IR 05000298/1987011
| ML20214S228 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 06/03/1987 |
| From: | Dubois D, Jaudon J, Plettner E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML20214S192 | List: |
| References | |
| 50-298-87-11, NUDOCS 8706090190 | |
| Download: ML20214S228 (9) | |
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APPENDIX U. S. NUCLEAR REGULATORY COMMISSION
REGION IV
NRC Inspection Report: 50-298/87-11 License: DPR-46 Docket: 50-298 Licensee: Nebraska Public Power District '(NPPD) P.~0. Box 499 Columbus, NE 68601 ' Facility Name: Cooper Nuclear Station (CNS) Inspection At: Cooper Nuclear Station, Nemaha County, Nebraska Inspection Conducted: tiay 1-31,1987 , . Inspectors: M Igm j I!#9!87 E. A. Plettner, Resident Inspector, (RI) Date / 5fc29fff
D. L. DuBois, Senior Resident Inspector, (SRI) Date tI4/ R S 3 [[ Approved: ~ , , J.f.Jybdon hief, Pr'oject Section A, Date / ' .Teacttr Pr ect Branch , O
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. Inspection Summary Inspection Conducted May 1-31, 1987 (Report 50-298/87-11) Areas Inspected: Routine, unannounced inspection of licensee action on previous inspection findings, notification of an unusual event, plant trips, operational safety verification, and monthly surveillance and maintenance activities.
Results: Within the areas inspected, no violations or deviations were identified, l
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4 ' DETAILS 1.
Persons Contacted Principal Licensee Employees
- G. H. Horn, Division Manager of Nuclear Operations
- C. R. Goings-Merrill, Regulatory Compliance Specialist
- R. Brungardt, Manager, Operations
- S. M. Peterson, Manager, Acting Plant Services
- H. A. Jantzen, Supervisor, Instrument and Control (I&C)
- E. M. Mace, Manager, Engineering
- D. R. Robinson, Acting Manager,-Quality Assurance J. M. Meacham, Senior Manager, Technical Support R. D. Black, Supervisor, Operations M. D. Hamm, Supervisor, Security The NRC inspectors also interviewed other licensee employees during the-course of the inspection.
- Denotes those present during exit interview May 29, 1987.
2.
Licensee Action on Previous Inspection Findings l The following items of noncompliance, deviation, or unresolved items were reviewed by the NRC inspectors to verify that the licensee's responses to the items iden'.ified in previous. inspection reports are now in conformance with regulatory requirements'and that corrective measures were completed in a timely manner.
(Closed) Violation 298/8627-07: This item involved the licensee's failure to have a procedure for controlling maintenance activities on the refueling bridge mast.
Corrective action taken by the licensee was to develop a specific maintenance procedure for replacement of the refueling bridge mast.
The RI reviewed Maintenance Procedure (MP) 7.4.31, i " Refueling Mast Removal and Installation," Revision 0, dated May 14, 1987, i and verified that licensee corrective action was complete.
This procedure revision was approved and implemented 44 days later than the licensee's commitment date of Ap il 1, 1987, referenced in a CNS letter (serial No. CNSS870060), but there was no refueling activity conducted during this 44-day period.
This item is closed.
(Closed) Unresolved 298/8703-05: This item involved the incorrect selection and testing of a radiation monitor during surveillance testing.
This error caused an unplanned automatic start of the standby gas treatment system (SGTS) and isolation of the secondary containment.
The SRI's review concluded that contributing factors leading to the occurrence J
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were personnel error, inadequate communications, procedural deficiencies, and insufficient component labeling.
A review of I&C technician training records and previous completed surveillance tests indicated a satisfactory knowledge of the radiation monitoring systems and surveillance test requirements and methodologies.
The licensee met NRC reportability requirements in a timely manner which included the submittal of LER 87-008 on February 26, 1987.
The personnel error mentioned above is an apparent violation of failure to adhere to procedure.
A Notice of Violation was not issued because the violation was self-identified by the licensee and it meets the remaining four criteria stated in Appendix C, Section V.A of 10 CFR Part 2.
This item is closed.
3.
Notification of an Unusual Event On May 18, 1987, between the hours of 12:00 noon and 5:00 p.m. (CDT), an increase in reactor water conductivity was noted.
The increase originally was attributed to normal startup activities.
At 5:30 p.m. reactor water conductivity continued to increase despite the licensee's efforts to control conductivity through the filter demineralizers in both the condensate and reactor water cleanup systems.
At 7:12 p.m. a reactor water chemistry sample indicated that conductivity was greater than 10 micro-mho per centimeter.
