IR 05000315/1999012
| ML17326A021 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 06/18/1999 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML17326A020 | List: |
| References | |
| 50-315-99-12, 50-316-99-12, NUDOCS 9906240252 | |
| Download: ML17326A021 (20) | |
Text
U.S. NUCLEAR REGULATORY COMMISSION
REGION III
Docket Nos:
License Nos:
50-315; 50-316 DPR-58; DPR-74 Report No:
50-315/99012{DRS); 50-316/99012{DRS)
Licensee:
Indiana Michigan Power Company Facility:
Donald C. Cook Nuclear Generating Plant Location:
American Electric Power Corporate Office Buchanan, Michigan Dates:
May 3-21, 1999 Inspector:
R. Mendez, Reactor Engineer Approved by:
Ronald N. Gardner, Chief, Electrical Engineering Branch Division of Reactor Safety 9906240252 990618 PDR ADQCK 050003i5 PDR
EXECUTIVESUNIMARY D. C. Cook, Units 1 and 2 NRC Inspection Report 50-315/99012(DRS); 50-316/99012(DRS)
This was an engineering special inspection to review the expanded system readiness review program. The inspection focused on the review of individual team assessments of licensing basis documents, the system indexed database system, design calculations and whether discrepancy records and the associated condition reports correctly classified items as restart or post restart.
The licensee's assessments were thorough and focused on design attributes.
The assessment teams identified significant design related issues (Sections E1.1, E1.2, E1.3 and E1.4).
The electrical safety bus and the 250VDC assessment teams identified a number of significant weaknesses with design calculations.
The teams found that the emergency diesel generator loading calculations had not been updated since 1992 and the DC voltage drop calculations did not determine the available voltage to the end devices.
(Sections E1.1 and E1.2).
The licensee appropriately characterized open discrepancy reports and corrective actions items as restart or post restart (Sections E1.1, E1.2 and E1.3).
The inspector identified that setpoints listed in the Technical Specifications and in the Updated Final Safety Analysis Report were not referenced or used as guidance in developing design calculations.
This was of concern because the setpoints could be less conservative.
In addition, there was no technical basis or calculations for some of the setpoints (Section E1.2, E1.3 and E1.5).
The assessment team system walkdowns were generally effective, however, the containment spray and the residual heat removal teams had not taken motor nameplate information from the motor operated valves that were within the boundaries of their system.
In addition, the reactor protection system team did not verify that balance-of-plant cables were not routed with redundant channels (Section E1.4 and E1.5).
The operability of the station batteries was in question in modes one through four and as a consequence, this was correctly classified as a restart issue.
However, the licensee did not have administrative controls to prevent large loads from being connected to the batteries in modes five and six. Controls were put in place after the inspection
~ (Section E1.1).
Re ort Details III. En ineerin Conduct of Engineering 250VDC Station Batteries Ex anded S stem Readiness Review ESRR Assessments Ins ection Sco e 40500 37550 37700 The inspector reviewed, completed assessments for the 250VDC system.
These assessments were completed through the 250VDC ESRR team manager review. The team assessments included reviews of the system indexed database system (SIDS),
licensing basis documents, design calculations and whether the discrepancy records and associated condition reports correctly classified issues as restart or post restart.
Observations and Findin s The scope of the 250VDC ESRR effort was defined in the system assessment matrix approved by the System Readiness Review Board (SRRB) on March 13, 1999. This matrix defined system attributes such as the battery and charger ratings, fuse and breaker coordination, environmental qualiTications, electrical separation and single failure criteria. These were reviewed in seven major topical areas of design basis, licensing basis documents, operations, maintenance, surveillance, physical plant, and programs/processes.
The scope of the areas for review was generally broad and consistent with the purpose of the review effort to confirm the performance of system safety functions. The SIDS and licensing basis assessments were performed in accordance with the expanded ESRR procedure, PMP 7200.RST.004, "Expanded System Readiness Review Program," Revision 5.
The inspector noted that the assessments identified signiTicant design issues and correctly classified items as restart or post restart.
The team's assessments of 250VDC battery sizing and voltage drop calculation identified that battery sizing calculations did not specify a minimum operable electrolyte temperature and did not calculate the available voltage to the end devices.
