IR 05000483/1990016
| ML20058C100 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 10/22/1990 |
| From: | Phillips M, Shembarger K, Yin I NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20058C098 | List: |
| References | |
| 50-483-90-16, NUDOCS 9010310261 | |
| Download: ML20058C100 (10) | |
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U. S. NUCLEAR REGULATORY COMMISSION y
REGION 111 l
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Report No.
50-483/90016(DRS)
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Docket No. 50-483.
License No. NPF-30 i
Licensee: Union Electric Company
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post Office Box 149 - Mail Code 400 St. Louis, MO 63166; i
Facility Name: Callaway Nuclear plant j
Inspection At: Callaway Site, Steedman, MO 65077
Inspection Conducted: October 1-5, 1990
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Inspectors:
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K is Sheinbarger -
Date-l Approved By:
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M.P.Phil1Jps,.hief
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Operational Programs Section,
I Inspection Summary
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Inspection on October 1-5, 1990 (Report No. 50-48$/90016(DRS))
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Areas Inspected:
Routine ennounced inspection of licensee corrective ~ actions initiated for the issues identified in its. self-initiated Safety System.
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Functional Assessment--(SSFA)'of' the Essential Service' Water 1(ESW')- system. ~ The
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-r inspection was based on NRC Inspection Procedure 92720.,
Results: Licensee efforts in conducting;the SSFA for the ESWJsystem were good.
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Based on this review and ev ~"tation, the inspectors determined the following:
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The scope of the SSFA was' comprehensive, and bounded'all the essential'~
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concerns and requirements delineated in the NRC's Generic Letter 89-13'on-
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l service. water systems.
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The SSFA was conducted in a' professional. manner. Many; issues identified-
were considered to be significant and upon completion of the corrective
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9010310261 901023 ADOCK 0500g 3 PDR
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actions, could result in system upgrades.
Examples involved the areas'of.
t design document control, predictive maintenance and essential service water availability to the safety: related equipment heat exchangers under
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most adverse plant conditions.
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3.
The inherent design features within the service water supply, such as
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multi-level filtrations and chemical treatmentsLresulted in an absence,of-
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biological fouling and microbiological 1y: influenced corrosion found in i
other nuclear plants.
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4.
Licensee corrective measures were. adequate and effective in all th'e areas -
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selected for evaluation, except seismic provision for the replacement,
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batteries inside the special scope emergency light stations. All remainwg open items were considered to, require long. term fixes. Some of
these issues and resolutions were governed by.other NRC concerns, such as'
a monitoring of service water systems.-and: verification of motor operated-i valve design and testing adequacy.
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5.
The establishment of design basis document retrieval and verification requirements for all new calculations; the pump. vibration monitoring; and the efforts to balance flow and to-improve water supplies in'each of the.
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two ESW trains were considered to be strengths'within the Callaway i
technical departments.
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DETAILS 1.
Persons Contacted gionElectricCompany(UE)
- W. R. Campbell, Manager, Nuclear Engineering (NE)
- J. D. Blosser Manager, Callaway Plant
- G. L. Randolph, General _ Manager, Nuclear Operations
- J. V..Laux, Manager, QA
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- D. S. Ilo11abaugh, Supervising Engineer, NE
- L. H. Kanuckel. Supervising Engineer, QA-L
- J. C. Gearhart, Superintendent, QA.
- J. M.'Gloe, Supervising Engineer, NE
- C, E. Slizewski, Supervising Engineering, QAQS
- R. D. Affolter, Superintendent. Systems Engineering -
- R. A. Hamblem, Supervising Engineer, NE
- T. W. Statius, Supervising Engineer, QAPS
- C, Pilkington 0utage Supervisor, NE
- D. Walter, Engineer, NE
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- J. D. Schnack, Engineer, QA
- P. W. Godt, Engineer, QA.
- J. L. Houska, Clerk. Administration K. Schweiss, System Engineer, NE G. J. Roesner, IST Engineer, NE W. A. Witt, Supervising Engineer, NE-S. Abel, Performance Engineer, NE h S. Nuclear Regulatory Commission
- Bruce L. Bartlett, Senior Resident inspector--
- Indicates those attending the exit meeting at the site on October L5,1990.
Other licensee personnel were contacted as a matter of routine during the-inspection.
2.
Background The licensee's QA Department, with help from engineering operations, and-instruments and controls, conducted three detailed = technical inspections:-
Safety (System Functional Assessment (SSFA) of.the Essential' Service-
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Water ESW) system, conducted in 1988, with the final report issued on March' 28 -1988.
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$$FA of Residual Heat Removal (RHR) system, all modes of operation,.
