IR 05000382/1993001
| ML20034H217 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 03/10/1993 |
| From: | Westerman T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML20034H213 | List: |
| References | |
| 50-382-93-01, 50-382-93-1, NUDOCS 9303160189 | |
| Download: ML20034H217 (14) | |
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APPENDIX
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U.S. NUCLEAR REGULATORY COMMISSION
REGION IV
Inspection Report:
50-382/93-01 Operating License: NPF-38 Licensee:
Entergy Operations, Inc.
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P. O. Box B Killona, La 70066 Facility Name:
Waterford 3 Steam Electric Station l
Inspection At: Taft, Louisiana Inspection Conducted:
February 8-12, 1992 Inspectors:
T. O. McKernon, Reactor Inspector, Operations Section Division of Reactor Safety R. B. Vickrey, Reactor Inspector, Engineering Section Division of Reactor Safety l
Approved:
7-3 - T-13 l
T. F. Westerman, Chief. Engineering Section Date l
Division of Reactor Safety Inspection Summary Areas Inspected:
Routine, announced inspection of corrective actions taken relative to the findings from the electrical distribution system functional (EDSFI) inspection (NRC Inspection Report 50-382/90-23).
Results:
Corrective actions taken relative to findings from the EDSFI were
complete and comprehensive.
The licensee's design engineering department was implementing procedural
and logistical changes in order to become more effective and efficient.
Summary of Inspection Findinas:
Violations 382/9023-01 and 382/9023-02 were closed (Section 2).
Deviation 382/9023-03 was closed (Section 2).
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Inspection Followup Items 382/9023-04,382/9023-05,382/9023-06,
382/9023-07, and 382/9023-08 were closed (Section 2).
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Attachments:
Attachment 1 - Persons Contacted and Exit Meeting
Attachment 2 - Documents Reviewed
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DETAILS
INTRODUCTION The NRC performed an electrical distribution system functional inspection (EDSFI) on December 4, 1990 through February 1, 1991, as documented in NRC Inspection Report 50-382/90-23. There were issues identified during the EDSFI which required additional licensee action and followup inspection by the NRC.
Some issues required subsequent correspondence with the NRC as a result of the licensee's continued review. This inspection was conducted to review the licensee's corrective actions for those EDSFI related findings.
2 ELECTRICAL DISTRIBUTION SYSTEM FOLLOWUP INSPECTION (2515/111)
The inspectors reviewed the status of the issues identified during the EDSFI as part of this inspection effort. The review of the engineering and technical staff area is also discussed in this report.
2.1 (Closed) Violation 382/9023-01:
Failure to Verify or to Check the Adeouacy of Desian This violation involved three examples of a failure to check the adequacy of design for the electrical distribution system as required by Criterion III of Appendix B to 10 CFR 50.
For the following examples, the licensee's corrective actions and a brief explanation of the issues are discussed.
2.1.1 Example (a):
Failure to verify or check design adequacy This example involved the failure to analyze for potential undervoltage conditions on Class IE electrical distribution systems. As a result, undervoltage relays were adjusted to a setpoint which would have resulted in inoperable 120 VAC safety-related equipment if a degraded voltage condition existed.
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In Letter W3F1-91-0298 dated May 10, 1991, the licensee committed to implement an upgrade program for electrical calculations and to consider the
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installation of new solid state under-voltage relays.
In addition, as interim.
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action the licensee implemented a precautionary measure through Standing l
Instruction 91-02 issued January 23, 1991, which requires the operations crew to monitor the systems for degraded conditions and take prescribed actions.
During the inspection, it was verified that the load and voltage drop analyses had been completed sufficiently to establish the optimum operating voltages for all safety-related buses. The inspector noted that Calculation EC-E91-050, Revision 0, documented the degraded voltage setpoint, Technical l
Specification values, and the minimum allowable operating voltages.
Design Changes 3358 and 9903358 were issued and required the installation of new undervoltage relays during Refueling Outage 5.
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The design changes and calculations appeared to adequately address the concerns of this example.