The team found that there were no calculations for fuse and breaker coordination and that incorrect fuses were installed in the field. The team found an example where there was no basis for the technical specifications (TSs)
surveillance 140A output current test for the battery charger because the full load output rating was 300A. Additionally, the battery voltage drop calculations determined the voltage.to DC distribution panels but not to the end devices such as solenoids.
Consequently, there were questions as to whether the DC or AC components fed from the inverters were capable of operating during a design basis accident.
The number of significant problems associated with the battery calculations caused the system manager to question the operability of the batteries in modes one through four. The poor quality of the battery calculations were correctly classified as restart issues.
Many of the calculations needed either extensive work or complete reconstitutio The inspector identified that there was a potential for the batteries to supply large DC loads in modes five and six. The inspector was informed by the licensee that during plant shutdowns the loads to the batteries were not controlled except in situations where the batteries were cross tied. Technical specifications required that one battery bank be operable in modes five and six. The licensee indicated during the inspection that they would review this.area further. On June 2, 1999, the inspector was informed that administrative controls were now in place to prevent large DC loads from being connected to the station batteries.
The inspector was concerned that battery capacity was not being properly calculated.
This occurred because the licensee did not use the appropriate discharge factors when developing battery capacity calculation PS-250VL-'017.
These rating factors are greater than one when the discharge rate is less than eight hour and less than one when the discharge rate is greater than eight hours. The licensee's procedure also used this same method to calculate the battery capacity. The licensee indicated that this calculation needed to be reconstituted due to the number of issues identified by the team.
The inspector reviewed the licensee's TSs and noted that the bases stated that safety-related batteries AB and CD provided power to the annunciators and to the control room emergency lighting. This statement was not entirely accurate because only the AB battery provided power to the emergency lighting and only the CD battery provided, power to the annunciators.
The NRC willassess the overall effectiveness of the 250VDC system during the scheduled ESRR validation inspection, as delineated in the NRC letter dated June 8, 1999.
Conclusions The inspector considered the planned review areas for the 250VDC system to be consistent with the purpose of the review effort which was to confirm the performance of system safety functions. The ESRR team identiTied a number of significant design issues which were correctly classified items as restart or post restart.
The ESRR team identified calculations that did not specify a minimum operable electrolyte temperature and did not calculate the available voltage to the end devices.
The assessment of the battery sizing calculations resulted in the licensee's recognition of the need to significantly revise or completely reconstitute affected design calculations.
The inspector noted that the licensee did not have adequate controls to ensure the operability of station batteries in modes 5 and 6. Subsequent to the inspection the licensee implemented administrative controls to prevent large DC loads from being, connected to the station batteries.
The NRC willassess the effectiveness of this system in a subsequent inspectio Electrical Safe Buses ESRR Assessments Ins ection Sco e
The inspector reviewed assessments planned for the electrical safety bus system.
These assessments were completed through the electrical safety bus ESRR team manager review. The team's review included review of SIDS items, licensing documents and whether discrepancy reports and condition reports correctly classified issues as restart or post restart.
Observations and Findin s The scope of the electrical safety bus ESRR reviews was defined in the system assessment matrix that was approved by the SRRB on March 8, 1999. The matrix included evaluation of system mitigation functions against plant configuration design, licensing, operations and maintenance documents.
This scope included design attributes for review such as verifying loading during accident scenarios, equipment ratings, electrical protection and coordination, containment isolation and maintenance of the switchgear.
Other design attributes were also defined that were common to other systems such as station blackout operation, high energy line break impact on the vital bus systems and seismic qualification of the safety related distribution system.
The completed assessments were thorough, focused on appropriate design attributes and were effective in identifying significant design issues.
Items were correctly classified as restart or post restart.
The team performed the review of assessments in accordance with the ESRR procedure.
The ESRR assessments identified a number of significant issues such as preventative maintenance tasks that were overdue.
The inspector considered the team's review of calculations thorough and probing. The team identified design calculations that contained incorrect assumptions and design bases and calculations that were not consistent with electrical standards referenced in the calculation.
