IR 05000298/1990034

Insp Rept 50-298/90-34 on 901017-1126.Noncited Violation Noted.Major Areas Inspected:Operational Safety Verification, Surveillance & Maint Observations,Onsite Followup of Events & Followup of Previously Identified Items

ML20058K235
Person / Time
Site:	Cooper
Issue date:	12/10/1990
From:	Harrell P NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
To:
Shared Package
ML20058K227	List: IR 05000289/1990034 IR 05000298/1990034
References
50-298-90-34, NUDOCS 9012170044
Download: ML20058K235 (11)

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APPENDIX U.S. NUCLEAR REGULATORY COMMISSION L

REGION IV

NRC Inspection Report: 50-298/90-34 Operating License: DPR-46 '

Docket: 50-298 Licensee: Nebraska Public Power District (NPPD)

P.O. Box 499 Columbus, Nebraska 68602-0499

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Facility Name: Cooper Nuclear Station (CNS)

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-3-DETAILS persons Contacted Principal Licensee Employees

• J. M. Meacham, Division Manager of Nuclear Operations

• S. M. Pe'erson, Senior Manager of Technical Support Services

• R. L. Gardner, Senior Manager of: Operations

• C R. Moeller, Acting Senior Manager of Staff Support

• J. V. Sayer, Padiological Manager

• M. E. Unruh, Maintenance Manager

• J. R. Flaherty Engineering Manager '

• R. A. Jansky, Outage and Modifications Manager

• H. 1. Hitch, Plant Services Manager

• Brungart Operations Manager ,

• C, D. Walgren, Senior Quality Assurance,(QA) Specialist

• L. E. Bray, Regulatory Compliance Specialist '

The inspectors also contacted other personne * Denotes .; hose present during exit interview conducted November 26', 199 ' Plant Status On October 17, 1990, the plant tripped from 100 percent power as a result of a ground fault on the 345-Ky Phase A line caused by a power supply s cable for a temporary construction elevator coming in contact with' the 345-Ky line. The licensee went to a cold shutdown condition to perform

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miscellaneous maintenanc During the shutdown, the licensee discovered a problem with the internals of residual heat removal Valve.RHR-MOV-278 (the shutdown cooling flow throttle valve). The reactor was taken critical on October 29 and synchronized to the grid on October 30. The plant operated at 100 percent power throughout the remainder of this inspection perio . Onsite Followup to Events (93702) I At1:50p.m.(CDT)onOctober 17,1990,'a reactor scram occurred following a main turbine generator trip. The turbine generator trip resulted from an electrical fault on the Mgh-voltage side of the  ;

main transformers caused by the power cable of a temporary elevator, used for repairs to the reactor building roof, being blown into the 345-LV lines by_high wind Approxinately 3 seconds after the scram,- a partial-loss of offsite !

power occurred when cable remnants blew across the 161-kV line, which powers the startup transformer, causing the startup transforner to-trip. The 161-kV line is located approximately 20 feet from the

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f 345-kV line. The emergency transformer remained energized during the event, supplying power to all critical equipment after the nomal load shedding time delay. Both diesel generators started but did not' '

load due to the emergency transformer being energize '

The plant responded as designe During the momentary loss of power

, to the critical buses during load shedding, the reactor protection -'

system (RPS) motor generator sets tripped, deenergizing the RPS distribution system. As a result of t1e loss.of RPS power, the main

> " steam isolation valves closed causing reactor pressure to increase.-

The safety relief valves (SRV) opened to maintain pressure less than 1100 psig. The reactor level decreased, due to the; scram and SRV actuation, causing coolant injection HPCI)(an automatic arj reactor initiation of thecooling core isolation high-pressure,

-(RCIC)

systems. The control rocin operators tripped RCIC and operated HPCI in manual to control icvel. The lowest recorded level was *

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During the event, the inspector observed problems with the' air compressors. The air system contains three air compressors that ga supply the instrument air system. Two of these compressors are -

E nomally cooled by the turbine equipment cooling (TEC) system and the other is normally cooled'by the reactor equipment cooling (REC)

system. During the event, power was lost to-the TEC pumps, which resulted in only one compressor being operational. Control room personnel directed a nonlicensed operator to transfer cooling for Air Compressor B from TEC to REC. While the transfer was being performed, the control room received a low-level alarm on the REC surge tank and a high-level alarm on the TEC surge tank. A reactor operator was then dispatched to correct the REC and TEC lineup After restoration, since there was no power to the demineralized water punps (the normal makeup supply to the REC surge tank), a fire hose was routed to fill the REC surge tan Af ter the inspector expressed concern about the near loss of REC, the licensee investigated the incident. The licensee detemined the

