ML18152A295
| ML18152A295 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 03/14/1989 |
| From: | Conlon T, Merriweather N, Tingen S NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML18152A296 | List: |
| References | |
| 50-280-89-03, 50-280-89-3, 50-281-89-03, 50-281-89-3, NUDOCS 8904040005 | |
| Download: ML18152A295 (19) | |
See also: IR 05000280/1989003
Text
UNITED STATES
NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTA STREET, N.W.
ATLANTA, GEORGIA 30323
Report Nos.:
50-280/89-03 and 50-281/89-03
Licensee:
Virginia Electric and Power Company
Glen Allen, VA
23060
Docket Nos.:
50-280 and 50-281
License Nos.: DPR-32 and DPR-37
Facility Name:
Surry 1 and 2
S. Tingen
Other Contributors to this Report:
C. Paulk
Approved bc;/.~~,p;;y,/,,';,,,A~
T. E. Conlon, Chief
Plant Systems Section
Engineering Branch
Division of Reactor Safety
SUMMARY
1-2, 1989
3*- /fL-t'J
Date Signed
,:'?
'
9.-,
.,;, .. - It-*/ r.* /
Date Signed
- 37~ 11/-CZ-9'
Date Signed
Scope:
This special announced inspection was conducted to followup on
recently identified operating events involving motor operated valve
deficiencies and degraded Silicone Rubber power feeder cables
supplying power to the Inside Recirculation Pump Motors.
Subsequent
to the inspection, a special inspection was also conducted on
February 1-2, 1989, at the GE Safe Apparatus Center in Memphis,
Tennessee, to examine damage discovered on the Inside Recirculation
Pump Motor cable leads.
The results of this inspection are* also
summarized in this report.
Results:
No violations or deviations were identified; however, one Unresolved
Item (URI) 280, 281/89-03-01, paragraph 4.a., was opened to further
investigate the root cause for the degradation of Inside Recircula-
tion Pump Motor Power Cables.
The cables were previously qualified
to the requirements of IEB 79-018,
11Guidelines for Evaluating Environ-
mental Qualification of Class IE Electrical Equipment in Operating
Reactors
11 *
The licensee 1 s actions in regard to this concern appear
to be reasonable and sound.
Management appears to be supporting this
effort at all levels.
040005 890317
8904
05000280
ADOCK
PNV
G
2
In paragraph 3.b, a weakness was identified that involved the licensee
1 s
slow response in evaluating root cause and determination of corrective
action to prevent reoccurrences for Station Deviations written against
motor operated valves during the present Units 1 and 2 outages.
During
the exit interview the licensee verbally committed to perform root cause
analysis of Station Deviations written against motor operated valves and
establish measures to prevent reoccurrences prior to the respective Unit
restarc.
In paragraph 3.b, deficiencies in the licensee
1 sBulletin 85-03 program
were identified that involved testing motor operated valves without
appropriate different i a 1 pressure which is not in accordance with the
Bulletin requirements, and an excessive amount of station deviations
written against Bulletin valves after completion of the Bulletin
program .
1.
Persons Contacted
Licensee Employees
REPORT DETAILS
- D. A. Christian, Outage Coordinator
- E. Grecheck, Assistant Station Manager
- R. Green, Supervisor - System Engineering
- G. D. Miller, Licensing Coordinator
W. Murray, Virginia Power Representative at GE Safe Apparatus Center
- J. W. Ogren, Superintendent of Maintenance
- T. B. Sower, Superintendent of Engineering
Other licensee employees contacted during this inspection included
craftsmen, engineers, technicians, and administrative personnel.
NRC Resident Inspectors
W. Holland, Senior Resident Inspector, Operations
- L. Nicholson, Resident Inspector
- J. York, Senior Resident Inspector, Construction
- Attended exit interview
Acronyms and initalisms used throughout this report are listed in the
last paragraph.
2.
Action on Previous Inspection Findings (92701)
(Open)
Inspector Fol lowup Item 50-280, 281/88-45-01,
MOV Deficiency
Followup.
For discussion of findings, see paragraph 3.a below.
3.
Motor Operated Valve Deficiency Followup and IE Bulletin 85-03 Followup
(92701)
a.
