IR 05000413/1993011
| ML20035H241 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 04/26/1993 |
| From: | Moore R, Shymlock M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20035H240 | List: |
| References | |
| 50-413-93-11, 50-414-93-11, NUDOCS 9305030392 | |
| Download: ML20035H241 (16) | |
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F3UCLEAR REGULATORY COMMisslON o
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101 MARIETTA STREET, N.W.
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ATLANTA,GEORGlA 30323
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Report Nos.:
50-413/93-11 and 50-414/93-11 Licensee:
Duke Power Company 422 South Church Street Charlotte, NC 28242 Docket Nos.:
50-413 and 50-414 License Nos.: NPF-35 and NPF-52 Facility Name:
Catawba 1 and 2 Inspection Dates: March 29 - April 2, 1993 khMLC s 4//t/ Q%
Inspector: c
'R. Moore Dafe Signed Accompanying Personnel: N. Salgado
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Approved By:y 47?Nb MP4' 43
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H. Shymlock/' Chief Date Signed Plant Systems Section Engineering Branch Division of Reactor Safety SUMMARY Scope:
This routine announced inspection was conducted to review the licensee's actions on outstanding electrical issues. The first issue was related to incorrect fuse sizes identified on installed 7300 process control system cards and control of the associated Bill of Materials (B0M), URI 93-02-01. The remaining issues were related to the licensee's resolution of EDSFI identified items. This included violations 92-01-01 through 05, Deviation 92-01-06, and Inspector Followup Item (IFI) 92-01-07 which included 12 findings.
Results:
The licensee's actions to identify and replace incorrect process card fuses and update the BOM were adequate to resolve this issue. URI 93-02-01 will be closed.
Overall, the licensee's actions to resolve EDSFI identified issues was adequate.
It was apparent that considerable resources were dedicated towards the evaluation of EDSFI items. Corrective actions for the violations were 9305030392 930427 PDR ADOCK 05000413
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complete and effective in resolving these deficiencies. These items will be closed. During review of violation 92-01-04, regarding Measurement and Test Equipment (M&TE) out of tolerance evaluations, it was noted that although the timeliness of evaluation performance had improved,. the quality of evaluations warranted increased attention by management (paragraph 3.d).
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The licensee's analysis of Deviation 92-01-06, regarding specific breaker coordination deficiencies, concluded no hardware changes were warranted (paragraph 3.f).
This item remains open pending further NRC review.
Ten of the twelve findings for IFI 92-01-07 were adequately resolved.
IFI 92-01-07 will be closed.
IFI 93-11-02 will be initiated to track resolution of long term corrective actions for EDSFI findings 1 and 5 which have not been completed.
Finding I was related to the lack of short circuit
studies for 4.16 kV essential switchgear (paragraph 3 9).
Finding 5 was
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related to the inadequate Diesel Generator (DG) dynamic analysis (paragraph
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3.k).
During the analysis of 125 VDC system EDSFI issues, the licensee identified that the calculated DC control power voltage to the essential switchgear
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breakers was below the vendor recommended values for 21 of 68 breakers
(paragraph 3.1).
There was no apparent operability concern because routine
Engineered Safeguards Features (ESF) testing demonstrated the breakers operate with the existing voltage. The ESF tested system configuration was more
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conservative than the calculation system configuration.
IFI 93-11-01.was
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initiated to track this issue.
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REPORT DETAILS 1.
Persons Contacted i
Licensee Employees i
i S. Chhak, Engineer, Duke Power Company, Nuclear Services
- A. Dickard, Electrical Engineering Supervisor, Design Engineering
- J. Forbes, Engineering Manager
- R. Futrell, Regulatory Compliance Manager
- J. Glasser, Electrical Engineer, Design Engineering l
S. Graham, Engineer, Duke Power Company, Nuclear Services i
- T. Harrall, Safety Assurance Manager
- J. Lowry, Regulatory Compliance Specialist
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G. Maddox, Associate Engineer, Catawba Power Systems J. McCart, Engineer, Design Engineering
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- J. Stackley, Electrical Engineering Supervisor, Component Engineering
J. Stoner, Jr., Engineering Consultant, Nuclear Services
- J. Thomas, Electrical Engineering Manager, Design Engineering i
- T. Van Deven, Senior Technical Specialist, Component Engineering
- D. Ward, Mechanical Engineering Supervisor, Design Engineering NRC Personnel
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- J. Zeiler, Resident Inspector I
- Attended Exit Interview Acronyms and Abbreviations are identified in paragraph 5.
