IR 05000277/1989007
| ML20247J191 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 03/21/1989 |
| From: | Anderson C, Thomas Koshy, Roy Mathew NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20247J149 | List: |
| References | |
| 50-277-89-07, 50-277-89-7, 50-278-89-07, 50-278-89-7, IEB-88-072, IEB-88-72, NUDOCS 8904050037 | |
| Download: ML20247J191 (35) | |
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i U.S. NUCLEAR REGULATORY COMMISSION l REGION I J Report No. 50-277/89-07 50-278/89-07 j Docket No. 50-277/50-278 i
License No. OPR-44/DPR-56 :
Licensee: Philadelphia Electric Company D.O. Box 7520
philadelphia, PA 19101 f Facility Name: Peach Bottom Atomic Power Station Units 2&3 i l
Inspection At: Delta, PA and at the Corporate Office in Phila., PA 1 j
Inspection Conducted: January ,30 to February 10, 1989 l
Inspectors: h, f Thomas Aoshy
{lL b r Reactor Engineer date
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. . . ( 3 bl Sf Roy Mathew, Reactor Lngineer date Also participating in the inspection and contributing to the report were C. E. Morris, Electrical Engine r, NRR, A. L. Della Greca, Reactor Engineer and J. T. Haller, NRC nsufa .
Approved by: '3 t/
C. J. /nderson, Chief, Plant Systems Section date Inspection Summary: Inspection during January 30 - February 10, 198 Report Nos. 50-277/89-07, 50-278/89-07 Areas Inspected: e Special, announced team inspection of the electrical power systems including (1) verification of as-built drawings, (2) adequacy of breaker and fuse coordination, (3) emergency loading of the diesel generators, (4)
plant modifications involving significant changes in the configuration of electric power systems, and (5) maintenance of breakers and protective relayin Results: Two violations were identified, (1) lack of drawing control and
{2) use of a under rated fus Several Engineering and maintenance deficiencies were identified in the electrical area. A summary of the inspection findings is provided in the following tabl PDR ADOCK 05000277 g PDC
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I SUMMARY OF INSPECTION FINDINGS Violations Section Number 50-277/50-278 Drawing Control 5. l Under Rated Fuse 5. Unresolved Items Voltage Adequacy for DC Equipment 5. . Capacity Margin for Batteries 5. . Undersized DC Bus Connection 5. , Emerg. Diesel Generator / Load l
Control 5. . kV Switchgear Interrupting Rating 5. . Mgmt. Controls on Deficient Equi . . Thermal Overloads at 480V MCCs 5. . Loose Terminal Blocks in 480V MCCs 5. . Separation between HPCI Swing Bus Power Sources 5. Fuse Discrepancies 5. l i 11. Feeder Cable Ampacity 5. Item Closed RHR Motor Surge Ring Bracket 5. _
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TABLE OF CONTENTS Page Persons Contacted............ ...................................... 4 I
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l Introduction and Background...................... .................. 6 1
1 Purpose and Scope.............. ....... ............................ 6
' Inspection Methodology.............................................. 7 l Detail s of Inspection of Electric Power Systems . . . . . . . . . . . . . . . . . . . . 7 5.1 General Review of Design Features.............................. 7 l
5.2 Verification of As Built Drawings............. ................ 8 5. Offsite Power Systems and 4kV Switchgear............. 9 l 5. '
l 480V AC Load Centers and Motor Control Centers and Di stribution Panel s. . . . . . ...................... 9 )
5. /125V DC System................ .................. 11 l 5.3 Electrical Configuration Control and Plant Modifications....... 14 5. Administrative Controls on Electrical Load Growth.... 14 5. Review of Modification Packages.......... ........... 14 5. RHR Motor Surge Ring Brackets........... ............ 15 5. Encapsulation of Raceways............................ 16 5. Molded Case Circuit Breakers............. .......... 16
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b 5.4 Review of Protection and Coordinatio ........................ 17 5. Off site Power System and 4.16kV Electrical System.. . . 17 ]
5. V AC Electrical System.......... .............. .. 18 5. /125V DC System.... ... ................... ..... 19 l 5.5 Electrical System Stability.................................... 21 l 5. Undervoltage Study.......... .......... ............. 21 5. Transmission System Stability........................ 22 5. Main Generator Stability............................. 22 Maintenance.................................................... 23
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5. Offsite Power System and 4.16kV AC
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Electrical System.................. ................. 23 l 5. V AC Electrical System............................ 25 l
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5. /125V DC System......... ......................... 26 5. Management Controls.................................. 27 5.7 Independent Calculations............. . ................ ...... 28 Conclusion ...... . ............................................. 28 Unresolved Item ...... .. ..... .. .......................... ... 28 Exit.......... .................................... ................ 29 Attachment 1 - Drawings Reviewed Attachment 2 - Modifications Reviewed Attachment 3 - Calculations Reviewed Attachment 4 - Philadelphia Electric Procedures I
Attachment 5 - Equipment Inspected
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l 1.0 Persons Contacted '
1.1 Philadelphia Electric Company (PECO) !
E. D. Baily, Procurement Engineer
W. J. Boyer, Manager Engineering Services Section R. Brower, Instrumentation and Controls Engineer J. F. Bustard, System Plt.nning i
J. Cockraft, Quality Assurance Superintendent J. Cohen, Operations Support Engineer, Instrument & Controls
J. B. Cotton, Operations Superintendent
'J. K. Coyle, Power Generation Engineer I
R. DellAngelo, Supervisor, Design
J. Dobbs, Maintenance Engineer J. P. Evens, Nuclear Quality Assurance
L. N. Ferrero, Corporate Quality Assurance Engineer
C. L. Fletcher, Supervising Engineer
J. Franz, Plant Manager
D. M Ganigan, Quality Control Superintendent
M. S. Hammond, Maintenance Engineer
G. J. Hanson, Regulatory Affairs ;
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A. L. Hartman, Project ElectrRa1 Engineer I A. S. Hegedus, Site Project Engineer '
M. J. Hochreiter, Modification Installation Engineer J. Huber, Regt.latory Af fairs j
G. A. Hunger, Jr. , Licensing Director J. D. Kane, Engineering Services l
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J. A. Kernaghan, Maintenance Service Engineer
S. J. Kowalski, Vice President, Nuclear Engineering Design i
M. C. Kray, Licensing Engineer
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R. J. Lees, Manager, Electrical Engineering *
l G. J. Lenggel, Maintenance Engineering M. W. Lohr, Engineering Services G. MacDonald,.Doble Test Group !
E. P. McKeown, Manager, Engineering Design Division J. B. McLaughlin, Modification Coordinator '
T. N. Mitchel, Operations Support Engineer J. S. Moore, Senior Engineer, Configuration Management D. 01cheswky, Operation Support. Technical Assistant
J. F. O'Rourke, Manager, Corporate Quality Assurance D. M. O'Rourke, Branch Lead, Structural Engineering '
R. A. Payne, Maintenance, Electrical Components / Systems J. M. Pratt, Manager, Quality M. Reitmeye , Lead Electrical Instrument Engineer R. B. Rock, Engineering Services J. W. Rogenmuser, Special Proj.ects, Maintenance
0. M. Smith, Vice President, Peach Bottom Atomic Power Station D. M. Spamer, Engineering Services P. Sulliven, Modification Coordinator
P. W. Thomas, Lead Field Engineer R. D Walker, Engineering Services D. Young, Maintenance, Electrical Foreman M. Warner, Maintenance Support J. E. Winzeried, Staff Engineer
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1.2 Atlantic Electric
P. J. Curham, Engineer
H. R. Abendroth, Engineer 1.3 Delmarva Power
8. Dodge, Engineer l
R. R. Richel, Engineer 1.4 Public Service Electric and Gas Company ;
- i M. Philips, Senior Engineer i
D. Taber, Principal Engineer 1.5 Bechtel Power Corporation T. K. Tam, Assistant Chief Electrical Engineer i i U.S. Nuclear Reculatory Commission l
