)
Netherlands
Biblis-A PWR 1167 Shut Down 1975 RWE Power AG Germany
Doel-1 PWR 392 Operating 1975 Indivision Doel (EBES, INTERCOM, UNERG)
Belgium
Doel-2 PWR 392 Operating 1975 Indivision Doel (EBES, INTERCOM, UNERG)
Belgium
Ringhals-2 PWR 870 Operating 1975 Swedish State Power Board Sweden
Tihange-1 PWR 962 Operating 1975 Electrabel Belgium
Neckarwestheim-1 PWR 785 Shut Down 1976 EnBW Kraftwerk AG Germany
Biblis-B PWR 1240 Shut Down 1977 RWE Power AG Germany
Fessenheim-1 PWR 880 Operating 1977 Electricite de France (EdF) France
Fessenheim-2 PWR 880 Operating 1978 Electricite de France (EdF) France
Bugey-2 PWR 910 Operating 1979 Electricite de France (EdF) France
Bugey-3 PWR 910 Operating 1979 Electricite de France (EdF) France
Bugey-4 PWR 880 Operating 1979 Electricite de France (EdF) France
Goesgen PWR 970 Operating 1979 Kernkraftwerk Switzerland
Unterweser PWR 1345 Shut Down 1979 EON Kernkraft GmbH Germany
5
Changing LTO horizon
• 1973: NPP Borssele in commercial operation; no end date
• 1994: political agreement on closing NPP Borssele in 2003
• 1994-2006: political discussions and lawsuits on closing date:
NPP Borssele has no end of license date!
• 2004: feasibility study on LTO (60 years): positive business case
• Covenant on June 16th 2006:
• Long Term Operation to 2034
• Borssele should be amongst the
Top 25% safest Western LWRs
• Sept. 2013 application for License Renewal
• March 2013: LTO-license signed, fought against by NGOs but
High Court rejected the objections: February 2014 irreversible
license!
6
Changing LTO horizon
7
Requirements for safe LTO
License Renewal Process: change of Safety Report (FSAR) to
comprise operation until 2034 based on:
• LTO assessment according to IAEA guidelines (SRS57)
• Assessment on organizational/human issues
The plant is among the 25% safest Western LWRs:
• To be judged periodically by the Borssele Benchmark
Committee
Not specifically related to LTO but necessary:
Further improving nuclear safety with the fourth PSR (2010-213)
Implementing measures based on stress test (Fukushima)
RPV inspection to rule out ‘hydrogen flakes’
8
License Renewal Process
Regulatory framework:
• Nuclear Energy Act (Kernenergie wet)
• Nuclear Safety Rules (NVR), based on IAEA Safety Standard Series
• Original NVRs provide no guidance on LTO
• PSR every 10 years
• Unlimited license (but agreement to shutdown before 2034)
• Safety Report: design life 40 years (Time Limited Ageing Analyses)
• Basis by IAEA LTO guidelines
• IAEA Safety Report No. 57 (Safe Long Term Operation of Nuclear Power Plants)
• IAEA Safety Guide No. NS-G-2.12 (Ageing Management for Nuclear Power Plants)
• KFD-review
• IAEA SALTO peer reviews
• GRS: review of all LTO reports
9
License Renewal Process
(continued)
Additional Requirements:
Dutch regulator KFD:
• IAEA SALTO peer review 2009:
- Verification of preconditions
- Active Components
• Include IAEA PSR Safety Factor 10
(Organisation and Administration) and PSR
Safety Factor 12 (Human Factor) in LTO
license change application
10
LTO assessment: the principle
• Structures and components of an NPP are subjected to
material degradation
• Task of the LTO assessment is to show that the NPP
safely can and will be operated despite (potential)
physical ageing of structures and components important
for safety
11
LTO assessment project (technical
part)
LTO “bewijsvoering”
KCB
Feasibility (3.1)
Verification of
preconditions (3.2)
Scoping (4.1)
Screening (4.2)
Check of existing
plant programmes
TLAAs (6)
RPV
EQDBA
LBB
Fatigue
Mechanical
Electrical
Documentation of basis
for LTO
IAEA Safety report Nr 57
Safe Long Term Operation of
Nuclear Power Plants
IAEA NS-G-2.12 (ch 6)
Ageing Management for Nuclear
Power Plants
Mechanical A
(barrier concept)Electrical Civil / structuralMechanical B
Implementation of plant
commitments for LTO
ActiveAMR (5)
Passive
Regulatory
framework
IAEA
guidelines
Phase prior to LTO
assessment
(SR57, fig1)
Phase LTO
assessment
(SR57, fig1)
Phase LTO
approval &
implementation
(SR57, fig1)
Civil / structural
VROM
Regulatory
Oversight
12
LTO assessment project (technical part)
• KCB project LTO “bewijsvoering” based on IAEA Safety Report 57:
• Feasibility and verification of preconditions;
• Scoping, screening and Ageing Management Reviews;
• Revalidation of the following TLAAs:
• Reactor Pressure Vessel (RPV);
• Fatigue;
• Leak Before Break;
• Qualification of Design Base Accident resistant electrical Equipment.