2.
Followup on Previous Inspection Findings (92701)
(Closed) Unresolved Item 50-413,414/93-02-01, Incorrect Fuse Sizing of Westinghouse 7300 Process Control System Cards and Failure to Control Vendor Manual BOM.
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An undetected circuit card failure occurred in the NSSS Process Instrumentation and Control System on April 29, 1992. An incorrectly sized fuse installed in the circuit card by the manufacturer, Westinghouse, contributed to the component failure. The licensee
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initiated a structured review of all plant 7300 series circuit cards.
This issue was reviewed initially during an NRC inspection on January 4-6, 1993 (NRC Report Nos. 50-413,414/93-02). At that time the t
licensee had completed inspection and replacement of Unit 1 installed process cards with incorrect fuses. The issue was unresolved pending the licensee's actions to complete the identification of incorrectly
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sized fuses installed in Unit 2 and the warehouse stock 7300 process
circuit cards at Catawba. Additionally, the operability impact of wrong size fuses was to be evaluated, and the vendor manual BOM was to be updated, t
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During this inspection the inspectors reviewed the licensee's actions to further identify and resolve process card fuse deficiencies. The inspector reviewed completed work procedures 92052812-01, Unit 2 Fuse Inspection, and 92051069-01, Warehouse Fuse Inspection. The licensee inspected an estimated nine-hundred 7300 series circuit cards.
Eighty i
incorrectly sized fuses on Unit 2 circuit cards, and fifteen incorrectly sized fuses on warehouse circuit cards were identified and replaced.
Twenty-three of the incorrectly sized fuses identified by the Unit 2
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inspection were 5 Amps instead of 0.5 Amps.
This was the particular sizing error identified in the April 29 1992, component failure. The inspectors independently verified the completed corrective action on the i
warehouse stock. Ten out of the fifteen circuit cards identified in procedure 92051069-01 were available for verification. No problems were
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identified. The inspectors concluded that the licensee had appropriately identified and replaced incorrectly sized fuses in station installed and stored 7300 process circuit cards.
The inspectors reviewed Problem Investigation Report (PIR) 0-C92-0813 which contained the operability evaluation of the circuit cards
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identified with incorrect fuses. The 7300 Process Control System is designed to be capable of enduring a single failure. The licensee concluded that although incorrectly fused printed circuit cards are
undesirable, the redundancy and automatic activation of safety circuits
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would have brought the plant to a safe shutdown condition assuming simultaneous multiple failures. Therefore, the system was considered operable for both past and present conditions for Unit I and Unit 2.
The inspectors concluded that the licensee had appropriately evaluated
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the operability impact of incorrectly sized fuses identified in the process 7300 circuit cards at Catawba.
Design Engineering was assigned the responsibility of correcting the vendor manual B0M. The licensee was developing a BOM specifically for fuses and fuse holders that will include all cards that the licensee could install into the 7300 cabinets. The updated BOM will be i
incorporated into the vendor manual. The licensee was communicating with Westinghouse, and was confident that they have correct fuse information for the B0M. The licensee was working with McGuire on a i
format for the fuse BOM that would be comprehensive, easy to update, and easy to understand. The licensee was scheduled to have the BOM updated by May 3, 1993. The inspectors concluded that the licensee has initiated the appropriate actions to update the fuse control design document (B0M).
The inspector concluded that the licensee's corrective actions, to date, have been appropriate regarding the licensee identified issue described in NRC Report Nos. 50-413/93-02 and 50-414/93-02. No problems were identified. URI 93-02-01 is closed.
On February 3,1993, Westinghouse released an Infogram titled: 7300 Process System Printed Circuit Board Fuses. The Infogram provided information about incorrect fuses being discovered on some Westinghouse
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7300 Process Systems printed circuit boards. Westinghouse recommended I
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that customers check the fuses installed on the 7300 printed circuit boards, and replace any incorrectly sized fuses per the enclosure of the Infogram. A proposed IN from the NRC is in concurrence. The NRC is also communicating with Westinghouse as to whether this issue should be a 10 CFR Part 21 notice.
3.
