ML15118A143
| ML15118A143 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 01/11/1996 |
| From: | Fredrickson P, Whitener H NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML15118A142 | List: |
| References | |
| 50-269-95-25, 50-270-95-25, 50-287-95-25, GL-89-10, NUDOCS 9611140002 | |
| Download: ML15118A143 (15) | |
See also: IR 05000269/1995025
Text
pjk REGLI.
UNITED STATES
REa
NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTA STREET, N.W., SUITE 2900
ATLANTA, GEORGIA 30323-0199
Report Nos. 50-269/95-25, 50-270/95-25, and 50-287/95-25
Licensee:
Duke Power Company
422 South Church Street
Charlotte, NC 28242
Docket Nos.:
50-269, 50-270, and 50-287
License Nos.: DPR-38, DRP-47
and DRP-55
Facility Name: Oconee Nuclear Station Units 1, 2, and 3
Inspection Conducted:
December 4-8 and 11-15, 1995
Lead Inspector: /1
,
/
7//
H. Whitener, Reactor Inspector
Date Signed
Accompanying Personnel: M. Miller, Reactor Inspector RII
T. Scarbrough, NRR
Holbrook, ,Contr ctor INEL
Approved by.-, ,--.
-i'
/
Paul Fredrickson, Chief
tate Signed
Special Inspection Branch
Division of Reactor Safety
SUMMARY
Scope:
This special, announced inspection was performed at the Oconee Nuclear Station
to assess the licensee's implementation and completion of commitments made in
response to Generic Letter (GL) 89-10, "Safety-Related Motor-Operated Valve
Testing and Surveillance."
Results:
The inspectors concluded that the licensee's implementation of the recommenda
tions of GL 89-10 had been completed in a satisfactory manner. Therefore, the
NRC staff is closing its review of the Oconee GL 89-10 program. However, the
licensee is still expected to maintain the GL 89-10 valves in accordance with
the recommendations in the generic letter. In addition, two inspector
followup items (IFIs) and several other concerns and commitments remain to be
completed. The first IFI concerns the licensee's need to respond to the
Vectra Report on butterfly valves. The second IFI addresses hard seat contact
for the "Anchor/Darling" Double Disc Gate valves. One violation identified
during the GL 89-10 Part 2 inspection was closed. There are no operability
concerns with any of the followup items and remaining items. These items are
listed below:
9611140002 960111
PDR ADOCK 05000269
G
2
Inspector Followup Items
(Closed) VIO 50-269/94-13-01, Inadequate Procedure Preparation For IST
Testing.
[Section 3.0]
(Open) IFI 50-269,270,287/95-25-01, "Response To Vectra Report
Butterfly Valves". The licensee needs to address and respond to three
areas in the report, 1) flow resistance, 2) procedure improvement, and
3) shaft orientation. [Section 2.5]
(Open) IFI 50-269,270,287/95-25-02, "Anchor/Darling Double Disc Gate
Flow Cutoff".
The licensee needs to address hard seat contact. The
licensee determined that the MOVs meet theoretical flow isolation of the
EPRI model but not hard seat contact. .[Section 2.5]
Remaining Items
Thirteen commitments which were stated in Attachment 1 of the licensee's
letter to the NRC, "Request for Closure of Generic Letter 89-10" dated
March 31, 1995, remain to be completed. All the other commitment items
addressed in the Request for Closure Letter have been satisfactorily
addressed by the licensee and were closed during this inspection.
[Section 2.0 and 2.5]
Strengths
1)
The licensee implemented "flow loop testing".
[Section 2.5]
2)
The licensee used innovative technology such as "bench testing"
and the Motor Power Monitor. [Section 2.10]
3)
Licensee personnel, including both engineering and maintenance,
were very knowledgeable of the issues related to GL 89-10.
[Section 2.0]
4)
The licensee personnel were pro-active in the MOV industry.
[Section 2.5]
S
REPORT DETAILS
1.0
Persons Contacted
1.1
Licensee Employees
- E. Burchfield, Manager, Regulatory Compliance
- T. Cline, Valve Engineering Support, General Office
- J. Davis, Manager, Engineering
- J. Hampton, Site Vice President
- T. Ledford, Engineer
- D. King, Valve Engineering
- K. Matthews, Valve Engineering
- B. Millsaps, Mechanical/Civil Engineering Manager
- D. Nix, Regulatory Compliance
- B. Peele, Station Manager
- B. Sealy, Engineer
- J. Smith, Regulatory Compliance
- C. Tompkins, Valve Engineering Supervisor
- L. Underwood, Engineer
1.2
U. S. Nuclear Regulatory Commission
- P. Harmon, Senior Resident Inspector
Acronyms and initialisms used throughout this report are listed in the
last paragraph.