For example, one calculation documented that relays did not protect for locked rotor conditions and that this was acceptable due to the nature of the loads; however, this was contrary to the electrical standard referenced in the calculation. The team found that there was no basis for the station blackout and loss of offsite power/ loss of coolant accident event sequencing of loads calculation. The team found that motor cable sizing calculations were based on the motors being rated 4160V but that most of the motors were rated 4000V. Consequently, some of the present calculations for determining motor full load current were non-conservative by approximately four percent.
Another calculation did not contain sufficient engineering justification to ensure that cables were correctly sized.
For relay setting calculations, the time overcurrent time dial settings were not addressed, reactive impedance was neglected and current transformer (CT) and potential transformer burdens were not calculated at the maximum available secondary current.
One assessment stated that CT saturation was challenging the accuracy of relay settings and coordination with upstream protective devices.
The inspector found similar problems identified by the team.
For example, calculation PSPKVP-001, "Calculation, documentation and 4kV essential service system motor protective relaying design basis," stated that consideration must be given to the
saturation of the current transformer when high currents were passing through the secondary circuit. It further stated that depending on the burden, the current transformer saturation could prevent the relay from performing its intended function. However, the calculation did not determine whether the expected secondary voltage was in the linear portion of the CT performance curve or in the nonlinear saturation range.
In reviewing the electrical loading calculations, the inspector also noted that the Updated Final Safety Analysis Report (UFSAR) and TS values were not referenced or included in the calculation.
For example, the inspector found that the calculations did not reference the TS engineered safety features actuation system (ESFAS) instrumentation trip setpoints for the 4kV bus loss of voltage value of 3280V and the 4kV bus degraded voltage which was set at 3638V. This was of concern because the calculation could potentially determine that the voltage setpoints were acceptable but the setpoints could be below the TS or UFSAR values.
Conclusions The completed assessments were thorough and focused on appropriate design attributes.
The ESRR assessments identified a number of significant issues such as preventative maintenance tasks that were overdue.
The inspector considered the team's review of calculations to be effective. The team found that design calculations contained incorrect assumptions and that calculations were not consistent with the electrical standards listed in the calculations, calculations that did not contain sufficient engineering justification to ensure cables were correctly sized and the possibility of transformer saturation that could challenge the accuracy of relay settings.
The inspector found that the relay calculations cautioned against transformer saturation but no attempt was made to determine the existence of excessive relay burden.
In addition, the inspector found that the calculations did not reference TS or UFSAR values.
Emer enc Diesel Generator EDG ESRR Assessments Ins ection Sco e 40500 37550 37700 The inspectors reviewed assessments planned for the EDG system.
These assessments were completed through the electrical safety bus ESRR team manager review. The inspector reviewed the team's assessment of SIDS items, licensing basis documents and whether items were correctly classified as restart or post restart.
Observations and Findin s The scope of the emergency diesel generator ESRR reviews was defined in the system assessment matrix that was approved by the SRRB. The matrix included evaluation of system mitigation functions against plant configuration design, licensing, operations and maintenance documents.
This scope included design attributes for review such as electrical capacity, voltage and frequency control, fault protection and automatic start capabilitie The inspector determined that the team was effective in identifying design issues.
A review of the discrepancy records and condition reports indicated the team had appropriately classified items as restart or post restart.
A significant issue found by the team was that the EDG steady state loading calculations had not been revised to incorporate the impact of recently installed design changes that affect EDG loading.
In 1992, calculation PS-EDGL-001, "Emergency Diesel Generator 1AB Steady-State Loading and Voltage Drop," was developed along with the calculations for EDGs 1CD, 2AB and 2CD. The team found that this calculation had not been revised since 1992. The licensee stated that the calculations had not been updated because of improper procedures and inadequate controls.
c.
The inspector noted that the licensee's TSs required that the EDG be operated at less than or equal to a power factor of 0.86 without establishing a lower limit. The manufacturer specified a power factor of at least 0.80. The inspector was concerned that ifthe power factor were to be excessively low due to problems with the generator, the EDG may not be able to supply emergency loads.
The inspector also noted that the power factor value was not validated by a calculation or standard.
Moreover, the licensee's surveillance procedures also required that the power factor be maintained at less than or equal to 0.86. However, the actual power factor was not recorded or determined.
