nrc staff please print and bring a hardcopy if you …hearing identifier:...
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From: Holonich, JosephSent: Monday, July 18, 2016 9:04 PMTo: Poehler, Jeffrey; Hiser, Allen; Hardies, Robert; Mchale, John; Amberge, Kyle; 'Ostroff,
James'; Burgos, Brian; Cheruvenki, Ganesh; Tilton, Caroline; John J. Sipos; Mihir Desai; '[email protected]'; 'Bergman, Jana'; Kuhlmann, Jenny
Cc: Hsueh, Kevin P; 'Molkenthin, James P'; 'Michael F Marino (Generation - 4)'; 'Demma, Anne'; 'Rudell, Bernie C:(GenCo-Nuc)'; 'Malikowski, Heather M:(GenCo-Nuc)'; 'Glenn A Gardner (Generation - 4)'; 'Wells, Tim G.'; 'Dyle, Robin'; Ross-Lee, MaryJane; Gray, Mel; Dentel, Glenn; Floyd, Niklas; Kulp, Jeffrey; Burket, Elise; Mangan, Kevin; Laur, Steven; Lyons, Sara; Clifford, Paul; Hickey, James; Alley, David; Haagensen, Brian; Ziedonis, Adam; Bower, Fred; Barkley, Richard; Siwy, Andrew; Draxton, Mark; Vadella, Robert; Finney, Patrick; R1DRPBR3CAL RESOURCE; Rudland, David; Nove, Carol; Turk, Sherwin; Wallace, Jay; Butcavage, Alexander; Werner, Greg; Anchondo, Isaac A; Drake, James; Hills, David; Holmberg, Mel; Fernandez, Edison; Schmidt, Colleen; Riemer, Kenneth; Ellegood, John; Taylor, Thomas; Cender, Laura; Domke, Matthew; Neurauter, James; Smith, Laura; Garg, Krishan
Subject: Background Information for Jul 19, 2016 Meeting on Baffle Former Bolts is attached. NRC staff needs to print their copy.
Importance: High
Below is the background information for the Jul 19, 2016 meeting baffle former bolts. NRC STAFF PLEASE PRINT AND BRING A HARDCOPY IF YOU WANT A COPY. THERE WILL BE LIMITED COPIES AVAILABLE IN THE MEETING ROOM AND THOSE ARE FOR STAKEHOLERS.
Hearing Identifier: IndianPointUnits2and3NonPublic_EX Email Number: 7475 Mail Envelope Properties (32dc897f00c142a69db50ae12d4df056) Subject: Background Information for Jul 19, 2016 Meeting on Baffle Former Bolts is attached. NRC staff needs to print their copy. Sent Date: 7/18/2016 9:03:42 PM Received Date: 7/18/2016 9:03:55 PM From: Holonich, Joseph Created By: [email protected] Recipients: "Hsueh, Kevin P" <[email protected]> Tracking Status: None "'Molkenthin, James P'" <[email protected]> Tracking Status: None "'Michael F Marino (Generation - 4)'" <[email protected]> Tracking Status: None "'Demma, Anne'" <[email protected]> Tracking Status: None "'Rudell, Bernie C:(GenCo-Nuc)'" <[email protected]> Tracking Status: None "'Malikowski, Heather M:(GenCo-Nuc)'" <[email protected]> Tracking Status: None "'Glenn A Gardner (Generation - 4)'" <[email protected]> Tracking Status: None "'Wells, Tim G.'" <[email protected]> Tracking Status: None "'Dyle, Robin'" <[email protected]> Tracking Status: None "Ross-Lee, MaryJane" <[email protected]> Tracking Status: None "Gray, Mel" <[email protected]> Tracking Status: None "Dentel, Glenn" <[email protected]> Tracking Status: None "Floyd, Niklas" <[email protected]> Tracking Status: None "Kulp, Jeffrey" <[email protected]> Tracking Status: None "Burket, Elise" <[email protected]> Tracking Status: None "Mangan, Kevin" <[email protected]> Tracking Status: None "Laur, Steven" <[email protected]> Tracking Status: None "Lyons, Sara" <[email protected]> Tracking Status: None "Clifford, Paul" <[email protected]> Tracking Status: None "Hickey, James" <[email protected]> Tracking Status: None
"Alley, David" <[email protected]> Tracking Status: None "Haagensen, Brian" <[email protected]> Tracking Status: None "Ziedonis, Adam" <[email protected]> Tracking Status: None "Bower, Fred" <[email protected]> Tracking Status: None "Barkley, Richard" <[email protected]> Tracking Status: None "Siwy, Andrew" <[email protected]> Tracking Status: None "Draxton, Mark" <[email protected]> Tracking Status: None "Vadella, Robert" <[email protected]> Tracking Status: None "Finney, Patrick" <[email protected]> Tracking Status: None "R1DRPBR3CAL RESOURCE" <[email protected]> Tracking Status: None "Rudland, David" <[email protected]> Tracking Status: None "Nove, Carol" <[email protected]> Tracking Status: None "Turk, Sherwin" <[email protected]> Tracking Status: None "Wallace, Jay" <[email protected]> Tracking Status: None "Butcavage, Alexander" <[email protected]> Tracking Status: None "Werner, Greg" <[email protected]> Tracking Status: None "Anchondo, Isaac A" <[email protected]> Tracking Status: None "Drake, James" <[email protected]> Tracking Status: None "Hills, David" <[email protected]> Tracking Status: None "Holmberg, Mel" <[email protected]> Tracking Status: None "Fernandez, Edison" <[email protected]> Tracking Status: None "Schmidt, Colleen" <[email protected]> Tracking Status: None "Riemer, Kenneth" <[email protected]> Tracking Status: None "Ellegood, John" <[email protected]> Tracking Status: None "Taylor, Thomas" <[email protected]> Tracking Status: None "Cender, Laura" <[email protected]> Tracking Status: None "Domke, Matthew" <[email protected]> Tracking Status: None "Neurauter, James" <[email protected]> Tracking Status: None