• Assessment of active components;
• Documentation for LTO basis;
• Regulatory oversight and the KCB implementation of plant commitments.
• The outcome of the project LTO “bewijsvoering” was submitted to the authority
for a license change procedure for long term operation of KCB until 2034.
LTO “bewijsvoering”
KCB
Feasibility (3.1)
Verification of
preconditions (3.2)
Scoping (4.1)
Screening (4.2)
Check of existing
plant programmes
TLAAs (6)
RPV
EQDBA
LBB
Fatigue
Mechanical
Electrical
Documentation of basis
for LTO
IAEA Safety report Nr 57
Safe Long Term Operation of
Nuclear Power Plants
IAEA NS-G-2.12 (ch 6)
Ageing Management for Nuclear
Power Plants
Mechanical A
(barrier concept)Electrical Civil / structuralMechanical B
Implementation of plant
commitments for LTO
ActiveAMR (5)
Passive
Regulatory
framework
IAEA
guidelines
Phase prior to LTO
assessment
(SR57, fig1)
Phase LTO
assessment
(SR57, fig1)
Phase LTO
approval &
implementation
(SR57, fig1)
Non technical requirements
IAEA Draft Safety Guide No. 426
Periodic Safety Review of Nuclear
Power Plants
SF 10 & 12
Civil / structural
VROM
Regulatory
Oversight
13
Overall schedule LTO-project
limited scope full scope follow-up
2014 201520132008 2009 2010 2011 2012
Scoping
SALTO peer reviews
Screening
Ageing Management Review of passive Structures & Components
Revalidation of Ageing design:Time Limited Ageing Analyses; Environmental Qualification
Formal License approval proces
License appl.
regulator review (GRS)
Verif. plant programmes
Active Components Assessment
Licensesigned
Additional measures and verification
Regulatory review of implementation license requirements
14
‘Going towards coordinated
Ageing Mgt’
Assessment on Ageing Management
System taking into account several
performed reviews on Ageing Management
(self, regulator and peers)
Basis: NVR NS-G-2.12 IAEA Safety
Guide ‘Ageing Management of Nuclear
Power Plants’ 2009
Currently three pillars on Ageing
Management:
1.Maintenance, Surveillance and Inspection
Process
2.Ageing Management Experience Feedback
Procedure
3.Ageing Management Reviews
LTO “bewijsvoering”
KCB
Feasibility (3.1)
Verification of
preconditions (3.2)
Scoping (4.1)
Screening (4.2)
Check of existing
plant programmes
TLAAs (6)
RPV
EQDBA
LBB
Fatigue
Mechanical
Electrical
Documentation of basis
for LTO
IAEA Safety report Nr 57
Safe Long Term Operation of
Nuclear Power Plants
IAEA NS-G-2.12 (ch 6)
Ageing Management for Nuclear
Power Plants
Mechanical A
(barrier concept)Electrical Civil / structuralMechanical B
Implementation of plant
commitments for LTO
ActiveAMR (5)
Passive
Regulatory
framework
IAEA
guidelines
Phase prior to LTO
assessment
(SR57, fig1)
Phase LTO
assessment
(SR57, fig1)
Phase LTO
approval &
implementation
(SR57, fig1)
Non technical requirements
IAEA Draft Safety Guide No. 426
Periodic Safety Review of Nuclear
Power Plants
SF 10 & 12
Civil / structural
VROM
Regulatory
Oversight
15
From a static LTO assessment to
living ageing management
• Ageing Management has
proven to be adequate
and largely consistent
with NVR NS-G-2.12 and
up-to-date
• Need for improvement on
coordination and
traceability
• Decision to implement a
specific SSC oriented
ageing management
process strongly based
on the LTO AMR
• Consistent with BBC
requirement
16
SSC based AM Strategy
• Ageing degradation mechanisms for SSC are determined
• Shows on a high level how these
ageing degradation mechanisms
are to be managed at KCB
• Based on AMR project documents