The inspector found that all the accident scenarios had power factors that the licensee had determined to be above the TS value of 0.86. The licensee indicated that the surveillance procedure would be changed to bound the power factor below 0.86 and above the manufacturer's specification of 0.80.
Conclusions The assessment team was effective in identifying design issues and had appropriately classified items as restart or post restart.
The team identified that the EDG loading calculation had not been updated or revised since 1992, although a number of modifications had been implemented that affected EDG loading. The inspector found that the EDG power factor listed was not documented during surveillance tests.
Additionallythe design load calculations did not reference the TS power factor value.
E1.4 Reactor Protection/Solid State Protection/En ineered Safet Features Actuation ESRR Assessments Ins ection Sco e 40500 37550 37700 The inspectors reviewed assessments planned for the reactor protection system.
These assessments were completed through the electrical safety bus ESRR team manager review. The inspector also examined the team's review of industry operating experience.
Observations and Findin s The scope of the electrical safety bus ESRR reviews was defined in the system assessment matrix that was approved by the SRRB on March 8, 1999. The matrix included evaluation of system mitigation functions (attributes) against plant configuration design, licensing, operations and maintenance documents.
This scope included design
attributes for review such as the initiation of engineered safety features actuation system (ESFAS) for fault conditions, logic and actuation, containment isolation, environmental qualification and electrical separation.
The assessment team found that the unit 2 TS reactor coolant pump trip undervoltage setpoints were higher than the TS reactor coolant pump ESFAS trip setpoints.
The undervoltage reactor trip and ESFAS trip setpoints are identical for unit 1. The team also identified a number of problems related to inadequate separation of the reactor protection system (RPS) cables.
However, in reviewing the assessments, the inspector noted that the RPS team did not verify, during the system walkdown, whether balance of plant cables that were routed with one channel were separated from redundant channels.
The requirement for separating RPS cables from balance of plant cables is identified in section 7.2-19 of the UFSAR. The licensee that this area would be examined further as part of the ESRR reviews.
The inspector also noted that the RPS team did not validate the ESFAS trip setpoints listed in TS. The team performed reviews to verify whether the values listed in the instrument data base matched the surveillance procedures.
However, these values were listed in millivoltvalues and not in the units listed in TS such as pressure or temperature.
Due to questions by the inspector, the RPS team performed the conversion for the high drywell pressure setpoint and this was found to be acceptable.
Conclusions The team determined that the TS reactor trip and ESFAS reactor coolant punip trip undervoltage setpoints were not identical. Cable separation problems were also identified, however, the inspector noted that bala'nce of plant cables that were routed with one channel were not verified to determine ifthey were routed with redundant channels.
Additionally, the team verified that setpoints listed in the surveillance procedures matched the instrument data base, however, the team did not verify that the setpoint value in millivolts matched the TS units of pressure and temperature.
iscellaneous Assessments The inspector performed a limited review of the containment spray, residual heat removal (RHR) and the offsite power ESRR team assessments.
The inspector reviewed technical specifications, calculations and walkdown findings that were part of the team's assessments.
Observations and Findin s The inspector found the team assessments, calculation review and walkdown findings to be acceptable except where noted below.
The offsite power team identified calculations that contained unsupported assumptions and incorrect references.
The inspector noted that for calculation PS-765-01, the licensee calculated the secondary voltage and excitation current.
However, there were
no cautions within calculation PS-765-01 for keeping current transformer burden below the saturation point. Although relay burdens were not exceeded, the team had not been reviewing relay burden.
Additionally, section 3.8.3.1 of the TS stated that the steady state voltage for the 69kV source shall be greater than or equal to 90 percent.
There were no calculations or basis to validate or support the 90 percent value.
However, it should be noted that the offsite power team system manager had not assembled the 69kV team to review these items.
It is likelythe team would have also identified this inspector observation during the subsequent ESRR reviews.
The inspector noted that the residual heat removal and the containment spray teams did not record the nameplate data for the 600V motors. The teams recorded the nameplate data for the RHR and containment spray motor but not for the 600V motor operated valves that were within the boundaries of their systems.