2.0
GENERIC LETTER (GL) 89-10 "SAFETY-RELATED MOTOR-OPERATED VALVE (MOV)
TESTING AND SURVEILLANCE"
On June 28, 1989, the NRC issued GL 89-10, which requested licensees and
construction permit holders to establish a program to ensure that switch
settings for safety-related MOVs were selected, set, and maintained
properly. Subsequently, six supplements to the GL have been issued.
NRC inspections of licensee actions implementing commitments to GL 89-10
and its supplements have been conducted based on guidance provided in
Temporary Instruction (TI) 2515/109, "Inspection Requirements for
Generic Letter 89-10, Safety-Related Motor-Operated Valve Testing and
Surveillance." Temporary Instruction 2515/109 is divided into Part 1,
"Program Review," and Part 2, "Verification of Program Implementation".
In a letter to the NRC dated December 12, 1994, the licensee provided
notification and requested closure of the Generic Letter 89-10 Program.
On January 23, 1995, a phone conversation was held between Duke and NRC
representatives concerning GL 89-10 closure. In that phone
conversation, Oconee stated they would provide the NRC a "Generic Letter 89-10 Closure Audit Package". In a letter to the NRC dated March 31,
1995, the licensee provided the "Supplemental Information for Closure
Audit". The supplemental information listed the licensee's commitments
in Attachment 1 of the letter. The inspectors verified that all
licensee commitments
2
listed in the March 31, 1995, Duke letter have been satisfactorily
addressed and are closed except for 11 Unit 1 and two Unit 2 items.
These remaining commitments are as follows:
Valves
Document
Modification or Work
1)
2-BS-001
W095067563
Replace motor
2)
2-HP-024
W095067625
Change motor gear set
3)
2-HP-025
W095067629
Change motor gear set
4)
2-HP-409
W095067535
Replace valve
5)
2-HP-409
W095064580
Replace operator
6)
2-HP-410
W095064581
Replace valve
7)
2-HP-410
W095067858
Replace operator
8)
2-CCW-10
W095067575
Change gear ratio
9)
2-CCW-11
W095067577
Change gear ratio
10)
2-CCW-12
W095067579
Change gear ratio
11)
2-CCW-13
W095067583
Change gear ratio
12)
3-LP-001
Replace actuator and (possibly) valve
13)
3-LP-002
Replace actuator and (possibly) valve
The Unit 2 items are scheduled for implementation during the next
refueling outage 2EOC15 in late Spring 1996. The Unit 3 items are
scheduled for implementation by the end of 1996. The inspectors
verified there were no operability concerns and the work order (WO)
schedule for implementation was satisfactory.
The current inspection assessed the completion of the licensee's
GL 89-10 program as stated in the closure letter. The assessment was
conducted utilizing guidance described in an NRC memorandum of July 12,
1994, "Guidance on Closure of Staff Review of Generic Letter 89-10
Programs" and in TI 2515/109, "Inspection Requirements for Generic
Letter 89-10, Safety-Related Motor-Operated Valve Testing and
Surveillance." The licensee's GL 89-10 program and its implementation
were previously examined and documented in NRC Inspection Reports
50-269, 270, 287/91-13 (Part 1 program) and 94-15 (Part 2
implementation).
Details of this inspection and findings are described
below.
SII
3
2.1
Design-Basis Reviews
During the Part 2 inspection, the inspectors examined the licensee's
design-basis documentation used in the implementation of the GL 89-10
Motor Operated Valve Plant Program for diagnostic testing of MOVs. That
examination included review of mechanical flow diagrams (piping and
instrumentation); design-basis calculation results of the expected
differential pressures; the sizing and switch setting calculations; and
diagnostic test data. The inspectors also conducted a walkdown of
selected MOVs. The inspectors reviewed the licensee's design-basis
documentation (DBD) to determine and verify its adequacy in general for
all MOVs in the program. In addition, the recommended action "a" of
GL 89-10 that requested licensees to determine the maximum differential
pressure and flow expected for both normal and abnormal (accident)
conditions was examined to verify that maximum parameters were used.
