IR 05000302/1990015
| ML20043D269 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 05/16/1990 |
| From: | Conlon T, Fillion P NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20043D264 | List: |
| References | |
| RTR-REGGD-01.097, RTR-REGGD-1.097 50-302-90-15, NUDOCS 9006070317 | |
| Download: ML20043D269 (7) | |
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101 MARIETTA STMEET,N.W.
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Report No.:
60-302/90-15 L
Licensee:
Florida Power Corporation t
3201 34th Street, South
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St. Petersburg, FL 33733
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Docket No.: 50-302 License No.: DPR-72 Facility Name: Cryk-0 " <er 3 Inspection Conducted:
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Inspector:
/16 NoJ be 8/b f 90 P. J. Fillion g
Date SMjned Approved by:
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T. E. Corilon, Section Chfef Date 51gned
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Plant Syttems Section Engineering Branch Division of Reactor Safety
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SUMMARY i
Scope:
This routinc, unannounced inspection was conducted in the areas of electrical systems modification and follow-up on previous inspection findings.
The inspection was conducted during a planned refueling / maintenance / modification outage (refuel No. 7 scheduled March 12 through June 18.) The NRC inspector witnessed testing of electrical control circuits, reviewed engineering analysis, confirmed corrective actions for violations, followed up on a 10 CFR 21 report and resolved an issue related to Regulatory Guide 1.97.
L Results:
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In the areas inspected, violations were not identified.
In the area of plant-modification testing, the inspector _ concluded that persons
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performing testing, of control circuits were competent 'and proceeding in a t
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careful manner.
Analysis performed by the licensee related to accident load sequencing, degraded grid voltage protection relays and a 10 CFR 21 report on
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battery chargers were accurate, complete and timely.
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A deviation from a commitment was cited because the licensee did not provide
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identification of instruments on the control board as specified in Regulatory
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Guide (RG) 1.97.
The deviation does not indicate. unresponsiveness to NRC initiatives because the special identification of instruments represents only a small fraction of'a large program mandated-by RG 1.97, j
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W for. the areas inspected, the licensee's performance of nucleat 'afety
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activities was good.. The summary of action on open items is:
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(Closed)IFI 89-31-02, AccidentLoadSequencing(section2.a)
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(Closed) LER 89-40, Unplanned Emergency Diesel Generator Actuation Caused
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by Degraded Voltage During Start of the "A" Condensate Pump (section 2.c)
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(Closed) IFI 88-19-01, No S Control Botrds (section 2.d)pecific Identification of Instruments on the
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(0 pen) Deviation 90-15-01, No Specific Identification of RG 1.97
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Instrutents on the Control Boards (section 2.d)
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(Closed) Violation 89-17-01, Inadequate Testing to Prove Operability of a f
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String (controlcircuit)fortheAutomtticStartingofEFP-1(section2.e)
(Closed) LER 89-23. Technician Error and Relay failure leads to Degraded
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Off-Site Power and Results in Reac*,or Trip and Emergency Feedwater Actuation (section2.e.)
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REPORT DETAILS
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Persons Contacted Licensee Employees
- J. Alberdi, Manager, Nuclear Plant Technical Support D. Carrico, Superintendent, Systems Protection, Crystal River Site G. W. Castleberry, Project Manager New Source of Offsite Power Project
- C B. Doyel, Manager, Nuclear Mechanical / Structural Engineering M. J. Fitzgerald, Supervisor, Site Nuclear Engineering Services
- B. J. Hickle, Manager, Nuclear Plant Operations R. J. Marckese Nuclear Project Engineer
- P. F. McKee, Director, Nuclear Plant Operations
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R. L. Muzzi, Supervisor. Site Nuclear Engineering Services
- V. R. Roppel Manager, Nuclear Plant Maintenance
- W. L. Rossfeld, Manager, Nuclear Compliance
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J. H. Terry, Supervisor, Modification Functional Testing
- R. C. Wide 11. Director, Nuclear Operations Site Support
- M. S. Williams, Nuclear Regulatory Specialist
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Other licensee employees contacted during this inspection included craftsmen, engineers, operators, technicians, and administrative
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perconnel.
