ML18036B125
| ML18036B125 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 01/08/1993 |
| From: | Blake J, Economos N NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML18036B123 | List: |
| References | |
| 50-259-92-43, 50-260-92-43, 50-296-92-43, NUDOCS 9301200059 | |
| Download: ML18036B125 (15) | |
See also: IR 05000259/1992043
Text
UNITED STATES
NUCLEAR REGULATORY COMMISSlON
REGION II
101 MARIETTASTREET, N.W.
ATLANTA,GEORGIA 30323
'+a*++
Report Nos.:
50-259/92-43,
50-260/92-43,-
and 50-296/92-43.
Licensee:
Valley Authority
3B Lookout Place
1101 Market Street
Chattanooga,
TN
37402-2801
Docket Nos.:
50-259,
50-260
and
50-,296
Facility Name:
Browns Ferry 1,
2,
and
3
License Nos.:
and
'nspection
Conducted:
Inspector:
N.- Economos
Dec
er 14-18,
1992
at
Signed
Approved by:
J.
J
Bl ke, Chief
Mat
i
s
and Processes
Section
Eng neering
Branch
Division of Reactor Safety
ate Signed
SUMMARY
Scope:
This routine,'nannounced
inspection
was conducted
onsite in order to observe
weld. overlay activities
on recirculation
and residual
heat
removal-=(RHR) pipe
Areas
examined during this inspection
included completed
overlays,
observation of surface
examination
on completed welds, fit up and
welding of structural
members
(beams)
to
a safety related
support,
review of
work specifications,
completed
work records,
surveillance reports,
and
certifications for material
and personnel
used
on this project.
Results:
The completed
weld overlays exhibited
good physical characteristics
and met
minimum dimensional
requirements.
Fabrication records
and completed
nondestructive
test records
were in order.
Welders,
NDE technicians
and
gC
inspectors
were adequately qualified to perform their assigned
tasks.
One violation was identified for failure to follow installation specification
requirements
paragraph
3.
9301200059
930112
ADOCK 05000259
REPORT DETAILS
1.
Persons
Contacted
Licensee
Employees
- H. Bajestani,
Technical
Support Nanager
- P. Burrell, Engineering
R. Craig, guality Assurance
- H. Harrell, Operations
Hanager
"J. Johnson,
guality Assurance
E. Knuttel, Licensing Engineer
- G. Pierce,
Nanager,
Site Licensing
T. Pitchford, Project Coordinator,
Pipe Replacement
- J. Smithson, Hodifications Engineer
J. Wallace,
Compliance
Engineer
- S. Wetzel, Site Licensing
Other licensee
employees
contacted
during this inspection
included .
engineers,
mechanics,
technicians,
and administrative
pei sonnel.
Contractors
General Electric, Nuclear
Energy
(GENE)
- R. Cameron,
gC Nanage,
Level III Examiner,
L. Grycko, Welding Specialist
J.
Nason,
equality Engineer,
Project Hodifications
R. Lietzak,
gC Supervisor
E. Ridgell, Acting Compliance
Nanager
NRC Resident
Inspectors
- C. Patterson,
Senior Resident
Inspector
- Attended exit interview
2.
Weld Overlay on Recirculation
and Residual
Heat
Removal
Piping Unit 3
This report is
a continuation of work activities performed
by regional
inspectors
to observe
and monitor the progress
on the replacement
of
recirculation piping and certain sections of reactor water cleanup
piping.
Similar work performed
in this area
has
been
documented
in
Region Report 92-31,
a
~
Codes
and Standards
The applicable
codes
and standards
used and/or referenced
in the
application of weld overlay are
as follows:
American Society of Hechanical
Engineering Boiler and Pressure
Vessel
(ASHE),
BEPV)
Code Sections III, V, and XI, 1986 Edition.
ASME,
B&PY Code Section II (89); Section
IX, Latest Edition.
American National Standards
Institute
(ANSI)- B31. 1,
1967 Edition.
. American Society for Nondestructive
Testing
(ANST) SNT-TC-lA, 1984
(GE)
'E-NE-532-101-0792,
Standard
Overlay Design for the
Browns Ferry
3
Recirculation
and
RHR System
GE-25A5195 Rev.
