IR 05000315/1993008
| ML18005A032 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 03/18/1993 |
| From: | Dunlop A, Jeffrey Jacobson, Pegg W, Replogle G, Roth D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML17331A116 | List: |
| References | |
| 50-315-93-08, 50-315-93-8, 50-316-93-08, 50-316-93-8, GL-89-04, GL-89-4, NUDOCS 9303290136 | |
| Download: ML18005A032 (12) | |
Text
U. S.
NUCLEAR REGULATORY COMMISSION
REGION III
Reports No. 50-315/93008(ORS);
No. 50-316/93008(DRS)
Docket Nos.
50-315; 50-316 Licenses No.
DPR-58; No.
DPR-74 Licensee:
Indiana Michigan Power Company 1 Riverside Plaza Columbus, OH 43216 Facility Name:
Donald C.
Cook Nuclear Power Plant Units
and
Inspection At:
Bridgman, MI Inspection Conducted:
February 22 through March 5, 1993 Inspectors:
e Approved By A.
Dun op G.
ge w.
p=gg r
B.
ot e
H. Jaco pone C ie ateriz~lk Processes Section
Date Date Date (rw a"
lYate Ins ection Summary A
OH~
~OL.
p)a OO P)A QO P3OR ma Owe Ins ection conducted Februar 22 through March 5.
1993 Re orts No.
50-315 93008 DRS
No. 50-316 93008 DRS Areas Ins ected:
Announced safety issues inspection of the licensee's incorporation of Generic Letter (GL)89-04e
"Guidance on developing acceptable Inservice Test Programs" into the Inservice Testing (IST) Program (TI 2515/114),
the licensee's program on check valves (TI 2515/110)s and licensee's self-assessment in these areas.
Results:
The inspection disclosed one non-cited violation (Paragraph 2.b.(3))
concerning reverification of pump reference values after maintenance, two unresolved items (Paragraphs 2.a.(1)
and 2.b.(l) concerning not including the closed safety functions of several safety injection component cooling water valves in the IST program and use of reference curves for pump testing, and one inspection follow-up item (Paragraph 2.b.(2)) concerning the use of tolerance bands on reference values'ased on this inspection, TI 2515/114 and TI 2515/110 are considered closed.
The licensee demonstrated a strength in the following area:
The extensive use of trending in the IST progra TABLE OF CONTENTS
~Pa e
1.
2.
3.
5.
6.
7.
Persons Contacted...............................
Inservice Testing (IST) of Pumps and Valves.......
a Scope.
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b.
Pump Testing.......
(1)
Pump Reference Curves........
(2)
Tolerance Band on Flow Reference Values (3)
Evaluation of Reference Values after Haintenance.
c.
Valve Testing.
d Trending
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Check Valve Program.....
a Scope..............
b.
Design Application Review.........
c.
Preventive Maintenance............
d.
Inservice Testing.
e.
Non-Intrusive Testing............
f.
Trending Licensee Self-Assessment..
Unresolved Items..
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Inspection Follow-up Items Violations For Which A "Notice of Violation" Will Not Be Issued..
8.
Exi t Meeting
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DETAILS Persons Contacted American Electric Power Service Com an D. Powell, Assistant Section Manager - Nuclear Engineering E. Gilabert, Nuclear Engineering Section XI D. Ritzenthaler, Check Valve Program
- H. Ackerman, Nuclear Licensing Indiana Hichi an Power Com an
- A. Blind, Plant Manager
- R. Baker, Assistant Plant Manager Production
- J. Ruteowski, Assistant Plant Manager - Technical Support
- J. Wiebe, Safety 8 Assessment Superintendent
- G. Weber, Plant Engineering Superintendent
- J. Schrader, Preventive Maintenance Supervisor
- F. Pisarsky, Maintenance Engineering Supervisor
- T~ Stephens, Production Supervisor Engineer
- C. Freer, Inservice Inspection Coordinator
- B. Bradley, Senior Performance Engineer -
- I. Fleetwood, Senior Performance Engineer Operations
- C. Jerz, Preventive Maintenance
- P. Leaver, Predictive Maintenance R. Ptacer, Licensing Coordinator B. Crowder, Senior Instructor Mechanical Maintenance R.
Hemmar, System Engineer M. Wiederwax, Safety K Assessment
- K. Worthington, equality Assurance Additional plant and corporate personnel were contacted ouring the inspection.
U.