• Provides the basis for the low-
level plant programs (AMPs)
• IGALL based document format
• KCB-specific implementation
• Provides link to (existing) activities
• Scope verification by mechanism matrix in
AM strategy documents
• Enables traceability and auditability
17
Example Steam Generator (PU-N12-50-302)
Steam generators
1. Introduction
• Scope
2. Component description
• Primary/secondary design description
• Design analyses
• Materials
• Operating conditions, media, water chemistry
3. Operational experience
Internal, including modifications
External
Relevant IAEA - IGALL documents
4. Ageing management of applicable mechanisms
5. Roles and responsibilities
6. Results matrix
18
Scope Steam generators
Primary side of both steam generators (YB)
• Primary chambers
• Tubesheet
• Division sheet
• Manholes primary side (including nozzle, -
sealing plates and covers)
• Tube bundle
• In- and outlet nozzles (YA)
• Dewatering primary chambers
• Dewatering manhole nozzles
Secondary side of both steam generators(YB)
• Shell
• Downcomer annulus
• Feedwater ringline
• Feedwater nozzle (RL)
• Steam outlet nozzle (RA)
• Nozzles for blowdown line (RY)
• Tube bundle support (straps, camconstruction,
distance strips)
• Manhole secondary side (including nozzle, -sealing
plate and cover)
• Handholes secondary side (including nozzles, -
sealing plates and covers)
• Instrumentation nozzles, level control
• Instrumentation nozzles, temperature control
• Instrumentation lines up until1st isolation valve
• Supports, welded to the outside of the steam
generator
19
Matrix of mechanisms Steam Generator, primary side
Age
ing
me
chan
ism
Bo
ric
Aci
d C
orr
osi
on
(P
U-N
12
-50
-46
1)
Inte
rcry
stal
line
SC
C
(PU
-N1
2-5
0-4
70
)
Pit
tin
g (P
U-N
12
-50
-46
3)
Stre
ss r
ela
xati
on
(P
U-N
12
-50
-44
0)
We
ar/f
rett
ing
(PU
-N1
2-5
0-4
30
)
PW
SCC
(P
U-N
12
-50
-46
2)
Cre
vice
co
rro
sio
n
(PU
-N1
2-5
0-4
63
)
The
rmal
Age
ing
(PU
-N1
2-5
0-4
10
)
Tran
scry
stal
line
SC
C
(PU
-N1
2-5
0-4
75
)
Fati
gue
(P
U-N
12
-50
-45
0)
Component
Outside area steam generator BCD ABC
Primary cambers and nozzles ABC A
Division sheet ABC A
Tube bundle ABC I A
Tube sheet AD FGH
Rolled plugs I
Explosion formed plugs ABC A A
Welded plugs AD
Manhole cover ABC DJ
Nozzle dam bolts ABC A
Dewatering lines ABC ABC A
Closure bolting BCD BC E F
A Water chemistry
B Leakage
walkdowns
C Leak monitoring
D ISI
E Preventive
tensioning
F Fatigue analysis
G Managing
transients
H FAMOS
I Loose Parts
monitoring
J Preventive
replacement
20
Example AMP for FAC (PU-N12-50-460)
Ageing Management Plan: Flow Accelerated Corrosion
Table of Contents
1. Introduction
2. Evaluation and Technical Basis
• Scope of the ageing management programme
• Preventive actions to minimize and control ageing
degradation
• Detection of aging effects
• Monitoring and trending of aging effects
• Mitigating ageing effects
• Acceptance criteria
• Corrective actions
• Operating experience feedback and feedback of
R&D results
• Quality management
3. References
4.Appendices
History of relevant KCB based events
History of pH value
Inspections
21
Continuous improvement
Improved coordination
Ownership
Review by specialist in SC working groups
Interface with existing ageing experience
feedback procedure
Cooperation with integral Equipment Reliability
process
22
Thank you for your attention
N.V. EPZ Zeedijk 32, 4454 PM Borssele Telephone +31 113 - 356000 epz.nl werkenbijepz.nl
EPZ: one GigaWatt of electricity!