0 BFN-3, Weld Overlay for Recirculation
and
Piping System
Rev. 2,'"Technical
Report
on Material Selection
and
Processing
Guidelines for
BWR Coolant Pressure
Boundary Piping."
I
US-NRC Generic -Letter 88-01,
"NRC Position
on
IGSCCC in
Austeni tic Stainless
Steel
Piping.
4
- Background:
The need to apply weld overlay on
some of the welds in the
recirculation
and
RHR systems
resulted
from the presence
of code
rejectabl,e,
intergranular
stress
corrosion cracks
(IGSCC), that
were found during volumetric inservice examinations.
When cracks
of significant magnitude
are discovered
in
BWR piping,
Rev.
2, provides guidelines for repairs
or replacement
of the
affected piping that must
be performed before'he
plant can
be
returned to service.
The weld overlay reinforcement,
or repair, consists
of applying
weld metal
over the weld and for a specified
minimum distance
beyond the weld on both sides.
This is done completely
around the
outside surface of the pipe overlapping
each 'pass.
IGSCC-
resistant,
low-carbon, high-ferrite type 308L weld metal is used,
and the process
is usually performed with an automatic welding
machine
using the
Gas Tungsten
arc
(GTAW) process.
is performed with cooling water in the pipe during welding.
Th'is
assures
high compressive
residual
stresses
on the pipe inside
diameter,
which tend to retard
IGSCC growth during future plant
operation.
Weld Overlay Design Criteria:
Rev.
2, provides
two acceptable
overlay designs
which
are identified=-as
STANDARD overlay
and
DESIGN overlay.
The
STANDARD overlay, selected
by the licensee,
assumes
that the
cracks were"completely through the wall for 360
.
Accordingly the
overlay weldment is designed
to provide a,nominal
margin of 2.77
against limit load failure.
The method of calculation is based
on
methods
and criteria in IWB-3640, -3641,
3642 of ASHE Section XI.
.The controlling
GE specification,
provided the
'echnical
basis for the design of the subject weld overlays
and
'he
analyses
performed.
These
included
a shrinkage
analysis to
determine
the influence of shrinkage
from the process
on the
piping systems
involved and
a flood-up evaluation to assure
structural integrity of the piping systems prior to and during the
weld overlay application.
By review of the
GE specification,
and other related
documents,
the inspector ascertained
that
GE had determined
the overlay
designs
were consistent
with- applicable
code
and regulatory
requirements,
that all shrinkage
stresses
associated
with the
welding process
were well below material yield strength
and
as
"such acceptable,
and that flood-up- evaluation
confirmed that net
section failure of the pipe at the cracked sections
would not
occur prior to and during weld overlay repair.
The actual
thickness of the overlays
was designed
so that
a factor of safety"
of 3.0 is maintained
against
net section collapse for normal
and
upset, load conditions,
and of 1,5 on emergency
and faulted load
conditions.
The
GE specification
also required the
use of 308L filler metal
welding wire with high delta ferrite content.
.Specific acc'eptance
criteria were established
on the ferrite content of the first
layer in that the average ferrite content
had to exceed
8FN with
no individual reading 'being less
than
5FN.
Production Welding {IP55050)
a.
Weld Operator Proficiency Review
The document
used-to describe
requirements for the fabrication of
field weld-.overlays is GE-25A5195,
Rev.
0.
As such, this
'pecification
referenced
the applicable
codes identified earlier
in this report; material
requirements;
qualification requirements;
general
welding requirements
which included process
control, heat
input distortion control, repairs,
and weld surface finish
conditions;
and
gA requirements.
Additional welding requirements
were included in GE's general
welding procedure
GWP-86-5.0
BF,
Rev.
1.
Weld procedure
specification,
WPS No. 8.8.20
- BF,
Rev.
B, with procedure
qualification records
PgR{s) 82-12-1
and 82-12-2 were used to
qualify welding operators
and-fabricate
the overlay weldments.