C. J. Anderson, Chief, Plant Systems Section 1
T. P. Johnson, Senior Resident Inspector !
W. F. Kane, Director, Division of Reactor Project I
J. C. Linville, Chief, Division of Reactor Projects {
R. E. Martin, Project Manager l L. E. Myers, Resident Inspector I R. J. Urban, Resident Inspector j i
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Present at the mini exit on February 3, 1989
Present at the exit on February 10. 1989 i
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2.0 Introduction and Backgrov.n_d i The electric power systems (onsite and offsite) are important to the safety of a nuclear power plant and must be designed and maintained accordingl ,
T a safety function of each electrical system (assuming the redundant l system is not functioning) is to provide sufficient capacity and capability l of electric power for the safe operation of the plant under all operating J modes including anticipated operational occurrences and postulated accident To achieve this safety function, 10 CFR 50, Appendix A, General' Design Criterion 17 and 18 Electric Power Systems, specify design requirements concerning provisions for the periodic inspection and testing of electric power system The Final Safety Analysis Report (FSAR), Chapter 8, Electric Power Systems, describes how these design requirements are met. It also specifies the licensee's commitments with respect t6 the applicable Regulatory Guides (RGs) and industry standards such as the Institute of Electrical and Electronics Engineers (IEEE) Standards. The licensee's electric power systems, as originally designed, were reviewed by the NRC prior to licensing the facilitie Following the issuance of the Operating License, plant modifications can be made which involve significant changes in the configuration of the electric power systems. These modifications may involve substantial load growth of the electric power systems. As a result, lacking adequate {
controls, the electrical power systems may be loaded to their rated q capacity, or overloaded. This may adversely affect the functioning of ,
the protective relays and coordination of the interrupting devices. Load growth may also create bus undervoltage conditions which may trip out or damage motors, result 1ng in unnecessary bus transfers, or cause other operational transient Therefore, plant modification ~s should be evaluated {
to assure that their effect on the electrical systems is in accordance i with General Design Criteria 17 and 18, and FSAR commitment I I
Types of significant changes in the configuration which might. adversely affect t'ie performance of electric power systems are: a transfer of a large load from one bus to another; replacement of system components such i as breakers and fuses with a component having different functional !
characteristics; and changes in the set point of protective relays or '
breakers. All such changes should be reviewed to assure the integrity of the electrical syste .0 Purpose and Scope The purpose of this inspection was to ascertain that the present j configuration of the offsite and onsite electric power systems is capable ;
of sustaining and/or switching loads as required to support the safe operation of the plant. This was accomplished by verification that the ,
physical configuration, including modifications, conforms to the current '
electrical drawing and that the evaluations of the configuration are current and that they support the required functioning of the power
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system Since Peach Bottom Units 2 and 3 utilize a twin plant electrical l system, this verification ras accomplished by a detailed review on one I segment of the electrical division including some equipment that is common j to both Peach Bottom unit !
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4.0 Inspection Methodology _ ;
i The team reviewed the adequacy of the safety related electrical ;
distribution system with respect to the following factors affecting !
system availability: (1) selectivity among the various protective l devices which respond to overload; (2) reasonable sensitivity and speed j of response of the protective devices, considering the characteristics 1 and criticality of the protected equipment; (3) accuracy of the coordination curves in representing the types, ratings, and settir.gs of the devices actually present in the plart; (4) adherence to the principal that no single failure (including a failure of a circuit breaker,-fuse, protective relay, or instrument transformer can disable more than one redundant safe-shutdown train and, (5) absence of apparent credible common-cause multi-train failure modes in those cases where complete selection coordination cannot practically be cchieve Primary emphasis was on the safety buses and connected loads, including 4160 Vac, 480 Vac, 120V Vital ac, 250Vdc and 126 Vdc. A selected sample
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I of Class 1E and Non IE buses was walked down to collect as-built data on relay set points, load configuration and equipment rating. This data was ,
compared to electrical one line drawings, protective device setpoint '
calculations and load studies. The licensee's analyses on selected pro-tective relaying and breaker coordination were reviewed and field verified to determine the electrical system capability to limit the effects of electrical fault A sample of significant electrical modifications was reviewed in detai The purpose of this review was to verify that appropriate controls for the assurance of quality were in effect and that adequate safety evaluations were performed by the licensee to ensure that no uneeviewed safety questions, as defined in 10 CFR .50.59, exis The onsite electrical power systems, emergency diesel generators and the 125V Batteries loading calculations were reviewed to verify the systems'
capability to respond to design basis event .0 Details of Electric Power Systems Inspection 5.1 General Review of Design Features The following documents were reviewed:
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Technical Specifications a
FSAR Section 8, Electric Power Systems
Electrical Single Line Diagram (A+.tachment 1)
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. Calculations and Studie (Attachment 3)
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j The scope of review was to ascertain tha l l
The systems as designed are capable of performing their j intended safety function ]
TM design meets applicable requirements and commitments General design requirernents and guidance such as Regulatory Guides and IEEE stendards currently applicable fcr the design of electrical ;
power systems are lined in NUREG-0800, Standard Review Plan, Revision 2 - July 1981, Section 8. However, many of these requirements and guidance documents do not apply to older plants such as the Peach Bottom Nuclear Stations. The applicable requirements and licensee commitments to guidance documents are specifically mentioned in j various sections of the Peach Bottom FSAR. This review was to ascertain '
that, for the current configuration of electric power systsms, these j specific requirements and commitments are satisfied. It should be noted that the scope of review was general in r.ature. Its extent 1 was restricted to those design featuces selected for the inspectio )
Emphasis was on the capacity and capability of the current configura-tion of the systems under various accfdent modes such as unoer voltage l
on the grid, Loss of Offsite Power (LOOP) and Loss of Coolant Accident (LOCA), Ath or without a Single Failure to perform the intended .
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5.2 Verification of As-Built nrawings i
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The as-built drawings, (single line diagrams) listed in Attachment 1 we e verified by the inspectors by comparing the drawings with the
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l field configuration in a plant walk-through. The objective of the verification was to identify the differences, if any, between the l j
as-built drawings and the field configuration. The comparison :
facused on items of potentiai safety concern and included the j following: I
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Additions, deletions, or transfer of loads on the buses which affect the system configuratio <
a Differences in name plate data (a.g., Horsepower, kW, kVA, j Thermal Overload Device, Full Load Ampere) of system component '
Differences in continuous, momentary and interrupting rating of circuit breakers or fuse .
Characteristics of replacement items which could potentially l alter the performance of the system (e.g., make, type, model !
number, ar.d design parameters of circuit breakers, fuses, l transformers, relays, etc.).
