IR 05000277/1987034

Insp Repts 50-277/87-34 & 50-278/87-34 on 871109-13.No Violations Noted.Major Areas Inspected:Licensee Followup & Corrective Actions Re Several NRC Previously Identified Items

ML20234B025
Person / Time
Site:	Peach Bottom
Issue date:	12/16/1987
From:	Anderson C, Woodard C NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
Shared Package
ML20234B011	List: IR 05000277/1987034 ML20234B007
References
50-277-87-34, 50-278-87-34, NUDOCS 8801050418
Download: ML20234B025 (8)

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U.S. NUCLEAR REGULATORY COMMISSION

REGION I

50-277/87-34 Report No /87-34 50-277 Docket No DPR-44 License No DPR-56 Licensee: Philadelphia Electric Company 2301 Market Street Philadelphia, Pennsylvania 19101 FaciH ty Name: Peach Bottom Atomic Power Station, Unit 2 and 3 Inspection At: Delta, Pennsylvania Inspection Conducted: November 9 - 13, 1987 Inspectors: h M M 4) ~

m[ N///#7 Carl H. Wo'od d, Reactor Engineer d'a te~

Approved by: .w, /2 /s!/7 Cliff />rd J. Anders.on, Chief Plant date Syftems Section, EB, DRS Inspection Summary: Inspection on November 9 - 13, 1987 (Combined Inspection Report Nos. 50-277/87-34 and 50-278/87-34).

Areas Inspected: A routine unannounced inspection was conducted to review the licensee's followup and corrective actions related to several of NRC's previously identified open item Results: A number of unresolved items and inspection followup items were close No violations were identified during this inspectio {DR ADOCK 05000277 DCD

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DETAILS 1.0 Persons Contacted 1.1 Philadelphia Electric Company

• D. Smith, Plant' Manager R. Brower,.I&C Engineer 'i

• C, Patton, Electrical Engineer

• M. Hammond, Construction Engineer V. Boyer, Senior-Vice President  !

C. Flecther, Electrical Engineer . _ . ___ _

• J. Coyle, Power Generation Engineer F.. Lear, Licensing Manager W. Clune, Electrical Engineer 1

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1.2 Nuclear' Regulatory Commission l T. Johnson, Senior Resident Inspector

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• L. Myers, Resident Inspector

• R. Urban, Resident Inspector

• Denotes those present at the exit meeting on November 13, 1987.

2.0 Licensee Activities Related to Previously Identified Items (Closed) Inspector Followup Items 81-19-05 and 81-20-02 Electrical Separation Deficiencies l In License Event Report LER 2-81-38/IP and 2-EI-38/IT, the licensee identified electrical separation problems in the control circuits for the eight 4KV emergency bus circuit breakers which provide power to the four emergency buses (for each unit) from off-site sources. The licensee reported that due to a design oversight, the controls and cables for these circuits breakers were not properly designated. As a consequence, they were not installed in accordance with separation requirements and therefore, were not in con.pliance with the NRC Code of Federal. Regulations single failure criterion of 10 CFR 50, Appendix A, Criterion 1 The nature and extent of the separation deficiencies identified and the actions required to provide proper separation were as follows: Since the control cables were not provided with adequate designation during design and installation, all cables required predesignation in their documentation, their qualification and in their physical installatio There are 32 cables for each uni _ - _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ - -

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3 Licensee inspection revealed that all 32 of the Unit 2 cables required rerouting to provide proper separation. Only 9 of the Unit 3 cables required reroutin . Each unit shutdown panel houses circuit breaker control. switches for-that unit. . Half of the redundant switches required canning to. pro-vide isolation within the panels. In addition, the control wiring from these switches required conduit to provide wiring. separatio . The' transformers differential current lockout relays provide control signals to the circuit breakers. The contacts of these relays did not provide adequate separation for the signals going to different i breakers. Interposing relays to provide signal separation to each circuit breaker were require The NRC inspector verified. licensee actions taken to resolve this problem as follows: Reviewed licensee plant Modification No. 922 which covers the work required for both Unit 2 and 3 and a safety evaluation of the impact of this modification work. The modification work was performed under various Modification Record Form (MRF) numbers. The following completed MRF documentation was examine MRF Numbers Description of Work Performed Unit 2 54-C-81-10 Preliminary separation work, 54-C-81-11, 12 Install interposing relay C-82-39, 40, 41 & 42 Replace / reroute control cables -

4KV switchgear, main control room and emergency shutdown pane Can circuit breaker control switche C-82-121 Replace spare relay Unit 3 54-C-81-50,51, 52, 53 & 54 Replace / reroute control cables -