The motors have nominal ratings of 575V and 550V which have different full load current ratings.
Consequently, the full load current calculations for the 550V motors could be non-'conservative ifa base of 575V were to be used in the calculation.
On March 19, 1999, the RHR team issued condition report 99-05588 because the operability of several ECCS motors was in question.
The emergency core cooling system (ECCS) motors were rated for operation up to 4400V. However, the EDG TS upper voltage limitwas listed as 4580V. The condition report also listed the lower EDG TS voltage of 3740V. This appeared acceptable because the ECCS motors were rated to operate down to 3600V. Therefore, the motors appeared operable at the lower voltage.
However, the condition report did not mention that the TS ESFAS undervoltage could be as low as 3578V. This was below the ECCS operability voltage of 3600V. The licensee issued another condition report to resolve the lower operability voltage for the ECCS motors.
Conclusions The inspector noted that the offsite power team had not evaluated the potential problem of CT burden and that the TS tolerance for the 69kV system was not supported by a basis or calculation. The containment spray and RHR assessment teams did not verify nameplate data for the 600V motor operated valves. This could resulted in calculations of full load current being non-conservative.
Additionally, the RHR team did not note that the emergency core cooling motors could be inoperable at the lower undervoltage ESFAS setpoint listed in TS.
E3 Engineering Procedures and Documentation E3.1 No Documentation to Indicate Nonconformin Molded Case Circuit Breakers MCCBs Were Re laced Ins ection Sco e 40500 and 37550 The inspector reviewed a licensee commitment that was in the licensee's SIDS database.
These items were required to be reviewed and evaluated by the ESRR team Observations and Flndin s During a review of licensee correspondence, the inspector asked whether nonconforming breakers had been replaced as part of the effort to address NRC Bulletin 88-10, "Nonconforming Molded Case Circuit Breakers."
The correspondence in, licensing commitment 2832 stated that the licensee would replace 50 of the remaining unit 1 breakers during'he scheduled 1990 outage.
A letter documenting closure of this issue stated that it was closed by quality assurance surveillance 90-11. The inspector asked the licensee for surveillance 90-11 and concluded the supporting closure documentation was not relevant to the Bulletin.
The licensee had previously identified a generic problem regarding the failure to follow up on NRC commitments.
As part of the ongoing reviews, each ESRR team was required to review and determine whether all commitments made to the NRC were implemented.
These reviews were performed by the ESRR teams that would examine the licensee's SIDS data base.
The licensee had previously issued condition report 99-04344 that identified commitments associated with Bulletin 88-10 that had been closed without sufficient documentation; however, the condition report did not list commitment 2832. The licensee stated that although the commitment was not included in the condition report, the review of the commitment would have been performed as part of the ESRR reviews. The licensee was reviewing job orders to determine ifall the MCCBs that were referenced in commitment 2832 had adequate traceability or had been replaced.
On June 1, 1999, a licensee representative stated that the. review was not complete.
The inspector was concerned because of the potential for common mode failures ifnonconforming breakers were found to be installed in the plant. This issue is considered and unresolved item (URI) pending the licensee'eview to determine ifthe nonconforming breakers were replaced (50-315/99012-01;50-316/99012-01(DRS)).
Conclusions The ESRR reviews ofSIDS items was found to be acceptable.
An unresolved item was identified pertaining to the traceability of MCCBs.
V. Mana ement Meetin s X1 Exit Meeting Summary The inspector presented the inspection results to members of licensee management at the conclusion of the inspection on May 21, 1999. The licensee acknowledged the inspection conclusions presented and did not identify any potential report material as proprietary.