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Characteristics of protective relay (set point changes) ;
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S. Offsite Power System and 4KV Switchgear The team reviewed the installatfor and configuration of the l offsite power sources for the Peach Bottom Stations. The transformers and the selected protective relaying, located at the North and South substations, were in agreement with the licensee drawings. Maintenance and housekeeping observations are addressed in section 5.6.1.- ;
5.2.2 480V AC Load Centers, 480V AC Motor Control Centers and ;
_120V AC Panelboards The inspection team conducted a "walkdown" of the equipment and components listed in Attachment 5. The team compared configuration, c6mponent nameplates, characteristics l l to as-built diagrams 6280-E-1615 (480V single line), 1 6280-E-1616, (480V equipment ratings and protective device settings) and 6280-E-1305, sheets 26 and 136 (panelboard
, schedules). The objective was to identify any differences l
between the "as-built" drawings and the actual plant con-l figuration. . In general, the "walkdawn" did verify the
"as-built" diagrams with the exceptions discussed belo '
The overload heater elements in motor control center 20B37, cells 30, 4C and 8A were found to be different than shown <
en diagram 6280-E-1616. The elements are dual range type i depending on how they are installed. In each case, the l elements were installed upside down, which results in the higher of the two current ranges. The lower current ranges l are snecified. This condition was brought to the attention l of the licensee. This is an Unresolved Item pending NRC i
review of the licensee's action to determine the significance of the finding and correct the thermal overload discrepancy; l (50-277/89-07-09; 50-278;89-07-09),
l The configuration within the various cells has the reversing l
starter contactors arranged side by side, horizontally. It I was noted that the reversing starter in cell'5C has the contactors turned 90 and arranged vertically. During the inspection, the licensee was unable to assure this to be an acceptacle configuration. Subsequent to the inspection, i the licensee contacted the equipment manufacturer and obtained I sufficient records to confirm the acceptability of the vertical installatio The inspection team noted that terminal block mounting screws in several cells were loose or mitsing. A screw from cell SB fell to the floor when the cell door was opened for this inspection. The licensee stated they were aware of this situation and had ordered replacement screws. Based on the NRC concern on this subject, the licensee conducted an i
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extensive review of the MCCs and found 62 brackets with top terminal block screw missing and 6 with the bottom screw missing. This is an unresolved item pending NRC review of the licensee's evaluation of the safety significance of this condition and corrective actions. (50-277/89-07-11; 50-278/89-07-11).
The breaker in cell 58 of MCC 20837, emergency channel
"ZB", is the alternate feed to the high pressure coolant injection (HPCI) steam line isolation valve reversing starte The other feed is from motor control center 20836, which is emergency channel "ZA". The reversing
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starter enclosure is remute from both motor control centers and contains a mechanically interlocked transfer switch to select the supply to the starte Both feeder breakers from motor control centers 20836 (Channel "ZA") and 20837 (Channel "ZB") are normally closed. This configuration was installed by Mod #E079 and the safety evaluation states that ". . . channel separation is maintained by this modifica-tion." Two energized cables carrying redundant sources of power are connected to the same panel. A physical barrier does not exist in the starter enclosure between the cabling from the two emergency channels. The licensee separation criteria in Diagram 6280-E-1317, sheet 22A1 indicates the need for a physical barrie PEco is picnning to justify this configuration. This is an Unresolved Item pending completion of the justification and review by the NR (50-277/87-07-12; 50-278/87-07-12).
Prior to the walkdown, the inspection team was informed that a plant . modification, Mod No. 25178, had been completed to f acilitate temporary power feeds to the various loads in the motor control centers whose bus had to be de-energized during maintenance. Further, until Diagram 6280-E-1615 could be revised, the change is shown on a controlled, marked copy of that diagram, referred to as a " Red'Line".
The " Red-Line" of Diagram 6280-E-1615 was viewed by the inspection team. It was noted that the markings show the addition of a three pole, single-throw switch and a set of (three) 60 amp fuses, to be used as a future, temporary feed to MCC 20B37 from MCC 20B39 (Emergency Channel "ZD").
The configuration actually found in the plant included two three pole, double-throw transfer switches and two groups of 4 sets of fuses. The licensee concurred that the
" Red-Line" diagram does not adequately show the configura-tion and agreed to revise the diagram to reflect the correct i representation of the installatio l l
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5. /125V DC System The team selected division II, Battery 28 system to assess the licensee's 125V/250V DC system configuration. A walkdown was performed by the team to collect as-built data to verify engineering calculations, relay set points, fuse, cable and battery sizing and also to review the overall protection and coordination of the DC syste The equipment verified is listed in Attachment The findings are as follows:
The battery inter connecting cables between cells 14 & 15 and 44 & 45 in battery ?BD01 appeared to be excessively bent with a 3 inch bending radius and installed using size 4/0 lugs. The team questioned the acceptability of this installation. Based on the evaluation of licensee's documents, it showed that the cable used is an extra flexible type 'M'
cable with approximately 4256 conductor The minimum bend radius of 3 inches is acceptable due to the large number of conductors in the cable. The cable is not susceptible to damage due to its flexibility. The size 4/0 lugs (Bundy Y28-2N) used for terminating size 3/0 cable is also acceptable since the Bundy Y28-LB (3/0) terminals that would normally be used for size 3/0 cable has the same tube size of 0.547 inches. The inspectors had no further questions regarding this matte The in:pector observed that the horizontal spacing between various cell jars of battery 28001 was inconsistent. The distance between cells 46 & 47 is 1 1/4" and between cells 52 and 53 is 1 1/2"; also, and foam separator existed between some cells. The team questioned the seismic quali-fication basis of the installation. The Exide battery installation drawings E13-115 and E13-123 indicated that the spacing between the battery jar covers (at the top) of adjacent cells to be a typical of 1/4". The Foam spacers are installed where the clamp assemblies are not installe The team verified the installation per the above drawing; and found the installation to be acceptabl The licensee's single line drawing E26, Sheet 1 of 2, Revision 37 , shows a pair of 200A fuses in box 2BD19X and 200A and 300A fuses in box 2B019, tc be Class RKS, Buss type FRN, 250V. The installed fuses were Gould-Shawmut, Class RKS, type TR-R 250V AC. The inspection team raised questions about the acceptability of this installatio The licensee issued a nonconformance report NCR No. P89025-312, dated January 27, 1989 identifying the above problem. An j engineering disposition was issued to revise the singla line diagram E26, Sheet 1, Revision 37, and to revise the calculation EE-7, section E6 using the time current 1
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characteristics for the type TR-R fuses. The time-current characteristic of the TR-R fuse was close to the FRN fuses ,
resulting in no change to the electrical coordinatio The
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team verified the adequacy of the licensee's corrective actions and found the corrective actions to be acceptabl A telephone memorandum dated November 1, 1985, regarding ,
the replacement of DC fuses for Mod 85-052 identified the '
use of type TR-R fuses. However, none of the affected documents were revised until the problem was rediscovered by the licensee, during a walkdown. The team did not find this item as a violation due to the following reason * The problem was identified by the licensee
- It fits in Severity Level IV or V
= It was corrected by the licensee
It was not a violation that could reasonably be expected to have been prevented by the licensee's corrective action for a previous violation The fuses installed in 125V de panel, 2BD306, circuits 29-BD-30604 and 29-80-30605. are 30 amps, type "NON" and
"KON". Single line diagram E26, Sheet 1, Revision 37, indicated that the fuses should be type "FRN." This condi-tion was brought to the attention of the license The licensee has generated a work order to replace the fuse i This is av an unresolved ' item pending NRC review of the licensee's action to correct the fuse proble (50-277/89-07-10; 50-278/89-07-10).
In 250V DC motor control center, 100A, 250V AC, TR-R type ;
fuses were installed in circuit 29-1100. These fuses are '
rated only for 200V DC per DC voltage ratings furnished by the manufacturer, "Gould". This deficiency was identified in calculation 18247-008-E6, Attachment D, dated July 10, 1986 and was not correcte The Peach Bottom Atomic Power Station QA plan Revision 0, Section NE 16.1 requires that measures shall be established to assure that deficiencies are promptly identified and corrected. This finding constitutes a violation of 10 CFR 50 Appendix B Criterion XVI. (50-277/89-07-04; 50-278/89-07-04).
In 250V de fuse box 2BD17, the bolted connection between the 1200A fuse and the bus wcs found to be undersized. The washer used for the connection was too small for the applicatio The washer was bent due to over torquing and barely covered the holes on the fuse. At the time of the inspection, there were no installation documents available l l
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to establish the acceptability of this connection. The ,
lilcensee has issued MRF# 2-578-8900935 to rework the bus
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connection. This is an unresolved item pending NRC review of the licensee's. corrective actions (50-277/89-07-05; 50-278/89-07-05).