S. Nuclear Re ulator Commission NRC J.
Isom, Senior Resident Inspector
- D. Hartland, Resident Inspector
- Denotes those personnel attending the exit meeting on March 5.
1993.
and Valves The inspectors reviewed IST procedures and completed IST surveillances.
Generally, the methods used for the testing of pumps and valves were adequate.
The test frequencies and acceptance criteria were specified and provisions were made for prompt operability determinations.
Areas reviewed are discussed belo ~Sce e
The scope of the licensee's IST Program appeared adequate.
Selected plant systems, Technical Specifications (TS)
and Emergency Operating Procedures (fOPs) were reviewed to evaluate the program scope.
Several valves were identified that appeared to have safety functions that would require inclusion into the IST program and are discussed below.
(1)
The IST program did not include a closed safety function for the four safety injection (SI)
pump discharge check valves.
It appeared that the valves perform a closed safety function as addressed in Generic Letter 89-04, position 3.
The SI pumps were lined up for parallel operation during the injection phase of emergency core cooling.
If one pump failed to operate and its associated discharge check valve failed to close, the discharge from the operating pump could bypass the reactor by flowing through the failed check valve and the idle pump.
The safety significance of this issue was reduced since three of the discharge check valves had been disassembled and inspected in accordance with the check valve program with no indicated problems.
In addition, the SI pumps were multistage that might minimize back leakage through an idle pump.
The licensee committed to incorporate the closed safety function for these valves in the IST program.
This will be considered an unresolved item (50-315/316-93008-Ola(DRS)) pending incorporation into the IST program and review of the testing method and schedule by the inspectors.
(2)
The IST program did not include the component cooling water (CCW) check valves (CCW-224 and CCW-225)
upstream of the reactor coolant pump (RCP) thermal barriers.
The section of piping between the thermal barrier inlet check valves and the two motor-operated isolation valves outside of containment was designed to withstand and isolate leakage from the reactor coolant system through the thermal barrier.
If the thermal barrier were to leak or fail, these check valves would be relied upon to isolate the high pressure coolant from the low pressure upstream piping.
This issue was under review at the conclusion of the inspection and will be considered part of an unresolved item (50-315/316-
'93008-Ola(ORS))
pending resolution by the licensee.
(3)
Industry information determined that the volume control tank (VCT) discharge check valve (CS-295)
has a safety function in the closed direction.
The check valve's closed safety function was subsequently included in the IST program to be tested on a cold shutdown frequency.
The station IST personnel determined that testing of this valve during cold shutdowns may not be possible if the charging system
Pum remained in service since suction for the pumps was from the VCT.
As such, the licensee intended to request relief from the Code and test on a refueling outage basis by use of radiography to verify valve closure.
This approach appears to be acceptable, though formal review of the relief request will be performed by NRR ~
Testin Pum Reference Curves (2)
(3)
The IST procedures for the centrifugal coolant charging (CC)
pumps used reFerence curves to define acceptance criteria for flow and differential pressure (d/p).
The use of pump reference curves may not be equivalent to the ASHE Section XI Code requirement.
This is considered an unresolved item (50-315/316-93008-02(DRS))
pending licensee actions to perform pump testing in accordance with the Code requirement or submittal of a relief request.
Tolerance Bands on Flow Reference Values The IST procedures for pumps included a tolerance band on the flow reference value of up to 2% (Code gage error is plus or minus 2%).
The purpose of the tolerance band was to relax the requirement to throttle to a fixed reference value for each test, which can be difficult to accomplish in some cases.
The Code.
however, does not allow for a tolerance band on the fixed reference value.
Subsequent discussions with NRR indicated that this was a generic issue throughout the"industry and guidance would be issued in the near future addressing acceptable tolerance bands.
This did not appear to be a technical concern since even though the procedures allowed tolerance bands.
in most cases the actual flows established were close to the fixed reference values.
The licensee should, however, review surveillance procedures were the allowed tolerance band was significant (e.g.,
high flow ES'W pumps)
and consider minimizing the acceptable tolerance band.
This will be considered an inspection follow-up item (50-315/316-93008-03(DRS)) pending issuance of the generic guidance and satisfactory incorporation into the IST program.
Evaluation of Reference Values After Maintenance Two quality assurance inspections revealed instances where the Code required reference value evaluations were not performed after pump maintenance activities (documented in Problem Reports 89-1307 and 92-1278, dated November 27, 1989, and August 5, 1992, respectively).
Although the corrective actions for the 1989 findings included an
administrative procedure change which specified that the job planner should interface with other departments to establish testing requirements (such as the IST staff), the IST coordinator was not always contacted and several oversights led to the second set of findings in 1992.