"Smith, Laura" <[email protected]> Tracking Status: None "Garg, Krishan" <[email protected]> Tracking Status: None "Poehler, Jeffrey" <[email protected]> Tracking Status: None "Hiser, Allen" <[email protected]> Tracking Status: None "Hardies, Robert" <[email protected]> Tracking Status: None "Mchale, John" <[email protected]> Tracking Status: None "Amberge, Kyle" <[email protected]> Tracking Status: None "'Ostroff, James'" <[email protected]> Tracking Status: None "Burgos, Brian" <[email protected]> Tracking Status: None "Cheruvenki, Ganesh" <[email protected]> Tracking Status: None "Tilton, Caroline" <[email protected]> Tracking Status: None "John J. Sipos" <[email protected]> Tracking Status: None "Mihir Desai" <[email protected]> Tracking Status: None "'[email protected]'" <[email protected]> Tracking Status: None "'Bergman, Jana'" <[email protected]> Tracking Status: None "Kuhlmann, Jenny" <[email protected]> Tracking Status: None Post Office: HQPWMSMRS01.nrc.gov Files Size Date & Time MESSAGE 263 7/18/2016 9:03:55 PM Agenda Jul 19, 2016 BFB Meeting.pdf 57828 1- Summary and Discussion of Recent BFB Inspections.pdf 869624 2- Industry Assessment of BFB Inspection Findings - WEC.pdf 104309 3 - Industry Assessment of BFB Inspection Findings - AREVA.pdf 300185 4 - Charter and Objectives of Industry BFB Focus Group.pdf 751798 5 - Next Industry Steps and Ongoing Related Efforts.pdf 514801 Baffle-Former Bolts Public Meeting July 19 NRC Slides.pptx 324516 Options Priority: High Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date: Recipients Received:
Agenda for U.S. Nuclear Regulatory Commission (NRC) Staff and Electric Power Research Institute (EPRI) on Recent Inspection/Operating Experience with Baffle-Former-Bolts (BFB) and
MRP-227-A, “Pressurized Water Reactor Internals Inspection and Evaluation Guidelines”
July 19, 2016 (Category 1 Public Meeting)
Time Agendum Lead
8:30 a.m. Introduction, Safety, Administration, Opening Remarks NRC Staff/EPRI
8:45 a.m. Summary Recent Inspections of BFBs - DC Cook 2 (2010) - Indian Point 2 (2016) - Salem 1 (2016)
EPRI/PWROG
10:15 a.m. Break All
10:30 a.m.
Industry Assessments of BFB Inspection Findings - 2012 Westinghouse Technical Bulletin - 2016 Westinghouse NSAL
EPRI/PWROG
11:15 a.m. Charter and Objectives of Industry BFB Focus Group
EPRI/PWROG
12:00 p.m. Next industry steps and on-going related efforts - Upcoming planned outage inspections (2016-2017) - Near-term Focus Group actions (6-12 months) - Longer-term Focus Group and industry actions
EPRI/PWROG
12:30 p.m. NRC staff perspectives, questions, discussion NRC
12:45 p.m. Public Comment and Concluding Remarks All
P R E S S U R I Z E D W A T E R R E A C T O R O W N E R S G R O U P
Global Expertise • One Voice
Baffle Former Bolt Overview of Industry Experience
Heather Malikowski (Exelon), Chair Bryan Wilson (Westinghouse)PWROG Materials Committee
July 19, 2016
P R E S S U R I Z E D W A T E R R E A C T O R O W N E R S G R O U P
Westinghouse NSSS Internals
Control Rod Guide Tube
Outlet Nozzle
Core BarrelThermal Shield
Former Plate
Hold Down Spring
Lower Core Support Plate
Vessel Head
Pressure Vessel
Inlet Nozzle
Upper Support Plate
Lower Core Plate
Bottom-Mounted Instrumentation Column Body
Lower Support Column Body
Upper Core Plate
Baffle Plate
Upper Support Column
2
P R E S S U R I Z E D W A T E R R E A C T O R O W N E R S G R O U P
Baffle-Former Assembly
ExampleBaffle-former
Bolt Locations
Thermal Shield
Core Barrel
Baffle Plate
Former Plate
Source: ML15331A264
3
P R E S S U R I Z E D W A T E R R E A C T O R O W N E R S G R O U P
Baffle-Former Assembly Details
Baffle
Baffle Plate Edge Bolt
Baffle to Former Bolt (Long & Short)
Corner Edge Bracket Baffle to Former Bolt
Core Barrel to Former Bolt
Core BarrelFormer
Source: ML15331A1794
P R E S S U R I Z E D W A T E R R E A C T O R O W N E R S G R O U P
Coolant Flow ConfigurationsUpflowConfiguration
Coolant Flow
Baffle Plate
Former Plate
New Flow Hole
Plug
Coolant Flow
Coolant Flow
Core Barrel
Thermal Neutron Shield
DownflowConfiguration
Source: ML0731903765
P R E S S U R I Z E D W A T E R R E A C T O R O W N E R S G R O U P
Timeline
Note: UT deployed as it became available and qualified for the various sites
DC Cook finds degraded bolts by visual
inspection
First UT baffle-former bolts (BFB) inspections in French PWR CP0 units and first cracks found
Indian Point 2, Salem 1 find
degraded bolts (visual+UT)
Ginna performs first MRP-227 inspectionsFirst degraded
baffle-former bolts found in U.S.