Electrical Distribution System Followup Inspection (TI 2515/111)
This inspection assessed the adequacy of the licensee's corrective actions for findings identified during the EDSFI conducted on January
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13 - February 14, 1992, (NRC Report No. 50-413,414/92-01). The EDSFI identified five violations and one deviation. Additionally, IFI 92-01-07 was identified. This IFI included 12 inspection findings
which will be addressed individually in this report. These items are addressed in the following paragraphs, a.
(Closed) Violation 92-01-01:
Failure to Maintain Configuration
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Control for Fuses and Electrical Thermal Overloads The EDSFI team identified several examples of incorrect fuses and i
thermal overload heaters installed in safety related control power
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circuits for motor operated valves (MOVs). The devices installed t
in these examples were not in agreement with the licensee's Bill
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of Materials and Drawing Load List. This design document provided i
the specifications for the installed devices. Additionally, there
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were minor drawing discrepancies in the electrical elementaries J
which incorrectly identified MOV motor horsepower. The licensee's
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response to the violation, dated April 16, 1992, stated that an as-built configuration inspection would be conducted on all l
essential motor control centers (MCCs) to verify fuse and overload heater sizes were in conformance with design documents.
Additionally, the electrical elementary drawings would be revised
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to correct the identified errors.
The inspectors verified that the licensee accomplished the as-built configuration inspections of the essential MCCs. The licensee's inspections identified 33 fuse discrepancies and 22 overload heater discrepancies.
The inspectors reviewed the licensee's reports which identified the above discrepancies, evaluated individual operability impact, and documented replacement of improper fuses or overloads. The licensee identified the root cause as a deficiency in the construction phase to verify proper equipment installation The inspectors reviewed the revised RN System RN Pump Motor Cooler Inlet Isolation Valve Drawings, CNEE-0138-01.07 and.08 revision 8, and CNEE-0238-01.07 and.08, revision 4, to verify correction of the drawing discrepancies. The inspectors concluded the licensee had completed the corrective actions stated in their response to the violatio !
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(Closed) Violation 92-01-02: Failure to follow Technical Specifications (TS) For Testing Of Station Batteries The licensee's TS stated that the battery service tests would be conducted each 18 months during unit shutdown. The EDSFI team identified several examples where this test was performed with the
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unit at power. The licensee's response to the violation, dated April 16, 1992, stated that the appropriate procedures would be revised to assure that future battery service tests would be accomplished with the unit shutdown.
The inspectors verified the battery service test procedures were revised to explicitly require the test to be performed during outages. Procedure changes 10 and 12 respectively, incorporated this requirement for procedures IP/2/A/3710/10 and IP/1/A/3710/10, 125 VDC Vital Instrumentation and Control Power System Battery Service Test, dated August 20, 1992. The inspectors reviewed data sheets dated August 20, 1992 and February 8, 1993 which documented performance of this test during outages for battery 2EBD.
Comparison of the data from service tests performed at power and shutdown demonstrated that the results were essentially the same for both conditions. The licensee had completed the actions specified in their violation response, this issue was appropriately resolved.
c.
(Closed) Violation 92-01-03:
Failure to Follow Procedure for Controlling Potential Missile Hazards During plant walkdowns, the EDSFI team identified several examples of movable electrical equipment in the safety related switchgear rooms which were not anchored to prevent inadvertent movement as required by the licensee's procedure for control of missile hazards. The equipment had not been assessed for potential seismic concerns as required for equipment not anchored. The licensee's response to the violation, dated April 16, 1992, stated the identified equipment would be provided with storage locations and methods to secure the equipment. The root cause of this problem was identified to be a lack of administrative controls related to equipment which could become missile hazards during a seismic event. The response further stated the administrative controls would be revised to address this weakness.
The inspectors performed a walkdown of the safety related electrical equipment spaces and verified that movable equipment was appropriately stored. The inspectors reviewed revision 11 of Station Directive 3.11.3, which provided administrative controls for storage of equipment to prevent missile hazards. Additionally, the inspectors verified the plant staff had received training on this station directive revision. The inspectors concluded the licensee had completed the corrective actions stated in their response and this issue was resolve. _ _
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(Closed) Violation 92-01-04: Failure to Perform Engineering Evaluation for Out of Calibration Equipment i
During a review of diesel generator maintenance activity, the EDSFI team identified that evaluations for out of calibration measuring and test equipment had not been accomplished in a timely i
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s manner. These evaluations validate the use of M&TE, which was found out of calibration, on previous safety related equipment tasks. The team identified 26 out-of-tolerance notices (OTNs),
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encompassing 185 work tasks, which had not been evaluated.
l Although the licensee's procedure for accomplishing this activity
required the evaluations for safety related equipment be performed
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within 15 days, the OTNs dated back to 1989.
