Session C3: Research Activities: Materials Degradation Detecting Material

Session C3: Research
Activities: Materials
Degradation
Detecting Material
Degradation: Today and
Looking Forward
Jim Lang
EPRI
USNRC Regulatory Information Conference
9 March 2005
The Silver Lining: We Have Lots of
Experience
SG tubing
BWR internals
RPV head penetrations
BWR piping
1970s
2
PWR butt welds
?
1980s
1990s
2000s
>….
Copyright © 2004 Electric Power Research Institute, Inc. All rights reserved.
With Experience We Have Refined
Inspection Techniques
Leak Detection
Visual
Dye Penetrant
Magnetic Particle
Radiography
Electromagnetic
Acoustic Emission
Ultrasonic
3
Copyright © 2004 Electric Power Research Institute, Inc. All rights reserved.
Experience Also Provides The Basis For A
Risk Informed Inspection Approach
RISK = (Core Melt Potential/Pipe Rupture) vs (Potential for Pipe Rupture)
Pipe
Leak
Rupture Conditions
Potential
HIGH
MEDIUM
Thermal Fatigue
Corrosion Fatigue
Stress Corrosion Cracking (IGSCC,
Small
TGSCC, PWSCC, ECSCC)
Corrosion Attack (MIC, Crevice
Corrosion and Pitting)
Erosion/Cavitation
RISK REGIONS
HIGH
MEDIUM
LOW
4
CONSEQUENCE CATEGORY
Core Melt Potential for Limiting Break Size
NONE
LOW
MEDIUM
HIGH
HIGH
LOW RISK
MEDIUM RISK
HIGH RISK
HIGH RISK
MEDIUM
LOW RISK
LOW RISK
MEDIUM RISK
HIGH RISK
SMALL
LOW RISK
LOW RISK
LOW RISK
MEDIUM RISK
None No Degradation Mechanisms
Present
DEGRADATION CATEGORY
Potential for Large Break/Rupture
LOW
Degradation Mechanisms To
Which The Segment is
Susceptible
Large Erosion Corrosion (FAC)
Water Hammer
Vibration Fatigue
Copyright © 2004 Electric Power Research Institute, Inc. All rights reserved.
I
n
s
p
e
c
t
Experience Has Clearly Identified Today’s
Material Degradation Issues
Nickel Based Alloy
Stress Corrosion Cracking
Carbon Steel Nozzle
Extent of Circumferential Crack
Blunts at Carbon Steel
Stainless Steel Pipe
Extent of Axial Crack
High Fluence in BWRs and PWRs
Steam Generator Tubing
5
Copyright © 2004 Electric Power Research Institute, Inc. All rights reserved.
Fuel Integrity
Experience Shows That NDE Is Reliable –
But There Are Gaps
Detection & sizing of small defects
given the projected fast crack growth rate
36" PWR STEAM GENERATOR NOZZLE CONFIGURATION (711/X)
304L SS CLADDING
INCONEL182 OR 82
308 SS
Accessibility for inspection
SA 216
316 SS
316
Rough/wavy surfaces
1.35
35.6" OD
27.5" ID
Complex configurations
Qualification of NDE – specific to configuration
6
Copyright © 2004 Electric Power Research Institute, Inc. All rights reserved.
27.75" ID
3.5
Research Is Underway To Close The Gaps
• UT Probe development to
handle real configurations
– EMAT
– Conventional
• UT Techniques
– Phased array
– SH wave
• Other methods
– Eddy current
– Radiography
7
• Database of as-built
configurations
• Database & assessment of
NDE performance
• Enhanced modeling
• Realistic samples for
technique development &
qualifications
• Intensive qualification effort
Copyright © 2004 Electric Power Research Institute, Inc. All rights reserved.
Tomorrow’s Issues May Be Unknown – But
We’ve Cataloged Our Vulnerabilities
PWR
Corrosion/Wear
C&W
SCC
SCC
Material
Reduction in Toughness
RiT
Fatigue
Fat.
1
Subdivision→
C&LAS
PWR
Pressurizer
(Including
Shell, Surge
and Spray
Nozzles, Heater
Sleeves and
Sheaths,
Instrument
Penetrations)
8
IG
?
e002
?
e002
IA
N
TG
?
e002
?
e002
N
C&LAS
Welds
?
?
N
Wrought
e012
e012
SS
?
Y
SS Welds & Y
e016
e017
e018
Clad
N
N
N
Wrought
Ni Alloys
N
?
N
Ni-base
e024
Welds &
Clad
LTCP
N
LC/Th
Y
e006
Y
e006
Env
Y
e007
Y
e007
Th
Y
e008
Y
e008
Emb
N/A
VS
N/A
SR
N/A
Thn
N/A
Fl
N/A
N/A
N/A
N/A
N/A
N/A
N
Y
e014
Y
e015
N
N/A
N/A
N/A
N/A
N/A
N
N
?
e014
Y
e015
Y
e022
N/A
N/A
N/A
N/A
N/A
N
N
Y
e014
Y
e014
Y
e015
N
N/A
N/A
N/A
N/A
N/A
N
N
N
Y
e014
Y
e015
N
N/A
N/A
N/A
N/A
N/A
PW
?
e003
?
e003
Wstg
Y
e004
Y
e004
Pit
N
Wear
N
N
N
?
e013
?
e012
N
N
?
e013
?
e019
N
?
e023
Y
e023
Y
e023
Y
e025
N
Irradiation
Aging
Component
FAC
Y
e005
Y
e005
HC
N
N
N
N
?
e020
N
N
N
N
N
Copyright © 2004 Electric Power Research Institute, Inc. All rights reserved.
And We Know Where To Look
RISK REGIONS
DEGRADATION CATEGORY
Potential for Large Break/Rupture
HIGH
MEDIUM
LOW
CONSEQUENCE CATEGORY
Core Melt Potential for Limiting Break Size
NONE
LOW
MEDIUM
HIGH
HIGH
LOW RISK
MEDIUM RISK
HIGH RISK
HIGH RISK
MEDIUM
LOW RISK
LOW RISK
MEDIUM RISK
HIGH RISK
SMALL
LOW RISK
LOW RISK
LOW RISK
MEDIUM RISK
I
n
s
p
e
c
t
PZR instrument
nozzles
CEDM motor housing
CEDM/ICI nozzles
to RV head welds
Monitor tube
RVH vent nozzle
PZR heater
sleeves
Safety & relief
valve nozzles
PZR surge
line nozzle
Heat transfer tubing
PZR & RC pipe-surge
line connections
Shutdown cooling
outlet nozzle
Tube-TS cladding weld
Spray nozzles
Partition plate & welds
Let-down & drain nozzles
RCS instrument nozzles
Primary nozzle closure
rings & welds
Safety injection &
SDC inlet nozzle
Bottom channel head
drain tube & welds
Charging inlet
nozzles
Guide lugs
flow skirt
ICI nozzles-ICI guide tubes
9
Tubesheet (TS) cladding
Copyright © 2004 Electric Power Research Institute, Inc. All rights reserved.
RCP suction
& discharge