WCAP-13266: BFB Program for the
Westinghouse Owners Group - Plant
Categorization
NRC Information
Notice 98-11 on BFBs MRP publishes
assessment of French BFB OE (MRP-03)
MRP publishes Reactor Internals
Inspection Guidelines (MRP-
227)
NRC reviews & approves MRP-227
Westinghouse Technical Bulletin TB-12-5, related to the DC Cook OE
Operating Experience
Guidance
6
P R E S S U R I Z E D W A T E R R E A C T O R O W N E R S G R O U P
EDF Experience 1989-Present• Baffle bolt failures reported 1989 – Present
– Limited to CP0 design• 3-loop (converted to upflow)• Significant plant-to-plant variability• CPY design (<5 indications over life of plant)
7
P R E S S U R I Z E D W A T E R R E A C T O R O W N E R S G R O U P
EDF Response• Safety Case
– LOCA Loads– Acceptable loads on remaining bolts– Acceptable loads on fuel assembly grids– Minimal number of “healthy bolts” ~30% with limits on distribution
• Periodic bolt replacement– Failed original bolts– Periodic replacements included previously replaced bolts– Sufficient number of “healthy bolts” to push next inspection to 10
years (based on projection model)
8
P R E S S U R I Z E D W A T E R R E A C T O R O W N E R S G R O U P
Joint Owners Baffle Bolt Program (15-22 EFPY)
• Sponsored Inspections of four plants– Point Beach Unit 2: 2-loop, Upflow (converted) , Type 347SS
• 8% UT Indications• Partial replacement program
– Farley Unit 1: 3-loop, Upflow (converted), Type 316SS• No UT Indications• Proactive replacement of minimum pattern
– Ginna: 2-loop, Downflow, Type 347SS• 9% UT Indications (Of these, 14 were sent for metallurgical examination. Results showed no
indications of cracking, so this 9% likely contains a number of false calls)• Partial replacement program
– Farley Unit 2: 3-loop, Converted Upflow (downflow at time of inspection), Type 316SS• No UT Indications• Proactive replacement of minimum pattern9
P R E S S U R I Z E D W A T E R R E A C T O R O W N E R S G R O U P
WEC MRP-227 Baffle-Former Bolt Inspections (25-35 EFPY)
• Point Beach Unit 1: 2-Loop, Upflow (converted), Type 347SS – 1st Inspection: No UT Indications
• Point Beach Unit 2: 2-Loop, Upflow (converted), Type 347SS – 2nd Inspection: 2% Additional UT Indications
• Ginna: 2-Loop, Downflow, Type 347SS – 2nd Inspection (partial inspection of 123 original bolts and 56 replacement bolts):
1 Additional UT Indications (Partial Replacement – 25 bolts)• Prairie Island Unit 1: 2-Loop, Downflow, Type 347SS
– 1st Inspection: 6% UT Indications• Prairie Island Unit 2: 2-Loop, Downflow, Type 347SS
– 1st Inspection: 10% UT Indications
10
P R E S S U R I Z E D W A T E R R E A C T O R O W N E R S G R O U P
WEC MRP-227 Baffle-Former Bolt Inspections (25-35 EFPY)
• Surry Unit 1: 3-Loop, Downflow, Type 347SS– 1st Inspection: <1% UT Indications
• Surry Unit 2: 3-Loop, Downflow, Type 347SS– 1st Inspection: <1% UT Indications
• Robinson: 3-Loop, Downflow, Type 347SS– 1st Inspection: <1% UT Indications
• Turkey Point Unit 3: 3-Loop, Downflow, Type 347SS– 1st Inspection: No UT Indications in 305 of 1088 bolts inspected
• Indian Point Unit 2: 4-Loop, Downflow, Type 347SS– Inspection results addressed in detail on a later slide
11
P R E S S U R I Z E D W A T E R R E A C T O R O W N E R S G R O U P
International Plants• Doel 1: 2-Loop Downflow, Type 316SS
– 1st Inspection: 2% UT Indications• Doel 2: 2-Loop Downflow, Type 316SS
– 1st Inspection: <1% UT Indications• Krsko: 2-Loop, Downflow (prior to inspection), Type 316SS
– 1st Inspection: <1% UT Indications• Tihange 1: 3-Loop, Upflow (converted), Type 316SS
– 960 of 1088 bolts inspected in each of the following inspections– 1st Inspection: 4% UT Indications– 2nd Inspection: 3% UT Indications– 3rd Inspection: No confirmed UT Indications (5 bolts either not inspectable or not interpretable)
12
P R E S S U R I Z E D W A T E R R E A C T O R O W N E R S G R O U P
B&W-Designed RV Internals Baffle-to-Former Bolt Examinations (19-32 EFPY) [1 of 2]
• Four baffle-to-former bolt (BFB) UT examinations completed at B&W-designed units to date– Oconee Unit 1
• No relevant UT indications• Four BFBs uninspectable due to large welds on locking bars
– Oconee Unit 2• No relevant UT indications• One BFB uninspectable due to UT probe not seating properly
– Oconee Unit 3• One BFB identified with crack-like indications• One BFB uninspectable due to UT probe not seating properly
– Crystal River Unit 3• No relevant UT indications• UT performed due to visual indication from baffle-to-baffle bolts
13
P R E S S U R I Z E D W A T E R R E A C T O R O W N E R S G R O U P
B&W-Designed RV Internals Baffle-to-Former Bolt Examinations (19-32 EFPY) [2 of 2]
• All BFBs Type 304 solution annealed stainless steel• B&W design is an upflow configuration• One BFB out of 3,450 BFBs UT examined identified with
crack-like indications• VT examination of all 3,456 BFBs identified no relevant
indications
14
P R E S S U R I Z E D W A T E R R E A C T O R O W N E R S G R O U P
Observations from Broader OE• With the exception of the OE at Cook Unit 2, Indian Point Unit
2, and Salem Unit 1 (discussed later in the presentation), the following observations can be made:– Bolts with UT indications tend to be randomly distributed– Distributions are consistent with expectations of IASCC failures– Quantity and distribution of bolts with indications bounded by
historical generic safety assessment (WCAP-15328)– Industry response to replacement of bolts with indications has
been positive
15
P R E S S U R I Z E D W A T E R R E A C T O R O W N E R S G R O U P
Experience with Clustered Bolt Failures
• DC Cook Unit 2 (2010 / 22 EFPY) (4-Loop Downflow Configuration)– Fuel failure in peripheral assembly attributed to wear against broken bolt head– Bolt heads and lock bars found on lower core plate– Visual inspections revealed 18 degraded bolts on single plate
• Additional bolts removed from plate with visual indications to define extent of localized degradation (approx. 40 bolts in single patch)
• Additional test bolts removed from symmetrical locations to evaluate potential for degradation on other plates (all of these test bolts were found to be intact)