2.1.2 Example (b):
Failure to verify or to check adequacy of a design calculation i
During the EDSFI, the team identified a number of calculations which were in error and nonconservative assumptions which were associated with Design Calculation EE-7-39-02, " Load Study for (Power Distribution Panel] PDP 390SA,"
Revision 3.
The design calculation should have been reviewed as part of Design Change Package DCP-3080, which changed loads to PDP-390SA.
As corrective action, the licensee committed to a calculation upgrade program for electrical systems. The program objective was to review and assure the adequacy of assumptions, methodologies, and results of the original electrical calculations on a prioritized basis. The design change process was also revised to require the original impacted calculationt to be evaluated.
During the EDSFI followup inspection, the inspectors verified that calculations associated with the EDSFI had been reviewed and upgraded. As part of the calculation upgrade program, the licensee committed to upgrade all safety-related electrical calculations by June 1993.
This effort includes calculations of plant voltage profiles under different operating / shutdown conditions with varying grid voltages and short-circuit calculations to confirm adequacy of plant equipment ratings and proper relay coordination.
Calculations for new batteries installed during RF-5 were performed to document loading requirements and terminal voltage levels during accident conditions.
Battery charger sizing and dc short circuit calculations were updated to reflect replacement battery parameters. The power distribution panels loading calculations were revised using actual plant load data. The emergency diesel generator (EDG) loading and fuel oil requirements were recalculated.
The preceeding portion of the calculation upgrade program was
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completed in December 1992. The calcualtion upgrade program for nonsafety-related calculations, that are de:ign basis sensitive,- is estimated for completion by June 1994.
In addition to these actions, Procedures N0ECP-303, Revision 4 and NOICP-Oll, Revision 0, were revised and implemented.
These procedures require that for revisions to calculations approved prior to November 30, 1991, the adequacy of assumptions, methodology, and results be evaluated.
The corrective actions taken for this example appeared acceptable.
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2.1.3 Example (c):
Inadequate DC Voltage at Input to Inverters This example involved the failure to verify adequacy of design for the safety-related inverters. The concern involved whether or not the inverters would remain operable when battery terminal voltage approached 105V dc.
The licensee corrected this issue by replacing the existing batteries with larger capacity Class lE batteries. As such, the design voltage at the battery terminals is higher than 105V. The installation of the new batteries eliminated the need to lower the alarm and shutdown setpoints for the static uninterruptible power supply (SUPS).
During this inspection, Calculation EC-E91-062 was reviewed to verify battery terminal voltage under accident conditions (109.44V) and at the SUPS (105V).
Further, it was verified that the maintenance procedure had been revised to incorporate periodic testing of the inverters for low voltage shutdown capability.
i Based on the above licensee actions and inspection results, it was determined that the licensee had implemented appropriate corrective action to address the identified violation.
2.2 (Closed) Violation 392/9023-02:
Failure to Establish. Follow. and Maintain Procedures Acoropriate to the Circumstances This violation was comprised of five examples of the failure to establish, implement, and maintain procedures as required by Technical Specification 6.8.1.a.
For each example of the violation, the licensee identified the corrective action to be taken and the date when full compliance would be achieved. These actions and the inspectors' reviews are individually discussed in the following sub sections.
2.2.1 Example (a): GE Undervoltage Relays and Drift Surveillance Procedure HE-003-319, "GE Undervoltage Relay Model 12NGV138,"
Revision 4, directed setting the relays' setpoints at the Technical Specification value without adequate consideration of tolerances or potential i
drift.
Furthermore, the procedure did not provide adequate guidance for engineering review responsibilities should the relays be found outside the
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acceptance band.
I The licensee's design engineering department committed to perform a review of
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all Technical Specification related electrical distribution setpoints to
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ensure that long-term drift was properly accounted for. Based on the results j
of that review, the appropriate procedures would be revised to incorporate the
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new setpoints. Additionally, existing plant procedures were to be upgraded so that "as-found" results of Technical Specification surveillance tests were adequately reviewed.
This procedure enhancement was to ensure that i.bnormal drift is identified and corrective actions are taken in a timely manner.