The licensee's
response dated, April 16, 1992, stated that the OTNs would be evaluated and a new flow path would be established to assure
evaluations were accomplished as required by procedure.
j The inspectors verified the OTNs identified by the EDSFI were evaluated and that current outstanding 0TNs were within the time requirements of the procedure, Station Directive 2.3.1,
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Maintenance and Test Equipment, revision 14.
Further, the
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inspectors verified the licensee established accountability for tracking and compl;
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comp'eted the corrective actions stated in the response and
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reso'ved the issue described in the violation.
Although the timeliness of OTN evaluations had substantially improved, the inspectors noted that improvement in the quality of the evaluations was warranted. The inspectors reviewed three completed evaluations: work order numbers 93006211, 93017054, and 93017053. The reviews lacked specific information as the basis for the conclusion. For example, the documents did not provide detail regarding the range of use in work tasks and range of the M&TE deficiency. The conclusions stated the device "was probably in tolerance when used", a statement which did not reflect assurance that the work tasks were acceptable. The inspectors concluded that increased management attention was needed in this area.
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(Closed) Violation 92-01-05:
Failure to Update the FSAR
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The EDSFI team identified that the Final Safety Analysis Report (FSAR) had not been updated to reflect actual equipment capacity i,
values.
For example, diesel generator (DG) loading values in Table 8.6 were incorrect. Additionally, information related to station batteries in Table 8.9 and figure 8-25 conflicted. The licensee response, dated April 16, 1992, stated that FSAR updates
would be submitted to correct these errors.
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The inspectors reviewed the 1992 FSAR update which resolved the-l discrepancies identified above. Table 8.6 was revised to provide the correct DG equipment load values. Figures 8-25 and 8-27 were
revised to provide correct battery load profiles. Table 8.9 was -
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were completed and the discrepancies resolved.
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(0 pen) Deviation 92-01-06:
Failure to Meet Commitment in IEEE 308 l
for Protective Device Coordination j
.g The EDSFI team identified protective device coordination l
deficiencies in the 125 VDC System and the 600 VAC MCCs. This was
a deviation from the licensee commitment stated in the FSAR to l
provide protective devices' setpoints in these systems to protect l
equipment. The licensee's analysis reviewed by the team' indicated l
that coordination did not exist for fault currents above 3500 A to
the maximum fault current of 9500 A.
For the 600 VAC MCCs, the.
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feeder breaker thermal elements were not coordinated with the MCC i
load breaker instantaneous elements.
For the 125 VDC system, the'
l main battery breaker instantaneous element was not coordinated l
with the battery charger breaker thermal element. The' licensee's
- I response to the deviation, dated April 16, 1992, stated-a study l
would be accomplished to evaluate methods to achieve coordination
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in these areas.
l The inspectors reviewed the licensee's study of this issue. The j
study concluded that no action would be taken to correct the
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identified coordination deficiency examples. An exception to the l
FSAR statement ~would be requested which would identify these
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specific exceptions. This conclusion was based on the' following
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factors. The analysis indicated that-the increase in safety i
factor was small relative to the extensive system modifications necessary to achieve the coordination. The type of fault to cause mis-coordination was very limited in' scope and of low probability.
If a mis-coordination occurred during plant operation it would not
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likely cause a trip or significant transient because the affected buses fed primarily standby safety equipment.
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history of this type of fault at any Duke plant and the impact of such a fault would be limited to a single train. This item remains open pending-further review by the NRC.
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(0 pen) Finding 1:
Short Circuit Studies Were Not Available
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During the EDSFI, the licensee was not able to provide a formal i
short circuit study for the medium voltage essential bus i
switchgear which considered worst case system conditions. The licensee provided preliminary calculations which demonstrated that the 4.16 kV essential switchgear was applied within its. ratings,.
but the short circuit levels were in excess of the values listed in the FSAR, section 8.3.1.1.2.4.
The FSAR also incorrectly:
listed the interrupting capability of the 4.16 kV switchgear. The preliminary calculation also demonstrated that the short circuit
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i levels used as inputs into calculation CNC-1381.05-00-004,
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revision 13 were non-conservatively low.