During this inspection, the inspectors examined the design-basis
calculations and the torque/thrust calculations to verify their adequacy
for all the GL 89-10 valves. The calculations were reviewed to ensure
all the GL 89-10 recommendations were included.
The design-basis calculations for differential pressure were reviewed to
verify electrical degraded grid voltage, flow, and temperature were used
in the design calculations for thrust and torque. The calculations were
reviewed to determine if the worst case design-basis differential
pressure and flow conditions, design temperature, and other design
parameters for each MOV selected met the recommendations of GL 89-10.
The inspectors verified that degraded grid calculations were included to
ensure that the lowest motor terminal voltage commensurate with design
basis conditions was factored into the determination of maximum thrust
ratings. The inspectors also verified that the licensee satisfactorily
addressed the Limitorque Part 21 high temperature motor concern.
The "design-basis" differential pressure calculations reviewed are as
follows:
CALCULATION
SYSTEM -
MOTOR OPERATED VALVES
1)
OSC-4374, R4 -----------
Main Steam (MS), MS
17,26,82,84
2)
OSC-4363, R5 -----------
MS-24,33,35,36,47,76,79
3)
OSC-4412, RO -----------
Purg (PR), PR-15, 19
4)
OSC-4416, R6 -----------
Low Pressure Service Water
(LPSW), LPSW-4, 5
5)
OSC-4564, RO -----------
LPSW-6, 15
6)
OSC-4502, RI -----------
LPSW-18, 21, 24
7)
OSC-4551, R3 -----------
LPSW-45
8)
OSC-4560, RO -----------
LPSW-137
9)
OSC-4553, R3 -----------
LPSW-139 (Unit 1)
10)
OSC-4536, R1 -----------
LPSW-565, 566
4
9CALCULATION
SYSTEM-MOTOR OPERATED VALVES
11)
OSC-4697, R2 -------------
High Pressure Injection (HP),
HP-3, 4, 20, 24, 25, 26, 27,
409, 410
12)
OSC-4676, R4 -------------
HP-398, 417, 426, 428
13)
OSC-4281, R4 -------------- Low Pressure Injection (LP),
LP-1, 2, 3, 14, 15, 16, 17,
18, 19, 20, 21, 22, 103, 104
14)
OSC-4542, R3 -------------- Building Spray (BS), BS-1, 2
15)
OSC-4784, RI------------
Component Cooling (CC), CC-3,
4, 5, 6, and 7
16)
OSC-4494, R2------------
Condensate Circulating Water
(CCW), CCW-1, 2, 3, 4, 5, 6,
7, 8, 10, 11, 12, 13, 90, 91,
93
17)
OSC-5628, RI -------------- CCW-268, 287
18)
OSC-4692, R2 -------------
CCW-269, 347
19)
OSC-4479, R3 -------------- Condensate (C), C-124, 152,
153, 156, 158, 391
20)
OSC-5692, RO------------
Core Flood (CF), CF-i, 2, 3,
4, 5, 6
21)
OSC-4385, R2 -------------- Feedwater (FDW), FDW-103, 104,
105, 107
022)
OSC-4431, R2 -------------- FDW-33, 36, 38, 42, 45, 47
23)
OSC-4643, R2 -------------
Reactor Coolant (RC), RC-3, 4,
5, 6
24)
OSC-4555, Ri -----------
igSpent Fuel (SF), SF-82, 97
During the Part 2 inspection, MOV LPSW-139 was identified as having a
small thrust margin. At that time the licensee indicated the actuator
would be replaced. The inspectors verified that the licensee had
replaced LPSW-139 using work order WO 95014138. In addition, the
inspectors reviewed the completed modification package, ID No.
TN/5/A/2972/AL1/01, "Replace Valve LPSW-139" dated December 3, 1995.
The inspectors concluded the licensee implemented appropriate corrective
action to increase the thrust (torque) margin of LPSW-139.
Concl usion
The inspectors concluded the licensee's satisfactory implementation of
the GL 89-10 recommendations for addressing the design-basis was
adequate for closure.
2.2
Motor Brakes
During the Part 2 inspection, the inspectors verified that Units 1 & 3
had been walked down and no motor brakes were installed on GL 89-10
MOVs.