(Open) 280, 281/88-45-01 MDV Deficiency Follow-up
During the. present Units 1 and 2 outages, the licensee has identified
numerous MOV deficiencies.
In order to become familiar with the MDV
defi ci enci es and the licensee responses to the defi ci enci es, the
inspector held discussions with licensee Technical Engineering and
Maintenance personnel and reviewed the following:
0
0
Approximately 200 Station Deviation. Reports written by
licensee personnel against Units 1 and 2 MDVs.
MDV
wa l kdown
data sheets for Unit 1 SMB-000 and 00
Limitorque actuators.
0
0
0
0
2
Engineering Work Request 89-061, dated January 22, 1989,
which documents the activities and decisions made for
inspection, repair, and replacement of Units 1 and 2 MOVs.
Surry Site Office Memorandum, dated November 10, 1988, to
R. H. Blount from
R. V. Green/J. LaFlam, Motor Operator
Evaluation, Surry Power Station Units 1 and 2, NP-1657/
PES NP-1718.
Section 5 of Surry Administrative Procedure SUADM-0-12,
Station Deviation Reports.
Licensee Event Report 50/280-43, dated December 9, 1988,
RSHX SW MOVs Discovered with Wrong Size Motors.
(1) Administrative Procedure SUADM-0-12 provides instructions for
reporting, processing, and disposition of Station Deviation
Reports.
Once a Station Deviation Report is initiated, it is
reviewed by station supervisory personnel to determine if
immediate action is required. Station Deviation Reports with a
fi na 1 response that include actions to prevent recurrence are
reviewed by the Station Safety and Operating Committee.
In
addition, Station Deviation Reports are trended in order to
identify problem areas.
Examples of Station Deviation Reports
written against Units 1 and 2 MOVs during the present Units 1
and 2 outages are as follows:
Valve
ID No.
1SW-104B/105C
SW-1068
Deviation
Re12ort No.
S2-88-929
Sl-88-1667
Sl-89-53
Sl-88-1250
S2-88-779
Sl-88-1261
Deficiency
New motor installed without tee
drains
Homemade tripper fingers installed
Non-factory tripper fingers
installed
Wrong size motors installed.
Have
2 ft.-lb. motors where other SW-104
and 105 valves have 5 ft.-lb. motor
(also addressed in LER 50/280-43)
Wrong tripper finger bolt installed
Tripper spring incorrect, appears
to be cutdown larger spring
Valve
ID No.
2FW-254A .
lSI-1842
Deviation
Report No.
S2-88-934
S2-88-935
S2-88-936
Sl-88-1246
Sl-88-1262
Sl-88-1463
Sl-88-995
S2-88-779
S2-88-779
S2-88-800
3
Sl-88-1278
Sl-88-634
Sl-88-600
S 1-88-611
Sl-88-593
S2-88-289
S2-88-904
Deficiency
Spring pack assembled incorrectly
Spring pack assembled incorrectly
Spring pack assembled incorrectly,
stem lock nut not tight or staked
Bevel gear on worm shaft backwards,
declutch spacer missing
Extra spacer in worm gear shaft,
pinion gear backwarps
Cracked limit switch block
Torque switch wired incorrectly
Drive sleeve staked incorrectly,
required drive sleeve replacement
Pinion gear installed correctly but
not complete contact with shaft*
Wiring in
MDV was found spliced
with unacceptable splice method
Incorrect
number
of
Belleville
washers installed and incorrectly
stacked
Va 1 ve would not open, draws high
current
Valve would not close with high
Differential Pressure
Would not operate during PT 25.2
Failed to open on Hi Hi containment
isolation signal per PT 8.5A
Valve
would
not
operate
electrically
Will not open electrically
Valve
ID No.
Deviation
Report No.