In addition, the I
preliminary calculation was non-conservative since it did not
assume worst case source voltage and cable temperature. The
~j licensee stated that formal short circuit studies would be i
developed to address these ' concerns.
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The licensee stated that short circuit study CNC-1381.05-00-0144 i
would be completed on June 1,1993. The calculation will include i
the appropriate' worst case voltage and cable temperatures. A
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cross reference to calculation-CNC-1381.05-00-004 will be
addressed appropriately upon completion of CNC-1381.05-00-0144.
The FSAR value of the available fault current at.the 4.16 kV-
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essential switchgear will be modified with respect to the
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calculation results.
In the next~ Catawba FSAR revision, the.
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rating of the 4.16 kV interrupting capability will be corrected to j
35 kA at 4.16 kV. This finding will remain open pending the j
licensee's completion of the short circuit studies.
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(Closed) Finding 2:
Procedures Relative To DG Ground Fault May be
Misleading
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The EDSFI team noted three procedures containing statements which a
could inhibit the operator's locating a DG ground' fault. These i
procedures were OP/1(2)/B/6100/10L,-Reactor Coolant Pump i
Operation, revision 4, EP/l(2)/A/5000/03, Loss of All AC Power, revision 11, and OP/1(2)/A/6150/02A, Annunciator Responses for
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Panel 1AD-11, revision 5.
The licensee response stated that the j
procedures would be revised.
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The inspectors reviewed the revised procedures. The revisions stated in the licensee's response were accomplished. This finding is closed.
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(Closed) Finding 3: Ground Fault Protection on 600 V System The EDSFI team noted that the ground fault detection capability of the 600 VAC MCC breakers had been jumpered out by the licensee to establish proper breaker coordination. The team noted that a low level arching fault may not be detected and could result in possible equipment damage. The licensee's response stated they would accomplish a study to evaluate the issue.
Potential i
corrective actions included installing ground fault detection or'
I resistance grounding to limit available ground current.
The inspectors reviewed the licensee's study which addressed this issue. Primarily the evaluation identified a low probability of this specific type' of fault, long duration - low level fault,
occurring at Catawba. This was based on a review of the armcred characteristics of plant cable and no history of occurrence of this type of fault at any Duke plant. ' The study considered the
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- most likely location for such a fault would be within the load device which was typically provided with thermal overload devices.
Faults in MCC or switchgear would be detected by smoke detectors.
P Based on the factors of low probability, no history of occurrence, and single train impact of this type of failure, the licensee concluded no hardware changes were warranted. The inspectors concluded the licensee had appropriately addressed this issue.
This finding is closed.
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(Closed) Finding 4: Overvoltage on Class IE 600 V MCC The EDSFI team noted that the 600 VAC MCCs were routinely experiencing a higher than nominal voltage, i.e. 650-660 V.
This condition could result in motors fed from these MCCs receiving voltages in excess of their 575 i 10 percent rating. The primary
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concern with equipment exposed to overvoltage was insulation breakdown and subsequent decrease in service life by early failure. The licensee's response stated they would accomplish a study of this issue including potential impact on equipment, resolution of the condition, and possible corrective actions.
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The inspectors reviewed the licensee's study of the issue. The licensee was able to slightly reduce the switchyard voltage level-by improvement on the switchyard monitoring circuit. This action reduced but did not completely eliminate the overvoltages. The study evaluated several options, including resetting load center transformer tap settings, lowering switchyard voltage, replacing
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equipment with higher rated equipment, and implementing a program to trend equipment insulation degradation. During plant walkdowns the inspectors noted the 600 VAC essential MCCs were indicating
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635 - 640 VAC which was an improvement over conditions noted during the EDSFI. Additionally, the licensee had developed a procedure for motor insulation testing, IP/0/A/3851/01, Motor Winding Insulation Testing, revision 2.
Periodic testing was
scheduled to begin during Unit 1 RF0 in September, 1993. Based on the licensee's completed and scheduled corrective actions, this finding is closed.
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(0 pen) Finding 5:
Inadequate DG Dynamic Performance Analysis The EDSFI team detennined that the DG dynamic analysis, calculation CNC-1381.05-00-0065, Revision 9, was non-conservative.
The model incorrectly used generator output terminal voltage when determining performance of loads, instead of the actual voltage available at load terminals.
In addition, the analysis did not consider the effect of large voltage dips on connected loads and the consequent affect on DG performance. The licensee had previously identified the need for a new DG dynamic analysis, but j
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it was not clear to the EDSFI team that the concerns previously noted had been recognized.