– No UT inspections performed in 2010 (at that time UT was not qualified or optimized for the Cook 2 bolt design)
– Degraded and test bolts replaced– Westinghouse issued Technical Bulletin TB-12-5– 100% Visual inspection conducted in 2012 with no additional indications
16
P R E S S U R I Z E D W A T E R R E A C T O R O W N E R S G R O U P
Experience with Clustered Bolt Failures• Indian Point Unit 2 (2016 / 31 EFPY) (4-Loop Downflow Configuration)
– Degraded bolts and lock bars noted in visual exams performed prior to MRP-227 100% UT exams that were planned to occur during this outage
– Markings on periphery of neighboring fuel assembly identified (no fuel failure).– Inspections identified 227 with visual degradation or UT indications
• Includes 14 that were not inspectable– UT indications were clustered
• Spanned various quadrants• Multiple groups of 10+ adjacent failures• At least one cluster of 50+ adjacent failures
– Observed failure pattern exceeds WCAP-17096 acceptance criteria– Site-specific response:
• Performed Acceptable Bolting Pattern Analysis (ABPA)• Performed Replacement Bolting Pattern Analysis• Performed engineering evaluations supporting Unit 3 Extent of Condition Evaluation• Performed engineering evaluations supporting Unit 2 Assessment of Potential Safety Impacts• Performed baffle-former bolt removal and replacement • Quarantined select bolts for potential future testing
17
P R E S S U R I Z E D W A T E R R E A C T O R O W N E R S G R O U P
Experience with Clustered Bolt Failures• Salem Unit 1 (2016 / 28 EFPY) (4-Loop Downflow Configuration)
– Conduct visual exams every other refueling outage in response to DC Cook Unit 2 OE and TB-12-5; MRP-227 exams were not planned until 2017
– Degraded bolts and lock bars noted in visual exams followed by performance of UT exams– Loose or protruding bolt heads resulted in fuel fretting and a leaker at one fuel assembly– Inspections identified 182 with visual degradation or UT indications
• Includes 18 that were not inspectable– UT indications were clustered
• Concentrated to a few adjacent octants• Multiple groups of 10+ adjacent failures• At least one cluster of 50+ adjacent failures
– Observed failure pattern exceeds WCAP-17096 acceptance criteria– Site-specific response:
• Performed Acceptable Bolting Pattern Analysis (ABPA)• Performed Replacement Bolting Pattern Analysis• Performed engineering evaluations supporting Unit 1 Justification for Past Operation• Performed engineering evaluations supporting Unit 2 Extent of Condition Evaluation• Performed baffle-former bolt removal and replacement• Quarantined select bolts for potential future testing
18
P R E S S U R I Z E D W A T E R R E A C T O R O W N E R S G R O U P
Conclusions from Recent OE• These three plants share a common plant design configuration (4-loop
downflow) and bolt design• Bolts with visual or UT indications tend to be clustered• Distributions seem to indicate the presence of a mechanism causing
adjacent bolts to become more susceptible to failure• Most likely cause is redistribution of a sustained stress resulting in
increased IASCC susceptibility• Quantity and distribution of bolts with indications warranted the
creation of an industry focus group and the issuing of Westinghouse NSAL-16-1 and AREVA CSB 16-02
19
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rada
tion:
–re
acto
r coo
lant
des
ign
conf
igur
atio
n (u
pflo
wvs
. dow
nflo
w)
–pl
ant i
nter
nals
des
ign
and
flow
rate
s–
bolt
desi
gn•
Affe
cted
pla
nts
brok
en d
own
into
4 T
iers
AP1
000
is a
trad
emar
k or
regi
ster
ed tr
adem
ark
of W
estin
ghou
se
Ele
ctric
Com
pany
LLC
, its
affi
liate
s an
d/or
its
subs
idia
ries
in th
e U
nite
d S
tate
s of
Am
eric
a an
d m
ay b
e re
gist
ered
in o
ther
cou
ntrie
s th
roug
hout
th
e w
orld
. A
ll rig
hts
rese
rved
. U
naut
horiz
ed u
se is
stri
ctly
pro
hibi
ted.
O
ther
nam
es m
ay b
e tra
dem
arks
of t
heir
resp
ectiv
e ow
ners
.
9
Wes
tingh
ouse
Non
-Pro
prie
tary
Cla
ss 3
© 2
016
Wes
tingh
ouse
Ele
ctric
Com
pany
LLC
. All
Rig
hts
Res
erve
d.
NS
AL
Rec
omm
enda
tions
•G
ener
al R
ecom
men
datio
ns fo
r all
Tier
s:–
If vi
sual
ly d
amag
ed b
affle
-form
er b
olts
or l
ock
bars
are
de
tect
ed, i
t is
reco
mm
ende
d th
at th
e fu
el a
ssem
blie
s th
at
wer
e ad
jace
nt to
the
baffl
e in
the
prev
ious
cyc
le, a
nd a
re
sche
dule
d fo
r use
in th
e ne
xt c
ycle
, be
insp
ecte
d fo
r fre
tting
w
ear o
n th
e fa
ce th
at w
as a
djac
ent t
o th
e ba
ffle
–It
is re
com
men
ded
that
the
plan
t con
tinue
s to
follo
w th
e cu
rren
t MR
P-2
27 g
uide
lines
and
impl
emen
t any
revi
sion
s to
th
e M
RP
-227
reco
mm
enda
tions
10
Wes
tingh
ouse
Non
-Pro
prie
tary
Cla
ss 3
© 2
016
Wes
tingh
ouse
Ele
ctric
Com
pany
LLC
. All
Rig
hts
Res
erve
d.
NS
AL
Rec
omm
enda
tions
(con
t’d.)
•Ti
er 1
a (4
-loop
dow
nflo
wpl
ants
with
Typ
e 34
7 bo
lt de
sign
):C
ompl
ete
a U
T vo
lum
etric
insp
ectio
n of
the
baffl
e-fo
rmer
bol
ts a
t the
nex
t sc
hedu
led
refu
elin
g ou
tage
–In
pre
para
tion
for t
his
insp
ectio
n, th
e pl
ant s
houl
d co
nsid
er d
evel
opin
g an
A
BP
A a
nd b
e pr
epar
ed to
repl
ace
any
baffl
e-fo
rmer
bol
ts w
ith v
isib
le
dam
age
or U
T in
dica
tions
–Lo
ng-te
rm m
itiga
tion
stra
tegi
es to
con
side
r inc
lude
upf
low
conv
ersi
on a
nd
pree
mpt
ive
bolt
repl
acem
ents
•
Tier
1b
(4-lo
op d
ownf
low
plan
ts w
ith T
ype
316
bolt
desi
gn):
Com
plet
e a
VT3
(vis
ual)
insp
ectio
n of
the
baffl
e-fo
rmer
bol
ts a
t the
nex
t sc
hedu
led
refu
elin
g ou
tage
–If
any
visu
al in
dica
tions
are
foun
d, it
is re
com
men
ded
that
the
plan
t co
mpl
etes
a U
T vo
lum
etric
insp
ectio
n of
the
baffl
e-fo
rmer
bol
ts–
If no
vis
ual i
ndic
atio
ns a
re fo
und,
it is
reco
mm
ende
d th
at th
e pl
ant
com
plet
es a
UT
volu
met
ric in
spec
tion
of th
e ba
ffle-
form
er b
olts
prio
r to
the
com
plet
ion
of th
e se
cond
refu
elin
g ou
tage
afte
r the
issu
ance
of t
his
NS
AL
11
Wes
tingh
ouse
Non
-Pro
prie
tary
Cla
ss 3
© 2
016
Wes
tingh
ouse
Ele
ctric
Com
pany
LLC
. All
Rig
hts
Res
erve
d.