4
lVS-lOOC
Sl-88-417
S2-88-496
SW-204A, C,D
S2-88-079
2SW-2058, D
S2-88-356
S2-88-709
S2-88-374
S2-88-853
S2-88-774
Sl-88-117
S2-89-026
lCH-12878
Sl-88-298
Sl-88-1252
Sl-88-524
S2-88-958
Sl-88-1672
Deficiency
Valve cannot ,be opened electrically
from main control room, it can be
closed electrically
Would not fully close electrically,
had leakage, had to manually close
Would not fully close
Would not fully open
Valve tagged shut but disc is one
inch from shut seat
Valve will not close electrically
Did not open when had Differential
Pressure across va 1 ve seat, va 1 ve
made clanking noise
With Differential Pressure valve
would
not
fully
close,
after
securing pump it closed
Valve goes past closed seat when
operated remotely
Motors 1 ocked up when attempt to
cycle from main control room
In
attempt to open
from
main
control room, valve would go to
intermediate position
and
motor
would keep running
Would
not
open
during
MOVATs
testing
Will
not close at Differential
Pressure
Did not indicate fully closed
Won't engage manually
Valve
ID No.
SI-1885A
lCW-1068
1S~!-105A
Deviation
Report No.
S2-88-899
S2-88-799
Sl-88-1514
S2-88-707
S2-88-736
S2-88-512
S2-88-807
S2-88-741
Sl-89-35
Sl-88-1564
Sl-88-1667
S2-88-985
Sl-89-53
lCH-12878
Sl-88-1072
Sl-88-1034
1SW-105A,B,C
Sl-88-647
1SW-104A,B,C
S2-88-499
5
Deficiency
Motor grounded
Motor grounded
Motor leads have improperly sealed
Raychem channe 1 s *
Torque switch cracked due to
improper installation
Motor 1 eads terminated with wire
nuts, should be Raychem splices
Open/close indication incorrect,
problem was incorrectly wired limit
switch
Worm shaft "O" ring missing, no
grease in actuator, worm shaft
bearing cracked and badly degraded
Pinion gear installed in reverse
direction
Torque switch installed backwards
No lubricant in actuator housing
Bad grease
Unapproved
lubricant in motor
housing
Tripper
finger
damage,
metal
filings in grease
Bad grease
Wrong type grease
Missing manual engage levers, signs
of use of pipe wrench to manually
engage valve
Valve found torn apart with yellow
tag on handwheel
( '))
,'-
Valve
ID No.
lRC-1593
Deviation
Report No.
Sl-88-527
S2-88-837
S2-88-826
6
Deficiency
Working wrong valves, in process of
repack when run into water
Adapter between HBC actuator and
valve broken
Declutch handle broken and wired in
place, handwheel removed and laying
in pump room corner
On November 3, 1988, Limitorque Corporation issued a 10 CFR
Part 21 Notification identifying a defect in SMB-000 and 00
actuators supplied with Mel amine torque switches that have
failed and recommended replacement with Fiberite torque
switches.
In response to this notification, the licensee
conducted a walkdown of all Limitorque SMB-000 and 00 actuators
to identify Melamine torque switches.
While performing these
wa 1 kdowns,
actuator extern a 1 components and 1 i mit switch
compartment internal components were inspected and deficiencies
documented in
Walkdown Data Sheets.
Examples of
deficiencies noted duri~g the walkdowns are as follows:
Valve
ID No.
Deficiency
Dirt and debris on valve stem and drive sleeve.
Severa 1 broken conductors at 1 ugs on fie 1 d and
jumper wires.
Several wires had tape at lug*to
wire junction.
Four 1 imit switch coverbolts
could not be torqued to 20 ft.-lb. because they
were stripped.
Stem not visable due to cover for contamination
and leak.
Upper bearing housing cover has slight
bow.
All power leads (field leads) have elec-
trical tape at lugs.
Dry Stem.
Wires have broken strands.
One upper
bearing housing bolt is stripped.
(
Dirty Stem.
Fingerboard missing
from lower set of limits.
Limit switch contacts
corroded.
D~clutch shaft is bent .
Valve
ID No.
(con 1d)
lCH-1370
lRC-1587
7
Deficiency
Deel utch 1 ever is very 1 oose due to worn key
slot.
Valve position indicator missing six of
Eight rivets.
Some separated grease at limit
switches.
Upper bearing and motor gaskets are
old and leaking.
SMB to HBC adapter has two
different size of bolts.
HBC mounting bolts do
not have full engagement (too short).
Dry dirty valve stem.
Wires exposed on lug,
broken connectors.
Operator * grease found
in
limit switch body.
Valve stem is dry and dirty with some oxidation.
Upper bearing housing gasket extremely worn.
