IR 05000298/1990013
| ML20042G692 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 05/11/1990 |
| From: | Constable G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML20042G691 | List: |
| References | |
| 50-298-90-13, NUDOCS 9005150297 | |
| Download: ML20042G692 (8) | |
Text
{{#Wiki_filter:-_ q f , . , APPENDIX-U.S. NUCLEAR REGULATORY COMISSION !
REGION IV
-! NRC Inspection Report: 50-298/90-13-Operating License:. DPR-46 y
Docket: '50-298-a Licensee: Nebraska Public Power District (NPPD) P.O. Box-499 Columbus, Nebraska-68602-0499 Facility Name: Cooper Nuclear Station (CNS) Inspection At: CNS, Nemaha County, Nebraska.
Inspection Conducted: March 16 through April '15,71990 Inspectors: G. A. Pick, Resident Inspector, Project Section C Division of Reactor Projects.
W. R. Bennett, Senior Resident Inspector, Project Section C j Division of Reactor Projects ! ~l ! Approved- > 9k G. L.~ Constable, Chief, Project Section-C D6te ' - ! Division of Reactor Projects a ' !, Inspection Summary .! l Inspection Conducted March 16 through April 15', 1990 (Report-50-298/90-13) f Areas Inspected: Routine, unannounced inspection _of operational safety verif1 cation, installation and testing of modifications, monthly-surveillance - observations, monthly' maintenance observations, and refueling activities.
Results: No violations or deviations were identified. The conduct ~of the refueling outage had improved from previous-refueling outages, primarily due.
to the newly implemented outage organization. _- Work accomplished by contract field engineers and quality control inspectors who were brought'in for the outage appeared to be well managed and successful'. ] The licensee promptly responded to events and equipment operability issues and ] ensured proper work perfonnance through aggressive management control.
9005150297 900511 ADOCK0500gg{8 DR i !
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Persons Contacted- - Principal Licensee Employees . ~
- G. R. Horn, Division Manager of. Nuclear Operations.
J. M.=Meacham,, Senior Manager!of Operations-
- J. R. Flaherty, Engineering Manager
. R. Brungardt, Operations Manager
- R. L._Gardner,' Maintenance-Manager:
- J. V.: Sayer, Radiological Manager
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- H. T. Hitch, Plant Services Manager.
- R..A. Jansky, Outage and Modifications Manager
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- G. R. Smith, Licensing Supervisor:
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- S, L. Bray, Quality AssuranceLSupervisor
R.;L. Beilke, Radiological Support-Supervisor-
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- L. E. Bray, Regulatory Compliance Specialist-
- Denotes those present during the-exit-interview conducted on April 23,
-! 1990,
, The NRC inspectors also interviewed-other licensee' employees _and- . contractors during the inspection period.
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plant Status The unit remained shut down throughout.the inspection period.
Reactor..
i refueling began ~on April 5, 1990, and remained in progress at the end of:
L the period.
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Ogerational Safety Verification (71707) _ The. inspectors observed shutdown operational activities throughout the inspection period.
Control room activities were observed to be well ' controlled even though several control panel modifications were being-implemented.
l Licensee control and. coordination of the overall refueling outage has L improved significantly over previous outages. The major reason-for this l appears to be a new outage organization which was implemented. The-I outage organization consists of coordinators from the engineering, ' operations, maintenance, and outage management departments.
These positions, as well as a senior manager,_are on site 24, hours a day to minimize outage-related problems. Work is prioritized, problems , identified, and personnel assigned and made-accountable to solve ' problems.
Communications and cooperation among~ departments has been excellent.
The engineering coordinators have acted as excellent liaisons between the site and the General Office and have demonstrated the-same , [ " sense of ownership" that is normally shown by site personnel.
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On March 16, 1990, during receipt inspection of flexible hoses, the- .. licensee determined that-the certificate of conformance was inadequate to meet the purchase order specifications.. Further~ investigation determined thatLthe manufacturer,'Crawford Fitting Company, although on the Approved - Suppliers List, does not supply and never. has supplied safety grade flexible hoses.- The licensee:had been purchasing the hoses through a distributor, Omaha Valve and Fitting Company, over_ the. last 10 years.
The hoses were installed _in the' emergency diesel generator (EDG). starting _ air system 'and the plant air system as well as other plant applications.
The _ licensee conducted an audit on_ March 19,'1990, at'Crawford Valve-Company. The audit'results indicated that all. hoses had<been pressure tested but that traceability does:not exist:following final-' acceptance.