During the inspection, the licensee stated that the procedure only provided administrative guidance and planners were not required to follow it.
Corrective actions in response to the second incident included plans to change all of the applicable maintenance procedures to include the appropriate notification of the IST coordinator when pertinent pump maintenance was performed.
The final corrective actions appeared to be acceptable.
The licensee performed an evaluation and determined that the safety significance of both sets of findings was minimal because no inoperable equipment went undetected as a result of the oversights.
Additionally, the evaluation indicated that none of the reference values would have changed as a
result of the errors identified in the 1992 report.
The failure to reevaluate the pump reference values was a
violation of Technical Specification 4.05, which requires, in part, pumps which are classified as AStiE Code Class 1,
Class 2 and Class 3 shall meet the requirements
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forth in Section XI of the ASHE Boiler and Pressure Vessel Code.
The ASHE Code,Section XI, IWP-3111 requires, in part, when a reference value or set of values may have b==n affected by repair or routine servicing of the pump, a
new reference value or set of values shall be determined, or :he previous value reconfirmed by an inservice test run prior io return of the pump to normal service.
Contrary to the above, the licensee identified several instances, as noted previously, where the requirec establishment of new reference values or the verificatio;. of the old reference values was not performed.
This violation is not being cited because the criteria specified in Section VII.B of the NRC Enforcement Policy were satisfied.
Valve Testin In most cases the guidance of GL 89-04 was incorporated into the IST program for valves.
Issues regarding the testing of check valves were documented in paragraphs 3.c and 3.d of this report.
A review of relief valve bench testing results indicated a
significant number of failures over the last 5 years.
Causes stated included use of new bench test equipment that allows for testing with either air or water and unclear understanding of what constituted a successful valve lift.
In the past, valves were tested with air; however, the setpoints were not correlated to the
valve's service medium.
Subsequently, relief valves were tested with the proper test medium.
Since the valves were initially set with air, the results of testing with water identified setpoint problems due to the density differences in the test mediums.
Differences in personnel understanding of what constituted a
successful lift varied as some considered when the valve started to simmer and weep as the setpoint, while others required full flow from the valve.
Guidance had been added to the relief valve test procedure discussing test mediums; however, no guidance on how the setpoint was to be determined was included in the procedure.
The licensee committed to incorporate this guidance into the procedure.
Actions taken appeared to be appropriate.
~Trendin The IST coordinator maintained a computer database of all pumps and valves in the IST program to trend pump and valve performance.
Graphic representation of the data allowed easy interpretation and comparison of test results to the appropriate alert and required action ranges.
All examined instances of components in the alert or action range and the subsequent correctIve actions were handled appropriately.
The trending program was a strength in that it allowed the IST coordinator to monitor component per formance and initiate necessary administrative processes and plan correc-.ive actions before components reached
-.he alert or action ranges.
Check Valve Pro ram
~Sco e
The scope of the check valve program was defined in DCCPV304(CNT
"Check Valve Preventive Ha'n-;enance Program,"
and was considered acceptable.
It included valves identified in INPO SOER 86-03,
"Check Valve Failures or Degradation,"
check valves in the IST program, and other balance of plant check valves.
There were 442 check valves included in th=
Pt< program.
There was almost a
100%
overlap between check valv=s in the IST program ard the PH program (299 out of 301).
The scop= of the check valve program was consistent with the SOER and had the proper amount of management support.
The corporate office managed the program with the station performing disassembly/inspections (D/I) and non-intrusive testing (NIT).
Personnel from both the corporate office and the station participate on the Nuclear Industry Check Valve Group (NIC).
Desi n
A lication Review Corporate engineering developed a technical evaluation report based on the SOER and EPRI report NP-5479,
"Application Guidelines for Check Valves in Nuclear Power Plants," to determine which check valves were more susceptible to degradation.
This evaluation included calculations for required and actual flow rates through check valves, maintenance history, and other design issues identified in the guidelines.
No problems were noted.
Preventive Maintenance Preventive maintenance program for check valves has primarily been 0/I, although NIT equipment was recently purchased.
The design application review determined check valve placement into one of the following categories:
High, Moderate, Low, Split Disc, D/I by IST program, or tested by IST program.
All categories except the last required 0/I at some frequency.
Split Disc valves were singled out as a separate category due to its poor maintenance history.
D/I was the primary means for evaluating check valve deoradation for the majority of valves in the check valve program.