No
stem
cover
on
operator.
Drive
is
extremely dirty.
Both open torque switch wires
are broken completely at terminal lugs on limit
switch.
Limit switch cover missing 2 bolts.
During the walkdowns numerous deficiencies were identified that
involved disconnected torque and limit switch wiring and broken
wire strands.
Past Surry practice has been to in sta 11 wiring
that is environmentally* qualified with wiring identifcation
number markings visible.
This resulted in excessively long
wires being installed in a small area.
The licensee considers
the cause of the broken wire strands and wires to be rubbing of
the limit switch cover on the wires during removal of the cover.
Corrective action involves installation of shorter limit and
torque switch wires.
b.
IE Bulletin 85-03 Follow-up (25573)
(Open) 50-280, 281/85-BU-03, T2515/73, "Motor Operated Va 1 ve Common Mode
Failure During Plant Transients Due to Improper Switch Settings.
11
The purpose of this Bulletin is to require licensees to develop and
implement a program to ensure that switch settings for High Pressure
Coo 1 ant Injection and Emergency Feedwater System Motor Operated Va 1 ves
subject to
testing for operational
readiness
in
accordance with
10 CFR 50.55a(g) are properly set, selected and maintain-ed.
In order to evaluate the Surry Bulletin 85-03 program, the inspector held
discussions with the appropriate licensee personnel and reviewed the
fo 11 owing:
0
Approximately 30 Stati.on Deviation Reports filed against Bulletin
85-03 valves.
0
0
0
8
Virginia Electric and Power Company's letter dated May 13, 1986,
Serial No.86-276, Surry Power Station Unit Nos. 1 and 2, Response to
Virginia Electric and Power Company's letter dated October 17, 1986,
Serial No. 86-276A, Supplemental Response to IE Bulletin 85-03.
Virginia Electric and Power Company's letter dated September 30,
1988, Serial No. 86-276B, Surry Power Station, Units 1 and 2,
Response to IE Bulletin 85-03.
Twenty-nine valves in each unit are in the Bulletin 85-03 program,
and per the licensee, all Bulletin action items were completed, with
the exception of submittal of the final response, during outages in
1987.
On September 30, 1988, Virginia Power issued their final
response to Bulletin 85-03 which implied that adequate measures had
been taken to ensure that valve operator switches are selected, set,
and maintained properly. During review of Station Deviation Reports
generated during the present Units 1 and 2 outages, the inspector
noted that there were deficiencies written on 17 of the 29 Unit 1
Bulletin valves and 8 of the 29 Unit 2 Bulletin valves.
Examples of
deficiencies written on Bulletin valves are as follows:
Valve
Deviation
ID No.
Report No.
Sl-89-067
Sl-88-0719
S2-88-0281
Sl-88-1450
S2-88-0124
S2-88-151
Sl-88-577
Sl-88-1503
Deficiency
Non-factory
installed
tripper.
fingers
Roll pin installed in lieu of dowel
pin, no shims installed in lower
bearing cup which caused improper
alignment of gears and subsequent
damage.
Va 1 ve wi 11 not close under differ-
ential pressure
Motor grounded
Valve failed to open
Would not close on termination of
safety injection
Valve
not
completely
closing
against fl ow
Motor will not engage electrically
and valve will not cycle electri-
cally
Valve
ID No.
lFW-151,B,D,
E,F
lFW-151,B,D,
E,F
Deviation
Report No.
Sl-88-1668
Sl-88-107
Sl-88-167
9
Deficiency
Valve wil 1 not manually engage,
hardened grease, worm gear won
1t
turn, broken teeth on worm shaft.
Metal filings in grease.
Bad motor
bearing
Valve will not go into manual and
grease separated
Tripper fingers are same length
Status of Surry Units 1 and 2 Bulletin 85-03 action items a. through f.
(1)Bulletin 85-03, Action Item a. requires the design basis for the
operation of each bulletin valve be reviewed and documented.
This
item has been completed.
The licensee documentation of the design
review states that an 80% degraded voltage criteria was applied to
the design thrust value~ for the Bulletin valves .
(2)
Bulletin 85-03, Action Item b. requires correct switch settings be
established and methods for selecting switch settings be reviewed and
revised as necessary.