23
Scope AMP for FAC
Scope of the AMP is based on expert
knowledge of the FAC mechanism
Scope determined during project with AREVA in 1988
Refined over the years due to operational experience
• E.g. areas with extremely low Oxygen content after Mihama
accident (Japan, 2004)
Scope laid down in FAC AMP
Scope not confined to SSC that are important for
nuclear safety or SSC whose failure may impact SSC
important to safety
- back -
24
Preventive actions
Preventive actions to minimize and control FAC
Ensure that plant is conductive to optimized water chemistry
• E.g. replacement of CuNiFe condensors with Titanium units
Maintain high pH levels, at KCB not below 9,3 since1978
Maintain water chemistry to support Magnetite (Fe3O4) protective
layer (Redox potential)
• Validated by replacement
of RK condensate line
section in 1990
- Back - 9
9.1
9.2
9.3
9.4
9.5
9.6
9.7
9.8
9.9
1073
75
77
79
81
83
85
87
89
91
93
95
97
99
01
03
05
07
09
11
13
pH
Jaar
pH in main condensate system
25
Detection of ageing effects
Main effect of FAC/EC is wall thinning at susceptible areas
• Determine susceptible areas by analysis
• Measure wall thickness by Ultrasonic Testing at representative areas
Visual inspection may also be performed in suitable
systems
• Large bore piping (1000 mm)
• Heat exchangers
Inspection frequency in line with operational experience to
prevent unacceptable extent of wall thinning
• Safety
• Code compliance
- Back -
26
Monitoring and Trending
Currently, monitoring and trending is based on engineering
judgment:
• Evaluation of FAC analysis
• Interpretation of UT test results by expert judgment (RTD and ISI
expert)
• Results show generally stable conditions
Application of COMSY in preparation
• Analysis of areas under suspicion (e.g. feedwater nozzle on SG)
• Verify current analyses
• Trending of inspection results
Pipe sections that are hard to analyse:
• At least a once-off UT inspection to provide insight in actual condition
- Back -
27
Mitigating Ageing Effects
Control of water chemistry:
• pH
• Oxidation / reduction potential
Repair or replacement
• Where possible using less FAC/EC susceptible materials
Investigation of other mitigating measures:
• Increase wall thickness of new components
• Reduce flow velocity by changing pipe configuration
- Back -
28
Acceptance criteria
Currently by conservative engineering judgment
• RTD inspection report
• Visual inspection
Prognosis of remaining number of operating cycles if
inspection results show degradation
Currently in preparation of implementing COMSY
• Conservative estimation of required ISI interval
• Verification of current prognoses
- Back -
29
Corrective Actions
Short term:
• Detailed evaluation
• Repair or replacement
Long term:
• Changes to operational conditions
• Design changes with regard to material selection or geometry
Design changes
• Where feasible, apply materials with higher Cr content
• Pay sufficient attention to downstream components after any design
change
- Back -
30
Operating Experience and
R&D feedback
Ageing related notifications:
• Application of VOB procedure PU-N12-19:
- Operational feedback by WANO, INPO, VGB, AREVA
- Internal experience (SWG – Failure analysis workgroup)
Active contribution to maintaining current with state-of-the-
art developments:
• Participation in relevant forums (VGB AK-KOM for component
integrity, VGB AK-ROHR specialized forum on piping systems)
• Attending applicable conferences by EPZ specialists, e.g. 3-yearly
International Conference on Flow Accelerated Corrosion, France
- Back -
31
Quality Management
EPZ Quality, process and document configuration
management procedures are applicable
The Ageing Management Process PU-N12-50 and its
supporting documents such as the Ageing Management
strategies and Ageing Management Plans form part of
EPZ’s Integral Management System.