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conducted in 1990, with the final report issued on August 28,.1990.'.
Safety System Outage Modification Assessment = conducted during the-third plant refueling outage in 1989, with the final report-issued t
on July 31, 1989.
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The purpose of this inspection was to evaluate the effectiveness of the j
corrective actions taken in response'to the issues identified during the S$fA of the ESW (system selected for the NRC inspection).
The NRC review
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the SSFA report concluded that the scope was extensive.
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a i.etter 89-13 was issued by the NRC to alert licensees of-service water
system problems affecting safety-related equipment that have occurred at.
j nuclear power plant-facilities. :The inspectors.found that the concerns
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raised by Generic Letter 89-13 had either been previously identified by'
i the licensee or had been identified by the:SSFA, which resulted'in adequate long term corrective action programs, such as corrosion / siltation a
monitoring and heat exchanger monitoring programs.
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Evaluation of Issues
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Licensee Correction Status
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The SSFA of ESW identified 48 issues requiring. followup as follows:
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9incidentsReports(irs)
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4RequestsforCorrectiveAction-(RCAs)
17 Request for Resolution (RFRs)
18Openitems(01s)
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AtthetimeoftheNRCinspectiontenissues'remainedopen(One-IR; four RFRs, and five Ols). The inspectors reviewed some of the open
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issues, such as installing vibration measurement. instruments atzthe i
ESW pumps, ESW flow balance monitoring, installation of differential l
pressure gauges at the flow orifices, and monitoring:of. heat exchanger g
performance.
The inspectors concurred with the licensee that these e
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would be long term fixes. During the course of NRC followup * review,
the inspectors concluded that substantial progress _had been made for
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all the open issues reviewed.
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Review of Specific-Issues (7.1.1.3.2) Callaway Modification Package '(CMP) 87-_434 added 14".
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isolation butterfly valves to ESW: trains A and B containment r.ooler supply and return -_ lines to allow. leak rate testing:ofivalves without-_
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taking either train A or B out of service.
The: issue raised was' that
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thehigherpumpheadlosshadnotbeenevaluated.L~Theinspectors'-
i review concluded the following::
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l (1). The original safety evaluation' performed in 1984 for thef
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modification was inadequate.to identify the issue stated above. The SSFA did not specifically_ point out thel 10 CFR 50.59a-
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requirement issue, which. was considered to' be_ a weakness. - The p.
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present UE modification procedure, Nuclear function.
Administrative procedure, APA-ZZ-00140, " Safety. Environment and Other Licensing Evaluations," Revisions 8 to 10 were reviewed by the inspectors. The NUMARC NSAC-125 guidelines and methodologies were found incorporated into the procedure.
The present procedure was considered to'be-comprehensive and easy to follow.
(2) The inspectors reviewed the present calculation M-EF-35 Revision 0, "ESW Minimum Heat Requirement, Pressure Drop Due to Addition of Boundary Valves," Addendum 1, dated October 31, 1988.
The inspectors were not able to evaluate for adequacy because the new calculation did not provide an assessment of the original design adequacies including retrieval of' sufficient amounts of design basis documentation to support-the present design revision. To address the inspectors' concern.-the licensee assessed the original Bechtel calculation, EF-20. "ESW System Differential Pressure, Normal Operation," Revision 0, dated January P9,1981 by checking and verifying head losses in a number of piping segments, and concluded that the present calculation was based on valid design basis and. assumptions.
(3) The licensee stated that M-EF-35, Addendum 1, was done prior to the design control upgrade.
The present Nuclear function Engineering Department procedure E0p-22-04023. "Calculaton,"
Revision 5, dated September 20, 1989, required each new calculation (including revision and addenda).to provide a
" Design-bases Data Input Forum," which includes design bases retrieval, review and update.(if required) the original design, and establishment of a computer tracking database. The inspectors considered this to be'a strength within the licensee's technical programs.
L (7.1.1.4) the SSFA identified two penetrations in'the electrical equipment rooms of the VHS cooling tower structure that were installed without seals. The concern documented in RFR 04939 was the intrusion of water from the cooling tower basin into the electrical l
equipment rooms during operation of the' ESW: system for an extended
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period of time. The inspectors reviewed the RFR and concurred with the licensees conclusion that the present design'and installation-of the penetrations were acceptable.
Because the pond spillway elevation l
(1996 feet,6 inches)islowerthanthatofthepenetration
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(1997 feet, O inches), backflow to fill-the basin to the penetration l.
elevation during an internal or external flooding event should not occur.