The licensee has completed this item.
(3)Bulletin 85-03, Action Item c. requires that switch settings be
changed as appropriate based on the design review performed, and each
valve be demonstrated operable by testing the valve at the maximum
differential pressure it will
see during the design accident
condition. If a valve is not differential pressure tested, justifi-
cation is then required, and at a minimum, the valve is required to
be stroke tested at static conditions to verify switch settings. All
Surry bull et in valves have been stroke tested with MOVATS test
equipment to verify proper switch settings.
Surry Bul 1 et in 85-03
program has identified 29 valves in each Unit. Differential pressure
testing has been performed on the following seven valves.
Valve No.
Manufacturer
Size
Valve Type
Anchor-Darling
311
Gate
Anchor-Darling
311
Gate
Anchor-Darling
3
Gate
Anchor-Darling
311
Gate
Walworth
311
Globe
Crane
611
Gate
Anchor-Darling
311
Gate
( 4)
10
Exmaples of* valves in Surry Bu 11 et in 85-03 program that were not
differential pressure tested.
Valve No.
Manufacturer
Size
Type
A 1 oyco
311
Gate
Aloyco
411
Gate
Aloyco
511
Gate
Velan
211
Gate
Velan
311
Gate
The purpose of Bull et in 85-03 differenti a 1 pressure testing is to
verify that the formula to determine required thrust to operate a
va 1 ve is correct.
The results of the Surry different i a 1 pressure
testing proves that the thrust formulas for 311 Anchor-Darling Gate
valves, 311 Walworth globe valves and 611 Crane valves are correct.
However, the thrust formulas for the Aloyco and Velan gate valves has
not been proven.
In addition, the Unit 2 FW-251 valves have been
replaced.
If the replacement valves are a different type than the
ori gi na 1 2FW-251 va 1 ve, then their thrust formulas must a 1 so be
vetified.
The inspector considers that the licensee Bulletin 85-03
program does not fully meet the differe~tial pressure test require-
ments in reference to the Aloyco and Velan valves in that these
valves were not differential pressure tested at maximum design
differential pressure, nor was acceptable justification provided for
not differential pressure testing.
Bulletin 85-03, Item d. requires procedures to be prepared or revised
to ensure that switch settings are maintained throughout plant life.
Applicable industry standards are considered in these procedures, and
procedures should include provisions to monitor valve performance.
The inspector did not review Surry MOV procedures or bulletin valve
post-maintenance test requirements during the inspection.
These
areas will be reviewed during a future inspection.
Per the licensee
bulletin valves are MOVATS tested during each refueling outage as one
of the means to verify valve performance through out plant *life.
During a future inspection the inspector will review the implementa-
tion of the diagnostic testing that is performed each refueling
outage and following post-maintenance testing.
(5)
Bulletin 85-03, Action Item e. is complete and documented in Inspec-
tion Report Nos. 50-280, 281/88-28.
(6)
Bulletin 85-03, Action Item f. requires that a written report be
issued to the NRC
on completion of the bulletin program.
The
licensee issued this report on September 30, 1988 .
11
The deviations for Bulletin valves questions the validity of the
licensee'sBulletin 85-03 program completed during previous outages.
All these valves were previously MOVATS tested as part of the
Bulletin 85-03 program.
The actuator grease was also replaced as
part of the Bulletin program.
The inspector considers that the Surry program does not fully meet
Bulletin 85-03 for differential pressure testing requirements.
Other
areas such as post-maintenance testing, monitoring of valve
performance and MOV procedures wi 11 be reviewed during a future
inspection.
The purpose of this inspection was to determine if licensee actions
in response to the MOV deficiencies identified during the present
Units 1 and 2 outages are adequate to restart Units 1 and 2.
Per
EWR-89-061, the licensee program to resolve MOV deficiencies
involves the following:
0
0
0
0
0
C
0
0
Resolve Environmental Concerns
Determine if valve operators with deficiencies were or were not
Trr date one Licensee Event Report, 50/280-88-43, has
been issued discussing the undersized motors inadvertently
installed on valves 1SW-104B and 1SW-105C.
Correct the deficiencies identified
MOVATS test all Bulletin 85-03 valves, valves that receive an
automatic signal, and valves that are operated per EOPs, and
correct deficiencies identified by MOVATS testing.