The licensee indicated that a motor brake walkdown inspection was
planned during the October 1994 Unit 2 refueling outage. During this
16
inspection, the inspectors reviewed work order Nos. 94010077 and
5
94020444 to determine the results of the Unit 2 motor brake walkdown
inspection. No GL 89-10 MOVs in Unit 2 had motor brakes installed.
Conclusion
The inspectors concluded that no motor brakes are installed on GL 89-10
MOVs.
2.3
Scope Change
The inspectors examined the scope change since the Part 1 inspection.
The licensee reduced by 15 the number of valves in the scope of the
GL 89-10 Program.
VALVES REMOVED
JUSTIFICATION
1(2,3)-CS-5
Diaphragm Type
1(2,3)-AS-40
Converted to Manual
1(2,3)-MS-47
Converted to Manual
1(3)-CCW-90, 91
Removed Valves
1(3)-LPSW-137
Ball Type
Conclusion
The inspectors concluded the removal of 15 MOVs from the GL 89-10 scope
was justified.
2.4
Establishing MOV Settings
The inspectors reviewed the following thrust calculations to determine
and assess the licensee's general requirements for switch settings. The
following thrust calculations were reviewed:
1)
OSC-5675, Revision 0
GL 89-10 MOV Calculation For Unit 2
Gate And Globe Valves At Oconee
2)
OSC-5761, Revision 0
GL 89-10 MOV Calculation For Unit 2
Butterfly Valves
3)
OSC-5859, Revision 1
Butterfly Valves On The ECCW System
4)
OSC-5760, Revision 0
GL 89-10 MOV Calculation For Unit 1
Butterfly Valves At Oconee
5)
OSC-5599, Revision 1
GL 89-10 MOV Calculation For Unit 3
Gate And Globe Valves At Oconee
- 6
6)
OSC-5762, Revision 0
GL 89-10 MOV Calculation For Unit 3
Butterfly Valves At Oconee
7)
OSC-5674, Revision 1
GL 89-10 MOV Calculation For Unit 1
Gate And Globe Valves At Oconee
The inspectors reviewed the thrust calculations and test packages for
each program MOV to verify the licensee had implemented the
recommendations in GL 89-10. In addition, the inspectors verified that
several findings identified during the Part 2 inspection were
satisfactorily resolved by the licensee. A fixed 15 percent thrust
margin was previously used to account for diagnostic equipment
uncertainty and torque switch repeatability. The current MOV setup and
calculations now properly account for VOTES diagnostic equipment
inaccuracies and incorporates Limitorque's published values for torque
switch repeatability. A fixed 15 percent margin was previously used for
load sensitive behavior (rate of loading). The method to determine this
margin has been revised to add 5.6 percent as a bias error and 26.4
percent as a random error. The random margin is combined with
diagnostic equipment uncertainty and torque switch repeatability using
the square root of the sum of the squares method. The approach using
this method was consistent with the load sensitive behavior measured on
the MOVs tested.
Conclusion
The inspectors concluded the licensee's satisfactory implementation of
GL 89-10 recommendations for addressing switch settings was adequate for
closure.
2.5
Design-Basis Capabilities
Conclusions
The licensee determined that several MOVs were marginal and established
plans to upgrade or replace those MOVs. The modifications to these
valves were commitments in Attachment 1 of licensee's letter, "Generic
Letter 89-10 Closure Audit Package" to the NRC. The licensee's closure
letter is discussed in Section 2.0 and the remaining MOV commitments are
also listed in Section 2.0.
The licensee typically assumed valve factors of 0.6 for gate valves and
1.1 for globe valves. The licensee supported these valve factors with
actual plant data, grouping of test data, or the application of the EPRI
MOV Performance Prediction Methodology. The licensee verified the
proper guide or seat area in predicting the thrust required to operate
For the 8-inch Posi-Seal butterfly valves, a licensee contractor
(Vectra) performed a similarity study to apply prototype test data from
Utah State University. Vectra provided several recommendations for
establishing the applicability of the prototype data to the Oconee
7
valves. The licensee had not documented its response to these
recommendations. This issue is categorized as an IFI 50-269,270,287/
95-25-01, "Response To Vectra Report-Butterfly Valves".
The licensee
evaluation of flow resistance, procedure improvement, and shaft
orientation will require further NRC review. Because the licensee's
response to inspector questions in this area revealed that the licensee
had considered the Vectra recommendations, the inspectors determined
that the staff's review of the licensee's GL 89-10 program can be closed
with this followup item.