4KV switchgear, main control room, and emergency shutdown pane Can circuit breaker control switche C-81-55, 56 & 57 Install interposing relay The completed I/RFs reviewed included appropriate descriptions and approvals of the work to be performed and also sign-off acceptance, certifications, and verification turn-over of the completed work from maintenance to operation The job check lists examined included

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maintenance engineering and QC acceptance of completed work. The MRF's 'also . included appropriate drawing modifications to cover the plant change . The inspector further. verified performance of Modification 922 to 1 correct the deficiencies by a physical walkdown of one complete Unit 2 circuit breaker channel of separation from the 4KV circuit breakers through the caole trays and conduits to the remote canned circuit breaker switches in the emergency shutdown panel. A sample of the drawings revised to indicate the modification was also examined. There were no outstanding problems identified by the inspector in the description of the work to be performed, the work j performed, and the updated plant drawing This item is close _(_ Closed) IE BLileti_n Item No. 84-02 Failures of General Electric Tyge HFA Relays Bulletin 84-02 identifies a history of failures of the GE type HFA relays dating back to 1973. Over the years GE has issued various service infor-mation~1etters discussing the relay failures and recommending their replacement with~ relays considered more suitable. Additionally, the NR has issued IE' Bulletin 76-02, Information Notices 81-01 and 82-13 and most recently IE Bulletin 84-02 for those GE relays covering the problems and identified replacement actions required to resolve these problem The inspector reviewed the licensee's letters dated June 28, 1984; October 1, 1984; and March 20, 1986 to the NRC concerning Bulletin 84-0 In the 1984 letters, the licensee identified 723 HFA relays in use in the class IE systems in both Units 2 and 3 and provided a plan which included interim surveillance and a schedule for replacement of the relay In accordance with the Bulletin 84-02, the licensee also performed a review of other relays in use which could be susceptible to failures similar to those experienced with the HFA relays. In the October 1, 1984 letter, the licensee identified other relays with potential problems and provided a replacement schedule for them. The relays identified were the Agastat GP series, the GE' CR120, the Cutler-Hammer Type M and the Agastat 7000 series relay The inspector confirmed license actions taken to comply with the replacement commitments made to NRC as follows:

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All GE HFA A-C coil relays have been replaced in both units. The D-C coil relays replacement in Unit 2 is complete and is in progress on Unit 3. Completion is scheduled for the current outage. This work is being performed under Modifications 959 and 959 l

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All Agastat GP series relays have been replaced in both units. This work was performed under Modification 1565. A total of 60 relays were replace The GE CR120 relays currently are being replaced under a series of Modification Request Forms (MRFs). Replacement ef these relays in both units is scheduled for completion during the current outage. A total of 66 relays are being replace The Agastat 7000 series relays currently are being replaced under a series of MRFs. The licensee plans to complete the replacement during the current outage. A total of six relays are being replace The Cutler-Hammer Type M relays have been replaced in both units under Modification 1563. A total of 58 relays were replace This item is closed based upon the licensee's replacement actions taken to re. solve the Bulletin 84-02 relay problems; the fact that the replace-ment are nearing completion; and the licensee's current commitment to complete the remainder of the work during this outag (Closed) Inspector Followup Item 85-44-06 Emergency Diesel Generator Blower Deficiency During January 24, 1986, the licensee reported a Unit 2 scram when the E-2 emergency diesel generator (DG) tripped after running approximately fifty-one hours at low load conditions. Subsequent investigations revealed that the DG trip was due to insufficient combustion air flow after failure of the scavenging air blower. On February 24, 1986, PECO issued a 10 CFR Part 21 report concerning the air blower failure. The DG is a Fairbanks Morse Model 3800TD8-1/8. It uses a turbo-blower parallel air system with the blower supplying combustion air at low load conditions and the turbo-chargers supplying air at the high load condition Fairbanks Morse had issued two service information letters (SILs) for similar air blower failures at another location in June,1984. The SIls warned against operating the DG at no load conditions in excess of a few minutes due to a thermal deformation problem with the blower housin Recommended corrective actions to permit long term light loading of the DGs was to replace the blowers with blowers having increased clearances or to re-machine the installed blowers for increased clearance The inspector confirmed that the licensee has taken appropriate action under Modification 1927 to send the blowers to Fairbanks Morse for rebuilding to provide the recommended increased clearances. All blowers except for the El OG have completed the modification and are reinstalle The El blower is scheduled to be completed during this outage. This item is close q l

