ML20216G516
| ML20216G516 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 06/17/1987 |
| From: | Ireland R, Norman D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML20216G362 | List: |
| References | |
| 50-498-87-21, 50-499-87-21, IEB-72-03, IEB-72-3, IEB-85-003, IEB-85-3, IEC-77-01, IEC-77-1, IEC-78-16, IEIN-86-003, IEIN-86-3, IEIN-87-029, IEIN-87-29, NUDOCS 8707010106 | |
| Download: ML20216G516 (8) | |
See also: IR 05000498/1987021
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APPENDIX B
U.S. NUCLEAR REGULATORY COMMISSION
REGION IV
NRC Inspection Report: 50-498/87-21
Construction Permit: CPPR-128
Docket: 50-498
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Licensee: Houston Lighting & Power Company (HL&P)
P. O. Box 1700
Houston, Texas
77001
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Facility Name:
South Texas Project, Unit 1
Inspection At:
Bay City, Texas
Inspection Conducted: April 13 through May 1,1987
Inspector:
[, Wpm-
6/7/4'7
D. E. Norman, Reactor Inspector, Engineering
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Section, Reactor Safety Branch
Approved:
/b 77/fbM-
4//7/F7
R. E. Ireland, Chief, Engineering Section
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Reactor Safety Branch
Inspection Summary
Inspection Conducted April 13 through May 1,1987 (Report 50-498/87-21)
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Areas Inspected:
Routine, announced inspection of actions relative to IE
Bulletins (IEBs) 72-03 and 85-03, IE Circulars (IECs) 77-01 and 78-16, and IE
Notices (IENs) 86-03 and 86-29.
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Results: Within the area inspected, one violation was identified (failure to
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adequately control the installation of valve operators, paragraph 2.b(3)(e)).
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Inspection Conducted April 13 through May 1,1987 (Report 50-499/87-21)
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Areas Inspected:
No inspection of Unit 2 was conducted.-
Results: Not Applicable.
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DETAILS
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Persons Contacted
Houston Lighting & Power Company (HL&P)
- W. P. Evans, Project Compliance Engineer
- D. W. Bohner, Operations QA
- E. Nichols, Jr., NP0D/ Electrical Maintenance Supervisor
- D. R. Nester, NP00 Lead Engineer
- H. Vann Weldon, Training
- J. E. Geiger, General Manager Nuclear Assurance
- S. Head, Licensing
Bechtel
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- R. W. Miller, Deputy Project QA Manager
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- R. H. Medina, QA Supervisor
- M. Mills, Startup Engineer
- R. J. Daly, Startup Manager
- D.
L. Long, Management
D. Parker, Startup Engineer
NRC
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- D. L. Garrison, Resident Inspector
- J. F. Lara, Resident Inspector
D. R. Carpenter, Senior Resident Inspector
C. E. Johnson, Senior Resident Inspector
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- Denotes those present at the exit. interview on May 1, 1987.
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2.
Inspection Summary
a.
IEB 85-03 (Closed)
IEB 85-03, " Motor Operated Valve Common Mode Failure During Plant
Transients Due to Improper Switch Settings," was issued as a result of
several events during which motor operated valves (MOVs) failed on
demand due to improper switch settings.
The Bulletin requested that
MOVs in certain systems be tested for operational ' readiness, and that
licensees develop and implement a. program to ensure that valve
operator switches are selected, set,'and maintained properly to
accommodate maximum differential pressure expected during both opening
and closing of the valve for both normal and abnormal events within
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the design basis.
The licensee made a submittal requested by the
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Bulletin to the NRC on June 2,1986, and an additional submittal of
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information requested by the NRC was made on February 27, 1987.
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This inspection was performed to followup on the licensee's activities
taken in response to IEB 85-03 and. commitments made by the licensee in
submittals regarding the Bulletin.
The inspection scope included the
following:
(1)- Procedures Review - The IEB 85-03 program, which includes
23 valves in the safety injection (SI) and auxiliary
feedwater (AFW) system, is implemented by procedures, elementary
diagrams, and documentation from valve and valve operator
vendors.
A brief explanation of the program is as follows:
Initially, the operator switches were adjusted statically
according to instructions presented in Procedure'SG-E-09,'
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Revision 3, " Generic Prerequisite Test Procedure for Motor-
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Operated Valves and Dampers" as' modified by Startup Field
Report (SFR) 086-0744.
Opening and closing torque switch
settings were adjusted to the index setting provided by the
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operator and valve manufacturers, which is related.to thrust
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required to close or open the respective valves.at'the design
basis pressure. The torque switch is-bypassed by.the torque
switch bypass during opening for 95 percent of the valve travel.
Valve opening is controlled by the.open limit switch'which is' set'
at approximately 95 percent open. . A check for excessive valve.
backseating is~made after the valve completes its coast toward
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the open direction.
During preoperational tests, the valves were checked again at, or
near the design basis pressure'to ensure openin'g under those
conditions.