For the Anchor/Darling double disk gate valves, the licensee set these
MOVs to accommodate a 0.6 valve factor. The licensee applied the EPRI
methodology for these valves and determined that they could meet the
thrust prediction for theoretical flow isolation but not for hard seat
contact. The licensee believed that its contractor (MPR Associates) had
assumed the more severe orientation of the valve disk than applicable at
Oconee. The inspectors determined that the licensee needs to resolve
the orientation question or determination whether these valves can meet
their performance requirements with possible leakage. This issue is
categorized as an Inspector Followup Item (IFI) 50-269,270,287/95-25-02,
"Anchor Darling Double Disc Gate Flow Cutoff".
Because the MOVs are set
to accommodate a reasonable valve factor for these type of valves, the
inspectors determined that the staff's review of the licensee's GL 89-10
program can be closed with this followup item.
The inspectors reviewed the licensee's application of similarity studies
conducted by Siemens for a group of Anchor/Darling double-disk gate
valves (approximately 1-inch in size) and a group of Borg-Warner
flexible wedge gate valves (4-inch and 6-inch) at Oconee. Because the
sizes of the grouped valves were similar, the inspectors did not
identify any concerns regarding the application of the similarity study
at Oconee.
For Kerotest globe valves, the licensee applied information from flow
loop testing of these valves in verifying the design-basis capability of
its similar valves. The inspectors did not identify any concerns
regarding the applicability of the flow loop data to the particular
valves at Oconee.
The licensee relied on an EPRI method to obtain a bounding rate-of
loading assumption (5.6 percent bias and 26.4 percent random).
The
inspectors consider the licensee's assumption to be supported by its
plant data.
The licensee had committed to perform certain MOV modifications in a
letter dated March 31, 1995. However, during this inspection the
licensee justified not replacing valve 1/2/3 CCW-287 based on its open
safety function (its close function had been eliminated) and not
replacing valves 2CCW-7 and 3CCW-93 based on a revised lower design
differential pressure. The inspectors considered these adjustments to
the licensee's commitments to be acceptable. The licensee stated its
8
S
intent to perform the remaining MOV modifications specified in the
March 31 letter.
The licensee determined that the diagnostic test data for 52 MOVs had
been outside the calibration range in the opening direction. The
licensee reevaluated these MOVs to verify their capability. The
inspectors considered 2LP-21 to be marginal.
However, there is no
safety concern since the licensee enters a "limiting condition of
operation" (LCO) whenever the valve is closed. Further, the licensee
plans to retest the MOV in April 1996 to verify margin.
The licensee is active in applying new technologies to improve the
performance of its MOVs. The licensee has conducted flow-loop testing
to provide information on MOV performance. The licensee has been
applying the EPRI methodology in some cases where plant test data was
not available. The licensee has been bench testing its motor actuators
to obtain detailed information on their performance capability. The
licensee has demonstrated strong technical expertise in providing
information to other licensees on MOV performance.
During the inspection the inspectors provided additional information for
consideration by the licensee. The licensee stated that this
information, discussed below, would be evaluated.
1)
-
The licensee applies linear extrapolation to its dynamic
test data. The licensee requires the test differential
pressure to be at least 50 percent of the design to perform
linear extrapolation.
-
Review of the EPRI guidance on extrapolation of test data
and the NRC safety evaluation for any adjustments to its
extrapolation technique.
2)
-
The licensee applied the EPRI methodology to verify the
design-basis capability of several MOVs in its GL 89-10
program. Review of the NRC safety evaluation (when issued)
on the EPRI methodology to determine whether any adjustments
to its capability determination are necessary.
3)
-
The licensee currently relies on a stem friction coefficient
of 0.2 in the justification for the design-basis capability
of its MOVs.
-
Justify use if a 0.15 stem friction coefficient is to be
assumed in its program in the future.
4)
-
For gate valves manufactured by Powell with inverted-guide.
design, the licensee applied the EPRI methodology in a best
possible effort to predict thrust requirements for these
valves. The inspectors considered the licensee's
determination of thrust requirements for these valves to
99
be adequate for closure of its review of the licensee's GL 89-10 program.
As part of the periodic verification program, confirm the
assumptions regarding these valves.
5)
-
For gate valves manufactured by Crane with non-stellite
seating material, the licensee applied the EPRI methodology
with an assumed friction coefficient for their seating
material.
The inspectors considered the licensee's
determination of thrust requirements for these valves to be
adequate for closure of its review of the licensee's GL 89
10 program.