After final acceptance of a hose; the manufacturing record is--maintained, but the unmarked hoses are placed in bins.,An>a'udit conducted by:the: licensee on' March 22 and 23-at Omaha Valve and Fitting. determined that other commercial grade items purchased-did not have similar problems. 'As a result, EGS International was contracted by'NPPD to developta commercial grade dedication package-to dedicate the affected hoses =which,the licensee . reviewed ~and; approved. The dedication package required vibration-aging testing, seismic testing, and pressure testing of.the: hose sample.
The 'l sample was selected from warehouse spares'that represented the different sizes used in'the plant and purchase orders from the'last'10^ years.
The licensee provided justification of EDG operability to the. inspectors .i prior to commencing refueling activities.
The completed dedi_ cation
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_ package was provided to, and reviewed by, the inspectors. The inspectors
noted no discrepancies during their review of.the' commercial' grade ! dedication package. The licensee verified that.0maha Valve and: Fitting j contacted other utilities-that may-have procured safety related flexible' j hoses which would have~been supplied as commercial grade. The licensee requested that Omaha Valve and Fitting evaluate the problem for j3 10 CFR Part 21 reportability.
.j i On March 19, 1990; the licensee operated EDG No. 2 'after completing the ]; annual maintenance inspection. Heating of newly installed head gaskets had caused excessive smoke generation which activated the' area smoke
alarm and caused-the subsequent discharge of carbon dioxide into the EDG-j room.
Personnel monitoring the test evacuated the room when the alarm J sounded. When the fire brigade responded, they-entered the room in self-contained breathing ~ apparatus, determined no fire existed, reset the EDG- 'l room ventilation,~and.took exygen level measurements.
During the fire brigade response, a large valve, that had been prestaged for installation in the plant, partially blocked access to the fire " brigade locker located closest to the room. The division manager of nuclear operations issued a memorandum on March 21, 1990, documenting the corrective action to be taken. This corrective action included marking i the area surrounding fire brigade lockers as a "N0 STORAGE AREA."
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, . . ' ' .. - . _ . _ , On April 3, 1990, 2000 gallons of service water (SW) was releared onto- , the-ground floor level-of the reactor building.. Maintenance was being l performed on the SW outlet from residual. heat-removal (RHR) Heat Exchanger; . ; A when an SW valve that adjusts flow through the reactor equipment.
_' ' cooling (REC) heat exchanger inadvertently opened. The SW supply to the
REC heat exchanger and to the-RHR heat exchanger share a common header so l that_once-there was flow in the SW line it flowed through.the open SW outlet valve.- The licensee determined-that-an accidental disconnection of i ! a control lead, during troubleshooting of another component, had caused. J the valve to open - Operators quickly isolated the SW after being informed of'the water release.-
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' Although service water is a clean water supply, the flow of water into q - _ . contaminated areas (>100 dpm) caused the ground level of the reactor , building and the lower level-quadrant rooms (quads), located in1each.. corner of the reactor building, to become contaminated in spots. Health - physics (HP) personnel immediately determined the, scope of the contamination and posted the affected areas.
Decontamination of.the affected areas was then performed.
No equipment damage resulted from the.
- spill.
. On April 13, 1990,_ engineered safety features (ESF) actuations occurred. -; when operators attempted to start Core-Spray Pump B.
During the-attempted r pump start, the station startup transformer (the normal power supply during shutdown conditions) electrically disconnected from.the grid. - As designed, the electrical system transferred -to the emergency transformer .; and both EDGs autostarted due to the low bus voltage. The EDGs did not . load since the emergency transformer had picked up:the bus.
The^1ow bus ' voltage caused Group II (shutdown cooling), Group III (reactor water cleanup (RWCU)), and Group VI-(containment. ventilation)'isolations. A , one-half Group I (main steam isolation valves)' isolation and a one-half ' scram occurred which, as designed, did not cause an > isolation or a scram signal. Operators restored all: systems within 15 minutes.
The licensee determined the cause of the loss of the startup transformer-to' ' , be an-inadequate knife switch connection on the startup bus manual disconnect, which had been repositioned on Apr,1 12, 1990. The inadequate connection caused a neutral overcurrent condition on the high voltage side of the station transformer when a load was placed on the , bus.
The attempted start of the core spray pump had been the first load ' placed on the bus.
At the end of the inspection period, the licensee was evaluating the cause of the inadequate knife switch connection and determining the root cause of the half scram.
On April 14, 1990, a second set of ESF actuations occurred while operators attempted to transfer offsite power from the emergency transformer to the startup transformer.
The actuations occurred when bus voltage was lost for 3-5 seconds due to an operator switching the supply' breakers out of sequence.
Shutdown cooling, RWCU, and containment ventilation fully isolated. A one-half Group I and a one-half scram signal were received , when the reactor protection system motor generator set breaker dropped i .. . , ..