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causes to be a lack of lighting in the control building basement (all valves to be operated are located in the overhead in a difficult-to-access location) and two valves (TEC-91 and -92) were inproperly labele Prior to startup, the licensee perfomed the following short-term corrective actions:

• Corrected the labeling error *

Modified the applicable procedure for crossconnecting REC and TE , -- --

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More clearly identified valves to be operated when crossconnecting REC to TE L i

Trained all operators on the modified crossconnection procedur l

In addition, the licensee committed to evaluate long-tenn, human-factors corrective actions prior to the next scheduled 4 refueling outage in October 1991. Actions being considered by the i licensee include modification of the TEC and REC systems to make the crossconnect valves more accessible to the operator i In addition to the lighting problems identified in the control i building basement, the inspector identified additional lighting problems in nonsafe shutdown areas during the event. The licensee evaluated the adequacy of emergency lighting in nonsafe shutdown areas of the plant. The resulting evaluation was forwarded to the Region IV office and the Office of Nuclear Reactor Regulation for review. This issue will be tracked as an inspector followup item (298/9034-01). Following the reactor trip on October 17, the licensee placed thei plant in cold shutdown to perform miscellaneous maintenance. O October 19, during shutdown cooling operations, the licensee observed

. a flow indication of 8000 gpm through-Valve RHR-MOV-27B while the valve indicated closed on the control room indicato ,

The licensee disassembled the valve-and found damage to the-interne', i anticavitation trim elements that had been installed during the previous refueling outage. A review of the valve failure and

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licensee's corrective actions are documented in NRC Inspection Report 50-298/90-3 ;

The licensee will document this failure in a licensee event repor In addition, the licensee notified the: vendor (Anchor / Darling Valve Company) in a letter (NLS9000490), dated October 31, 1990,.of.the potential 10 CFR Part 21 reportability issue associated with the valve failure. It is the licensee's understanding that the vendor i will redesign the valve trim, as required, and complete installation <

during the next refueling outage. The-licensee stated that they would contract an independent, third-party reviewer to perform a design review of any modification made to the-valve by the vendo in summary, the plant responded, as' designed, following a reactor scram 1 and partial loss of offsite power. The licensee took prompt, thorough corrective actions following failure of Valve RHR-MOV-27B problems concerning crossconnection of TEC to REC, and nonsafe shutdown lightin The licensee comitted to evaluate-long-term, human-factors corrective actions concerning crossconnection of the TEC/ REC systems prior to the next refueling outag i

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6-l 4 Operational Safety Verification (71707)

The inspectors observed operational activities throughout this inspection period. Proper control room staffing was neintained and control room ,

professionalism and decorum was observe Discussions with operators determined that they were cognizant of plant status and aware of the reason for each lit annunciator. The inspectors observed selected shift turnover neetings and noted that information concerning plant status and 4 planned evolutions was properly comunicated to the oncoming operator The inspectors verified, by visual inspection of emergency core cooling system valve indications, that the systems were maintained in a standby condition. The ins for vperation (LCO)pectors observed were properly that alland docunented required limiting tracked by theconditions control room staff, During control room tours, the inspectors noted a large number of log i entries concerning fire protection system flow tests with high i differential pressures. Discussions with the operators revealed that 1 the discharge pressure of the recently installed jockey pump created a higher system operating pressure than the previous jockey pum The fire system flow test is perforned to verify that there is no blockage in the piping. The test is perfomed by pumping water through the system with the flushing pump and measuring the differential pressure (dp). With the old jockey pump running, the low discharge pressure from the pump did not effect performance of ,

the test. With the new jockey pump installed, the higher discharge i pressure effected the flow test performance by causing higher dp indications. To appropriately perfom the flow test, the jockey pump should have been secure The licensee identified the procedure discrepancy during system testing; however, they did not issue a temporary or interim procedure change to provide instructions to stop the jockey pump. Instead, operations followed the instructions of the fire protection engineer by noting test discrepancies in the procedure and making control room log entries for any high differential pressures observe .