As part of the periodic verification program, confirm the
assumptions regarding these valves.
6)
-
The licensee used a run efficiency in determining the output
capability of certain Limitorque MOVs when operating in the
closed direction.
-
Evaluate recent industry and research test information
concerning Limitorque actuator efficiency.
Conclusion
The inspectors concluded that the licensee's satisfactory implementation
of GL 89-10 recommendations for addressing design-basis capability was
adequate for closure.
2.6
Periodic Verification of MOV Capability
Recommended action "d" of Generic Letter (GL) 89-10 requested the
preparation or revision of procedures to ensure that adequate MOV switch
settings are determined and maintained throughout the life of the plant.
Section "j" of GL 89-10 recommends surveillance to confirm the adequacy
of the settings. The interval of the surveillance is to be based on the
safety importance of the MOV as well as its maintenance and performance
history, but was recommended not to exceed five years or three refueling
outages. Further, GL 89-10 recommended that the capability of the MOV
be verified if the MOV was replaced, modified, or overhauled to an
extent that the existing test results are not representative of the MOV.
Conclusion
The inspectors concluded that the licensee has an adequate program for
closure of the NRC staff review of GL 89-10 with respect to periodic
verification to ensure MOV capability. However, the NRC is preparing a
generic letter on the periodic verification of MOV design-basis
capability. Consequently, the inspectors did not evaluate the
4
licensee's long-term periodic verification plans. The NRC.will review
10
the licensee's MOV periodic verification program following issuance of
the new generic letter.
2.7
Post-Maintenance and Post-Modification Testing
The inspectors identified that the post-maintenance and post
modification test requirements for GL 89-10 MOVs were specified in Duke
Power NRC Generic Letter 89-10 Program Document, Section 5.10 and Figure
4, Post Maintenance Test Matrix. These documents listed the test
requirements and guidelines for maintenance and modification activities.
These activities were placed in three categories, Minor, Intermediate,
and Major. The "Minor" activities category include actuator PMs, motor
control center PMs, limit switch adjustment, limit stop adjustment for
gears, and replacement of certain seals and gaskets. Post-maintenance
testing for "Minor" activities required electrically stroking the MOV
twice. The "Intermediate" activities category included stem packing
replacement/adjustment. Post-maintenance testing for this activity
involves verification that the MOV running load has not increased beyond
acceptable limits, or engineering justification. The current practice
is to perform a new baseline test measuring stem thrust or torque to
quantify packing load changes. Engineering justification can be used
only in situations where available margin conservatively bounds packing
load changes due to adjustment. The "Major" category included
activities such as actuator removal and installation, actuator/gearbox
rebuild, torque switch adjustment, valve disassembly, stem/nut
replacement, spring pack adjustment, motor replacement, and upper
housing cover bolt tightening or gasket replacement. Post-maintenance
testing for major maintenance activities involves performing a new test
equivalent to the baseline diagnostic test.
Conclusion
The inspectors concluded that the licensee's satisfactory implementation
of the GL 89-10 recommendations for addressing post maintenance and post
modification testing was adequate for closure.
2.8
MOV Failures, Corrective Actions, and Trending
Recommended action "h" of GL 89-10 requested that licensees analyze and
justify each MOV failure and corrective action. The documentation
should include the results and history of each as-found deteriorated
condition, malfunction, test, inspection, analysis, repair, or
alteration. All documentation should be retained and reported in
accordance with plant requirements. GL 89-10 also recommended that the
material be periodically examined (every two years or after each
refueling outage after program implementation) as part of the monitoring
and feedback effort to.establish trends of MOV operability.
Equipment failure trending and analysis is specified in the Oconee
Nuclear Station Engineering Manual.
For MOVs the licensee combines the
information obtained from a number of sources. For instance, reports
11
generated quarterly which look at the equipment trends over a 12 month
period include:
-
Average Failure Frequency Report (AFFR)
-
Repeat Work Order Report
-
Unit Trip Report
-
Component Failure Analysis Report (CFAR)
The data base for these reports are the Nuclear Plant Reliability Data
System (NPRDS) and the Work Management System (WMS) which includes
equipment history and corrective maintenance work orders.