Therefore, seals'on.the penetrations would not be required.
l (7.1.1.7) The SSFA found-that,UE had committed to implement:NRC:
L IE Bulletin 79-15 to regularly. take shaf t vibration: orbit measurements for ESW pumps; however, the commitment _was not
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shown on the tracking system, and no measurements had been ;crformed.
l To resolve the problem, only proximity probes were required to be
installed at motor and pump coupling; but the licensee took an extra
step to ensure early detection of pump bearing wear, internal rubbing, e
and shaf t cracks by installing velocity probes on~ the flanges i
between the two pump stages. All installation was being scheduled
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for completion during the ongoing refueling outage.
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The inspectors concluded that the licensee pump vibration measurement
program, established mainly for commercial-reasons, exceeded the L
ASME Section XI requirements, and was considered to be a strength
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among the licensee's technical programs.
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(7.1.3.1.1,-and 2) the SSFA identified two concerns relating to ihe
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seal water supply to the ESW B pump.
The first dealt with whether seal water flow to the pump met vendor manual requirements, since the seal wcter supply piping appeared corroded and deposits inside the seal might exist. However, since the pump was designed to function without seal water to cool the upper bearing,.the concern was considered an observation, without followup action required.
The inspectors reviewed the vendor manual and documentation provided.
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by the licensee and considered that the licensee had taken necessary i
actions to ensure acceptable operation of the pump. The second concern was that an internal screen in the seal water supply tank i
had never been inspected or cleaned. This concern was addressed in an Open item. PreventiveMaintenanceRepeatingWorkRequest(WR)
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P438636 was generated and will be performed at 18 month intervals to
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ensure proper screen operation..The inspectors found the corrective
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actions to be adequate.
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(7.1.3.3.1) All the Nickel Cadmium batteries installed inside the special scope emergency lights required during; fire fighting and.
i emergency plant safe shutdown operation had gradually.been replaced
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Since.the new batteries were much t
smaller in size, there was a need to_ install spacers / racks for seismic considerations inside the emergency light stations, which
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also housed the controls and fast and trickle chargers. The SSFA i
and prior licensee engineering walkdowns had identified deficiencies t
in the installation of the required spacers. The inspectors reviewed the previous site inspection completed in January 1988, and considered
it to be questionable, because there was no checklists or plans to define workscope, and no records to document the results. The
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licensee.stoff ~ stated that there were many WRs issued.to correct all
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the adverse findings; but the documents were not self-explanatory.
To assess.the corrective actions, the inspectors inspected six
emergency light stations in Control Building Rooms 3101;and 3102 on floor elevation 1974 feet. The findings'were as'follows:.
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All were in. proper operating condition.
- One had a missing spacer component.
- One spacer stop was not adjusted correctly.
- The battery spacer / rack design was questionable, because -
it provided only one directional restraint and no means-to prevent tilting.-
The licensee. concurred with the inspectors' concern, and promptly.-
initiated the following corrective actions:
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WRs were generated to correct the specificJadverse conditions-
identified by the'NRC.
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A Central: Action Tracking System (CATS)~ item was generated to.
upgrade instructions on how-to adjust the spacer stop and check-the overall installation; A RFR was written to evaluate th'e battery rack spacer design.
- A Suggestion Occurence Solution ($05)-was generated by QA to-
track the corrective action completion.
Craf t and QC staff were to be verbally instructed prior to;
resumption of pH activities.
(7.1.3.3.3) The S$FA found that valve EF-HV-0026 was atfleast 35 feet aWay and on the wrong side.of the pipe from the emergency light which was identified to serve it. The inspectors observed the emergency light station QD-362-installation, and concluded that it.was in-proper operating condition, and the light head ~was. oriented in the-correct direction _to provide adequate illumination for access and.
egress to the valve.
L (7.1.3.6.7) The SSFA noted that components in_the. room below the,
l auxiliary feedpump rooms were rusting due to excessive humidity
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caused by. steam emission from the floor' drains. The corrective-
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action was to install removable;(screw'on) plates on two of the,f
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floor-drains where steam was observed. escaping during a. variety o conditions. The source'of the steam was determined to be the-keep-warm steam' for-the_ turbine-driven aux 111ary teedpump.
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closure of the two floor drains was evaluated extensively by the
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licensee; and it was concluded that safe plant system operation a
would not be affected.
The inspectors reviewed and concurred.with-
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During NRC walkdown of the affected room areas, surface rusting was
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observed to be common, such as on valves, pipe restraint clamps; and:
l all fastener bolt threads. Most of the' piping surfaces had been
.t painted, and were in fair condition.
The, inspectors raised a concern regarding component material surface condition monitoring to
prevent severe degradation.. This concern was based on the: fact that.