In response to this concern, the licensee agreed to consider expediting the revision of the dynamic analysis.
The licensee's new analysis was not yet completed. This analysis will utilize a new computer program, CYME, that will model
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individual loads. The licensee anticipated that the CYME program
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would be validated by July 15, 1993. The CYME program validation will require testing to be performed on the DG and its associated loads. The final dynamic analysis will address the voltage dips effects appropriately. The more detailed dynamic analysis will be completed by July 15, 1994. This finding will remain open pending completion of the DG dynamic analysis.
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(Closed) Finding 6:
120 VAC and 125 VDC Systems The EDSFI team performed calculations which indicated that for some system configurations, the smaller 825 AH station batteries did not have the capacity to power two load channels per battery.
The licensee's response, dated May 14, 1992, stated that administrative controls would be established to prevent the questioned configurations, a 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> LC0 would be defined for this condition, and a study would be performed to review the issue.
The inspectors verified the incorporation of the administrative controls to restrict this two channel load configuration.
Technical Specifications (TS) Interpretation item 3.8.2.1, DC Sources - Operating, defined the Limiting Condition for Operation (LCO) requirement for this configuration. Operating procedure, OP/l(2)/A/6350/08,125 VDC/125 VAC Vital Instrument and Control l
Power, revision 4, incorporated the requirement to declare these batteries inoperable in this configuration. The administrative controls resolved operability concerns with the 825 AH station batteries. The licensee indicated this is an interim solution until the nominal duty cycle of the batteries is reached. The station anticipated increasing the capacity of replacement batteries. This finding is closed.
During analysis of the 125 VDC system, the licensee identified that the calculated DC control voltage at 21 of 68 essential switchgear breakers was below vendor recommended values. For l
example, the vendor recommended closing coil voltages were 90 and 100 VDC; the recommended opening coil voltage was 70 VDC. The l
calculated voltages were as low as 79.38 VDC in the worst case.
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Most of the voltage deficiencies were between 1 and 6 VDC.
There was no apparent operability concern because recent Engineered Safeguards Features (ESF) testing verified operation of these breakers at a more conservative system configuration than the system configuration used in the calculation. The calculation configuration was with one battery supplying one channel. The ESF
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test configuration was one battery supplying 2 channels.
Additionally, the inspector reviewed documentation of breaker l
testing of similar ITE ABB medium voltage HK breakers at Oconee.
j Nuclear station which demonstrated the breakers operate adequately l
at voltages below vendor recommended values. OSC 4701, dated
April 15, 1972, documented breaker operation in the 50 to 65 VDC
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range. The lowest calculated value at Catawba, 79.38 VDC, allowed
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considerable safety margin.
The licensee indicated they~would verify actual DC control voltage-l at the breakers and investigate modifications to resolve.this
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issue in conjunction with the breaker vendor. The licensee i
initiated PIR 0-C93-0233, to track this deficiency. This issue
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will be identified as IFI 93-11-01. Calculated DC Voltaae at i
Essential Switchaear Below Vendor Recommended Values,
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(Closed) Finding 7:
Battery Charger Capacity j
The licensee's analysis of the battery charger provided to the EDSFI team indicated that the 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> charger capacity of 200 A stated in the FSAR did not meet system recharge requirements. The
team noted that the licensee's worse case load study indicated a j
load of 210 A.
This value did not assure sufficent margin existed i
to recharge the battery in the rec 1 red 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> while carrying the
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anticipated load. The study used assumed load values rather.than j
actual tested values. The licensee's response, dated May 16,
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1992, stated they would accomplish a study of the charger capacity i
and system load requirements which would include information from
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battery loading tests. This more accurate input would replace i
assumed values in the previous calculation which were overly
conservative.
The inspectors reviewed the revised calculation CNC-1381.05-00
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0011, 125 VDC Vital Instrumentation and Control System Battery and-l Battery Charger Sizing Calculation. The revision primarily added a more accurate accounting of battery loads. The conclusion
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indicated the battery charger capacity was adequate. The worse case load was determined to be 183 A.
This value indicated that i
sufficient margin existed to meet the FSAR stated specification.
This finding is closed.