NS
AL
Rec
omm
enda
tions
(con
t’d.)
•Ti
er 2
a, 2
b, a
nd 2
c (2
-and
3-lo
op d
ownf
low
plan
ts):
–P
lant
s th
at h
ave
prev
ious
ly c
ompl
eted
UT
insp
ectio
ns s
houl
d re
view
the
insp
ectio
n re
cord
s to
iden
tify
any
indi
catio
n of
the
onse
t of c
lust
erin
g be
fore
th
e ne
xt s
ched
uled
refu
elin
g ou
tage
–C
lust
erin
g is
def
ined
as
3 or
mor
e ad
jace
nt b
olts
or a
tota
l num
ber o
f fa
ilure
s in
a s
ingl
e ba
ffle
plat
e >
40%
of t
he to
tal n
umbe
r of b
olts
on
that
ba
ffle
plat
e–
Any
indi
catio
n of
clu
ster
ing
shou
ld re
sult
in th
e co
nsid
erat
ion
of a
n ac
cele
rate
d re
-insp
ectio
n sc
hedu
le•
Tier
3 (C
onve
rted
upf
low
plan
ts):
–4-
loop
pla
nts
that
hav
e op
erat
ed in
a d
ownf
low
conf
igur
atio
n fo
r mor
e th
an
20 y
ears
sho
uld
eval
uate
the
need
to p
erfo
rm a
UT
volu
met
ric in
spec
tion
of
baffl
e-fo
rmer
bol
ts o
n an
acc
eler
ated
sch
edul
e–
All
othe
r pla
nts
shou
ld fo
llow
the
Gen
eral
Rec
omm
enda
tions
for a
ll Ti
ers
prov
ided
on
Slid
e 9
•Ti
er 4
(Des
igne
d up
flow
plan
ts):
–Fo
llow
the
Gen
eral
Rec
omm
enda
tions
for a
ll Ti
ers
prov
ided
on
Slid
e 9
AREVABaffle-to-Former Bolt Customer Service Bulletin No. 16-02
S. Fyfitch, AREVA Inc.
B&W-Design Baffle-Former Assembly
Baffle Plate
Former Plate
Core Barrel
Thermal Shield
Core Ba
Baffle-to-Baffle Bolt Locations
Core Barrel-to-Former Bolt and Baffle-to-Former Bolt Locations
Baffle-to-Former Bolt Locations (1/8th core)
B&W-Designed RV Internals Operating Experience
Four baffle-to-former bolt (BFB) UT examinations completed at B&W-designed units to date
One BFB out of 3,450 BFBs UT examined identified with crack-like indicationsVT examinations of all 3,456 BFBs identified no relevant indications
Concluded there is very high probability this was a random failure and not an indication of active degradation mechanism having initiated
AREVA Customer Service Bulletin No. 16-02 (1/4)
Customer Service Bulletin released July 14, 2016Subject:
Preliminary evaluation of relevance of recent BFB degradation at Westinghouse-designed 4-loop units to B&W-designed 177-FA unitsPreliminary evaluation relative to risk to safety and operability of B&W-designed 177-FA units
AREVA Customer Service Bulletin No. 16-02 (2/4)
Conclusions:BFBs and baffle-to-baffle bolts (BBBs), regardless of RV internals design, are potentially susceptible to irradiation-assisted stress corrosion cracking (IASCC)
Two primary factors affect IASCC-Accumulated fluence-Stress
Several key stress drivers for IASCC-Relatively high stress due to reactor coolant design configuration (downflow vs. upflow)
-Bolting installation and design characteristics- Bolt fabrication process- Bolt length- Bolt head-to-shank design- Initial torque levels
AREVA Customer Service Bulletin No. 16-02 (3/4)
Conclusions (cont.):Very unlikely that failure rate leading to unacceptable BFB configuration could occur before performing next MRP-227 examinations (initial or subsequent) at any B&W-designed 177-FA unitRisk of observing OE similar to that seen at Westinghouse-designed units to date is low
AREVA Customer Service Bulletin No. 16-02 (4/4)
These recommendations are provided until further evaluation and assessment of current issue is completed through PWROG and industry BFB Focus Group:
It is recommended that B&W-designed 177-FA units continue to follow BFB and BBB (and BFB and BBB locking devices/locking weld) inspection guidelines of MRP-227 and implement any future MRP guidance changesIt is also recommended that B&W-designed 177-FA units maintain increased awareness of telltale signs of BFB and BBB degradation through continuation of existing activities:
Evaluating reactor coolant radioactivity levels during fuel cyclePerforming loose parts monitoring and foreign object search and removal (FOSAR) examinations as part of normal refueling activitiesPerforming visual examinations of peripheral fuel assemblies currently identified for assessment of fuel performance
Additional details are provided in Customer Service Bulletin
QUESTIONS
© 2016 Electric Power Research Institute, Inc. All rights reserved.
Tim WellsBFB FG Chairman
Brian BurgosBFB FG EPRI Project Lead
Charter and Objectives
7/19/16
Industry Baffle-Former Bolt Focus Group
NRC Update
2© 2016 Electric Power Research Institute, Inc. All rights reserved.