PARTIALLIST OF PERSONS CONTACTED Licensee J. Arias, Compliance Manager C. Bakken, Site Vice President P. Barrett, Manager Performance Assurance J. Burford, Regulatory Licensing Manager D. Cooper, Plant Manager W. Elliott, Instrumentation and Controls M. Finissi, Plant Engineer R. Huey, Performance Assurance B. Kalinowski, Performance Assurance W. Kropp, Performance Assurance J. Molden, Maintenance Director F. Poppel, Regulatory Affairs M. Rencheck, Vice President of Engineering G. Stein, Performance Asssurance T. Taylor, Licensing L. Thornsberry, Engineering Restart K. Van Dyke, Regulatory Affairs R. White, System Engineering Manager INSPECTION PROCEDURES USED IP 40500:
IP 37550:
IP 37700:
Effectiveness of Licensee Controls in Identifying, Resolving, and Preventing Problems Engineering Design Changes and ModiTications ITEMS OPENED, CLOSED, AND DISCUSSED
~Oened 50-315/99012-01; URI Traceability of nonconforming MCCBs 50-316/99012-01 Closed None Discussed None
DRS ECCS EDG ESRR ESFAS MCCB NRC RHR RPS SIDS SRRB TS UFSAR URI LIST OF ACRONYNIS USED Current Transformer Division of Reactor Safety Emergency Core Cooling System Emergency Diesel Generator Expanded Systems Readiness Review Engineered Safety Features System Actuation Molded Case Circuit Breaker Nuclear Regulatory Commission Residual Heat Removal System Reactor Protection System Systems Indexed Database System System Readiness Review Board Technical Specification Updated Final Safety Analysis Report Unresolved Item
.
PARTIALLIST OF DOCUMENTS REVIEWED Procedures:
I 1IHP4030.SMP.115, Revision 0, "Steam Generator Level Protection Set I Functional Test and Calibration" 1IHP4030.SMP.119, Revision 1, "Steam Generator 182 Steam/Feed Flow Mismatch and Steam Pressure Protection Set I Functional Test and Calibration" 1IHP4030.SMP.123, Revision 1, "Lower Containment Pressure Set I Functional Test and Calibration" 1IHP4030.STP.033, Revision 9, "Reactor Coolant Pump NO. 2 Undervoltage Bus 1C" 2IHP6030.IMP.073, Revision 0, "Time Delay Relay Calibration" 1IHP6030.IMP.309, Revision 3, "4KVBus Loss of Voltage and 4KV Bus Degraded Voltage Relay Calibration" 2IHP4030.SMP.221, Revision 0, "Steam Generator 183 Steam/Feed Flow Mismatch and Steam Pressure Protection Set II Functional Test and Calibration" PMP 7200.RST.004, Revision 4, "Expanded System Readiness Review Program" Safe Evaluation:
Safety Evaluation, Dated March 11,1985 Replace Unit/GRID Inverter and Install Transformer Calculations PS-EDGL-001 PS-250VL-007 PS-250VL-012 PS-250VL-024 PS-250VL-017 PS-26KVP-001 PS-34KVP-002 PS-4KVP-001 PS-4KVP-007 Emergency diesel generator 1AB steady state loading and voltage drop Load study of the train A 250VDC system during a station blackout accident scenario Document detailed battery 1CD circuit loading during a loss of coolant accident/loss of offsite power events Development of the modified performance test load profiles for the train A, B and N batteries Battery 1CD composite capacity and voltage drop study Unit auxiliary transformer BDD settings Calculate reserve auxiliary transformer BDD relay settings'alculation, documentation and 4kV ESS motor protective relaying design basis Undervoltage/degraded grid relay settings ESRR S stem Assessment-250 VDC DSMI001 JBAL004 JBAL006 JBAL007 Conduct a review of the SIDS database system for open temporary modification or bypasses Review vendor technical information associated with the AB/CD batteries Perform a review of the availability/reliabilityattributes versus the UFSAR Verifythe 250VDC system battery chargers are sized to maintain the batteries in an available standby state
J BAL008 JBAL009 JBAL018 JBAL021 JBAL023 JBAL027 JBAL031 JBAL032 JBAL037 JBAL039 Review the fuse/breaker coordination study for the 250VDC system Verifythat the capacity and sizing of the AB and CD batteries willsatisfy a four.