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The inspectors reviewed Calculation EC-E91-053, " Technical Specification Relay Drift (IAC and IAV Relays)," Revision 1.
This calculation provides evaluation and establishes Technical Specification related electrical distribution setpoints. The inspectors also reviewed the applicable surveillance procedure changes and found that changes were made to as-found and as-left calibration ranges. Additionally, the procedures added the requirement to notify Design Engineering - Electrical for calibration ranges that exceeded the design ranges.
The inspectors also reviewed applicable changes to Procedure HD-001-016, i
" Failure and Trend Analysis," Revision 1, Calculation EC-E91-050, " Degraded Voltage Relay Setpoint and Plant Load Study," Revision 0, and Design
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Change 3358, which addressed the installation of new solid state relays.
The inspectors determined that appropriate corrective action had been i
implemented.
I 2.2.2 Example (b): GE Magne-Blast Breakers Surveillance Procedures ME-004-131 and ME-003-327, "4.16kV GE Magne-Blast Breakers," did not incorporate applicable maintenance checks for the tertiary
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contacts as specified in the vendor's maintenance manual.
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The licensee corrective action committed to a review the vendor's general maintenance instructions in order to identify other potential cases wherein vendor recommendations might be generally and not specifically stated. After a review, maintenance procedures would be revised to ensure that they provided explicit instructions for requisite maintenance. Additionally, a self assessment of the potential for generic problems in the vendor equipment and Technical Specification information program was to be conducted by the operations support and assessments (0SA) group.
During this inspection, the inspectors reviewed procedure changes for ME-004-131, Revision 8, and ME-003-327, Revision 6, "4.16kV GE Magne-Blast Breakers,".and ME-004-lll, Revision 7, and ME-003-325, Revision 6, "6.9kV GE Magne-Blast Breakers." These changes consisted of the sequence that the
specific maintenance requirements be performed and the clarification of
measuring trip armature travel. The licensee's self-assessment was documented in OSA Reports 100-91 and 030-92. The inspectors reviewed the report findings and closure actions related to those findings.
The inspectors determined that appropriate corrective action for this example had been implemented.
2.2.3 Example (c):
Fuse Control The licensee had failed to establish appropriate procedures for a formalized fuse control program to ensure configuration management relative to fuses used
in safety-related applications. Recent fuse problems experienced in the Process Analog Cabinet OP26 indicated that the licensee could not establish j
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that the existing configuration was identical or equivalent to the initial plant licensing configuration.
The licensee committed to the establishment of a fuse control task force, generate procedures to control fuses from receipt to replacement, select and sample fuse groups, and integrate the reviewed groups of fuses into the Station Information Maintenance System (SIMS) with proper controls.
During this inspection, the inspectors reviewed the 13 fuse control task group meeting minute letters. The licensee had established a fuse control program that was implemented by Procedure UNT-005-025, " fuse Control Program." The licensee had divided fuse inspection into ten groups and a schedule was developed and work authorizations issued to record fuse type and sizes. This information was forwarded to maintenance engineering for evaluation.
Incorporation of electrical fuse information had been established in the SIMs database.
Initial sampling of actuation fuse groups for accessible equipment was completed during Refueling Outage 5.
Other actuation groups' scheduled to be completed during Refueling Outage 6 were being tracked by CMS Commitment A20121.
The inspectors determined that appropriate corrective action for this item had been implemented.
2.2.4 Example (d):
Static Uninterruptible Power Supplies Maintenance Procedures ME-004-175, "Uninterruptible Power Supply 3A-S and 3B-S," Revision 3, and HE-004-172, " Static Uninterruptible Power Supplies 3MA-S, 3MB-S, 3MC-S and 3MD-S," Revision 4, did not incorporate testing requirements specified in the applicable vendor technical manuals. The licensee committed to have engineering establish a method for testing of the power supplies. The testing provisions were to be incorporated into the appropriate procedures.
During this inspection the inspectors reviewed Maintenance Procedures HE-004-172, " Static Uninterruptible Power Supply 3MA-S, 3MB-S, 3MC-S,and 3HD-S," Revision 5, and ME-004-175, " Static Uninterruptible Power Supply 3A-S and 3B-S," Revision 4.