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(Update) Unresolved Item'86-25-03 Licensee Prugram for Defining Existin AC/DC Loads and. Control of Load Groups

. Review of the licensee's current status of an electrical load control program disclosed the following:

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.The' licensee has now established a load data base for all of the connected load The load classification groupings have been made and each load group has its own load lists. These have been distributed to th plant staff for walkdown ~ confirmation of all connected loads to. all . _

buse The licensee is working both with an inhouse computer program and a Bechtel Computer Program (which was developed for and is in.use for Limerick) to perform steady state and transient analysis of the electrical loads and determine the resultant voltage profiles through-out the plan Initial electrical load studies will be made using worst case nameplate ratings of electrical devices and maximum short circuit and starting current Loadings will also consider the maximum numbers of electrical items that could be operated during each time interval, Subsequent studies will be made using data which more nearly approximates the actual load. condition The licensee expects to have this program operational during the

.first. quarter of 198 NRC will continue to follow this work under unresolved item 86-25-0 (Update) Unresolved Item 86-25-11 Unrestrained Seismic Missiles due to Circuit Breakers on Rollers not Tied Down The inspector observed that there are unrestrained circuit breakers on the floor outside the circuit breaker cubicles in the safety-related 4KV switchgear rooms. The licensee stated that these breakers are in process of rebuild / refurbishment by GE and will be reinstalled within the switchgear cubicles when work is complete which would resolve this

proble The NRC will continue to follow this work under unresolved item 86-25-1 Status Review of Information Notice 87-82 General Electric Model 12 CFD Relays The inspector reviewed Information Notice 87-82 which provided licensees with an alert of a potential significant safety problem involving General Electric Model 12 CFD relays that are not seismically qualified for Class 1E safety service when in the de-energized state of operatio _ - ._

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The inspector found that these relays were used as the differential current protection relays for each of the four emergency diesel genera-tor The inspector confirmea that the licensee.has replaced these GE Model CFD relays with seismically qualified GE Model LJD relays under plant Modification 1205 which was completed October 25, 1987 to resolve this proble Status Review of Licensee Event Report (LER) 2-86-12 Emergency Buses Loss of Power The inspector reviewed LER 2-86-12 which reported a loss of power to the E-22 and E-23 4KV en ergency buses that was attributed to a f ailed .

energency diesel generator (DG) engine speed sensing switch. The diesel ._

generators are Fairbanks Morse Model 3800 TD8-1/8. At the time of the event, the E-2 DG was supplying E-22 and E-23 buses with 4KV power. These

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buses are normally supplied by offsite power sources; however, a few hours

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earlier one of the two offsite sources had been lost as a result of a fire at the North Substation (LER 2-86-10). When only one offsite power source !

is available, the eight 4KV emergency buses are usually aligned such that six are supplied by the available offsite source and the E-22 and E-23 buses are supplied by the E-2 diesel generator. This line-up allows the

'"A" and "B" reactor protection system motor generator sets on both Unit 2 and Unit 3 to be supplied by separate power sources, thereby preventing a full scram from occurring on loss of a single. power source. This was the line-up at the time of this even The DG engine speed switch contains two sets of contacts identified as SSW-1 and SSW- SSW-1 contacts close at 250 RPM increasing engine speed and SSW-2 contacts close at 850 RPM increasing engine speed (rated speed is 900 RPM). A failed drive pin at the connection between the engine drive shaft and the speed switch created a slippage condition which caused the speed switches to alternately cpen and close. This caused follower control and alarm relays to open and close actuating diesel generator alarms and causing oscillating green and red control lights on the control board. The chief operator tripped off the DG with a resulting loss of power to buses E-22 and E-23 during the interval when these buses were being transferred from the diesels to the offsite power sourc Licensee analysis of the failure concluded that the switch failed as a consequence of its normal usage for more than ten year Licensee corrective actions included replacing the speed switches on all four diesel engines and adding the speed switches to the DG annual inspection program.

l The inspector made a review of the LER failure report; found no history of l like failures at other plants, reviewed licensee's corrective actions to resolve this problem and had no further question L

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3.0 Unresolved Items Unresolved items are matter about which more information is needed to determine whether it is acceptable or a violation. Unresolved items are discussed in Paragraph .0 Exit Meeting The inspector met with the licensee's representative (ider.tified in paragraph 1.0) at the conclusion of the inspection of November 13, 1987, to summarize the findings of this inspectio During this inspection, the inspector did not provide any written material to the licensee. The licensee representatives did not indicate that the inspection involved any proprietary information.

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