Remove motors and inspect mechanical parts (pinion gears for-
reversed installation, hardened grease, tripper fingers, etc.)
for safety-related valves.
If the grease in safety-related valves was not replaced during
the previous outage, replace it during present outage.
Actuators that have been identified to be undersized perform
differential pressure testing to verify operability.
Develop a long-term compre~ensive MOV program.
In addition to the actions specified in EWR 89-061, the licensee has
raised the awareness of MOV deficiencies with all station personnel
and has encouraged people to write station deviations when a
deficiency exists or if not sure if a condition is acceptable .
12
During outages, the licensee has extensively utilized contractors to
perform MOV corrective maintenance.
Prior to the start of the
current outages, the licensee requested resumes for contractor
personnel and reviewed the resumes to verify MOV experience.
Prior to restarting each unit, the inspector considers that the
licensee needs to complete the action specified in EWR 89-061 and in
addition perform root causes analysis of station deviations written
against MOVs and establish measures to prevent recurrence of the
i dent i fi ed MOV problems.
The licensee committed to perform these
additional actions during the exit meeting.
The licensee was
informed that prior to the restart, the inspector will return to
review root cause analysis, corrective measures, and
fo 11 ow-up on
Bulletin 85-03 valve deficiencies.
During the exit meeting it became
apparent that performing root cause analysis and determining
corrective actions would delay Unit 1 restart.
Surry Nuclear Site Memorandum from
R. V. Green/J. LaFlam to
R. H. Blount, dated November 10, 1988, indicates that the licensee
management was aware of MOV program problems.
This memorandum stated
that the problems were attributed to 1 ack of guidance either
procedurally or supervisory, lack of root cause evaluation program,
and lack of a comprehensive MOV program.
The inspector agrees with
the licensee's assessment of the MOV program contained in the
November 10, 1988, memorandum; however, with the exception of
increasing supervisor involvement, little or no action has been taken
in the areas of procedure improvement, root cause determination, and
program development since the memorandum was issued.
c.
Followup on Motor Operator Valve EQ Concerns
The 1 icensee identified on Station Deviation S2-88-0069 that
potentially non-EQ wire may have been installed in EQ L imitorque
valve operator 2-CH-MOV-2275B.
In a memorandum dated November 10,
1988, from R. V. Green to R. H. Blount, the licensee stated that all
EQ motor operators had been inspected or walked down in 1986 with
qualified EQ wire being installed.
Subsequent to this walkdown, EWR 88-224 was worked to add jumpers in some IEB 85-03 valves.
This EWR
required the use of qualified wire to be installed; however, it did
not specifically name what type of wire to use.
In working
EWR-86-224, the licensee indicated that the craft did not follow the
EQ program procedures by installing jumpers of appropriate length
with the vendor name and type of wire.
Thus, the jumpers discovered
were not identified by vendor and wire type.
The proposed corrective
action recommended in the subject memo was that the limit switch
compartment covers be removed on several EQ valves as identified in
13
the memo and inspected for uni dent ifi ed wiring.
The inspector
questioned the licensee regarding the qualifications for the
non-identifiable wire found in
EQ operators.
The licensee was
requested to provide the records of the cable reels, issue tickets
and any other supporting documentation that would demonstrate that
the wire was indeed EQ qualified and did not change the qualified
status of the EQ operator.
The licensee indicated in the exit that
this information had been reviewed by them and confirmed that the
wire was qualified.
However, it was not provided to the inspector.
The inspector informed the licensee that this would be examined
further as part of the follow-up to Inspector Follow-up Item 280,
281/88-45-01.
Other concerns identified during this outage regarding the EQ
qualified status of motor operated valves involves. separation of
grease or grease hardening and
non-EQ torque switches in
operators.
The inspector discussed these two concerns with licensee
representatives to understand what the licensee had concluded as far
as the root cause for these problems.
Based on these discussions,
the inspector determined that no previous qualification problem
existed regarding non-EQ torque switches in EQ operators.
The EQ
operators all contained torque switches with white colored melamine
torque switches that had been previously qualified by the vendor.