These procedures were found to have been revised to incorporate testing requirements related to the applicable vendor technical manual shutdown features.
The inspectors determined that appropriate corrective action for this example had been implemented.
2.2.5 Example (e):
Biennial Review of Procedures Procedure UNT-001-003, " Procedure Initiation, Review and Approval; Change and Revision; and Deletion," Revision 13, requires a biennial review of plant procedures.
During the inspection, Procedure OP-6-001, " Operating Procedure Plant Distribution (7kV, 4kV and safe shutdown) Systems" was found not to have been reviewed within the required 2-year review perio.
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The licensee identified several procedures which had passed the biennial review schedule which were recorded on quality notices (QNs).
The licensee committed to review and revise these procedures as appropriate.
During this inspection, the inspectors reviewed QNs QA-91-019, 044, 045, 046, 047, and 050. These QNs documentad the review and the revision of some of the procedures which had passed the biennial review schedule. The licensee established a computerized procedures information database that would flag the need for reviews 2 months before the due dates.
On September 25, 1991, the licensee received approval from the NRC to no longer perform a biennial review of procedures. This was based on the licensee's dynamic process (programmatic control requirements) and biennial QA audit to verify compliance with existing programmatic controls used to maintain procedures current.
Based on the documentation reviews and inspection results, it was determined that the licensee had implemented appropriate corrective actions to address the identified violation during the period that the biennial procedure review was still required.
2.3 (Closed) Deviation 382/9023-03:
Deviation for licensee Commitment to RG 1.97 This deviation involved shedding of Category 1 instrumentation to reduce loading on the Class IE batteries during a design basis accident or a station blackout.
The instrumentation had included the pressurizer level recorders.
The licensee committed to updating the post-accident monitoring equipment labeling program, revising the FSAR, and conducting RG 1.97 training for both engineering and operations personnel.
In addition, the procedure for loss of offsite power / station blackout recovery, OP-90Z-005 was revised.
During the EDSFI followup, the inspectors verified that the licensee had
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completed the RG 1.97 instrumentation update in the control room (December 1991); had updated their FSAR to update / clarify information provided in Table 7.5-3, " Accident Monitoring," and revised Procedure OP-902-005, " Loss of Offsite Power / Station Blackout Recovery Procedure," Revision 8.
The licensee's actions appeared to adequately address this concern.
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2.4 (Closed) Inspection Followup Item 382/9203-04:
" Station Groundino Grid adtpuacy" During the EDSFI, the team identified discrepancies with the licensee's station grounding grid.
It was indeterminate whether or not the design of the
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grounding grid was in compliance with NC/IEEE-80, " Safety in AC Substation
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Grounding," dated 1976.
The licensee committed to produce the necessary design calculation to verify the grounding grids design.
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During the EDSFI followup inspection, the inspectors reviewed Calculation EC-E-91-008, " Station Grounding Calculation," Revision 0, which was used to verify the design.
A review of the grounding grid calculations indicated that, for the assumed station area of 479,541 square meters, the touch and step voltage criteria calculated meets the touch and step criteria under ground fault current
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conditions. The calculation appeared to adequately address the design requirements of IEEE-80.
2.5 (Closed) Inspection Followuo Item 382/9023-05:
Review Calculations Concernina Replacement of Batteries 34-S. 38-S. and 3AB-S During the EDSFI, the team' identified a number of issues related to. Station Batteries 3A-S, 38-S, and 3AB-S.
The issues included concerns with battery sizing calculations using an implied electrolyte temperature and the temperature used in surveillance procedures; and the lack of margins used in the calculations.
The licensee committed to revising battery calculations and evaluating a new battery replacement life.
Procedures associated with periodic battery surveillance and maintenance would be revised to resolve battery room temperature concerns.
Further, the licensee decided to replace the existing batteries with larger capacity batteries.