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some condensation still-existed due to the difference of temperatures i
between service water in the piping and.the ambient room. ' The licensee
.i responded by presenting to the inspectors the'following procedures i
where material surface conditions were to be monitored:
APA-ZZ-0030, which required system engineers walkdown.
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ODP-ZZ-00016, which: required Equipment _ Operator t
walkdown.
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APA-ZZ-00800, which required Supervisors to perform f
zone general housekeeping inspections.
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CperatingQCManual(00CM)SectionLl',whichrequired
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QC inspection of material conditions during. normal.
operational maintenance and special modification
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activities, j
QCP-ZZ-05041, which required visual examination in f
accordance with ASME Section XI VT-2clevel. inspection.
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The inspectors stated that they had no-further questions regarding
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(7.2.1.1) The SSFA questioned the current status of flow balancing-
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testing, incident reports, and other operational l. records. ;Thet
inspectors reviewed'the latest'ESW flow' balance test conducted in.
May 1989 for both Train A'and Train'B.~ Each ESW train supplied =
L cooling water to 14 different: components-operating during the.LOCA-
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L mode. All components received adequate.ESW supplyfexcept the-
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FSAR Required flow Measured Flow-Train Component (GPM)-
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A Control Room 140 113 A/C condenser A
Fuel Pool Cooling-29 13.
Pump cooler B
Diesel generator 1200
.1170 Coolers B
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- 118 A/C Condenser B
fuel Pool Coo' ling
'21 Pump Cooler The cause of the problem was determined to be corrosion buildup in-some of the smaller diameter piping which caused flow reduction.-
The inspectors reviewed the safety evaluation for the less than' FSAR-flow problems contained in RFR 06497A dated May 19, 1989, and-had no adverse comments. The inspectors further reviewed the licensee's
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planned corrective actions, and considered them to be adequate. : The actions included:
Reduction (updating) cf FSAR values by utilizin'g actual. VHS
pond outlet temperature, and realistic heat loads of-equipment, diesel, and room coolers.
- Increasing ESW flow by replacement of specific segments of corroded piping with stainless steel pipes; chemical cleaning _
of some piping segments; cleaning some heat exchangers-during the refueling outage; and improving-cooler efficiencies by1 cleaning heat dissipation surface ~ areas.
The licensee's long term monitoring;of SW/ESW performance will
be in accordance with the NRC_Gl. 89-13,~which includes. heat'
exchanger performance' verifications during plant refueling outage.
The licensee stated that the absence of biologically-induced fouling.
and corrosion at Callaway was attributable to the inherent design-features in the SW/ESW systems, which consisted of multi-level water intake purification and treatment. This included sludge removal from the stilling basin.-coagulant:and chlorination' treatment,-and processing through a flocculator prior to supplying make-up water to-the cooling tower basin and the ESW UHS. pond. The inspectors had no further questions.
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(7.2.2.1)TheSSFAstatedthatSectionXIISTforESWpumpAwasdone at around 13800 GPM, and for pump B at around 10000 GPM.
The pump degradation at FSAR post-LOCA plus make-up flow of 14839 GPM was unknown. The inspectors reviewed the ESW pump'B performance test conducted in April 1988. The flow versus total pump head measurements during the pump test were taken at various flow rates from about 8000 GPM to 16000 GPM.
In comparison with the pre-operation test performance curve, the inspectors observed there was:
(1)no-(2) a loss of approximately 6 feet of.
degradation up to 11000 GPM;(3) a loss of approximately 7~ feet pump pump head at 14C39 GPM; and head at 16000 GPM. The inspectors concurred with the' licensee's conclusion that the pump performance changed very little.
In conjunction with piping replacement and chemical cleaning as part of the flow balance and supply improvement program, the pump head loss-was expected to be even less...The inspectors concluded that _the licensee's actions taken to address the SSFA concern were ' adequate.
(Training) The inspectors selected four Callaway Modification Packages (CMPs) fnr the ESW system to determine whether the operations staff had been trained on the modification.
Training in the form of required reading and/or classroom presentations had been provided to the operations staff.
Documentation associated with classroom training for licensed-operators could not be readily retrieved =for two CMPs. The training received in the form of required reading was sufficient to ensure safe operation of-the plant for all'four CMPs.
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Exit Interview The inspectors met with licensee representatives (denoted in Paragraph 1)
at the conclusion of the inspection on October 5, 1990 at;the Callaway Nuclear Plant.
The inspectors summarized the purpose' scope, and findings-l of the inspection. The licensee representatives acknowledged-this~.
L information.. The inspectors also discussed the.likely informational; content of the inspection report with regard to. documents or. processes (
reviewed during the inspection. The licensee representatives did not; identify any such documents / processes as proprietary.
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