In order to verify.the accuracy of motor loads shown on i single line diagram E-26 Revision 37,'the team randomly selected six motor operated valves from 250V d.c. motor ,
control center, 20D11. The team verified that five out of _ 'I six motor _ operated valves horse power ratings were different '"
from the single line diagram E26, Sheet 1. The results are tabulated below:
As found Motor Horse Power MCC Circuit Motor Operated Name Plate Shown Number Valve Number Horse Power _ In Dwg. E26 29-1103 MO-2-23-021 .6 29-1109 M0-2-023-016 .6 29-1110 M0-2-023-017 0.722 .0.65 29-1105 MO-2-023-57 0.722 0.65
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29-1106 M0-2-023-58 0.722 0.65 l The one line drawings were used for design calculations.
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Appendix B of 10 CFR 50, Criterion V and the Peach Bottom-Atomic Power Station QA plan, Revision 0, Section NE requires that activities affecting quality be prescribed by drawings and be accomplished in accordance with these drawings. This constitutes a violation. 10 CFR 50 l
Appendix B, Criterion V. (50-277/89-07-02; 50-278/89-07-02).
The team observed that a splice connection in MCC 20011, circuit 29-1101 was in a stretched condition. The incoming field cables were under stress and the ends of the splice were taped with electrical tape. Based.on the splice detail i, on dwg, E1317, the licensee took prompt action to support ,
the cables to relieve the stress. In addition, the temporary tape connection was remove The team found the splice connection acceptabl .
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The team verified the accuracy of overload heaters (as-built vs. drawing) installed in motor control center 20D11. .This inspection revealed that the overload heaters are insta'lled i in accordance with the drawings E-2071 and 6280-E-23. The DC motor overload heater trip contacts used at Peach Bottom Atomic Power Station are bypassed for automatic . safety related valve operation and a feature exits to bypass the overload trip manually from the main control room. Valve overload conditions are annunciated in the control roo The team found this to be an acceptable configuration.
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14 l 5.3 Electrical Configuration Control and Plant Modification l 5. (0 pen) Unresolved Item (50-277/86-25-03) Administrative Controls on Electrical Load Growth The team reviewed the licensee program for electrical ;
modifications. During a Probabilistic Risk Assessment ]
(PRA) inspection (86-25) conducted in 1986, the NRC team i looked into the licensee's program for tracking load growt l The unresolved item raised concerns on the lack of a program to review short circuit rating, interrupting capacity and relay coordination whenever electrical loads are adde j In a PECo letter dated April 24, 1987, the licensee committed to establish an electrical load list by the first quarter l'
of 198 However, the current program remains as an informal and an off line function in the modification program. The l computerized system, as stated in the licensee's letter is i l not in servic l l
l The team also reviewed the licensee's calculation " Emergency l Loading Cycle" dated April 9, 1973. This calculation has not been updated subsequent to the above date. The electrical power demand during pump runout conditions, and motor effi-ciency were not considered. The absence of an on-line program to track load growth, raises a question regarding the loads presently cornected to the diesel generato This item will remain unresolved pending NRC review of the licensee's action to update the emergency loads on the diesel, the development of a formal program to track load grcwth and confirm the adequacy of equipment rating and/or capacity. Following the inspection, PEco conducted a preliminary evaluation of the diesel load. This evaluation was documented in a letter to the NRC dated March 17, 198 This evaluation concludes that the potential for diesel overload has been avoide . Review of Modification Packages
Several plant modification packages were reviewed by the team to assess the impact of the design on the plant's safety related auxiliary electrical system and to determine
, if it was adequately addressed in the package. Packages l were checked for safety evaluations per 10 CFR 50.59, independent design review, post-modification testing, the effectiveness of quality assurance and administrative controls. The packages reviewed were found to be edequate.
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Mod. No. 1359 This modification was performed to replace an aging static-inverter. The engineering review request P3943 indicates the Reactor Protection System (RPS) load to be 70 amps.
l The Battery calculation accounted for this load as 60 amps.
i The inspector's questioned the impact of this and other possible load differences on the capacity of the batter This concern is further amplified in section 5. Mod. No. 957
" Elimination of Fuses in Valve Circuit M0-13-15 and M0-10-18". The purpose of the modification was to remove fuses from the control circuit neutral lead and thus make the circuitry consistent with the other AC valve control circuit Mod. No. 1029J
Installation of Either Thermal Magnetic Breakers or Power Fuses in Various AC MCC Compartments on Common Plant".
The modification was made to provide compliance with 10 CFR 50, Appendix R and dealt with circuit protection coordinatio Mod No. 1029K (Same as Mod 1029J except for Unit 2 rather than common I plant)
5.3.3 _(Closed) Unresolved _ Items (50-277/87-22-02; 50-278/87-27-02)
RHR Motor Surge Ring Brackets This item relates to NRC Information Notice No. 87-30,
" Cracking of Surge Ring Brackets in large GE Electric ,!
Motors." The licensee Modification No. 1742 addressed the
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removal of this bracket for Residual Heat Removal (RHR)
System Motors. The primary purpose of the surge rings and brackets, which are placed around the end turns of the'
motor stator windings, is to withstand the forces in the windings during motor starting. Failure of this bracing-structure in a motor could allow the windings to flex and possibly cause insulation cracking. Several of the RHR motors at Peach Bottom have experienced broken and/or cracked surge ring bracket GE has recommended that an annual inspection of surge ring !
brackets be performed on motors in which bracket failure !
has not been identified. For motors which have !
experienced broken surge ring brackets or in which brackets have been removed, GE recommends that licensees develop a plan for maintaining operability of the motors.
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The licensee has'been following GE's recommendation for a short term fix to allow operation of the motors through the next fuel cycle (18 months) for Un't 2. This fix included the following:
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removal of the damaged brackets from motors 2A and 2C;
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perform insulation tests on motor windings; I
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install additional heaters in motors to prevent condensation on windings; and,
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perform surveillance'e. tests during the fuel cycle to I assure heater operatio The. inspection team concurs with the actions being taken by the licensee to comply with GE's recommendation, thus unresolved item UNR 87-22-02 is close .)
5. Encapsulation of Raceways During the walkdown, the inspection team noted several electrical raceways (later identified as conduit) that had been encapsulated with a fire retardant materia The team raised a question regarding the impact of the material on the ampacity of cables in the conduit and the impact of the weight of the material on seismic consideration The licensee produced calculations EE-1029A-1 and EE-2078 as examples of the method of derating _ cable ampacity ~for the applications. Derating was based on data for the material used, "Thermo-Lag 330-1" as supplied by the manufacturer, TSI, Incorporated. Example calculations.ME-80 and ME-85 were also observed that demonstrated that the seismic l concerns were also addressed. The licensees responses to the concerns are considered adequate,
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l 5. Molded-Case Circuit Breakers I The inspection team reviewed the actions being taken by the licensee in response to NRC Bulletin No. 88-10,
" Nonconforming Molded-Case Circuit Breakers". The actions requested by the Bulletin are to provide reasonable assurance.that molded-case circuit breakers purchased by the licensee for use in safety-related circuits without ,
verifiable traceability to the manufacturers, will perform their safety function The licensee advised that they had procured 246 breakers from a vendor that were later found to be suspect. An inspection of these breakers by the licensee indicated that many did not appear to be new equipment and were nonconforming. All 246 breakers, less a number that had been discarded, were returned to the vendor. The vendor is obtaining replacement breakers to fulfill the order
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which should include new breakers traceable to the original equipment manufacturer. The inspection team concurs with the actions being taken by the license Hewever, the requested actions to establish the traceability and the trip capability of the breakers are yet to be complete ,
The licensee plans to provide a written report by !