0/I was also used in the IST program to meet Code exercising reouirements.
The visual examination report completed during 0/I included verifying free disc movement in the as-found condition.
However, if maintenance had to be performed that required further valve disassembly, there was no verification of free disc mov=ment once the valve was reassembled.
Although good maintenance practice should ensure free disc movement, for valves 0/I for th= IST program a verification signature was not included to confirm this condition existed.
The licensee committed to review th'.s issue to include a verification signoff for free disc movement i.
the as-left condition.
During a walkdown of installed check valves it was note-that several Centerline split disc check valves when located in horizontal pipe runs were installed with the disc stem in the horizontal position.
The maintenance procedure used when these check valves were last disassembled stated that the disc stem should be installed in the vertical direction, if possible.
This procedure had since been revised with a note that stated disc stem must be installed vertically in horizontal runs of piping.
The vendor was contacted and stated that the valves would function as required in this orientation; however, it may increase the likelihood of accelerated shaft wear.
Based on the vendor response the valves should function as require Work requests and inspection results were reviewed to ensure proper implementation of the D/I program.
The process for visual inspections of check valves appeared to be acceptable.
After obtaining sufFicient information from D/I, several check valves have been re-categorized based on these results.
Inservice Testin Check valve testing, in most cases, was in accordance with GL 89-04.
Exceptions were identified and noted below.
Testing to verify a valve would go to its full open position was accomplished by establishing the full system flow or by D/I.
Verifying a check valve would close was accomplished by seat leak testing, pressurizing downstream piping and verifying no pressure increase on the upstream piping, D/I, or for pump discharge check valves, verifying no reverse pump rotation.
Procedure IOHP 4030.STP.022E,
"East ESW Pump Operability Test,"
contained closure acceptance criteria (25 psid) for check valve I-ESW-10IE (ESW pump discharge valve) that was significantly lower than the d/p typically measured across the valve during the tests (typically 86 psid).
The acceptance criteria was based on static head requirements; however, since the valve was tested with one ESW pump running, the actual d/p would be significantly higher.
The licensee agreed that the d/p acceptance criteria was too low and agreed to revise the procedure to reflect more meaningful acceptance criteria.
The corrective actions appeared to be acceptable.
The safety significance of this issue was minimized because of the outstanding trending program that should have identified any anomalous test and would have prompted further investigation.
However, revising the test acceptance criteria would ensure that any degradation in check valve performance would be addressed in a
timely manner.
Non-Intrusive Testin The station has recently purchased a NIT system, but has not yet included it use in the check valve program.
The intent was to familiarize plant personnel with the equipment prior to takino credit for its results.
Use of this system should provide a
consistent method of identifying the internal condition of valves without D/I.
~Trendi n The corporate check valve coordinator was responsible for reviewing D/I results for all valves whether they were included in the program or not.
The results were trended and analyzed for incorporation back into the program.
The trending process allows for optimization oF the progra Licensee Self-Assessment The licensee performed several self-assessments in the inservice testing area.
Several good issues were identified during these assessments including one discussed in paragraph 2.b.(3) of this report.
Unresolved Items Unresolved items are matters about which more information is required in order to ascertain whether they are acceptable items, items of noncompliance, or deviations.
Unresolved items disclosed during this inspection are discussed in Paragraphs 2.a.(1)
and 2.b.(1) of this report.
Ins ection Follow-u Items Inspection follow-up items are matters which have been discussed with the licensee which will be reviewed further by the inspector and which involve some action on the part of the NRC or licensee or both.
One inspection follow-up item was identified during this inspection and is described in Paragraph 2.b.(2).
Violations For Which A "Notice of Violation" Will Not Be Issued The NRC uses the Notice of Violation to formally document failure to meet a legally binding requirement.
However, because the NRC wants to encourage and support licensee's initiatives for self-identification anc correction of the problems, the NRC may not issue a Notice of Violation if the requirements set forth in IO CFR Part 2, Appendix C, Sections VII.B.1 or VII.B.2 are met.
Violations of regulatory requirements identified during the inspection for which a Notice of Violation will not be issued is discussed in Paragraph 2.B.(3).
Exit Meetin The inspectors met with licensee representatives (denoted in Paragraph 1) at the conclusion of the inspection on March 5, 1993.
The inspectors summarized the purpose, scope and findings of the inspection and discussed the likely informational content of the inspection report.
The licensee identified none of the documents or processes reviewed by the inspectors during the inspection to be proprietary.