The inspector detemined that the safety review group (SRG) had not issued the procedure changes required by the jockey pump modification because the design change was proposed in 1987, prior to establishment of the SRG. Additionally, the inspector determined, from discussions with the licensee, that the responsible project engineer had failed to identify that the higher system operating pressure would require a procedure chang The failure to change a procedure to conduct testing appeared to be in violation of NRC requirements; however, the violation is not being cited because the criteria specified in Section V.A of the Enforcement Policy (10 CFR Part 2, Appendix C) were satisfied. The

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i 7 1 licensee's corrective actions to revise the procedure were promptly initiated and no previous similar occurrences were observe ,

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The licensee comitted to review all outstanding desi n changes to-ensure that required procedure changes are being tracked and

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implemented before,they are needed. The licensee also comitted to issue a letter to the plant staff reminding them of their

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responsibility to ensure that adequate procedures are being use The SRG is on distribution to receive a-copy of each new design change so they can independently assess the necessity for procedure changes. These actions should prevent recurrences of this proble ,

- An unrelated procedure problem was identified at the end of the last inspection period. The method for testing check valve back leakage, *

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by measuring the difference in pressure between two^ gauges, failed to account for the pressure head caused by the gauges being at different'

elevation The procedure had been revised by the contract pincedure writers and reviewed by both the SRG and the responsible enginer. Discussions with the licensee indicated that this procedure was field verified by the contractor but not by the responsible engineer. The failure to account for the difference in elevation was an isolated case; however, the inspector identified to licensee management that this .'

concern was considered to be similar to an observation on procedure walkdowns contained in NRC Inspection Report 50-298/89-09. The licensee reviewed previous test performances and detemined that the tests were acceptable when corrections for gauge elevation differences were incorporated. Subsequently, the licensee changed the test method for identifying check valve backleakage, issued a temporary procedure change to the procedure so a retest of the check valves could be conducted, and processed a permanent procedure change to reflect the new method of testing for backleakage, The inspectors performed periodic tours of the reactor plant to-verify proper system lineups and cleanliness. The inspectors periodically verified that electrical lineups were maintained for-components needed to mitigate an accident. The inspectors determined that plant housekeeping had been naintained at an excellent level-throughout the. inspection period, On October 29, 1990, the inspectors observed a reactor startup following the trip which occurred on October 17. The inspectors observed that all prerequisites were properly met prior to commencement of startup. The evolution was deliberate and well-controlled. A second licensed reactor operator verified that all rod movements were in accordance with the startup procedure. The reactor'

was declared critical at 10:30 p.m. on October 29 and paralleled with

. the grid at 1:12 p.m. on October 3 !

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J 8 On October 31, 1990, the licensee issued Quality Assurance Plan (QAP)-2500. " Quality Control," Revision 0. The issuance of this QAP i demonstrated an interest by the QA departnent in the quality control (QC) program. While QC had previously been checked periodically during perfonnance of surveillances and audits, now surveillance and audits will be specifically perfonrred nn the QC l functio l The inspectors verified that selected activities of the licensee's radiological protection program were properly implemented. Radiation and contaminated breas were properly posted and controlled. Health ,

physics personnel were observed touring work areas to ensure proper ;

t implementation of the program. - Radiation work pennits contained

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appropriate information to ensure that work could be perfonned in a

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safe and controlled manne The licensee continued to assess the possibility of establishing a l single entry for the radiologically controlled area (RCA). A study l on the feasibility of a single-entry RCA was completed and recommendations were made to management during this inspection perio The inspectors observed security personnel >erfonn their duties of vehicle, personnel, and package search. Ve11cles were properly authorized and controlled or escorted within the protected area (PA).-

The inspectors conducted site tours to ensure that compensatory measures were properly implemented, as required. Personnel access was observed to be controlled in accordance with established procedures. The PA barrier had adequate illumination and the isolation zones were free of transient material .

p In summary, the licensee perfonned a reactor startup in a safe, controlled -

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manner. The licensee is considering going to a single entry for;the RCA.

l ' '5. Surveillance Observatiors (61726) On October 29, 1990, the inspector observed the performance of Surveillance Procedure (SP) 6.3.5.1, "RHR Test Mode Surveillance l Operation," Revision 32, dated September 6,1990. This test was l performed as a prerequisite for reactor startup. The test was l performed by a qualified reactor operator in the control room.

Proper c?nsnunications were maintained throughout the performance of l the-test. All test results were within acceptance criteria and al required reviews were properly perfonned, On November 21, 1990, the inspector observed the Technical Specification (TS)-required valve operability test of RHR system valves. The functional test was performed in accordance with SP 6.3.5.2,."RHR Motor Operated Valve Operability Test," Revision 27, dated September 6,1990.. During perfonnance of the test, no discrepancies were identified. An operating license candidate

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orfomed the valve m6nipulations for the Train A valves while being aserved by a licensed operator, Following discussions with resident inspectors at other sites, the inspectors requested that the licensee detemine if the perfomance of any SPs placed TS-required systems in a conditior where they would not be able to perfom their intended safety functio The licensee does not normally consider a system in an LCO during the performance of surveillance tests. The licensee was still evaluating SPs at the end of this inspection period. Operability of systems during surveillances is considered an open item pending the completion of thelicensee'sevaluation(298/9034-02).