April, 1989 as requested by the Bulleti :
5.4 Review of Protection and Coordination 5. Offsite power System and 4.16kV Electrical System '
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The onsite power distribution supplies the AC power required j i to safely shutdown the reactor and maintain it in the l
shutdown condition. The distribution system also provides power to operate all auxiliaries necessary for safe startup, operation and shutdown of the statio Four 4.16kV buses per station connected to two tie buses comprise the safety related portions of the distribution system. The safety related buses are separate from the non-safety auxiliary power distribution system, which is fed by the auxiliary transformers from the main generator The power supply to l the eight 4.16kV safety buses (four per unit) is either from 2 EAT and 2SUEAT transformers supplied by the 230kV transmission line (220-08) crossing the two unit site, or from 3 EAT and, either 35VEAT and #1AT, or SVT343, from the 500kV system or the 230kV system, respectivel The differential relaying (DR) on 4kV, 13kV, and 230kV buses l was reviewed by the team with PECo engineers. A differential l relay differs from an overcurrent or undervoltage relay l which sense current or voltage at one point, in that the ]
DR, algebracially sums the currents from a pair of current transformers (CT) at two different points of an electric circuit. A fault between the CT locations will produce a difference current, which activates the D Because the l differential relay responds only to difference currents I between two points, it can protect a section of bus connect-ing transformers, breakers, and other devices in series, by causing breakers to trip at current levels much less than in rush and full load currents - and without additional delay The team reviewed the DR between the low side of the E22 and E33 4kV emergency bus source breakers E222, E322, E223 and E323 and the high side of the 13kV load breakers 3 SUE and 25UE.
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18 .j Coordination between 4kV load breakers 152-1605 and supply breakers 152-1601, 1606, 1608 on buses E22 and E23 was reviewed by drawing the time-current curves, using. verified'
as-built relay settings. Adequate coordination was foun Time-current curves were drawn for the 13kV breakers, 2 SUE, ],
3 SUE, 3435, SU35, and 230kV breaker SU25 with the 4kV breakers, l Adequate coordination was found, in all cases examined, when the differential. relaying was also considere The team reviewed the licensee's calculation E-2, date'd August 8, 198 This calculation indicated that the minimum probable fault current at the 13.8kV bus to be 20,198 amp <
The rating of the switchgear is 20,455 amps. This leaves a ]
margin of only 1.25's. The adequacy of this margin was questioned for the following reasons: !
The lack of a load tracking program which makes it impractical to account for all loads; and,
The unsupported assumption that the recirculation i system motor generator set will not contribute to the limiting fault current It was noted that the 13.8kV switchgear need not be treated as safety grade equipmen However, this switchgear is )
normally used to provide offsite power to the 4160V safety '
grade buses. The capability of the 13.8kV bus to interrupt a fault without permanent damage and to recover the offsite power supply in a reasonable time is important to ensure the availability of the offsite power supply. This is an unresolved item pending NRC review of the licensee action to establish the adequacy of the 13.8kV switchgear (50-277/89-07-07; 50-278/89-07-07).
5, V AC Electrical System i
The 480V circuit protection at the load centers, is I provided by drawout type circuit breaker trip device These devices have long time delay, short time delay and instantaneous pickup settings adjusted to provide acceptable equipment or circuit protection and acceptable protection coordination. Trip settings associated with breakers in load center 20B11 were checked and verified to agree with the breaker calibration sheets (provided by Maintenance) and the coordination study, Calculation EE-7, Section E-3. Circuit protection at the motor control centers is provided by thermal magnetic molded case circuit breakers or by magnetic (only) molded case breakers in series with fuses. Motor overload protection is provided by thermal overload heater elements installed in the motor
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starter contacter Breaker continuous ratings and trip settings and overload identification are listed on Diagram 6280-E-1616. The settings and identification of devices associated with motor control center 20B37 were checked and verified to agree with breaker calibration sheets (provided by Maintenance), Diagram E-2071-4 (for thermal overload heater elements) coordination study, Calculation EE-7, Section E-3.
l A review of the Calculation EE-7, Section E-3 has indicated that acceptable coordination of protection does exist in the 480 volt system. Also, a review of Section E-5 of that calculation has indicated that acceptable coordination does exist for the engineered safeguards 120 VAC system panelboards up to the load center breaker It was noted in section E-3 of the licensee's calculations that the ampacity of twenty-five feeder cables should be checked. The comment was to lower the feeder breaker pickup setting or to increase cable siz The licensee was unable to confirm that any action was taken in this regar This is an unresolved item pending NRC review of the licensee action to review the ampacity of the subject cables (50-277/89-07-13; 50-278/89-07-13).
5.4.3 250/125V DC System The DC system is divided into two division For each unit, Divisions I & II have two 125V Batteries consisting of 58 cells of GN-23 type Exide Batteries. Batteries AD01 and ,
CD01 form Division I and Batteries BD01 and DD01 form j Division I These batteries (Division I & II) are located '
in separate rooms and mounted on seismically qualified rack The batteries in each division have dedicated battery chargers for each battery group and are powered from two redundant safety related motor control center DC power required for larger loads, such as DC motor driven pumps and valves, l is supplied at 250V through motor control centers (the two l 125V sources connected in series to produce 250V DC). The smaller loads are distributed through 125V distribution panel The battery system is ungrounded. The only failure that can be postulated is a multiple ground. The DC system is equipped with ground fault detection, 125V DC power distribution panel under voltage relays, 250V DC MCC under voltage relays, and battery charger under voltage relays to annunciate in the main control room.
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20 Protection and Coordination 1 i
A Peach Bottom DC system coordinat' ion study E-6, dated -)
August 14, 1986, was reviewed to assess _the protectio _n.and 'j coordination of the DC distribution systems. This study- !
covers the overall 125V and 250V DC system as described by -)
drawings E-26 and 27. All overcurrent devices in the 125/250V DC system are fuse Therefore, this is a fuse to fuse coordination study. During the field walkdown, the .
as-built fuse ratings were collected and this was compared i to the single line diagrams E-26 & 2 o The coordination study is a time-current analysis of pro- ,
tective devices. The underlying principle of coordination is to isolate the faulted portion of the system while 1 having the minimum'effect on the rest of the system (i.e.,
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the fuse furthest from the source acts first). The 1 coordination curves were reviewed for 250V de and 125V de for Battery 2B system. All curves showed proper coordina-tion within their portions of the de system. The team concluded that de system fuses are adequately coordinate The team reviewed the licensee's 2BD01/20001 Battery sizing and load profile calculations using calculation numbers EE 1359-1, dated' February 10, 1987, EE-6 dated February 17, 1987 i and SQEP50080 sheet 9 dated May 19, 198 In these calcula-tions, the licent.ee used the temperature correction factor as 1.08, design margin factor as 1.0 and aging factor as 1.1 IEEE 485-1978 Section 6.2.3 recommends an aging factor of 1.25 for a reduction of 80% capacity over the, life time of a batter According to the manufacturer, the qualified life of GN-23 battery is 20 years if the average ambient temperature is maintained at 77 F each year. The licensee is maintaining the battery room and electrolyte temperature between 75 F and 77 F. Since the aging factor is 1.15, the licensee's calculations showed the battery's expected life to daliver rated capacity to be only 10 year The existing batteries are 3 years old. The team concurs j with the licensee's calculations.to reduce the battery's -l life from 20 years to 10 years with no immediate impac The licensee has made several changes to the DC system since February 17, 1987. This was noticed during the i as-builtmotorhorsepowerverification(discussedin i section 5.2.3) and the modification review (section 5.3.2).