As
stated earlier, the vendor, Limitorque, recommended in a Part 21
report to NRC, dated November 3, 1988, that Melamine torque switches
in SMB-000 and 00 operators be replaced with qualified Fiberite
(brown) torque switches.
Thus, when the licensee began these
walkdowns in 1988, there was some confusion regarding the qualified
status of the Melamine torque switches and the craft annotated on
several station deviations that non-EQ torque switches were found in
EQ operators.
This was further compounded by the fact that the
licensee staff issued a memorandum to Electrical Maintenance, dated
April 22, 1988, which identified the qualified limit switches and
torque switches as (brown) Fiberite.
In addition, the licensee had
information discussing a generic concern regarding unqualified SMA
style torque switches which were supplied by the vendor in some EQ
motor operators.
The licensee indicated during this inspection that
the walkdowns did not identify any non-EQ torque switches in EQ valve
operators.
The torque switches were Melamine and were identified on
station deviations to be replaced as recommended by the vendor.
However, several non-EQ valve operators were observed with SMA style
torque switches installed.
The valves were safety-related both
bulletin 85-03 and non-bulletin valves.
The licensee has proposed to
replace these SMA torque switches when replacement parts become
available.
The last EQ issue concerning MOVs involves hardening of grease or
separation of grease in EQ operators.
Interviews with licensee
personnel revealed that all EQ operators were inspected and reworked
in 1986 by Station Maintenance Procedures.
The scope of the rework
included replacement of the gear case grease with Exxon EPO or EPl
14
which is the qualified lubricant for EQ valves.
The inspector
requested the documentation that changed out the lubricant in 1986.
The licensee was not able to provide this documentation for the
inspector prior to the conclusion of the inspection. Therefore, this
concern wil 1 a 1 so be examined during fo 11 ow-up of the i tern 280,
281/88-45-01.
4.
Inside Recirculation Pump Motor Feeder Cables
a.
Degradation of Inside Recirculation Pump Motor Cables
On January 20, 1989, the Unit 1
118
11 Inside Recirculation Spray Pump
(IRSP) motor feeder cable was found to have deteriorated insulation.
The braided outer jack.et of the power feeder cable was frayed in
several locations and the conductor insulation was cracked.
As a
result of this finding, the licensee began inspecting all power
- feeder cables to the Inside Recirculation Spray Pump motors on both
Units.
The results of the visual
inspections revealed that
significant degradation had occurred on Unit 1 1 s
118
11
IRSP and
Unit 2
1 s
11A
11 and
118
11 IRSP motors.
The 1 i censee sent samples of the
Silicone Rubber cable, manufactured by Continental, to an independent
lab offsite for further testing and final determination of equipment
operability.* As part of this review, the licensee is conducting an
engineering evaluation to determine the root cause for the insulation
damage.
The
NRC
inspector accompanied
licensee personnel
in
inspecting Unit l's
11A
11 IRSP motor power cable and Unit 2 1 s
11A
11 and
118
11 IRSP motor power cables. * The damage appears to be consistent
with earlier reports provided by the licensee, fraying of the jack.et
and cracking of the insulation.
Additionally, when the licensee
determinated the feeder cable to pump motor 2-RS-P-lB, the crimped
termination lug came off of one of the motor pigtail leads.
The
licensee is also investigating the root cause for why this occurred.
The qualification documentation for the Continental Silicone Rubber
Cable is contained in Qualification Documentation Report QDR-S-6.4.
The report identifies the cables installed in Surry Units 1 and 2 as
Continental Silicone Rubber insulation with an overall glass braid.
The formulation for the cable is identified as CC2115 with a maximum
conductor temperature rating of 200°C.
The basis for qualification
is the DOR Guidelines.
The QDR states that the cable has a qualified
life of 40 years in an ambient environment of 125°F based on test and
analysis.
The cable is considered qualified for a TIO radiation
exposure of both beta and gamma of 1 x 10 8 rads (required 5.93 x 10 7
TIO using IEB 79-0lB).
A large part of the qualification for this
cable is based on the assumption that this cable is the same as the
cable formulation that was tested in Franklin Test Report F-C2935.
During the inspection, the licensee failed to provide installation
records to the inspector such that the as-built installation could be
15
traced back to the qualification records.
In the QDR the licensee
states that type NJA and NPA cable codes are installed on Units 1 and
2, respectively (page G.1-25).