The CNS Technical Specification Section 3.6.B, titled " Coolant Chemistry," requires that if reactor water conductivity is greater than 10 micro-mho per centimeter, the limiting condition for operations (LCO) is that the reactor shall be shutdown and placed in the cold shutdown condition.
Also, the CNS Emergency Plan Implementing Procedure, Section 5.7.1, " Emergency Classification," in Attachment "B," Section 6.1.1," has the requirement for the licensee to implement a Notification of an Unusual Event (NOVE) when any Technical Specification LC0 results in a reactor shutdown.
The licensee commenced a normal shutdown at 7:50 p.m. and declared a NOUE at 8:15 p.m.
Plant shutdown was completed at 10:57 p.m. by manual scram from 12 percent power.
The scram resulted in Groups 2, 3, and 6 Isolations.
The reactor plant was subsequently cooled down and depressurized and a continuous feed-and-bleed was established to reduce reactor water conductivity.
The NOUE was terminated on May 19, 1987, at 9:15 a.m. when reactor water conductivity was reduced to less than 10 micro-mho per centimeter.
Licensee corrective actions included identifying and plugging leaking condenser tubes.
The reactor was restarted at 10:10 a.m. on May 22, 1987.
On May 23, 1987, at 1:38 a.m., the reactor was manually scrammed from 11 percent power because of increasing reactor water conductivity.
Licensee corrective actions included identifying and plugging additional leaking condensor tubes.
The reactor was restarted at 2:06 p.m. on May 26, 1987.
The main turbine generator was loaded at 1:08 a.m. on May 27, 198. o ,
4.
Plant Trips-Safety Systems Challenges The NRC inspectors held discussions with operations personnel and reviewed control room records including log entries, recorder traces, and computer printouts associated with an unscheduled reactor scram that occurred on May 17, 1987, at 1:30 a.m.
The reactor was in run mode at 74 percent , power and at steady-state conditions prior to the event.
Operations personnel were performing applicable steps of Surveillance Procedure (SP) 6.4.8.2.3, " Main Turbine Trip Functional Test," Revision 7, dated August 7, 1986.
Procedure 6.4.8.2.3 contains a caution statement, which directs the operator to maintain the test handle in the test position while testing the trip feature.
During the performance of SP 6.4.8.2.3, the operator released the handle too soon while testing the thrust bearing feature. This resulted in the Main Turbine Trip which caused the resulting scram.
Primary containment Isolation Groups 2, 3, and 6 actuated at the Low Water Level Setpoint (+12.5 inches).
The SGTS
automatically started because of the Group 6 Isolation.
Both diesel generators were started, but not loaded, when station power automatically transferred from the normal to startup transformer.
No other safety systems were required to actuate.
Following the scram, water level was maintained usir.g the Reactor Core Isolation Cooling System and one reactor feedpump.
The reactor was restarted at 6:42 a.m. May 18, 1987.
The main turbine generator was loaded at 3:49 p.m. on May 18, 1987.
On May 17,1987, at 11:05 a.m., an inadvertent Group I Isolation occurred.
While the reactor was shutdown and pressurized to 240 psig, operations personnel were performing applicable steps of SP 6.2.1.5.1, "PCIS Main Steam Line/ Reactor Water Sample Valve Isolation Logic Functional Test," Revision 10, dated October 30, 1986.
A licensed operator was performing the functional Primary Containment Isolation System (PCIS) test, which required the removal of fuses to verify that half PCIS isolation signals were generated in the reactor protection system.
The operator inadvertently pulled the wrong set of fuses and generated a full PCIS isolation signal, thus causing a closure of all Main Steam Isolation Valves (MSIV).
The MSIVs were subsequently reopened and the test was satisfactorily completed.
On May 18, 1987, at 7:28 p.m., Diesel Generator No. 2 started when an undervoltage condition occurred on Bus 18.
The licensee was transferring load from the startup transformer to the normal transformer when feeder breaker IBN failed to close.
This resulted in the undervoltage condition on Bus 18.
The diesel generator was started but not loaded as emergency power was available from the 69 KV line which normally feeds the vital switchgear.
On May 21, 1987, at 5:59 p.m., a Group I Isolation occurred while the reactor was shut down, cooled down to 235 F, and all control rods fully inserted.
Preparation for a reactor startup was in progress prior to the event.
The reactor operator was repositioning the reactor mode switch from the refuel to the Start / Hot-STBY position.
He apparently moved the _ _ _ _ _. _. -_ _ _ _. _ _ _ _ _ _ - - _. _ - - _ _ _ __
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switch momentarily to the run position resulting in the MSIV Group I Isolation due to low main steam line pressure. Additionally, the reactor protective system generated a full scram as a result of the MSIV closure.
5.
Operational Safety Verification The NRC inspectors observed control room operations, instrumentation, controls, reviewed plant logs and records, and they conducted discussions with control room personnel and performec system walF-downs to verify that: Minimum shift manning requirements were met.