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J out. EDG No. 1_autostarted due to the low bus voltage but did not supply
the bus because the' emergency transformer powered the bus. 'All equipment i functioned as designed.
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The licensee' attributed the operator's mistak'e~ to : human error / lack of l concentration. A bright yellow caution plaque (operator: aid) and i procedural guidance stated, specifically, to not operate the breakers in - the order he did because. normal power supplied to the bus.would be. lost.
, 'The inspectors have not observed a pattern of errors. caused by a lack'of l concentration by operators during the outage.
' - The inspectors verified that; selected activities of'the-licensee's: I radiological protection program were implemented in conformance with.
-! . facility policies, procedures', and regulatory requirements.. Radiation ~..
and/or contaminated areas were properly posted and controlled.
Radiation a work permits contained appropriate information to. ensure that work could.
-{' be performed in a-safe and controlled. manner.
Radiation monitors were' properly utilized to check for contamination, t During the week of March 26, 1990, several contract HP technicians workings onsite called in sick apparently in support of a national contract HP' strike When the contract; HP technicians called in sick,.the licensee used chemistry and training personnel with HP experience ~to supplement.the plant staff and the remaining contract HP personnel. The inspectors reviewed the licensee's actions and noted during tours that adequate coverage of all plant activities.was maintained.
- No violations or deviations were identified in this area.
The engineering and quality assurance departments were responsive to a potential problem < with flexible hoses.
System-operability determinations were made promptly . and were consistent with plant evolutions.
The.: response:to contract HP2
' technician support of a national strike ensu' red.that all ongoing work had adequate HP coverage.
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Installation and Testing of Modifications (37828) On March 25, 1990, the inspector observed contract-electricians conducting Step 6.3.65.6 of Design Change (DC) 87-15MA, which implemented a portion of the annunciator upgrade..This step required the termination. of 15 control cable ~ leads used to. measure main condenser-conductivity.
The electricians took proper precautions to assure that an' inadvertent . ,
grounding did not occur due to adjacent equipment being energized. They insulated the screwdriver tip with ele'etrical tape prior to tightening the terminal screws and insulated :the control lead ends prior to routing - ' the cables-in the cabinet. They also placed wire identification markers on the leads as specified in the procedure.
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On March 27, 1990, the inspector-observed a calibration check of RWCU temperature elements (TE)-92, TE-94, and TE-106. The instrument and control (I&C) technician checked the Type T-thermocouple TEs using a direct reading temperature potentiometer.
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..: 6- > ! calibrated and-the TEs met required specifications. ; Discussions with the I&C technician indicated he was familiar with the test equipment.
-On March'27, 1990, tho inspector observed.an ultrasonic (UT) examination'. of RHRBIA manual injection isolation valve: pipe-to-valve weld RAD-BJ40. - The licensee's QA department ~ performed a. surveillance-of the contractor !
' at the same time.. The UT revealed no' deficiencies.- 'On April 2,1990, the inspector ' observed torquing of the flange bolts on
l an air-operated, 24-inch, primary containment vent and purge valve, PC-A0V246AV..The-contractor pipefitters used.a calibrated wrench to' torque the flange bolts for a 20-bolt pattern as delineated in the- ' procedure.
Field engineering quality control verified adherence to the " bolting sequence and proper use of the toroue wrench.
No violations or-deviations were identified in this area. The_ contractor.
craftsmen observed during the outage appeared to be skilled.and they were conscientious about their workmanthip.
The.. hiring of contractor field ' engineering and independent design change quality control inspectors.
! prevented major complications from occurring. by resolving-problems quickly ~ and effectively.
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Monthly Surveillance Observations (61726) ' On March 26, 1990, the in'spector observed as-found and'as-left mechanica'l-snubber testing as required in TS..The mechanic conducted the testing in J accordance with Maintenance' Procedure 7.2.34.8, " Pacific Scientific i Snubber Functional Test," Revision 1, dated February 8, 1990, Both-snubbers being tested, MS-SNUB-PSA10-406 and MS-SNUB-PSA10-459M, met the
acceptance criteria.. The computer controlled test rig operates ' , automatically after the mechanic inputs the snubber specifications. A contractor checks the test rig calibration each cycle. prior to start of-the testing, The mechanic knew the purpose of the test and knew-the significance of the different measurements taken.
He wes :very' familiar with the procedural steps and proficient:with the test rig operations.
On March 29, 1990,- the. inspector observed performance-of Surveillance Procedure (SP)'6.3.8.4, "SLC Manual Initiation Test Tank To Reactor ' Vessel," Revision 17, dated March 15, 1990.