Industry Plans
The Industry Baffle to Former Bolt (BFB) Focus Group was formed to support an integrated approach among industry organizations to address recent operating experience– AREVA– EPRI– PWROG– Utility Staff– Westinghouse– Others
Focus Area Lead Organization
#1 – /Extent of Condition, Interim Guidance, Technical Interfacing with the NRC
MRP
#2 – Plant/Fleet Operating ExperienceAssessment PWROG
#3 – Repair/Replacement PWROG
#4 – Inspection/NDE MRP
#5 – Irradiated Testing Support MRP
#6 – Aging Management Assessment MRP
Six focus areas with key actions defined
3© 2016 Electric Power Research Institute, Inc. All rights reserved.
Industry BFB FG Charter
The purpose of the BFB Focus Group is to coordinate industry activities relative to – understanding issues associated with recent baffle former bolts
operating experiences to prevent unnecessary duplication of time and effort
– to coordinate an agreed upon industry approach to resolving issues.
It will act to coordinate industry activities to resolve outstanding issues relative to the potential degradation of baffle former bolts and its impact to plant operations Vendors, MRP, PWROG and utility staff will work together to define a unified approach and will give regular updates to the Joint MRP/PWROG Reactor Vessel Internals Planning Team
4© 2016 Electric Power Research Institute, Inc. All rights reserved.
Industry BFB FG Charter
The Focus Group is NOT going to involve itself in other issues related to reactor internal components directly – The focus will be only dealing with issues related to baffle former bolts – There may be some actions taken by the team that also facilitate a
broader understanding of IASCC mechanisms which will be beneficial to reactor internals as a whole, but this will be a serendipity of the results obtained from activities coordinated by the focus group
Primary members of the BFB Focus Group will consist of EPRI staff, PWROG, NSSS Vendor staffs, and utility personnel – It is desired to have a well-balanced focus group that can provide
technical areas of expertise in irradiated materials degradation, structural design probabilistic fracture mechanics, and licensing
5© 2016 Electric Power Research Institute, Inc. All rights reserved.
Industry BFB FG Charter
BFB Focus Group Chairman: The BFB Focus Group will be headed by a Chairman appointed by the Joint PWROG and MRP RV Internals Planning Team leadership– Represent the Industry BFB Focus Group for reporting out activities to
key stakeholders– Act as the industry representative for interactions with the regulator
Project Lead: An EPRI staff member will be appointed as project lead to assist the Chairman in tracking and coordinating the activities of the Focus Group and the implementation of the Charter guidelines described here within– Coordinate all tele-conference and face to face meetings– Implement the Communication Plan
Primary Member: It is expected that primary members will participate in all calls and meetings to the best of their ability and to participate in various focus group activities at a high level
6© 2016 Electric Power Research Institute, Inc. All rights reserved.
Industry BFB FG Charter
Communication to BFB Focus Group members will be through a combination of emails, tele-conferences and face to face meetings – A weekly email will be sent out summarizing team activities
accomplished during the week along with upcoming short term activities
– Email updates will also be distributed to members of the Joint PWROG/MRP Reactor Vessel Internals Planning Team to keep them abreast of this specific issue and actions being taken by this team
– Updates will be given to the MRP Assessment/IC TAC and the PWROG MSC (that govern the RV Internals Planning Team’s work) at their respective meetings held throughout the year
– Monthly updates will be provided to the PMMP/MAPC EOC Updates will be given to the CNOs upon request
7© 2016 Electric Power Research Institute, Inc. All rights reserved.
Industry BFB Focus Area Objectives
Cause and Extent of Condition, Interim Guidance (Focus Area #1)– Develop BFB OE database and verify data– Evaluate/trend BFB OE– Develop Interim Guidance– Technical interactions with the NRC
Plant and Fleet Operating Experience Assessment (Focus Area #2)– Westinghouse to complete the 10CFR21 evaluation– Westinghouse to complete an NSAL; AREVA to produce a similar
document for B&W plants (Customer Service Bulletin)
Repair and Replacement (Focus Area #3)– Work with vendors to develop a contingency plan for tooling and bolt
inventory for the upcoming outage seasons (Fall 2016 / Spring 2017)
8© 2016 Electric Power Research Institute, Inc. All rights reserved.
Industry BFB Focus Area Objectives
Inspection / NDE (Focus Area #4)– Review bolt inspection protocols to see if lessons learned suggest
modifications– Understand UT Probability of Detection as related to UT-acceptable bolts
Irradiated Testing Support (Focus Area #5)– Establish an integrated testing plan to build upon the Indian Point 2 root
cause evaluation/analysis and further advance IASCC susceptibility knowledge
– Evaluate the need to include Salem 1 and Ginna BFBs into the integrated testing program
Aging Management Assessment (Focus Area #6)– Review previous aging management assessments and compare to
current OE experiences– Evaluate prediction models like the Weibull distribution in MRP-03 (which
is based on French data)– Potential revisions to MRP-227
9© 2016 Electric Power Research Institute, Inc. All rights reserved.
Industry Communications
Weekly updates to Industry BFB FG membersSupported presentation to NSIAC on 5/23/16– Westinghouse Technical Bulletin TB-12-5 remains valid
Provided Industry Alert Letter from the PMMP Chairman on 6/1/16– We fully expect that NEI 03-08 Interim Guidance will require the 4-
loop plants identified in the Westinghouse TB-12-5 bulletin to perform UT inspections of all the BFBs or replace an acceptable pattern of bolts at their next outage.
– Consideration should also be given to proceeding with procurement of replacement bolts prior to issuance of interim guidance due to potentially long manufacturing lead times.
10© 2016 Electric Power Research Institute, Inc. All rights reserved.
Together…Shaping the Future of Electricity
11© 2016 Electric Power Research Institute, Inc. All rights reserved.
Backup slides
12© 2016 Electric Power Research Institute, Inc. All rights reserved.