However, the file only shows that
type NPA cable code was procured from Continental under Specification
NUS-326 and Purchase Order SN-330.
As part of the continuing
investigation into the degradation of this Silicone Rubber cable, the
inspector requested the licensee to provide additional information
regarding the traceability of these as-built cable installations.
This item is considered unresolved pending further review of the test
report and review of installation/qualification records on the
as-built cable installations.
This item will be tracked as URI
50-280, 281/89-03-01, Degraded IRSP Motor Power Cables.
Preliminary
results from a licensee representative *indicated that the cable
damage may be mechanical in nature caused by overstressing the cable
during installation.
Other failure modes such as. high ambient
temperatures, overcurrent due to bad cri~ps resulting in high contact
resistence on the motor leads does not appear to be the most likely
cause of the damage.
The licensee also believes the discoloration
identified was due to corrosion in the PVC jacketed flex conduit.
Other possible failure modes being investigated are radiation and
chemical interaction.
b.
Inspection of IRSP Motors at GE Safe Apparatus Center in Memphis,
The Unit 1 Inside Containment Recirculation Pump motors (1-RS-P-lA,
18) were sent to the GE Safe Apparatus Center in Memphis, Tennessee,
for evaluation and repair and arrived on February 1, 1989.
The
Unit 2 motors were scheduled to arrive on February 3, 1989.
The Unit 1 motors were heavily contaminated (up to 270,000 dpm) and
required respirators to be worn
during the disassembly.
The
disassembly and decontamination were lengthy but thorough.
Both
motors exhibited signs of over-lubrication of the bearings. Grease
had leaked out of the end cap and was blown around by the cooling
fan.
The GE representatives provided information to the 1 icensee
representatives as to what measures should be taken for the lubrica-
tion.
The licensee indicated that a formal transmittal shol]ld be
made by GE to VEPCO on the lubrication issue.
The motor leads were visually inspected.
The leads with the lugs
were about four inches long.
The cable had two Raychem shims from
the lug to the potting material that provided the seal to the.motor.
No evidence of overheating or damage was apparent.
The Raychem shims were then removed.
The licensee. provided verbal
instructions to the vendor technicians who had never removed Raychem
previously.
During the removal process, some damage may have been
done to the varnish coated glass tape.
The function of the varnish
was to hold the glass tape in place and prevent it from unraveling .
16
The glass tape was a mechanical protection for the Kapton Mica Mat
Silicon tape.
No damage was noted to the Kapton tape.
Electrical tests were performed on the motor and no indication of a
problem with the motor was found.
There was no discoloration on the
terminal lugs, no carbonization on the cable, nor any discoloration
or hardening of the cables.
There were no indications of degradation
as the result of heat or radiation.
The brittleness referred to in
the initial report is presumably the varnish coated tape.
This would
be as expected since the varnish would not be very thick.
It would
not be a concern since it. was for mechanical protection, not a
moisture seal.
The repair of the leads was under discussion between the licensee and
the vendor. " Both parties were ensuring that whatever the method
decided upon would result in the motor being in a qualified configu-
ration with the supporting documentation.
5.
Exit Interview
The inspection scope and results were summarized on January 27, 1989, with
those persons i ndi ca ted in paragraph 1.
The inspectors described the
areas inspected and discussed in detail the inspection results listed
below.
Although reviewed during this inspection, proprietary information
is not contained in this report.
Dissenting comments were not received
from the licensee.
In the exit, the licensee verbally committed to perform root cause
analysis of Station Deviations written against motor operated valves
during the present Unit Nos. 1 and 2 outages and establish corrective
measures to prevent recurrences prior to the respective Unit restart,
paragraph 3.b.(6).
Unresolved Item 50-280, 281/89-03-01, Degraded IRSP Motor Power Cables,
paragraph 4.a.
The status of a previous Inspection finding is discussed in paragrah 2 .
17
6.
Acronyms and Initial isms
- Charging
- Environmental Qualification
- Engineering Work Request
- General Electric Company
IRSP
- Inside Recirculation Spray Pump
LER
- Licensee Event Report
MDV
- Motor~Operated Valve
- Recirculation Spray Heat Exchanger
- Safety Injection