Each cycle during the' '4 refueling outage, either Standby Liquid Control (SLC) Pump A or.SLC Pump B, is tested to ensure proper operation of the pump and the explosive , valve..The pumps are tested in alternate years to assure that both trains are tested within two operating cycles as required by TS.
Proper reviews j and approvals had been obtained prior to start of the. test. Test limitations, such as test tank sampling by chemistry for the presence of '3 contaminants (boron), were met prior to the test performance. A licensed operator, having identified a procedure deficiency during SLC. system , restoration, submitted a procedure change to correct the deficiency.
On April 15, 1990, the inspector observed, in part, the concurrent
performance of SP 6.3.5.2, "RHR Motor Operated Valve Operability Test," < I . . - - -.. - , , . .. !
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. Revision 25,~ dated June 8, 1989, and-SP 6.3.10.24, " Inservice Testing Position Indicator Test Procedure," Revision 0, Attachment 10, dated April.20, 1989.
SP 6.3.5.2 implemented the quarterly inservice test (IST)- valve timing requirements and SP 6.3.10.24, Attachment 10, verified the position.of the valve stem movement locally... Review of.the completed ,' test data indicated that the valve-stroke times met specifications.. ' Valves not-tested due~to tagouts were identified and scheduled-to be- . completed as they became available.
~The local stem position verification must be conducted biennially as-required-by ASME'Section XI. The-IST coordinator had identified in January 1988-that the' test had never been formally accomplished as an .IST.
Subsequently, the IST coordinator wrote a nonconformance report (NCR).
In response to the.NCR, position verifications on. accessible , valves were accomplished dur.ing regularly scheduled'surveillances.
Position-indication testing of the remaining' valves occurred during the unscheduled outage commencing on January 28, 1988. The NCR response indicated.that-the required IST. verifications-had been accomplished and
-documented in the past through other.than a' formal IST;Etherefore, the ={ licensee determined the nonconformance to.be=not reportable.
The-licensee-i generated and performed the formal IST procedure during the 1989. refueling j outage.
j No violations or deviations were identified in this area. After the IST.
l coordinator identified the IST program deficiency, a thorough-NCR response ]l was prepared and proper corrective action was implemented.- . 6.
Monthly Maintenance Observation (62703) j < On March 29, 1990, the' inspector observed the' removal o'f Control' Rod j Drive Mechanism (CRDM) 34-15. The mechanics were adept at their task, ! working quickly but carefully, minimizing exposure.. HP provided e.ontinuous j job monitoring and, as the CRD was transferred from the area under C.e ! vessel, the telescopic detector read 2.8 R/hr on contact'at the CRDM tip.
! On April 4, 1990, the inspector observed a plant electrician troubleshooting the power supply. breaker for RHR Shutdown Cooling Suction Valve RHR-M0150. The maintenance work request required him to j " investigate possible motor failure." Results from the power cable ! meggering indicated no breakdown in the insulation; however, when~the
electrician checked the overload relays he found them burned and melted i due to overheating.
The limitorque operator and valve motor inspection , revealed discolored limit switches and burned motor windings.
l The inspector determined from discussions with the licensee that they-attributed the root cause of this failure to miscommunication between the ' electricians restoring the valve and the operations' department.
Normally, i operations will not provide power to a recently repaired valve or pump.
without the craft present at the component in case a problem occurs;. , t however, in this instance, an operator supplied power to the valve without l the electricians present.
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, c. J c.; -.,;4 .i ... ^ 8-The electricians determined that the-limit switches had been' installed a-180 degrees out of position. With'theilimit switches set in.this manner, ' - the motor closed the valve,' which continued in; the close direction,. until , the overloads melted breaking the circuit.
This appeared to be-an isolated i case since 41 other valves had received-similar: repairs.without' j encountering. any problems.during their return to. service.
~ No' violations or deviationsLwere identified in this area.. The plant
~ electrician doing the' troubleshooting.was knowledgeable and. experienced.
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Refueling Activities- (60710) l On April 15, 1990,'the inspector. observed:the reload of several~ fuel t bundles. Proper communications-were maintained'and proper _controlfof- -loose articles over the reactor; vessel' andLfuels pool were' maintained..- , Refuel floor personnel followed proper radiological practices.
No violations or deviations werel identified in this area.. ,. . 8.~ Exit Interviews (30703) An exit-interview.was' conducted on April 23, 1990, with' licensee. . , representatives identified in Paragraph 1. -During the interview, the NRC' , inspectors reviewed the-scope and findings of the inspection.
Other meetings between the NRC' inspectors and licensee management were held , periodically-during-the inspection pericd.to discuss identified conce' ens.
' The. licensee did not identify as. proprietary any.information provided to, or reviewed by, the NRC inspectors.
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