Industry BFB FG Charter – Org Chart
Industry BFB FG Team Leads
Tim WellsIndustry BFB Focus
Group Chairman
Brian BurgosIndustry BFB Focus Group Project Lead
Overall Program Updates
Joint MRP / PWROG Reactor Internals
Planning TeamPMMP / MAPC EOC
US NRCTechnical Issues
PWROG MSCMRP TAC & IC
MRP PWROG Vendors Utility FG Members
MRP Assessment TAC
Brian Burgos Kyle Amberge
M&T TACJean Smith
MSCJim Molkenthin
WestinghousePatty Paesano
AREVATammy Natour
3rd Party Vendors(SIA, DEI, etc)
Aging Management Assessment
Irradiated Testing Support
Repair / Replacement
Plant / Fleet Operability Experience Assessment
Provide Guidance and Oversight
EOC / Interim Guidance /
Regulatory Tech. Interfacing
Inspection TAC Jack Spanner
Inspection / NDE
US NRCLicensing
Issues
Industry Baffle-Former Bolt Focus Group
Organizational Layout
13© 2016 Electric Power Research Institute, Inc. All rights reserved.
Industry BFB FG Charter - Participants
Focus Area #1Cause/Extent of Condition / Interim Guidance
Focus Area #2Plant and Fleet Operating Experience Assessment
Focus Area #3Repair and Replacement
Focus Area #4Inspection / NDE
Focus Area #5Irradiated Testing Support
Focus Area #6Aging Management Assessment
Leads Tim WellsBrian Burgos
Heather MalikowskiBryan Wilson
William SimsGreg GontisWade Markham
Rachel DossJack Spanner
Chris KoehlerJean Smith
Glenn GardnerKyle Amberge
Additional Vendor / EPRI Support
Bryan WilsonSteve FyfitchMark Richter (NEI)Bruce Montgomery (NEI)Anne DemmaKyle AmbergeTim GriesbachChris LohseJim Molkenthin
Kyle AmbergeGreg TroyerJim AndrachekJim Molkenthin
Jim MolkenthinKyle Amberge
Pat MinogueDavid CisloAnne Demma
Mike BurkeSteve FyfitchAnne Demma
Josh McKinleyGreg TroyerAnne DemmaRandy Lott
Utility Participation
Nelson Azevedo Nelson Azevedo Heather Malikowski William Sims Nelson Azevedo William Sims
Tom Malota Greg Kammerdeiner Steve Petro Greg
Kammerdeiner Tom Malota Steve Petro
Glenn Gardner Tom Malota Eric Brackeen Kevin Hacker Jim Cirilli Mo Dingler
Jim Cirilli Glenn Gardner Dave Mora Ed Maloney / Kris Garg
Heather Malikowski
Rachel Doss Tim Wells Tim WellsMo Dingler Rebecca SiegristEd MaloneyHeatherMalikowskiGay HaliburtonEric Brackeen
© 2016 Electric Power Research Institute, Inc. All rights reserved.
Tim WellsBFB FG Chairman
Brian BurgosBFB FG EPRI Project Lead
Next Steps
7/19/16
Industry Baffle-Former Bolt Focus Group
NRC Update
2© 2016 Electric Power Research Institute, Inc. All rights reserved.
Upcoming Planned Refueling Outages
Upcoming Refueling Outages will help to inform us further on fleet trendsAdditional OE from upcoming domestic refueling outages will add to our knowledge base– Fall 2016: 3 planned MRP-227 UT inspections (2 of 3 are Tier 1a
plants)– Spring 2017: 3 planned MRP-227 UT inspections (all Tier 1a plants)
and 1 VT-3 inspection (Tier 1b plant)– Fall 2017: 3 planned MRP-227 UT inspections (1 of 3 is a Tier 1a
plant)– Spring 2018: 1 planned UT re-inspection (Tier 1a plant)
Additional International OE is expectedOut year planning will be important for inspection tooling preparation and for potential use of replacement equipment.
3© 2016 Electric Power Research Institute, Inc. All rights reserved.
Extent of Condition / Interim Guidance / NRC Interfacing (Focus Area #1)
Primary objectives in the short term:– Developed an OE database and analyze for trends to identify potential
relationships between known failures and plant design/operating conditions
This will be a significant input in developing Interim Guidance– Issue initial NEI 03-08 Interim Guidance to MRP-227/228 in the Fall 2016
timeframePotential update to Interim Guidance in 2017 based on OE from Fall 2016 and Spring 2017 refueling outages and other focus group activities
– Confirm refueling outage schedules for the next 2 years to feed into Focus Area #3 (Repair / Replacement needs)
This is needed to develop planning for both UT and replacement tooling and inventory assessment of typical BFB designs
– Support interfacing between regulatory authorities and industry groups
4© 2016 Electric Power Research Institute, Inc. All rights reserved.
Extent of Condition / Interim Guidance / NRC Interfacing (Focus Area #1)
Many combinations of data are being assessed– Are there plant parameters that indicate susceptibility?– Are there combinations of parameters that indicate trends?– Are there design parameters that indicate trends?
Trending of data continues and will support the development of Interim GuidanceDevelopment of the Industry BFB OE database is ongoing and will provide a means to capture and assess results of future inspections
5© 2016 Electric Power Research Institute, Inc. All rights reserved.
Plant/Fleet Operating Experience Assessment (Focus Area #2)
Primary focus is on the development of the Westinghouse NSAL and the AREVA Customer Service Bulletin– NSAL issued 7/5/16– AREVA CSB issued 7/14/16
Assisted in the development of an operating experience assessmentWill continue to review OE
6© 2016 Electric Power Research Institute, Inc. All rights reserved.
Repair / Replacement (Focus Area #3)
Recent OE at IP2 and Salem 1 identified issues related to replacement tooling availability– Delays in BFB replacement tooling were experienced due to
limited availability of equipment Key input for this focus area is the development of the outage schedule for the next 2 years along with scheduled inspections (volumetric or visual)Fall 2016 refueling outage support:– Contingency plan recommendations are being developed to
assist plants
7© 2016 Electric Power Research Institute, Inc. All rights reserved.
Repair / Replacement (Focus Area #3)
Ongoing evaluations are underway for vendor capital and/or PWROG tooling investment– What is the appropriate amount of tooling needed– How do the outages overlap in Spring 2017– Are modifications or changes needed to the existing equipment for
production or reliability
Material availability assessment completed – Both vendors have bolting material to fabricate roughly 1,500 BFBs– Items under consideration
Are increased machining rates required to potential provide sufficient bolts in a timely manner if requiredIs a common bolt design possible to allow for faster machining rates
8© 2016 Electric Power Research Institute, Inc. All rights reserved.