NRC Resident Inspectors
- W. H. Bradford
- P. Holmes-Ray
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InspectionDetailsandActiononPreviousInspectionFindings(92701)
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This was the sixth inspection of Crystal River 3 since October 1989 that concentrated on various issues related to electrical systems.
It focused primarily on resolution of previous inspection findings and post-modifica-tion testing.
Licensee Event Reports and' a 10 CFR 21 Report were also inspected.
Inspection details and findings are described in items a.
through f.
a.
(Closed) IFl 89-31-02, Accident Load Sequencing.
A concern was identified that when sequencing of accident loads onto the offsite power source there could be an overlap of starting currents of different lead blocks due to the tolerance band of the electro-
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mechanical timing relays.
The tolerance band is plus and minus 10 percent of the set point value.
This implies that the longer the time setting ~ the larger the tolerance band.
With load blocks sequenced at 5 second intervals by design, the 10 percent tolerance
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band can significantly reduce the time available for motors to accelerate from zero to rated speed.
The issue was addressed by Nuclear Plant Systems Engineering (NPSE).
NPSE demonstrated by analysis (as opposed to testing) that overlapping of starting currents of different load blocks could not occur at Crystal River 3 (CR3) even when the timing relay tolerance band is considered.
A modification being implemented this outage to increase the number of load blocks m6y have created this overlap problem.
But a Field
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Change Notice initiated by NPSE modifiec' the proposed design such that the number of load blocks would be increased while the overlap problem is avoided.
Therefore, IFl 89-31-02, Accident Load Sequencing, is closed.
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Changes to the diesel generators load sequencing and load shedding schemes.
Modification package MAR 88-05-24-01 implements changes to the diesel generator sequencing scheme aimed at reducing the load seen by(OH)
the diesel generators.
On* part of the MAR provides a decay heat pump / emergency feedwater (EF) pump interlock to automatically prevent concurrent operation of the DH and EF pumps during LOOP events by starting DH at 500 psig RC pressure and tripping EF. Another part of the MAR rearranges the loads in each load block and increases the number of load blocks. The purpose of rearranging the load blocks is to im) rove the voltage profile during accident load sequencing onto the d'esel generator.
A portion of the inspection was devoted to witnessing functional testing required to confirm proper operation of the sequencing circuits after the modification was made. The procedure being worked during the inspection was a component level check-out type test, segments of which were observed by the NRC inspector.
Sufficient testing was observed by the NRC inspector to conclude that the persons doing the testing were very competent cnd were proceeding in a careful manner, c.
(Closed)LER89-40:
This LER deals with an event where the degraded
voltage protection relays operated to start the diesel generators upon starting a condensate pump.
In most cases wheh the condensate pump starts, the degraded voltage relays see a voltage @ below their setpoint but the voltage recovers before the time' delay runs out, and therefore, the degraded voltage relay does not pick up.
However, motor acceleration time and the corresponding voltage transient duration is a function of the pre-start voltage. When the grid voltage is at the lower end of the allowable range motor acceleration time is about equal to the relay time delay setting, and occasionally the degraded voltage relay.will pick-up, sending a start signal to the diesel. A detailed review of the degraded voltage relay setpoint by the NRC inspector together with licensee engineers resulted in the conclusion that the relay has proper voltage and time
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delay setpoints.
Safety considerations and system constraints dictate a " trade-off" with respect to condensate pump starting.
An occasional spurious start of the diesel generator is not a safety concern, and poses absolutely no threat to the bealth and safety of the public.
In consideration of the above discussion, LER 89-40 is closed.
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(Closed) IFl 88-19-01:
No specific identification for Regulatory Guide 1.97 instruments on the control board.
Regulatory Guide (RG) 1.97, " Instrumentation for Light-Water-Cooled Nuclear Power Plants to Assess Plant and Environs Conditions During and Following an Accident," Rev. 3, dated May 1983, contains a design criteria for equipment identification that applies to Category 1 and 2 variables.
The design criteria states:
Types A, B and C instrunents designated as Category 1 and 2 should be specifically identified with a connon designation on the control panels so that the operator can easily discern that they are intended for use under accident conditions.