. Technical Specification requirements were observed.
. Plant operations were conducted using approved procedures.
. Plant logs and records were complete, accurate, and indicative of . actual system conditions and configurations.
System pumps, valves, control switches, and power supply breakers . were properly aligned.
Licensee systems lineup procedures / checklists, pl?.nt drawings, and . as-built configurations were in agreement.
Instrumentation was accurately displaying process variables and . protection system status was within permissible limits for operation.
When plant equipment was found to be inoperable or when equipment was . removed from service for maintenance, it was properly identified and redundant equipment was verified to be operable.
Also, the NRC inspectors verified that applicable limiting conditions for operation were identified and maintained.
Equipment safety clearance records were complete and indicated that . affected components were removed from and returned to service in a correct and approved manner.
Maintenance work requests were initiated for equipment discovered to . require repair or routine preventive upkeep, appropriate priority was assigned, and work commenced in a timely manner.
The conditions of the plant and equipment such as cleanliness, . leakage, lubrication, and cooling water were controlled and adequately maintained.
Areas of the plant were clean, unobstructed, and free of fire . hazards.
Fire suppression systems and emergency equipment were maintained in a condition of readiness.
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Security measures and radiological controls were adequate.
. The NRC inspectors performed a lineup verification of the following systems: Reactor Water Clean Up (RWCU) . Residual Heat Removal (RHR) Loop "A" . Standby Liquid Control (SLC) . The NRC inspectors reviewed and observed performance of the following procedures on the indicated dates: May 18, 1987: General Operating Procedure (GOP) 2.1.1.1, " Reactor . Startup Review," Revision 0, dated May 29, 1986 . May 18, 1987: GOP 2.1.1.2, " Technical Specifications 3 Startup . Checks," Revision 6, dated August 8, 1985 May 18, 1987: GOP 2.1.2, " Hot Startup Procedure," Revision 26, dated . September 4, 1986 May 18, 1987: GOP 2.1.3, " Approach to Critical," Revision 11, dated . September 18, 1986 May 18, 1987: Nuclear Performance Procedure (NPP) 10.13, " Control . Rod Sequence and Movement Control," Revision 15, dated October 30, 1986 'f May 22, 19R7: System Operating Procedure (SOP) 2.2.6, " Condensate . System," Revision 26, dated April 30, 1987 The tours, reviews, and observations were conducted to verify that facility operations were performed in accordance with the requirements established in the CNS Operating License and Technical Specification.
No violations or deviations were identified in this area.
6.
Monthly Surveillance Observations The NRC inspectors observed Technical Specification required surveillance tests.
Those observations verified that: Tests were accomplished by qualified personnel in accordance with . approved procedures.
Procedures confermed to Technical Specification requirements.
. Tests prerequisites were completed including conformance with . applicable limiting conditions for operation, required administrative approval, and availability of calibrated test equipment.
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Test. data was reviewed for completeness, accuracy, and conformance .. with established criteria and Technical Specification requirements.
Deficiencies were corrected in a timely manner.
. The system was returned to service.
~ . The NRC inspectors observed the licensee's performance of the following surveillance tests on the indicated dates: May 18, 1987: Surveillance Procedure (SP) 6.4.8.11, " Mechanical . Vacuum Pump Isolation Valve Operability Test," Revision 0, dated August 16, 1978 May 18, 1987: SP 6.4.1.5, "CRD Cumulator Alarm Indicating Lights . Functional Tests," Revision 7, dated April 10, 1986 The reviews and observations were conducted to verify that facility surveillance operations were performed in accordance with the requirements established in the CNS Operating License and Technical Specification.
No violations or deviations were identified in this area.
7.
Monthly Maintenance Observation The NRC inspectors observed preventive and corrective maintenance activities.
These observations verified that: Limiting conditions for operation were met.
. Redundant equipment was operable.
. Equipment was adequately isolated and safety tagged.
. Appropriate administrative approvals were obtained prior to . commencement of work activities.
Work was performed by qualified personnel in accordance with approved . procedures.
Radiological controls, cleanliness practices, and appropriate fire . prevention precautions were implemented and maintained.
Quality control checks and postmaintenance surveillance testing were . performed as required.
Equipment was properly returned to service.
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1 i These reviews and observations were conducted to verify that facility I maintenance operations were performed in accordance with the requirements established in the-CNS Operating License and Technical Specification.
No violations or deviations were identified in this area.
8.
Exit Interviews Exit interviews.were conducted at the conclusion of each portion of the inspection. The NRC inspectors summarized the scope and findings of each inspection segment at those meetings and at a summary exit interview on May 29, 1987. }}