During the EDSFI followup, the inspectors reviewed desijn calculations for station batteries under station blackout and a design basis accident with a loss of offsite power (LOOP). Battery maintenance and surveillance procedures were reviewed to ascertair, whether the' changes resulting from the batteries'
replacement were appropriately translated into the procedures.
In addition, Technical Specification Change Request NPF 38-121 was reviewed to ascertain the correct electrolyte temperature translation.
The inspectors verified that the design calculation for the new station batteries utilized a new temperature correction factor of 1.04 (70 F), and
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aging factor of 1.25, and a design factor of 1.10.
The calculations verified
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that the batteries could withstand the design-basis accident with loss of.
offsite power and/or a station blackout.
However, it was noted that the 3AB battery bus was marginally overloaded for the design life cycle of the 3AB
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batteries, but is acceptable for this operating cycle.
The licensee recognized this condition and planned to correct the condition during the next refueling outage.
The licensee has revised the Technical Specification (4.8.2.1.b) to require an minimum battery electrolyte temperature of 70 F.
Also, the limits for electrolyte-specific gravity was changed in the Technical Specification.
Additional calculations were performed to verify the adequacy of the battery charger.
The calculations verified that the chargers had sufficient capacity to recharge the batteries within an acceptable time period.
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-10-2.6 IClosed) Insoection Followun Item 382/9023-06:
DC short-Circuit Calculations This item concerned inconsistencies in the licensee's de calculations for short-circuit currents at dc buses 3A-DC-S, 3B-DC-5, and 3AB-DC-S. The calculations had not considered the effect of higher battery electrolyte temperatures of 77'F, there were inconsistent values for maximum short-circuit current for the batteries and those used in the calculations, and the lists.of loads from the studied buses was inaccurate.
In response to this finding, the licensee re-performed short-circuit calculations EC-E91-250, EC-E91-251, and EC-E91-252. These calculations verified that the worst case was 12,466 amp short-circuit current at PDP 3A-DC-S, which was less than the 20,000 amp bus rating. Also, the protected circuit breakers and fusing for tie PDP and SUPS were appropriately sized for the calculated fault current.
For example, SUPS 3A-S, input breaker had an interrupting rating of 10,000A and the calculated fault current was 7281A.
The licensee's revisions to calculations appeared to adequately address this concern.
2.7 (Closed) Insoection Followuo Item 392/9023-07: Uncontrolled Chain Hoists This item involved the observation of less than ideal methods of hoist storage when not in use. The licensee had no specific administrative controls for ensuring that hoists were properly secured when not in use.
Since the potential for equipment and personnel hazard could exist through improper
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storage, the licensee agreed to evi.uate the need for appropriate controls.
As a result of an engineering walkdown, the licensee developed recommendations for the dismantling and storage of the various rigging assemblies in the
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plant. The licensee committed to revise appropriate maintenance procedures and Design Specification LOV 1564.729.
During this inspection, the inspectors reviewed Procedures HM-007-002, " Crane and Hoist Inspection and Testing," Revision 4, MM-004-541, " Monorail and Miscellaneous Hoist," Revision 5, and HM-003-015. "18 Month Emergency Diesel Engine Inspection," Revision 8.
The inspectors found that the procedures contained appropriate notes and procedural steps for storage of the rigging assemblies. Additionally, DRN C9101370 was reviewed. This DRN revised design specification LOV 1564.729 to require storage positions to be indicated on design drawings.
Based on the above documentation reviews and inspection results, it was determined that the licensee had implemented appropriate corrective actions to address the identified item.
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-11-2.8 (Closed) Insoection Followuo Item 382/9023-08:
Review Licensee's Activities to Correct Station Battery Electrolyte and EDG Mechanical System Inconsistencies This followup item involved the evaluation of station battery electrolyte values in order to resolve inconsistencies between vendor values and those specified in the Technical Specification. The inspection followup item also addressed inconsistencies in the EDG mechanical systems such as the starting air system and fuel oil storage / surveillance testing.