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(Closed) Finding 8:
Procedure Deficiency Which Could Result in Starting Air Flow Path to the DG Being Lost The EDSFI team noted that the licensee's procedure for valve alignment verification of the DG, PT/l(2)/4350/16A(16B), VG System Valves Verification Test, did not assure the starting air discharge valves were opened during the system' alignment verification. The licensee stated the procedure would be revised.
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The inspectors reviewed the procedure changes for these procedures-j and verified the revisions were accomplished.
The revisions,
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changes 4 and 5 respectively for Unit.I and 2, provided the i
appropriate valve position designation and directed the operator
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to report valve position to the Unit Supervisor if valves were i
improperly positioned for plant conditions. The inspectors
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concluded the licensee had adequately resolved this issue. This
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finding is closed.
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(Closed) Finding 9:
Perform Water Hamer Analysis of Nuclear l
Service Water System l
The EDSFI team identified a potential water hammer condition in
the RN system which could impact the service water supply to the l
DGs. The licensee stated they would accomplish a water hammer
analysis and evaluate the impact on DG operation.
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The licensee was developing the water hammer analysis. A model-l developed by Georgia Institute of Technology was being employed to j
evaluate the system. The analysis had provided a theoretical J
pressure transient in the vertical portion of piping located a-
considerable distance from the DGs. The pressure transient had'
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not been translated into a force transient which can then be j
analyzed against system structural capability. Additionally, i
system testing had'not yet been accomplished to verify the
applicability of the model.
Discussion with the licensee indicated that no impact on DG l
cooling water supply was anticipated from a water hammer. The
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piping and support structure between the DGs and potential water
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hammer location would absorb the kinetic energy from a' water hammer event. Further, a piping break in the piping subject to the water hammer would not permit a volume of water to pass which would challenge the DG supply. The inspectors concluded the
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licensee had determined that a' system water hammer would not i
impact DG operation. The licensee will continue their analysis to i
determine water hammer impact on the overall-service water system.
l This issue is closed with respect to water hammer impact on DG j
operation.
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(Closed) Finding 10: RN Pump Structure Minimum and Maximum l
Temperatures Outside the Design Limits j
i The EDSFI team identified input. errors in the HVAC calculation for-
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the RN pump building. During the EDSFI the licensee corrected the calculation. The corrected calculation indicated that temperatures within the building could exceed the original design i
envelope of 40 - 104 *F stated in the Catawba design documents.
The licensee's response stated an analysis would be performed to-
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review operability of safety related equipment in this space due to the new temperature envelope of 35 - 115 *F.
Additionally, the design documents would be revised to reflect the new temperature envelope for the RN pump building.
The inspectors reviewed the calculation CNC-1211.00-00-0019, RN Pump Structure Load and Static Pressure Calculations, revision 9, which identified equipment in the area and evaluated the expanded temperature envelope. The analysis adequately evaluated equipment operation in the envelope and concluded equipment rating was adequate. Additionally, the inspectors verified the FSAR, Equipment Qualification Control Manual, and Design Base Document were updated to reflect the revised temperature envelope.
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(Closed) Finding 11: Housekeeping for Safety Related Electrical Equipment During the EDSFI, the team identified several examples of poor housekeeping inside of switchgear cubicles. There was no program requirement for cleaning of the cubicles. The licensee's response stated that predefined work orders would be developed to clean the switchgear cubicles during outages and to establish this cleaning as a periodic work requirement.
The inspectors reviewed the PW0s for cleaning switchgear cubicles, reviewed completed work orders for switchgear cleaning, and inspected essential cubicles for 4.16 kV and 600 VAC breakers.
Procedure IP/0/A/3850/03, Procedure for Inspection and Cleaning of Electrical Enclosures, revision 1, provided guidance for cleaning.
The 4.16 kV train B switchgear were cleaned in the previous
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outage. The inspectors reviewed a sample of switchgear cubicles.
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which had been cleaned by the PW0s and cubicles which had not been cleaned.
The cleaned switchgear were in good condition and contained no accumulation of dust or debris, as did those which l
had not been cleaned. The licensee established procedures for i
periodic cleaning of switchgear cubicles. The inspectors concluded the licensee had appropriately addressed this issue.
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(Closed) Finding 12: Undetectable Failure Mechanism on MOVs I
The EDSFI team identified that some MOV circuits utilized dual fuse design. One fuse provided power for the indicating lights, and the second fuse provided power for the motor starter contactor, or in some cases a remote location control circuit.