hour station blackout design basis event Review of the UFSAR functional and design basis criteria associated with the 250VDC distribution panels Review of the UFSAR coordination requirements and assure the 250VDC system complies with these requirements
'eview of the UFSAR with respect to design basis information associated with the station battery chargers Review the annunciation/indication calculations for the 250VDC system Evaluate the effects of temperature on the system Review the design basis documents with respect to temperature effects on the 250VDC system Review and compare the fuse coordination requirements such as type and sizes found in the calculations Evaluate the effect of temperature on the 250VDC battery system associated with a design basis accident ESRR S stem Assessments-Emer enc Diesel Generator WFER006 Review sequencing of load during a loss of offsite power event WFER007 Review loss of offsite power concurrent with a safety injection signal WFER008 Review loss of offsite power concurrent with a containment spray signal
~
WFER009 Review generator rating versus bounding load duration WFER010 Review emergency diesel generator maintenance ESRR S stem Assessments-Offsite Power GMAV001 GMAV002 GMAV003 GMAV004 GMAV005 The assessment was performed to determine now the station is back fed from the offsite system Determine ifthe large transformers and in particular the generator step-up transformers have been evaluated for static electrification Determine ifthe present semi-annual surveillance program for gas-in-oil analysis is adequate to monitor the internal condition of the transformers Review vendor manuals and assess the maintenance program and condition of the equipment Perform an assessment of the switchyard equipment to review programmatic conditions related to the system readiness review ESRR S stem Assessments
- Electrical Safe Buses DCAR001 DCAR002 DCAR004 DCAR005 Protective circuitry for faults. overloads and grounds Design basis document requirements for containment penetration protection 4KV balance of plant motor electrical protection relay settings Phase overcurrent relay settings for reserve auxiliary transformer and unit auxiliary feeds to the 4KV buses
DCAR006 ELEE001 ELEE002 ELEE003 FFIS002 FFIS003 JMAL002 JMAL003 JMAL004 JMAL005 JMAL006 JMAL007 JMAL008 JMAL011 JMAL019 KRUS007 600V AC balance of plant motor load protective relay setpoint calculations Ensure the 4KV and 600V switchgear system maintains a high degree of reliability, Assess the maintenance of motor control centers and molded case circuit breakers Assess the maintenance of transformers that feed the 600V buses Motor control center thermal overloads AC power restoration Evaluate Calculation to ensure sufficient voltage is supplied to safety loads Determine the degraded grid voltage settings and ensure sufficient voltage at the
, safety Assess industry experience of design configuration Evaluate industry operating experience of system voltage Equipment redundancy was confirmed, however, some discrepancies were identified There are no calculations to support transformer sizing Design basis document comparison with calculations, drawings, UFSAR and configuration management Determine ifthe design supports the licensing basis Determine ifthe correct size and type of cable has been chosen to satisfy ampacity and voltage drop criteria 4KV essential motor electrical protection - settings for 50, 50N and 51 devices Condition Re orts 98-08285 99-03036 99-03390 99-03691 99-04288 99-04344 99-04721 99-04826 99-04940 99-05017 99-05023 99-05540 99-05818 99-06043 AC rated fuses in DC applications Battery sizing calculation conflicts with loss of all AC power procedure Residual heat removal motors are not reconditioned periodically to maintain their reliability The elementary diagrams contained generic identification problems for the GRID system Replacement of inverter capacitors were not performed prior to scheduled date Commitments related to Bulletin 88-10 were inappropriately closed Discrepancies found with battery charger calculation The battery chargers were found to be tested to 140A, however, the full load rating of the chargers is 300A Train separation discrepancies were found with the solid state protection system train A input cabinet 4 It is indeterminant ifthe degraded grid voltage relays are properly set There are no formal calculations.to support plant fuse/breaker coordination Unit 1 AB and CD battery charger do not have the vendor recommended fuses installed Component cooling heat exchanger outlet temperature alarm calibration surveillances were deleted without a safety evaluation Preventative maintenance job order for the inverters were found to be past due
i 99-06518 99-06679 99-08706 99-10494 99-11441 99-11691 99-11763 No preventative maintenance has been performed on the containment spray eductors Documentation that commitments made for NRC bulletin 88-10 were ever closed properly Slope setting for relay was selected inappropriately Review of the calculations determined that the time overcurrent characteristics for some relays do not provide full protection for some motors Some cable sizing calculations are incorrect or are not properly justified Calibration of meters and preventative maintenance tasks of internal tasks were not completed by scheduled'dates Generic issues associated with vendor recommended preventative maintenance were identified by the ESRR teams 16