Metal deposition
was accomplished
with the machine
gas
tungsten'rc
welding
{GTAW), process
using pulse
mode- and remote control.
Filter metal
used,
was 308L low carbon stainless
steel wire, 0.035
inch diameter with ferrite content in the
9FN range.
In addition to the areas
addressed
above,
paragraph
3.5.3 of
specification
GE-25A5195
Rev.
0 provided requirements
for mockups,
simulating the production weldment configuration
and
space
b.
"
limitations, to be welded, with the approved welding procedure,
in
order to demonstrate
acceptable
proficiency.
This proficiency was
to be demonstrated
by each welding operator
scheduled
to work on
this project.
Paragraph
3.5.3.7, of the specification,
provides
an alternative
to mockup qualification.
This alternative
method requires that
the contractor
(GE) prepare
a formal document for the
TVA engineer
to review and approve prior to commencing production welding.
The
document is to contain
a detail record of the operator's
overlay experience
or. recent experience
in operating the
same type
of equipment,
in- the
same environment
as
a weld'overlay,
and
as
a
minimum, provide adequate
description of the work experience
to
allow verification that mockup requirements
had
been
met for each
situation for which relief from mockup fabrication
w'as requested.
On December
17,
1992,
the inspector discussed
this area of the
specification with the cognizant
GE welding specialists
to
determine
which of the two options
was followed,
so
as to proceed
with the retrieval
and review of the. appropriate
records,
From
this discussion,
the inspector ascertained
that
GE had elected to
pursue
the alternative to mockup qualification approach.
Also at
this time, the inspector ascertained
that overlay proficiency-
mockup welds were performed in the lab shop but that this was done
on an, informal basis,
meaning that detail records of each
operator's activity/participation had not been generated.
Moreover,
the inspector
was informed that
TYA had performed
an
ultrasonic examination
on
a proficiency mockup,
but neither
GE nor
TYA could retrieve the record
because
the examiner
was
on vacation
and
was not expected
to return to work until sometime
near
the end
of December.
Additional discussions
with GE's cognizant quality
engineering
personnel
and supervision disclosed that. the formal
document,
described
in paragraph
3.5.3.7 of the subject
specification,
which was required
by the
GE specification,
to be
generated
by
GE and'ubmitted
to TVA for review and app'roval prior
to the start of production welding,
was never
issued,
On
December
18,
1992,
GE,issued
nonconformance
report
5-1BNH9-116
.
Rev.
0, to address
this finding and take appropriate
corrective
action.
At.the time of this finding seven of the nine'elds
had
been
completed.
On December
18,
1992 the inspector
informed the
licensee that
a failure to follow installation
specification/procedures
for activities affecting quality was
a
violation of Title Ten Code of Federal
Regulations,
Part
50
(10
CFR .50), Appendix B, Criterion V.
This violation was
identified as 50-296/92-43-01:
Failure to Implement Weld Overlay
Installation Specification
Requirements.
Inspection of In-Process
and Completed
At the time of this inspection,
seven of the nine welds designated
for weld overlay had
been w'elded,
ground flat for inservice
"
inspection
purposes,
thicknesses
had
been
taken
and recorded,
and
5
liquid penetrant testing had'been
completed.
The'nspector
examined
each of the completed
welds for appearance,
surface
condition of the overlay material
near
and adjacent to the overlay
for evidence of undercut, identification, weld width, uniformity
and cleanliness.
Weld identification and results
obtained
from
fabrication records
and the specification, were
as follows:
Overall
Minimum
Thickness
Ferrite
0~ii
id
h
Thi
k
~lb
N
b
~li k
GR-3-03 .'lbow to Valve
6 %"
0.50
0.500"-0.705"
9.5
1/16"
GE-3-54
GR-3-60
Elbow to Pipe
7.0"
~
0.45"
0.472"-0.658"
9.6
3/64"
Elbow to Pipe
7.0"
0.45"
0.480"-0.578"
10.7
1/16"
GR-3-57
Valve to Pipe
6j"
Elbow to
Pump
. 7.0"
DSRHR-3-11
Elbow to Pipe
7.0"
GR-3-27
Pump to Pipe
7)"
0.45"
0.494"-0.674"
10.7
1/8"
0.109"
0.45"
0.493"-,0.708"
10.7
7/32"
0.50"
0.561"-0.797"
10.0
1/4"
0.40"
0.403"-0.634"
10.5
C.