Purpose of the EPZ Integral Management System is to
provide support for:
• Obtaining operational targets
• Risk management
• Compliance with legislatory and regulatory requirements
- Back -
32
Inspections
AKS Omschrijving Component deel Aspect Inspectie interval (Jaar)
PMID PMRQ Scope
RA000Z007 LEIDENDE LEIDING Bocht 1 UT-W 12 4882 3 FAC
RA000Z008 LEIDING Bocht 18 UT-W 12 4883 2 FAC
RA000Z011 LEIDING T-stuk 3 UT-W 12 4885 2 FAC
RA000Z020 LEIDENDE LEIDING UT-W 10 4886 1 FAC
RB001Z003 Leiding waterafscheider-herverhitter VT 8 5206 3
RL000B001 VOEDINGSWATERONTGASSER Stomp 20 RP021S009 UT-W 4 5345 1
RL010Z001 T-stuk UT/W Eenmalig 2004 FAC
RL011Z001 LEIDENDE LEIDING T-stuk 3 UT-W 4 5345 3
RL011Z001 LEIDENDE LEIDING T-stuk 9 UT-W 12 5429 2
RL011Z001 LEIDENDE LEIDING Verloop 10 UT-W 12 5429 2
RL011Z003 LEIDING Bocht 3 UT-W 12 5431 2 FAC
RL011Z008 LEIDING T-stuk 2 UT-W 5 5432 1 FAC
RL011Z008 LEIDING Verloop 1 UT-W 5 5432 1 FAC
RL012Z001 LEIDENDE LEIDING Verloop 10 UT-W 12 5478 3
RL012Z009 LEIDENDE LEIDING T-stuk 1 UT-W 5 5482 1
RL013Z007 LEIDENDE LEIDING Verloop 10 UT-W 5 5531 1 FAC
RL023Z009 LEIDING Bocht 4 UT-W 8 5603 1
RL023Z009 LEIDING T-stuk 1 UT-W 8 5603 1
RL031B001 HD VOORVERWARMER Wand t.p.v. RF-stomp UT-W 4 5646 4
RL031B001 HD VOORVERWARMER Wand t.p.v. RP-stomp UT-W 4 5646 4
RL031Z001 T-stuk UT/W Eenmalig 2004 FAC
RL032B001 HD VOORVERWARMER Wand t.p.v. RF stomp UT-W 4 5658 4 FAC
RM020Z001 LEIDENDE LEIDING Reduceer naar RM023Z001 UT-W 6 5965 8 FAC
RM020Z001 LEIDENDE LEIDING T stuk aansluiting RM020Z005 UT-W 6 5965 5 FAC
RM023Z001 LEIDING Bochtstuk na RM020Z001 UT-W 6 5983 1 FAC
RN021Z003 Leiding na meetflens RN021F001 UT/W Eenmalig 2004 FAC
RT000Z002 LEIDENDE LEIDING Verloop 1 UT-W 10 6488 1 FAC
RU000B002 LD-ONTSPANTANK UT-W 10 6550 1 FAC
RY010B002 SPUIKOELER UT-W 8 6621 4 FAC
SD013B003 Standpijp "C" DN 1000 VT 6 6980 1 FAC -Back-
33
Integration in operations
34
Closing the loop
- Back - - End -