The team determined that the second fuse could be blown, and an undetected failure could exist that could render the MOV inoperable. The team's concern was to ensure that safety related MOVs would actuate properly when required. Of particular concern were those MOVs which require repositioning via operator action from the control room, as more time would be required to achieve i
the MOVs safety function. The licensee indicated that they would
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perform an engineering evaluation to determine the design basis for the dual fuse design, and evaluate actions to assure circuit E
' operability.
l The licensee's engineering evaluation examined each system
.l schematic to identify MOVs with the dual fuse design. The
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evaluation concluded that only Auxiliary Shutdown Complex (ASC)
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and Safe Shutdown Facility (SSF) related M0V circuitry contained
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dual fuse design. To be assured that all MOVs would actuate properly when required, the licensee was incorporating periodic-i testing on both trains of the Auxiliary Shutdown Panel and the
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Auxiliary Feedwater Control Panel and SSF Panel. The inspectors reviewed the recently completed test results from procedure
. l PT/2/A/4700/012, Standby Shutdown Facility (SSF) Control Panel i
Functional Verification, and procedure PT/2/A/4350/22, CA Control
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from SSF Operability Test. The inspectors identified no problems.
i The licensee was writing a procedure that would test.the Auxiliary-i Shutdown Panel. The test will be performed during the next RFO.
l The licensee's schedule will allow for one panel to be tested per
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RFO. Therefore, the completion date for initially testing all eight panels (both units) will be October 1,1996. The panels a
will be test periodically thereafter by the licensee. The
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inspectors concluded that the licensee had adequately evaluated this issue and addressed operability of dual fuse circuitry.
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Conclusion I
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Overall, the licensee's actions to address the EDSFI issues were l
appropriate. The licensee had dedicated considerable resources to
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evaluate these issues.
IFI 92-01-07 which included the 12 EDSFI findings will be closed.
IFI 93-11-02 will be opened from this
insoection to track resolution of EDSFI Findinas 1 and 5.
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Although Violation 92-01-04, regarding the timeliness of M&TE out
of tolerance evaluations, was closed, the quality of the
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evaluations warranted licensee's management attention. Deviation 92-01-06 remains open pending further NRC review of the licensee's
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resolution of this breaker coordination deficiency.
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Exit Meeting I
The inspection scope and results were summarized on April 2,1993, with those persons indicated in paragraph 1.
Proprietary information is not contained in the report. Tne inspectors described the areas inspected and discussed in detail the inspection results below. There were no dissenting comments received. from the licensee.
(Closed) URI 93-02-01, Incorrect Fuse Sizing of Westinghouse 7300 Process Control System Circuit Cards and Failure to Control Vendor Manual /BOM (Closed) Vio 92-01-01, Failure to Maintain Configuration Control for Fuses and Electrical Thermal Overloads
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(Closed) Vio 92-01-02, failure to follow TS for Testing of Station Batteries
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(Closed) Vio 92-01-03, Failure to Follow Procedure for Controlling Potential Missile Hazards l
(Closed) Vio 92-01-04, Failure to Perform Engineering Evaluations for Out of Calibration Equipment
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(Closed) Vio 92-01-05, Failure to Update FSAR
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(0 pen) Dev 92-01-06, failure to Meet Commitment in IEEE 308 for Protective Device Coordination
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(Closed) IFI 92-01-07, EDSFI Report Findings 1 through 12 (0 pen) IFI 93-11-01, Calculated DC Voltage to Essential Switchgear Below Vendor Recommended Values
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(0 pen) IFI 93-11-02, EDSFI Findings 1 and 5 5.
Acronyms and Abbreviations Amps (A)
Amperes ABB Asea Brown Boveri i
ASC Auxiliary Shutdown Complex B0M Bill of Materials CA Auxiliary Feed (system)
CFR Code of Federal Regulations
DG Diesel Generator EDSFI Electrical Distribution System functional Inspection ESF Emergency Safeguards Features FSAR Final Safety Analysis Report
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kA Kilo-Amperes kV Kilovolts LC0 Limiting Condition _ for Operation MCC Motor Control Center
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MOV Motor Operated Valve NSSS Nuclear Steam System Supplier OTN Out of Tolerance Notice PIR Problem Investigation Report
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PWO Predefined Work Order RF0 Refueling Outage RN Service Water (system)
SSF Standby Shutdown Facility TS Technical Specifications URI Unresolved Item VAC Volts Alternating Current
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VDC Volts Direct Current VG Diesel Air Start (system)
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