If necessary, the' torque switch settings were'
increased to prevent premature tripping of' the torque' switch.
The valves are included in the plant periodic maintenance (PM)
program and are programmed to.hav'e switch testing performed each
78 weeks (nearest outage) per Station Procedure'0PMP05-ZE-0300 to
ensure proper continued settings of the switches to ensure valve
operability.
(2) Data Review.- Test documentation for the static and flow tests
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were reviewed by the NRC. inspector and results were found to be.
in compliance with the' procedures and. instructions discussed'
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above.
It was- found during ~ the inspection that the applicant"had
documented and~ implemented la' program to adjust Limitorque valve.
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operator switches and to retest.theLoperators each'78' weeks!(or-
nearest outage')'to ensure continued' valve. operability.' Region IV'
effort concerning IEB 85-03 is considered closed;;however, the
Bulletin requires the applicant to submit = a fina.1 report;of the
completed program to NRC. headquarters.
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During the inspection, it was found that gate valves, which'are
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not a part'of the IEB 85-03 program, in the following systems had
been set to close on limit switch actuation rather than torqua
switch actuation.
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Reactor Coolant System - two valves
Safety Injection System - one. valve
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. Chemical and Volume Control System - nine valves
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Residual Heat Removal System - eight valves
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The limit switches are set to actuate just.as the gate makes
contact with the seat.' The' torque switch is set-at a minimal
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. setting, predetermined for~each valve, and will actuate should
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the limit switch fail to actuate.
By setting the valves to~close
by this method,'it appears that there is.a possibility that
valves will not close sufficiently to prevent leakage between the
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gate and' seat.
The valves had been tested during preoperational
tests; however, information could not be provided dur.ing the
inspection to show if leakage'did exist.~ The applicant is to
evaluate whether leakage is permitted and whether leakage did
occur. during hot functional' or other tests.
This is considered
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an open item (498/8721-01).
b.
IfN86-03(Cloud)
IEN 86-03, " Potential Deficiencies in EQ of Limitorque MOV Operator
Wiring," was issued to alert recipients of a potential EQ problem with
operator control wiring-and to consider actions to preclude a similar
problem at their facilities.
No specific action or. written response
was required.
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This inspection was conducted by the NRC to. determine what wiring was
installed in Limitorque valve operators, to-review the' applicant's EQ
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documentation to ensure that wiring qualification was adequately
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established, to review the applicant's action relative to IEN 86-03,
and to review the status of Limitorque' operator qualification with
respect to issues other than control wiring.
The inspection scope.
included the following:
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(1) Procedures Review - Construction Inspection' Planning (CIP) 2.2-62
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provides instructions for performing inspections and rework
necessary to identify and correct deficiencies in 'Limitorque
valve operators at STP.
The procedures include a comprehensive-
checklist of previously identified Limitorque problems, which
includes wiring, for the operators.
All wiring which_was..not
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either Raychem Flamtrol or Rockbestos.Firewall III was required
to be replaced.
Paragraphs 9.0 and 14.0 of CIP 2.2-62 require verification.that
bearing lock nuts for SMB operators 'and lock' nuts' for operators
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-with' ACME stem nuts have been staked.
The procedure does not
require that the nuts be checked for tightness prior to staking.
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Since assembly, these operators have experienced movement due to
shipment, storage, and operation which could result in loosening
of the lock nut, if not staked.
If the lock nuts are loose, the
operator may not function properly and could eventually result
in operator failure.
Pending' verification by the applicant that
the nuts had been checked for tightness prior to staking, this
is considered an open item (498/8721-02).
'(2) Data Review - The NRC inspector reviewed several' checklists
completed as a result of the applicant walkdown inspections.
The
walkdown appeared to be comprehensive and several problems had
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been identified and corrected.
(3) Walkdown Inspection - STP, Unit 1, has 178 safety-related
Limotorque valve operators, of which approximately 140 are _
located in a harsh environment. A sample of 10 operators was
selected by the NRC inspector for the walkdown. inspection. One
of the ten was later found to be in a mild environment; therefore,
the walkdown sample consisted of nine harsh environment and~one
mild environment operator. The result of the walkdown are as-
follows:
(a) All wiring was found.to be either Raychem or Rockbestos-
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which was determined to be qualified. The applicant's
action, relative to'IEN 86-03, was therefore, determined to
be acceptable and the IEN is considered closed.
(b) EQ documentation requires two motor T-drains for operators
inside containment and either one or no T-drains (depends on
test report used to document qualification) for operators
outside containment. CIP 2.2-62 requires two T-drains in
all motors. T-drains are to be located at the lowest point
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in the motor. Contrary to the requirements, the following
conditions were observed:
T-drains had been painted over and plugged in-
operators CC-132 and CC-52.
T-drains were not at the lowest point in CC-204 and
SI-14A.