Two additional data bases important for MOV trending are:
-
Votes "Sensor" Test Report Analysis Guideline
(Trends diagnostic test results with previous test data)
-
Problem Investigation Process (PIP) reports
(Documents all MOV problems and associated corrective actions)
Since the Part 2 inspection, the licensee had generated a number of PIPs
related to valves in the GL 89-10 program. Of these, 31 PIPs were open
including 5 PIPs related to a potential for pressure locking and/or
thermal binding. The inspectors reviewed the issues identified in the
open PIPs and discussed with licensee engineers the determination of
operability and proposed corrective actions.
Conclusion
The inspectors concluded that the licensee has an adequate program for
identifying, tracking and reporting MOV problems. Review of the issues
identified in PIP reports indicated a thorough analysis, accurate
determination of operability and appropriate short term corrective
actions. Long term corrective actions were identified and considered
adequate for program closure.
2.9
Pressure Locking and Thermal Binding
The inspectors reviewed the licensee's actions taken to evaluate thermal
binding and pressure locking in accordance with recommendations of
GL 89-10 and the recently issued GL 95-07, "Pressure Locking and Thermal
Binding of Safety-Related Power-Operated Gates Valves". The inspectors
determined that the licensee was in the process of reviewing systems and
valves for pressure locking and thermal binding in accordance GL 95-07.
The inspectors reviewed seven problem investigation process (PIP)
reports in which the licensee had identified and documented short term
corrective actions for valves susceptible to pressure locking or thermal
binding. The inspectors did not identify any concerns with the PIPs.
12
In regards to GL 95-07, the licensee had completed its 90-day review.
The licensee stated that valves 2/3 LP103 and 104 had been declared
inoperable as a result of its review and that alternate paths were being
relied on to meet their safety function. The licensee had drilled holes
in the disk of these valves in Unit 1. The staff will evaluate the
licensee's response to GL 95-07 when the 180-day review package is
submitted.
Conclusions
The inspectors concluded that the licensee's satisfactory implementation
of the GL 89-10 recommendations for addressing pressure locking and
thermal binding was adequate for closure.
2.10 Quality Assurance Program Implementation
During the Part 2 inspection, the inspectors concluded that the licensee
had satisfactorily implemented the GL 89-10 recommendations for quality
assurance.
2.11 Walkdown
The inspectors conducted a walkdown of MOV Bench Testing Facility to
observe the use of the motor power monitor. The licensee demonstrated
all the functions and capabilities of the motor power monitor in
conjunction with the use of a torque test stand developed by Kalsi
Engineering. The inspector considered the licensee's bench testing of
actuators and use of the motor power monitor as an innovative approach
using advance technology. Several of the licensee's valve engineers are
pro-active in this testing area. The inspectors concluded the use of
this test facility and the advanced equipment was a strength in the
GL 89-10 program.
3.0
Followup of Previous Items (92701)
(Closed) Violation 50-269/94-15-01, Inadequate Procedure Preparation For
IST Testing. On June 21, 1994, during plant heat up, the 10 year IST
Pressure Test No. 11HN-169 was performed on a section of piping between
valves 1-LP-103 and 1-LP-104 using Work Request No. 94013014. Test
Procedure MP/0/A/1720/016 was used. Valve 1-LP-103 was damaged because
the test pressure and temperature exceeded valve set-up requirements.
The inspectors concluded the IST Test procedure was inadequate since it
did not address all parameters for conducting the test.
The inspector verified that the licensee revised IST Test Procedures
MP/O/A/1720/016 Revision 13 and MP/0/A/1720/010 Revision 26 to address
system parameters such as pressure to prevent damaging MOVs. In,
addition, the MOVs were listed to be reviewed prior to testing. The
inspectors concluded the licensee implemented appropriate corrective
action to prevent future occurrences. This violation was closed.
13
4.0
Exit Interview
The inspection scope and results were summarized on December 14, 1995,
with those persons indicated in paragraph 1. Although proprietary
information was reviewed, none is contained in this report. Dissenting
comments were not received from the licensee.
5.0
Acronyms and Intialisms
-
Design Basis Document
DP
-
Differential Pressure
-
Electric Power Research Institute
GL
-
Generic Letter
IFI
-
Inspector Followup Item
INEL -
Idaho National Engineering Labratory
-
Inservice Test
LSB
-
Load Sensitive Behavior
-
Motor Operated Valve
NRC
-
Nuclear Regulatory Commission
-
NRC Office of Nuclear Reactor Regulation
-
Problem Investigation Process Report
-
Quality Assurance
TI
-
Temporary Instruction
-
Work Order