A nonconformance
report
(NCR),
No. 067,
had
been
issued to
document
a
PT indication found in the toe of overlay GR-3-57,
extending out to the valve body.
Details of the indication were
documented
in
PT report OL-3-57-1.0-1-58 PT-l, dated
October
15,
1992.
The indication was
removed
by excavation to
a depth of less
than 0.035."
No repair welding was required.
Welds GR-3-54
and
-60 had undergone
baseline ultrasonic
examination to satisfy
ASHE Code Section
XI requirements.
The
examination
involved automatic
and manual
scanning
techniques,
using
0
,
60 L, 70
RL and
OD creeping
wave 85
transducers.
No
indications greater
than
20% of .full screen
height were
observed/documented.
Those indication that were observed
in the
greater
than
20% range
were evaluated/dispositioned
as surface
irregularities resulting in nonrelevant lift-offtype indicatioris.
Procedures
and Documents
Reviewed
The inspector
reviewed the following documents
and procedures
for
technical
content,
completeness
and accuracy.
DCN-W18848
019155A
Weld Overlays for Unit 3
RHR and Recirculation Piping
Safety Assessment/Safety
Evaluation for Temporary
Supports
GE-TVA-5.0 Rev.
Cleanliness
Control
6
II
N-UT-24 Rev.
8
Ultrasonic measurement
of Wall Thickness
TVA-25.0
Rev.
C. General
Visual Examination
TVA-26.0
Rev.
B. General
Examination
In addition to the above,
the inspector reviewed
GE's Special
',
Process
Manual, containing weld procedure
specifications
and
associated
procedure qualification records
(PAR) used for the
overlay welds
and other welding in progress
at the time of this
.
inspection.
Through this review, the inspector
noted that the two
. PgR(s),
used for the qualification of weld procedure specification .,
(WPS-8.8.20
-
BF Rev. B), used
on the overlays,
were missing from
the manual.
This occurred*even
though the manual
was
a controlled
copy and
had
been
reviewed
by the appropriate
personnel.
Upon
further review,
GE determined that
PgRs
were missing from two
other weld procedure specifications,
WPS-3.3.6-BF
and WPS-8.8. 13-
BF.
Following a document search/investigation
and through
discussions
with document-control
management
(DCRH),
GE determined
that the
PgRs
had
been incorrectly removed
from the
WPS package
by
OCR'ersonnel,
and mis-filed with the general
welding procedures.
Copies of the missing
P(Rs were
made available for inclusion in
the subject manual,
which corrected
the problem.
GE instructed
DCRH personnel
on the proper handling of these
documents.
d.
Record
Review
For each of the seven
completed
the inspector
reviewed the fabrication records
including travelers, joint and
special
process
control sheets
and non'destructive
examination
records
to assure
that critical inspections,
measurements,
and'old
points, etc
, were being performed in the prescribed
manner
and
on
a timely basis.
In addition, the inspector
reviewed
performance qualification records for fifteen (15), weld operators
who participated
in the weld overlay application.
All had
attended
the prejob briefing held
on September
3,
1992
and
had
qualified to weld under the applicable
weld specification.
guality records
in the form of 'certified material test reports for
the filler metal
used
were reviewed
and found to be in order-
these
were
as follows:
Size
0. 035'S
Heat
XT6207
Ferrite
No.
'ther quali'ty records
reviewed'included
those for liquid penetrant
. materials
and ultrasonic equipment listed below:
Liquid Penetrant:
~Aent
Cleaner
Penetrant
1
Developer
Ultrasonics:
Manufacturer
Sherwin/OR-60
Sherwin/DP-40
Sherwin/0-100
Batch
No.
224-F4. and 24-L4
18-D1
,126-BG
Instrument
Model:
Tran sducers
USK70
S/N E17127
S/N E16545
S/N 54304,
0.5" diam.