Several others which were not included on the
walkdown sample were observed to not be at the lowest
point.
SI-18B had only one T-drain.
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Theseconditionsareconsideredunresolved(498/8721-03)'.
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The applicant should correct CIP 2.2-62~to-reflect-
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requirements of qualification test' reports, and T-drain
installation should comply with those requirements.
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(c) EQ documentation requires a gear box relief valve for
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certain operators. The relief, valve is not addressed in
CIP 2.2-62; therefore, the presence of the caps was not
identified during the applicants walkdown inspections and
the operators had been turned over to operations with caps
in place. All operators inspected -during the walkdown had a
relief valve; however, a shipping cap installed over the
valve had not been removed on SI-39B, SI-18B, SI-04A, SI-14A,
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CV-8377A, CC-52, and RA-04. ' The applicant is to verify that
all shipping caps have been removed from relief valves on
installed operators. This is considered an open item
(498/8721-04).
(d) SI-18B was found to have either pitted or dirty limit switch
contacts and limit switch gear grease had been leaking into
the limit switch housing.
The operator was considered
operable, but could have experienced an early failure of the
contacts. This was considered an isolated incident and
pending correction by the applicant, this is. considered an
open item (498/8721-05).
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(e) SI-188, CV-8377A, and CV-25 which had dual voltage motors,
had motor leads spliced with blind barrel crimp splices.
Documentation used to substantiate qualification of the-
operators made no mention of the splices, nor had the
splices been tested'and qualified separate from the
operators. This is considered a' violation of NRC
requirements (498/8721-06).
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(f) The limit switch material in CV-8377A and both the limit and
torque switches in CV-25 were Durez which has not been
qualified for use in harsh environments. CV-25 was
subsequently replaced with another operator since it had
previously been identified by the' applicant on.an NCR as
being unqualified. CV-8377A plus seven other operators in
the chemical and volume control. system (CVCS) have been
determined by the applicant to perform no essential safe
shutdown nor post accident functions; therefore, it was -
stated by the applicant that the operators were not required
Memo. (qualified. .This rationale .is discussed in InterofficeIOM) 42
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ComponentEvaluationWorksheet-(SCEW). Additional
information:is required in this matter. The licensee.should
remove the CVCS operators'from the EQ master equipment list
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if they do not need to be quali_fied.to the rules of
110 CFR 50.49. This item is considered unresolved pending
the review (498/8721-07).
(g) The nameplate data for Reliance motors for in containment
operators RH-60A.and SI-39B. indicated Class F type.RCP-318.
LR insulation. Documentation indicated that traceability.of
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production units to EQ test reports was established by
Limitorque specification No. RCP-318.
Westinghouse EQ Data
Package H01A and EQ Test Report WCAP-8687 documented
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qualification for the operators for 5 years at which time
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they must be replaced unless additional tests or analysis
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are performed to extend the qualification.
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c.
IEB 72-03 (Closed)
IEB 72-03, "Limitorque Valve Operator Failures," was a notification of
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a malfunction of torque switches in SMB-00 and SMB-000 operators
manufactured between 1969 and mid-1971.
The applicant determined that
no operators manufactured during_this period were installed or in
storage at STP.
Procedures are also in place to review additional
operators which may be received at the site for applicability of the
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IEB.
No response was required to this Bulletin unless applicable
operators were identified.
This item is closed.
d.
IEC 77-01 (Closed)
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IEC 77-01, " Malfunctions of Limitorque Valve Operators," was a.
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notification that valves had failed to open because of a premature
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opening of the torque switch bypass.
This same condition was
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addressed in IEB 85-03 which has been previously discussed in this
report.
This item is closed,
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IEC 78-16 (Closed)
IEC 78-16, "Limitorque Valve Actuators," discusses a clutch failure in
Type SMB-0, 1, 2, and 3 operators equipped with 3600 RPM motors.
The
failure resulted from clutch wear which was due to manual operation of
the valve and improper heat treatment of the clutch material.
The
applicant has implemented in CIP 2.2-62 the requirement to verify that
the clutch for applicable operators has been heat treated and then an
operability check is required to be performed in accordance with
Station Procedure OPMP05-ZE-0300 at each periodic maintenance.
This
item is closed.
f.
IEN 86-29 (0 pen)
IEN 86-29, " Effects of Changing Valve Motor Operator Switch Settings,"
was provided as an alert that setting torque bypass switch to meet
requirements of IEB 85-03 could effect valve position indication and
signals such as "permissives" to other equipment.
The problem occurs
when the torque bypass switch and valve position indicators share the
same limit switch rotor.
Therefore,'when the position of.the rotor is
changed to extend the range of the torque bypass switch,.the closed
position indication is also changed.
The applicant has not completed
the review of this item; therefore, it will remain open.
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3.
Exit Interview
The NRC inspector met with the applicant representatives denoted in
paragraph 1 on May 1, 1987, and summarized the scope and findings of the
inspection.
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