6. Maintenance Observations (62703) The inspectors observed portions of the valve trim replacenent on Valve RHR-MOV-278. The work was performed in accordance with Maintenance Work Request (MWR)90-394 The MWR was properly reviewed and approved by the Station Onsite Review Comittee (SORC).

Performance by engineering personnel concerning the redesign of the valve trim and concerning the failure-analysis of the valve was excellent. Postmodification testing, consisting of a full-flow test of residual heat removal (RHR) and demonstration of shutdown cooling capabilities, was appropriate. No problems were identified, On November 8,1990, during surveillance testing, the licensee identified a pinhole leak in the service water supply piping to Emergency Diesel Generator (EDG) The licensee declared the EDG inoperable, and issued MWR 90-4191 to weld a patch over the lea The inspector reviewed MWR 90-4191 and determined that all required reviews were properly docunented. QC checks had been specifie The. inspector observed performance of the welding. A fire watch was properly posted and QC checks were properly performe Postmaintenance testing was properly prescribed and performe In sunrr.ary, engineering perfomance during repair of Valve RHR-MOV-260 was excellent. The licensee implemented an adequate maintenance progra . Followup of Previously Identified Items (92701-and 92702) (0 pen)OpenItem 298/8626-03: Inconsistency in the .TS' for the tems

" system" and " subsystem" The licensee initially prepared a TS change clarifying the~ term Subsequently, the licensee decided not to-issue the4TS change until reviewing the results of the BWR Owners Group involvenent-in the TS improvement progra The inspector discussed with licensee management the, timeliness of improvements from this program. The licensee :9bsequently stated

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-10-that they are considering reissuing the TS change, and that it is scheduled for SORC review in January 1991. This item remains ope (Closed) Deviation 298/8901-01: Failure to lock or seal reactor protection system instrument shutoff valves The licensee determined that training of personnel and the use of procedures would be sufficient.to control the positions of isolation valves. The licensee submitted a change to the Updated Safety Analysis Report (USAR) that deleted the requirement to use locking j devices or seals on the instrument isolation valve The-inspector verified that the requirements were removed from the OfAR. The inspector observed numerous instances of the return to se rvice and independent verification of reactor protection system itistruments. No problems with valve position were identifie ! (Closed) Violation 298/8918-01: Failure to follow the procedure for velve tagging The inspector found an isolation valve shut while danger tagged open, ,

Ti.e licensee determined that the valve closed upon receipt of an attomatic isolation signal. In addition, the licensee had utilized I one clearance tag to isolate seven valves for performance of  !

maintenance on individual hydraulic control unit The licensee innediately added a danger tag to deenergize the power !

supply to the isolation valve to prevent further inadvertent  :

actuation. Since the maintenance activities had been completed, the operators returned the hydraulic control units to servic The inspector verified that the revised Station Procedure 0.9,

" Equipment Clearance and Release Orders,". required the power or air supply to be' removed from service and-tagged for components'that could be automatically started or repositione The licensee altered the hydraulic control unit system procedure "to require one danger tag for operational aurposes. A note was added that required all associated valves to se tagged whenever maintenanc was performed, u

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No problems were noted during review of this item. , e c,. (Closed) Violation 298/8937-01: Failure to include a HOLD tag:in the-work order package as required by plant procedure ,

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The root cause of this problem involved the failure of licensee-  !

personnel to understand procedurri requirement Plant incorrectly assumed that the nonconformance report (NCR) personnel

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was th tracking mechanism. The licensee stated, in response to this ,

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violation, that,~ in the future, the NCR would be the tracking" nechanism for corrective actions related to nonconforming materials, l' ,

l The inspector verified that the plant procedure had been moif fied-to

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reflect the proper way to handle nonconforming items. . Addif.ionally, the inspector verified that the appropriate personnel reviewed the violation response and the procedure change No problems were l- note .. Exit Interview '

t An exit meeting was conducted on November 26, 1990, with licensee representatives identified it, paragraph 1. During this interview, the inspectors reviewed the scope and findings of the inspection. Other-neetings between the inspectort and licensee nanagement were held periodically during the inspection period to discuss identified concern ;

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During the exit meeting, the licensee did not identify, as proprietar any information provided to, or reviewed by, the inspector ,

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