The licensee's corrective action involved changing the Technical Specification for battery electrolyte temperature from a minimum limit from 60*F to 70"F and resolving inconsistencies between Technical Specification bases and vendor technical information for electrolyte specific gravity. This resulted in the Technical Specification specific gravity limits in Table 4.8-2 being raised by
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Further, the licensee performed EDG starting air tests which confirmed that the air receivers were adequately sized ta support five EDG starts. The FSAR was changed to incorporate the use of a portable diesel driven air compressor to charge an air receiver in the event electrical power is lost to the installed compressors. Other clarifications were made to the FSAR Section 9.5.6 to state that the receivers were sized to start the engines five times based upon a nominal air receiver pressure of 250 5 psig.
In addition, the licensee generated Calculation EC-E90-006, " Emergency Diesel Generator Loading and Fuel Oil Consumption," Revision 0, dated April 15, 1991.
The calculation verified that the onsite fuel oil storage capacity was sufficient to meet the EDG loading requirements for a 7-day period, under load management contraints. This calculation has satisfied, in part, the requirements of ANSI N195.
The licensee has reviewed the EDG fuel oil issues with regard to surveillance testing and has submitted Technical Specification change request (NPF 38-114)
to the Office of Nuclear Reactor Regulation. This issue is now considered a licensing action.
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ENGINEERING AND TECHNICAL SUPPORT During the inspection, discussions with key design engineering personnel were conducted to ascertain what improvements had been made to the engineering department during the interim period since the EDSFI.
It was noted that the licensee is consolidating its engineering staff into one building which also i
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Procurement of a sufficient number of computers will ensure that all design engineers will have access to a local area network. Other attributes noted were that almost all design engineers
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had received root cause training and most had completed systems training. A review of the past years design engineering performance indicators showed that j
the overall number of problem evaluation information requests had declined and
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the design engineers were more timely in completing modification packages prior to outage.
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The engineering staff appeared to be making efforts to streamline and become more effective and efficient.
4 CONCLUSION The licensee performed well in addressing the EDSFI findings. With the installation of new banks of batteries and digital undervoltage relays as well as the verification of several design calculations, the licensee strengthened the plant's design and demonstrated the technical capability of its design engineering staff.
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O ATTACHMENT 1 1 PERSONS CONTACTED 1.1 Licensee Personnel
- R. Azarello, Design Engineering Director
- J. Becker, Operations Experience Engineer
- T. Brennan, Design Engineering Technical Assistant
- L. Harrel, Records
- S. Hewitt, Records
- J. Holbrook, Systems Engineering
- J. Hologa, Principal Engineer Mechanical / Civil
- G. Koehler, Quality Assurance Supervisor t
- R. Logan, Engineering Programs
- B. Morgan, Records
- R. Murillo, Licensing
- P. Prasankumar, Electrical /I&C Principal Engineer
- D. Schultz, Operations
- G. Singh Matharu, Design Engineering
- M. Smith, Electrical Maintenance 1.2 NRC Personnel
- J. Dixon, Resident Inspector
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- E. Ford, Senior Resident Inspector In addition to the personnel listed above, the inspectors contacted other
personnel during this inspection period.
- Denotes personnel that attended the exit meeting.
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2 EXIT MEETING An exit meeting was conducted on February 12, 1993. During this meeting, the inspectors reviewed the scope and findings of the inspection.
The licensee did not identify as proprietary any information provided to, or reviewed by, the inspectors.
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ATTACHMENT 2
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DOCUMENTS REVIEWED Surveillance Procedure, ME-003-220, " Station Battery Bank and Charger,"
Revision 9 Surveillance Procedure, ME-003-230, " Battery Service Test," Revision 8 Surveillance Procedure, ME-003-240, " Battery Performance Test," Revision 8 Surveillance Procedure, ME-003-200, Station Battery Bank and Charger (Weekly)," Revision 7 Nuclear Operations Engineering and Construction Procedure N0ECP-303,
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Revision 4, Design Change Package dated October 2, 1992 Nuclear Operations Engineering and Construction Procedure N0ECP-011,
" Performance of Calculations," Revision 0 dated May 15, 1992 NOTE:
In addition to the above, other documents were reviewed during this inspection.
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