Inspection / NDE (Focus Area #4)
Current methods are identifying defectsReview bolting UT results for lessons learned relevant to the protocol Provide input to Focus Area #5 on recommended NDE examinations of bolts received from IP2 and Salem 1– Recommended PT prior to Destructive Examination
Evaluate the ability to correlate UT signals with measured crack size from destructive examination– May be impractical with multiple bolt designs and varying
vendor UT techniques– Internal hex head bolts and locking devices are
particularly difficult to UT
9© 2016 Electric Power Research Institute, Inc. All rights reserved.
Irradiated Testing Support (Focus Area #5)
Short-Term Testing (2016)• Work to support Indian Point and Salem root
cause and operability analyses
Intermediate-Term Testing (2016)• Testing with fleet-wide applicability
resulting from the OE
Long-Term Testing (2017+)• Evaluation of IASCC susceptibility of BFB
materials with respect to dose and time
• IP2 has shipped 32 bolts to the Westinghouse Hot Cell Facility (received 6/29/16)• Shipment of Salem bolts (6+) to follow• Ginna bolts (6) to be shipped in August 2016
10© 2016 Electric Power Research Institute, Inc. All rights reserved.
Irradiated Testing Support (Focus Area #5)
Activity Notes
Bolt Receiving & Transportation into Hot Cell 32 bolts (IP2), 6 bolts (S1)
Bolt Fracture Surface Examination• Optical microscopy, SEM• Identify fracture modes (IASCC, fatigue, creep)• Correlate with opposite fracture surface to assess potential
relative motion or rotation
Work supports root cause analyses
Remaining Property Testing• Room temperature pull tests of bolts determined by NDE to
have crackingAlloy Chemistry Confirmation
Radionuclide Analysis (dpa) Can be conducted on same sample as alloy chemistry
Technical Report
Clean-up & Return of Materials to Site All material to be returned to utility after testing
Proposed Short-Term Testing (2016)
11© 2016 Electric Power Research Institute, Inc. All rights reserved.
Irradiated Testing Support (Focus Area #5)
Focus Area #5 Action Items:• Develop testing plan by the end of July based on clear test
objectives and outcomes• Prioritize needed information to optimize funding• Coordinate funding sources such as utility, PWROG, MRP,
and DOE
12© 2016 Electric Power Research Institute, Inc. All rights reserved.
Aging Management Assessment (Focus Area #6)
Focus Area #6 is taking a long term approach toward understanding the mechanisms and adjusting the guidance of MRP-227 as required; for example:–Review previous aging management assessments
and compare to recent OE–What materials/structural models best replicate
observed OE and what do they predict for the futureIdentify any requirements that would modify the interim guidance issued by Focus Area 1
13© 2016 Electric Power Research Institute, Inc. All rights reserved.
Aging Management Assessment (Focus Area #6)
Recommend any updates for future MRP-227 revisionsEvaluation of repair/replacement modifications– Account for these within MRP-227– Relative effectiveness of options over the long term
Recommend adjustments to WCAP-17096 methodology as appropriate
14© 2016 Electric Power Research Institute, Inc. All rights reserved.
Near Term Industry BFB FG Actions to be completed
Assessment of Fall 2016 and Spring 2017 outage seasons for developing a contingency plan for tooling and BFB material needsDevelop NEI 03-08 Interim Guidance taking into account trending of BFB OE database and recent OEFinalize integrated irradiated testing plan which will feed into Focus Areas 1, 2, 4, and 6
15© 2016 Electric Power Research Institute, Inc. All rights reserved.
Together…Shaping the Future of Electricity
U. S. Nuclear Regulatory Commission
NRC Perspectives on Baffle-Former Bolt Degradation
July 19, 2016
1
Recent Operating Experience
• From 2010-2016, MRP-227-A inspections were performed at several Westinghouse 2-loop and 3-loop plants
– 2-loop plants had 5-10% degraded baffle-former bolts
– 3-loop plants had very few degraded baffle-former bolts
• In 2010, one Westinghouse 4-loop plant visually noted a large number of degraded bolts on one baffle plate (not during MRP-227-A inspection)
• In 2016, two Westinghouse 4-loop plants performed MRP-227-A inspections and found more degraded bolts than expected (27% and 22%)
• Plants with significant degradation are Westinghouse 4-loop designs with a “downflow” configuration and Type 347 stainless steel bolts
2
NRC Response to Recent OE
• Reviewed recent industry and vendor guidance on this issue
• Evaluated immediate safety significance of issue through internal processes (LIC-504)
• Regional staff has been alerted to issue and have engaged the licensees at sites with susceptible reactor designs
• Conducting baseline inspections focused on the issue at the two plants with extensive bolt degradation in 2016
3
NRC Inspections
• The NRC staff performed targeted inspections at the two plants with significant degradation.
• Inspection focused on:
– NDE quality and accuracy (VT, UT)
– Corrective actions, including evaluation of operating units
– Adequacy of replacement bolt pattern, including margin for additional failures during next cycle
• Results of the NRC inspections will be documented in publically available inspection reports.
4
Safety Significance
• NRC initial conclusion is that susceptible plants do not need to immediately shut down:
– The consequences of baffle plate detachment during normal operation would be limited to localized fuel damage, detectable by periodic coolant activity monitoring required by the TS
– Only certain events (large LOCA, medium LOCA, or seismic events) have the potential to rapidly detach the baffle plate due to baffle-former bolt degradation
– In such an event, the detachment of a baffle plate is not expected to pose a significant challenge to the ability to shutdown the reactor and cool the core
– Initial assessment is that the frequency of such events does not rise to the level of an “imminent safety concern” and does not require any immediate shutdown
• Many degraded bolts retain significant load-bearing capacity such that they would resist failure during a LOCA or seismic event
• NRC is monitoring inspection plans of susceptible plants.
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NRC Ongoing Actions
• NRC is gathering information on the root cause analyses and the metallurgical analysis of the bolts as it becomes available
• NRC will monitor EPRI MRP changes to inspection guidelines based on current events.
– NRC will review and issue a safety assessment on interim guidance issued by MRP related to baffle-former bolts
– NRC may also address this issue under the review of MRP-227, Rev. 1.
• NRC is evaluating the need for a generic communication, such as an information notice.
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