The load profile study presented a projected worst case loading profile which covered 0-4 hours duM ng a Loss Of j Offsite Power (LOOP), loss of all battery chargers, and a '
small break Loss of Coolant Accident (LOCA). Load additions without an up-to-date consideration for load growth and adequate review of changes can significantly '
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influence the availability of the battery system during a LOCA/ LOOP scenario. Most of the motor currents and the duration of operation were obtained from the 1972 Bechtel battery study on Unit Since that time, no further reviews of the loads were performed. Since the Battery B&D design margin is 1.00 and the licensee has not established the actual design drawing control of load addition, the team questioned the adequacy of the existing load profile which was used for battery sizing. This is an unresolved item pending evaluation of licensee actions to establish the adequacy of B&D battery capacity. (50-277/89-07-02; 50-278/89-07-02).
Voltage Adequacy of DC Equipment The licensee had not calculated the voltage drops in the de system to confirm that motors and coils have sufficient voltages available during a design basis event. Information Notice No. 88-72 " Inadequacies in the design of dc Motor i
Operated Valves" was the subject of reduced or degraded de l voltage available at de motors. This notice emphasized the l need for performing voltage drop calculations for de system I Reduced or degraded dc bus voltage conditions could occur during accidents in which battery charging capacity 1.s los The most significant voltage degradation would be observed for connected loads farthest away from the dc bus, and for motors with higher capacity, and motors with starting resistor Some other examples of voltage sensitive devices are contactcrs, solenoid operated valves and relay At the time of the inspection, the team noted that the licensee had not done any cable voltage drop calculations in the de system to establish the adequacy of voltage ;
available at the terminals of the dc electrical loads during i worst case conditions. The licensee has processed an !
engineering work request (EWR) number P-50721 to obtain the response to the above concern items. This is an unresolved item pending NRC review of the licensee actions to resolve the undervoltage issue in the de system. (50-277/89-07-01; 50-278/89-07-01).
5.5 Electrical System Stability 5. Undervoltage Study The licensee submitted a draft copy of the Voltage Regulation Study. This document indicated a setpoint of 98% for the undervoltage relay on the 4.16kV bus. The team observed 510 volts on the 480V load center. The team expressed a i
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concern regarding potential over voltage stresses on the electrical equipment. The licensee agreed to address this issue. The issue of under voltage is currently under review by the NRC office at NRR.
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At the request of the NRC, the System Planning Division of !
Philadelphia Electric Company reviewed the transient ,!
voltages that would appear on the transmission side of j Peach Bottom startup transformers during a fault on the !
transmission system. The results show a 3-second time period from the fault until Peach Bottom Units Nos, 2 and 3's angle swings are dampe '
Results also show that voltages are-low for the duration of the fault. During the post fault period, voltages range from 10% below to 6% above the initial operating point voltage. At the end of the 3-second simulation, voltages are within 1% of the initial operating point voltage These voltage swings should cause no problems for the Peach Bottom auxiliary buse The fault chosen for this example is similar to fault number 10 from a'1986 review that was previously supplied to the NRC. As before, a 3 phase fault is put on the 5010 line with the 5012 line out for maintenance. However, in the present simulation, the 3 phase fault duration is 3.5 cycles, which is the requirement of our Mid-Atlantic Area Coordina-tion Group /(MAAC) reliability region and is the actual primary clearing relay time at Peach Bottom for this type of faul The 3 phase fault duration of 8 cycles from the previously supplied data was done only to test the degree of stability ef this stable statio . Main Generator Stability On March 1, 1989, the team received an additional main ;
generator stability study, entitled, Peach Bottom - Voltage j on Startup Transformers During and After a Transmission '
System Fault. The response shows a zero volt transient for 3.5 cycles on the North and South substations and a )
cycle. 0.22 per unit and 0.73 per unit voltage transient on j the Unit 3 and Unit 2, respectively; offsite power sources to the emergency service buses. A 3.5 cycle, 0.22 per unit i voltage transient to the emergency service buses supplied !
by #343 SU transformer should not cause the undervoltage- i relay (UVR) to cause bus transfers to alternate power l supplied because the UVR have time delay The subject response is acceptable to the team as it shows that alternative power supplies to Peach Bottom Safety buses are not disabled by a fault on the main transformers or the connected 500kV/230kV buse ;
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5.6 Maintenance j 5. Offsite Power System and 4.16kV System Maintenance procedures for protective relays on 4kV.and ]
13kV safety system switchgear were reviewed with the license The identity of each relay and its calibration history are preserved by the site relay group to trend the performance so that problems which may arise can be detected in advance of most failures. The relay calibration procedures ano;the frequency of calibration were found to be adequate. The licensee has a scheduled program to Doble Test and perform gas analysis for the transformers. These test results are trended to predict maintenance for transformers. The team reviewed the maintenance performed on voltage relays, over- q current relays and timing relays associated with switchgear i and the emergency diesel generator. 'The maintenance program addressed all the selected relays except for voltage relay 27FF. The licensee agreed to include this in the maintenance progra The' transformer, lightning arrester, and breaker maintenance schedules were discussed with Peach Bottom Station personnel. The team did not observe an discrepancie The team also reviewed the power supplies to the substation control battery chargers, and to the air blast circuit breaker compressor Sufficient redundancy was available to assure reliable substation operation. The record for l the last five years operating supports this appraisal since l
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despite component failures, there has not been a failure to connect either the main generators or the emergency buses j to the offsite power networ '
During the walkdown, the ir.spection team observed a plunger misalignment on a 13kV breake., 2SU-A. This plunger operates the switch contacts that indicate the breaker open and closed status. The licensee contacted the manufacturer, j General Electric and assessed the significance of the
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problem. The licensee reviewed all other breakers of similar construction and observed 5 misaligned plungers in j the 4kV switchgear. Maintenance management has committed I to rectify this proble l The 13kV switchgear, 3SU is located in a room that does not have temperature control. The team observed that some of the space heaters, required to prevent condensation were not functional. The PECo maintenance y sonnel inspected the space heaters in all the switchgear compartments and found that 25% of the space heaters were out. The_ licensee committed to correct this problem and include the space heater functional check into the maintenance check lis .
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, On January 21, 1989, a 100 foot pole in the North substation broke twenty feet from the top, in a high wind,
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because of corrosion within the pole. The other poles hav ,
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been inspected but further action has not been decided upon beyond reinforcement, where rust is found. The inspection team expressed an interest in a timely resolution of this l 1ssue because, although' generation and power transfer over I the substation tie lines was continued without interruption, i l ore tie line and-one offsite transmission line were disabled l for days by the falling pol Further damage is conceivable if such a tower were to fail nearer to its base. The-licensee has a program to inspect all the poles of similar construction and reinforce the poles if they are found to be cracked.~The team had no further question The transformers that reduce 13kV power to 4160V are located outside the plant building. The team noticed water accumula- j tion at the base of 6 transformers. The continued submersion .t of the transformer supports could lead to premature support I failure. The team also observed a minor oil leak. The licensee promptly generated work requests during the inspection to rectify these deficiencie The team also observed a nylon rope in the 13kV switchgear cubicle raceway. The team inquired if combustible materials are in the plant raceways which cross the fire zones. The licensee stated that propagating materials were removed during the fire seal installation. The team had no further question The output cables of the emergency diesel generators were inspected by the team at the E22 emergency auxiliary switchgear. The power cable from the diesel generator goes through a second termination at the diesel generator switchgear building, an underground duct of 200 feet with aluminum cables, a transition to copper cable inside the plant building and then two connections to Unit 2 and Unit 3 rwitchgear. The Peach Bottom station has not had a diesel power cable failure except when one was caused by drilling into it. However, cables in outdoor 6sct banks are more susceptible to failure than indoor cables. The team discussed with the licensee the potential value in the testing of these cables to assure the integrity of the insulation. The licensee indicated they would look further into this matter. The team had no further question I
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4kV Breaker Distorted Linkage LER88-022-00(10-19-88) concerned distorted elevator mechanism linkage such that 4kV emergency diesel generator breakers might not function in an earthquake. The PECo; procedure, 5.8.3.L, Rev. 4, Checkout of 4kV Breaker Prt'or to Return to Service, was given to the team by the license This precedure lists the steps to be taken to assure that a withdrawn 4kV breaker has been returned to its operating position, in an operable conditio The damage occurs when the breaker is being removed from its. cubicle. The damage to the call switch control linkage is detectable when the breaker is out of its cubicle. Hence, following the withdrawal of the breaker, any damage to the cell switch control linkage caused by the withdrawal can be.found'and corrected. The' breaker can then be returned to its cubicle and its operability verified by cycling i These circumstances give assurance that the breaker is free from the damag The inspection team was shown a breaker and cubicle type GE AM4.16-250 of the type susceptible to cell switch control'
linkage damage, the components which distort were pointed ou The significance of the damaged cell switch control linkage is described in the EAB outline 88-46. The failure of the linkage disables automatic and manual closure circuitr The LER description is that unless the freedom from distortion of the cell switch control linkage is verified while the breaker is out of its cubicle, it could be returned to the cubicle, be found operable, and then-fail if shaken by an earthquake. However, the problem is precluded, if the breaker checkout procedure is properly implemented - until the GE upgrade kits are installe Peach Bottom has written in the subject LER that GE upgrade kits will be installed in approximately sixty months (3
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l refueling outages). These kits are said to be capable of preventing damage to cell switch control linkages during a l breaker withdrawal from its cubicle. For the short term, !