Although not stated in the RG, the purpose of the common designation of instruments is to provide information to the Operator as to which instrument loops meet all the design criteria of the RG, recognizing that redundant instrument loops may be on the panel that do not neet the design criteria.
Examples of acceptable methods for accomplishing this requirenient are identification labels having a different background color than other labels or instrument bezels color coded to indicate RG 1.97
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During an NRC inspection conducted on June 27 - July 1, 1988, of CR3's compliance with RG 1.97, it was obvious that CR3 did not have the common designation of instruments required by the RG.
CR3's position on this matter was that CR3's " Detailed Control Panel Design Review" concluded that the methods ave.ilable to provide the connen designation (described above) were considered poor from a human engineering viewpoint.
A later NRC inspection (Report 89-22)
conducted on August 28 - September 1, 1989, revisited this issue, but positions had not changed.
Since CR3's argument for not having the specific identification had some validity, the NRC regional office referred the matter to NRC headquarters for resolution on a generic.
basis.
After due consideration, the NRC has decided that specific l
identification of instruments as specified by RG 1.97 is required at
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Crystal River Unit 3.
This applies to Category 1 variables only.
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Therefore, IFI 88-19-01 is closed and upgraded to a Deviation, and will be tracked by item No. DEV 302/90-15-01, No specific identification of RG 1.97 instruments on the control board.
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(Closed) Violation 89-17-01 and LER 89-23.
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An event described in LER 89-23 involved a lot of offsite power and a failure of the motor driven emergency feedwater pump to automatically start.
A contributing cause of the loss of offsite
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power was misoperation of a breaker failure relay.
To help prevent recurrence of the relay problem, the licensee will replace the breaker failure releys with ones having greater speed and
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improved characteristics than the originals.
The new relays will be model SBC 31 AID which is produced by General Electric Company.
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contributing cause of the failure of the motor driven emergency feedwater pump to automatically start was an inadequate surveillance procedure that failed to detect a broken relay.
In the response to the Notice of Violation the licensee committed to revise Surveillance Procedure SP-416, Emergency feedwater Automatic Actuation, and issue en instructive memorandum to persons responsible for developing and reviewing surveillance procedures.
Each of these corrective actions was confirmed by the NRC inspector.
Violation 09-17-01 and LER 89-23 are closed, f.
(Closed)P2189-17,a10CFR21reportonbatterychargers.
C&D Charter Power Systems sent a letter of notification and a request for determination of a possible safety-related problem to Florida Power Corporation, on August 14, 1989, concerning printed circuit
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boards used in model ARR battery chargers.
During this inspection
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the NRC inspector confirmed that the C&D notice had been received by FPC, and properly dispositioned.
The NRC inspector reviewed documentation which gave evidence that the problem described in the
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C&D notice had been addressed by the appropriate persons, adequate resolution from a technical standpoint was provided and the action received management review.
This documentation was dated September 4,1989, indicating that the review was timely.
P2189-17 is closed.
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Exit interview The inspection scope and results were summarized c., April 27, 1900, with those persons indicated in paragraph 1.
The inspector described the wreas inspected and discussed in detail the inspection results listed below.
Proprietary information is not contained in this report.
Dissenting comments were not received from the licensee.
(Closed)IFI 89-31-02, AccidentLoadSequencing(section2.a.)
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(Closed) LER 89-40, Unplanned Emergency Diesel Generator Actuation
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Caused by Deg)raded Voltage During Start of the
"A" Condensate Pump (section 2.c.
(Closed) IFI 88-19-01, No Specific Identification for Instruments on
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the Control Boards. (section 2.d)
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(0 pen) Deviation 90-15-01, No Specific Identification of RG 1.97
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Instruments on the Control Board (section 2.d)
(Closed) Violation 89-17-01, Inadequate Testing to Prove Operability
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of a String for the Automatic Starting of EFP-1 (section 2.e.)
(Closed) LER 89-23. Technician Error and Relay Failure leads to
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Degraded Off-Site Power and Results in Reactor Trip and Emergency Feedwater Actuation-(section 2.e)
(Closed)P2189-17,Part21fromLimerickregardingnewcircuitboards
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caused battery charger current to be insufficient to supply station loads and batteries unable to reach fully charged state within the required time. C&D notifying all purchasers, i
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