4KHz,
0
54303,
2(5x10)
2MHZ
Calibration Blocks
BL O'BF-83
Simulator 6026-83
Within the areas
examined violations or deviations
were not identified
except for the one identified in sub-paragraph
3; a.
Pipe Anchor Support
X14, Unit 3
{IP55100)
Other work in progress
at the time of this inspection
included the
fabrication of anchor ring
No. 3-,47B406-273
and pipe anchor support
structure
in penetration X14.. The support
and anchor ring will secure
the six inch (6"), reactor water cleanup
(RWCU) pipe going through this
This work was being performed
under Design
Change Notice
(DCN), W18484. and
Work Plan 3783-92.
The applicable. drawing was
No. 3-48E1032-2.
Work was being documented
on Traveler
N X14ANC.
The
controlling standard for fabrication
and erection
was the AISC 8th
. Edition and TVA's specification
G-29C.
NDE requirements
for structural
steel joints called for visual inspection
per G-.29C.
The 'inspector
observed
the fit-up.of horizontal
beam
No.
9 (WBx3lx4'-6") to embed
No.
EMB-3-48NI008-126.
The
beam
was fit-up and tack welded in place,
well
within the applicable tolerance,
The inspector
reviewed
an
NCR issued
to document rejectable
indications
(gouges)
in the two embeds,
No. 3-
and
-128, in the area of the penetration.
The gouges
were
weld repaired
and ground flush.
Within the areas
inspecte'd violations
or deviations
were not identified.
'
8
Inspection
on Completed
(57060PT),
(57050VT)
In addition to the above work effort,
GE was involved in the
installation/replacement
of small
bore piping in the
RWCU system located
in'the non-regenerative
heat
exchanger,
room and the
pump room.
Work was
being performed
under:OCN
No. M17810A, Project
No. 92NJ815500.
In the
heat exchanger
room, the inspector
observed
visual
and liquid penetrant
examination of five (5) welds.
Twd of these
were
on instrument lines,
and three
on vent and drain line', of the
RWCU system.
Meld
identification and location were
as follows.
Instrument Line
G001
G015
G024
G025
G030
MAPS
MP370392-1
Rev.
0
WP370392-15
Rev.
1
WP370592-24
Rev..O
WP370592-24
Rev.
0
WP370592-24
Rev.. 0
Size
One Inch
'ne
Inch
, One Inch
One Inch
'ne
Inch
~Te
Socket
Socket
Socket
Wel.d
Socket
Socket
~lne ection
VT/PT
VT/PT
VT/PT
YT/PT
YT/PT
G025
and
G030 exhibited rejectable
PT -indications that were
removed
by grinding,
and weld repaired.
A subsequent
PT examination
showed both welds were acceptable.
guality records
including those of
liquid penetrant materials,
identified earlier in this report,
and
examiner certifications
were reviewed for- completeness,
accuracy
and
compliance with applicable
standards.
Within the areas
inspected,
violations or deviations, were not
identified.
Review of Onsite Audit Activities, (40704) Unit 3
The inspector
reviewed reports of audits/surveillance
p'erformed
by
'and
TVA on work activities related to the pipe replacement
project
and
the ongoing -weld overlay effort.
The review included reports of audits
performed
from June to. November of 1992.
Activities audited
by both
organizations
included machining, welding, review of field generated
records (travelers),
material certifications,
review of radiographs,
weld repairs,
an'd implementation of the
gA program requirements.
Problem areas identified were'nvestigated
and dispositioned
in
a
satisfactory
and timely manner.
Within the areas
inspected,
violations or deviations
were not
identified.
7.
Exit Interview
d results
were summarized
on December
18,
1992,
h
1
Th 'o
d
b d
ssed
in detail the inspection results
d 'th'
t'o
o
'
d 'his report.
Dissenting-comments
were
information is not contained
in
is repor
.
- not received
from. the licensee.-
(Open) Violation 50--396/92-43-01:
Failure to Impl ement Meld, Overlay
Specification
Requirements
'