there is reasonabt ssurance for Peach Bottom that checkout procedure 5.8.3.L will prevent recurrence of the cell switch control linkage damage to 4kV breaker .6.2 480 V AC Electrical System i
The inspection team reviewed the maintenance procedures for the 480V load center circuit breakers, M-55.1, and for the 480V motor control center units, M-56.1. Circuit breaker routine maintenance includes cleaning, examination, repair i
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adjustments and calibration of trip settings. Contactor (starter) maintenance includes the control transformer fuses, thermal overload elements, contacts and interlock QC witness points are included. Scheduled routine mainten- )
ance frequency is every third refueling outage for the load center breakers and once every five years for motor contro center units. Both procedures M-55.1 and M-56.1 were found to be acceptable by the tea . /125V de System The team reviewed the licensee's battery surveillance pro-cedures ST 8.2-2A " Station Battery Weekly Inspection-125/250V dc," ST 8.3-28," 28001 and 2DD01 station battery quarterly inspection" and the battery manufacturers inspec-tion manual E-13-109-2 " Instructions for Inspecting and Operating Station Batteries." This review and walkdown verified that the station batteries were maintained by the above procedures and should be capable of supplying reliable de power to the safety related load The team also reviewed the licensee's surveillance test, l ST 8.4-28, " Unit 2B 125/250V Battery Discharge Performance i
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Test" and ST 8.5-2B " Unit 28 125 Volt Battery Service Test." The discharge rate determined from battery rating (performance test) is performed every five years until degradation is noted and then the test is to be performed annually. The purpose of this test is to verify the ability
, of battery to supply the rated current, to establish the l overall battery condition and to detect any potential i
' degradation. The service test is performed once per operat-ing cycle to establish the ability of batteries to supply sufficient current based on the LOCA load profile. Both tests follow the guidelines of Regulatory Guide 1.32, IEEE standards 308-1980 and 450-1980 titled, " Criteria for Cla w IE Power Systems For Nuclear Power Generating Station,"
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%i;aftuaN For Class 1E Power Systems For Nuclear Power Generating Stations" and " Recommended Practice For Mainte-nance Testing And Replacement Of Lead Storage Batteries For Generating Station and Substations," respectively. The team reviewed the test data. No deficiencies were identifie The inspection team verified the batt:ry room temperature measurements surveillance program and temperature measure-ment history for 28D01/20001 battery room. The battery room ambient temperature measurements are taken in accordance with station procedure ST 8.2-2A " Station Battery Weekly Inspection 125/250V DC" and ST 8.3-2B" "2B001 and 200001
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Station Battery Quarterly Inspection." Both procedures define acceptable limit of ambient temperatures to be between 65 F and 90 F. The history of ambient temperature for the battery room 28D001 for the last 5 months showed that the temperatures were monitored and meet the requirements of IEEE 45 The team also verified the calibration procedure'TL-11-04-004 and test data for calibration testing of instantaneous under voltage relays. These relays have control room annunciation to indicate and to warn the operator of degraded de voltag Maintenance on battery charger 2BD03 was performed every refueling outage per the Exide Operating and Service Instructions, Section 58.45, and Maintenance Procedure M-57.4, "125 volt battery charger maintenance program."
No discrepancies were observe .6.4 Management Controls
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The station suffered a major auto-transformer failure in 1985 that affected the offsite power source. It came to i
the teams attention that the licensee's maintenance I program had detected the degraded condition of the transformer several years before th3 actual failur Also, in the recent past, there was a low power transformer failure which was predicted by the maintenance personnel. The licensee made a conscious decision to i leave the transformers in service with the knowledge that they might fail. These decisions were not formally reviewed by any of the nuclear safety oversight groups 3 regarding the impact on nuclear safet Further, the licensee is currently planning to transfer
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I the maintenance responsibility of the substations to'an organization that does not report to the nuclear station managemen The team reviewed the licensee's action to continue operation of an RHR pump motor with cracked surge ring brackets. Although the licensee conducted informal
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discussions to continue operation of the' motor with the deficient condition, the licensee could not produce documented evidence that management had given operational j approva '
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The concern for the above conditions is that the plant 1 operating staff and safety review committees should be- "
aware of degraded equipment that has a potential to impact the operation of the plant and assess any risk associated with the decision to leave the equipment in operation. This L is an unresolved item pending NRC review of the licensee action to implement a program for the management evaluation {
of deficient onsite and substation equipment and conditions important to safety. (50-277/89-07-08; 50-278/89-07-08).
5.7 Independent Calculations The team performed independent calculations to verify the technical adequacy and accuracy of the licensee calculations associated with protection and coordination. As these calculations are involved, only portions of the calculations were verified. The portions of-the calculations verified by the team included the voltage study, short circuit studies, coordination study, and the emergency diesel generator loading stud .0 Conclusions Two violations involving inadequate corrective action.and lack of drawing control were identified at the end of the inspection. Eleven items remained unresolved. The team-identified the need for management atten-tion to assure the prompt resolution of the following items:
Voltage adequacy of de equipment;
13kV switchgear interrupting rating;
Capacity margin for batteries;
Emergency diesel generator loads and load control; and, 4
- 480V Feeder cable ampacit The above findings are discussed in detail in Section 5.0. Subsequent to the inspection, in a letter to the NRC dated March 3, 1989, the licensee agteed to correct the above mentioned issues before March 31, 1989. Based on the teams' inspection and the review of committed corrective actions, it was concluded that there is reasonable assurance that the Peach Bottom Electric Power System is capable of supporting the safe operation of the plan .0 Unresolved Items l-l Unresolved items are matters for which more information is required in order to ascertain whether they are acceptable, violations or deviations, i Unresolved items are discussed in section 5 of this repor ;
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a 8.0 Exit Interview At the conclusion of the inspection on February 5,1988, the inspection team met with the lensee representatives, denottd in section The team leader summa the scope and findings of the inspection at that tim No written material was provided to the licensee by the team, i l
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l ATTACHMENT 1 Drawings Reviewed E26 Sheet 1 of 2, Revision 37 Single line diagrams 125/250V DC and 38 System Unit 2 E26 Sheet 2 of 2, Revision 36 Single line diagram 125/250V DC System Unit 2 E13-115, Revision 2 Assembly 58GN-23 on two tier seismic resistant racks E22, Revision 0 Tabulation of DC motor operated valves and pumps overload protective equipment for 125/250V DC system MCC's E430, Revision 2 Electrical secondary and control connection, generator and transformer protection control board 20C22, Unit 2 E-425, Revision 23 Electrical secondary and control connectio Feedwater and recirculating control board 20C18, Unit 2 '
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6280-M-1-EE-221(1), Revision 59 Connection diagram panel 9-18 E-2903, Revision 0 Electrical schematic diagram Alternative control instrumentation E7-141, Revision 21 Metal clad switchgear connection diagra',n E621, Revision 26 Electrical secondary and control connection E2 Diesel Generator Engine Control E5-45(2), Revision 23 Wiring Diagram Generator Board E-13-109, Revision 2 Instructions for Installing and Operating !
Station Batteries E13-48, Revision 2 Exide filtered constant voltage float charger M57.4, Revision 3 125 Volt Battery charger maintenance E248 Sheet 2 of 2, Revision 32 Electrical Schematic Diagram Main Control Room Annunciators Generater and Electrical Auxiliary System and Channel II E13-32, Revision 8 Schematic Diagram 125V, 20A DC Battery charger
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ATTACHMNENT 1 2 E-1, Rev. 16 (3/18/88) Single Line Diagram, Station i
E-8, Rev.11 (5/6/88) Single Line Meter And Relay Diagram, Standby Diesel Generators & 4160 volt Emergency Power System, Unit No. 2 E-1615, Rev. 26 (10/11/88) Single Line Meter and Relay Diagram E-124 & E224 Emergency E-124-R-C and E221R-B Reactor MCC and and T-B and E224-T-B Turbine MCC 440V, Unit E-1616, Rev. 37 (10/27/88) Tabulation of 440V Motor and Feeders Overload Protective Equipment for E124 &
E224 Emergency L.C. E124-R-C & E224-R-B Reactor MCC and E124-T-B and E224-T-B i Turbine MCC. Unit 2 4 i
E-1617, Rev. 21 (10/11/88) Single Line Meter and Relay Diagram E324 &
E424 Emergency L.C. and E324-R-8, E424-W-A, E324-R-D and E424-R-D Reactor MCC. 440V, Unit 2 6280 E-1305, Sheet 26, Rev. 4 Panel Schedule No. 26 LD 6230 E-1305. Sheet 136, Rev. 119 Panel Schedule No. Y36 (11/21/88)
6280 E-1317, Sheets 21-25, Wire & Cable - Notes and details, Rev. 50 (10/7/88) Power, Control & Instrumentation 6280 M-1-S-36, Sheet 15 Electrical Schematic Diagram, High Pressure Rev. 53 (11/2/88) Coolant Injection System Cutler Hammer, In Bechtel No. 6280-E11-142-4. Motor control D9801E0343S-93 Sheets 1-2 center layout, notes and tabulation sheet Revised 2/4/75 ITE Imperial Corp Bechtel No. 6280-E10-63-6 33-44640-D-10 Hev. 6 General Arrangement - Emergency Auxiliary Load Center No. 20B11 Philadelphia Electric C Volt Motor Control Center Thermal E-2071-4, Rev. 4 (1-21/83) Overload Heater Selection Table and Control Transformer Fuse Table
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I ATTACHMENT 2 MODIFICA1 IONS REVIEWED The following is a list of the plant's electrical modification packages made available by Philadelphia Electric Compa y'that were reviewed during the inspectio Mod No. 957 - Eliminatten of Fuses in Valve Circuit .i MD-13-15.aud M0-10-18 Mod No. 1029J - Installation of Either Thermal Magnetic Breakers' or Power Fuses in Various AC MCC Compartments on Common Plant Mod No. 1029K - Installation of Either Thermal Magnetic Breakers or Power Fuses in various-AC MCC Compartments on Unit 2 )
Mod No. 1742 - Removal of the RHR Motor Stator Winding Support Mod No. 2083 - . Circuit Breaker Re-Calibration and Replacement Mo Mod No. 1359 - Replacement of Static Inverter
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i Mod No. 1352F - Alternate DC Power Suppl !
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ATTACHMENT 3 CALCULATIONS REVIEWED l
The following is a list of the electrical calculations relating to the plant that were made available by Philadelphia Electric Coyany and reviewed during j the inspectio j l
EE-7 Electrical Engineering Calculation J
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Section E-2, Rev 1, dated 8/6/36 - AC system Fault Calculation 1
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- Section E-3, Rev 0, dated 8/12/86 - Coordination study for 480 Volts )
LC's and MCC's Supplied by Ee I Buses l
- Section E-5, Rev r, dated 8/11/86 - 120V AC Systere Coordination Study 18247-026, Rev 0, dated 1/86 - Voltage Regulation Study EE-1029A-1, Rev 3, dated 1/13/87 - (Calculation to determinc cable ;
ampacity in encapsulated conduit)
EE-2078, Rev 2, dated 3/30/87 - (Calculation to determine cable ampacity in encapsulated conduit)
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ME-80, Rev 2, dated 1/17/89 - Calcu)ation to provide methodology for evaluation of encapsulated conduit)
NE-85, Rev 0, dated 8/11/83 - (Verification that streuses in conduit / supports are within allowable limits af ter ,
encapsulation)
18247-008, E-1 - 125/250V DC System rault Current Calculation 6280-2, IA - 125V/250V Station Battery Sizing EE M00 1048(1), Rev 1 - Lond Profile on the Unit 2 125/250 Vol t DC Battery 50EP-50080 Rev 0 - Battery Room Temperatures Calculation No, EE-6 - PBAPS 125/250V DC Battery Load Profile as a Result of- Load Additions
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l ATTACHMENT 4 PHILA0ELPHIA ELECTRIC PROCEDURES $
Ine following is a list of Philadelphia Electric Company procedures reviewed {
during the inspectio M-55.1, Rev 2, dated 12/2/88 - 480 Volt Load Center Circuit Breater Maintenance !
M-56.1, Rev 8, dated 7/15/88 - 480 Volt Motor Control Center Circuit !
Breaker Assembly Maintenance l
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ST 8.2-2A, Rev 2 - Station Battery Weekly Inspection -
125/250V DC ST 8.3-28, Rev 2 - 28001 and 20001 Station Battery l Quarterly Inspection l l
TL-71-04004, Rev 2 - Calibration Testing Instantaneous l Voltage Relays !
I ST 8.5-28, Rev 5 - Unit 28, 125V r,attery Service Test ST 8.4'28, Rev 3 - Unit 2B, 125/250V Battery Discharge Performance Test 18247-008, E-6 Rev 1 - 125/250V de System Coc,rdination I I
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ATTACHMENT 5 l EQUIPMENT INSPECTED l
2B Battery 2BD01 (Exide Type GN-23) {
250V DC Fuse Box / Bus 28017 1 250V DC Distribution Panel, 2BD18 !
250V DC Mctor Control Cer,ter, 20D11 i 2FBX Fuse Box, 2BD19X !
2FB Fose Box, 2B019 j k 2BCB Battery Charger, 2B003 .
2 PPB,12SV DC Power Distribution Panel, 20022 .
2 PPB, 125V DC Of stribution Panel, 2803G6 j 2PPBD,125V DC Distribution Panel, 20025 l 12CV DC Distribution Panel, 08013 j 480V Load Center Transformer, 20X30 ;
480V 1.oad Center (Switchgear), 20B11 1 48.0V Motor Cof, trol Center, MCC 20B37 !
120/208V P.anelboard 20Y36 i 120/2CSV Panelbcard 26LO !
480V Transfer Switch / Starter Cubicle 206324 j 490V Tratisfer Swttch/ Starter Cubicle 11210025A i 480/ Fira Pump Motor 39 Fed and Contrdi Cubicle CIES 480V Reactor Building Cool Water Pump Mot.cc 2BP10 l 4POV Drywell Cooler Fan Motor 2BV94-B ]
480V Turbine Germrator Turning Gear Motor ^0S0 i I
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