IR 05000528/1991012
| ML17305B483 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 04/12/1991 |
| From: | Wong H NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | |
| Shared Package | |
| ML17305B481 | List: |
| References | |
| 50-528-91-12-MM, 50-529-91-12, 50-530-91-12, NUDOCS 9104300019 | |
| Download: ML17305B483 (67) | |
Text
U.S.
NUCLEAR REGULATORY COMMISSION REGION V
Report Nos.
50-528/91-12, 50-529/91-12, 50-530/91-12 Docket'os.
50-528, 50-529, 50-530 License Nos.
NPF-41, NPF-51, NPF-74 Licensee:
Arizona Public Service Company P. 0.
Box 53999, Station 9012 Phoenix, Arizona'5072-3999 Facility Name:
Palo Verde Nuclear Generating Station Units 1, 2, and
Meeting Location:
NRC Region V Office Malnut Creek, California Meeting Conducted:
March 15, 1991 Prepared by:
W. P. Ang, Project Inspector Approved by:
Summary:
H. Mong, Chic Reactor ProjectsSection II Hr~ el Date Signed A management meeting was held on March 15, 1991 at the NRC Region V office to discuss the preliminary Palo Verde Probabilistic Risk Assessment results, safety system unavailability history and goals, engineering involvement in plant operations, and non-quality related welding problems.
VioiS000>9 9locta PDR ADOCK 05000528
'I
DETAILS eetin Attendees rizona Public Service Com an APS WE Conway, Executive Vice President, Nuclear J. Levine, Vice President, Nuclear Production E. Simpson, Vice President, Engineering and Construction J. Bailey, Director, Nuclear Engineering S. Guthrie, Deputy Director, gA/gC C. Hauldin, Manager, Site Maintenance C. Stevens, Manager, Nuclear Engineering Analysis H. Powell, Manager, Nuclear Licensing G. Sowers, Technical Assistant for the Vice President; Nuclear Production D. Fan, Supervisor, PRA uclear Re ulator Commission J. Hartin, Regional Administrator K. Perkins, Deputy Director, DRSP D. Kirsch, Chief, Reactor Safety Branch G. Yuhas, Chief, Reactor Radiological Protection Branch H. Wong, Chief, Reactor ProjectsSection II R. Huey, Chief, Engineering Section D. Coe, Senior Resident Inspector W. Ang, Project Inspector G. Cook, Regional Public Affairs Officer W. TenBrook, Senior Radiation Specialist Probabilistic Risk Assessment PRA Safet S stem Unavailabilit Hr. Perkins opened the discussions by stating that Region V was interested in the preliminary PRA results and the Core Damage Frequency
"(CDF) for the most dominant PRA scenarios, the near-term corrective actions undertaken by APS to address the identified concerns, and the integration of safety system availability goals with the PRA.
Hr. Martin added that the NRC understood the major issues of the PRA, but was also interested in discussing the engineering leadership role for the PRA.
He noted that the preliminary PRA information was available since approximately Hay 1990.
He was concerned, however, that during his visit to the plant in February 1991, very few of the Operations personnel he talked with, including managers and supervisors, had an understanding of the high risk vulnerability identified by the preliminary PRA results.
He stated that he wanted to discuss the engineering leadership role in the operations of'the plant and how the PRA results could be used to further define that role.
Hr. Stevens began the APS presentation by briefly describing how APS was in the process of performing an NRC required Individual Plant Examination (IPE).
A level
PRA was being performed as part of the IPE requirement and initi~l results identified two dominant scenarios that led.to a
CDF of,4XIO per reactor year.
The most dominant scenarios
both involved the loss of a Class 1E DC bus, with the loss of the "A" train bus (PKA-H41) being most dominant since four of five feedwater sources would be disabled upon loss of the affected DC distribution panel (PKA-D21).
The initiating events for the dominant scenarios were identified as (1)- loss of all ventilation to the DC equipment rooms resulting in the failure of the battery chargers and vital inverters caused by high temperature and, (2)
an electrical fault ~r component
.
failure in the DC distribution system.
The5CDF of 4X10 assumed no operator action and would decrease to 2X10 with operator action to mitigate the consequences of the event.
Mr. Stevens enumerated the equipment affected by the dominant scenarios as listed on the enclosed APS slides.
Hr. Levine continued the APS presentation by reporting the interim compensatory measures that had been initiated to mitigate the dominant scenarios identified.
A policy statement was issued the previous week for entering an action statement to perform voluntary maintenance.
The policy statement controls and minimizes maintenance on the Auxiliary Feedwater (AFW) system, High Pressure Safety Injection system and the Emergency AC power systems.
In addition, the current Preventative Maintenance.(PM)
tasks for the AFW system had been reviewed to reduce system unavailability and the Diesel Generator and 120 volt AC and DC systems will be reviewed over the next six weeks.
Lastly, temperature monitoring of DC equipment rooms was initiated and temporary backup ventilation equipment were staged to compensate for a potential loss of room ventilation.
Hr. Martin inquired if APS was comfortable with the actions being taken to reduce maintenance activities.
He stated that he did not necessarily know what the best activity level was, but felt that it should be at a
level that was managed; well thought out, and thoroughly considered what maintenance needed to be done.
That level should be one that APS was comfortable with rather than a reaction to NRC inquiries.
Hr. Levine responded that the maintenance activity level had been studied by APS for some time and was not just a reaction to the questions being asked.
Hr. Levine continued the discussion by enumerating actions taken and being planned to enhance recovery from the loss of Train A DC bus event.
Those actions are listed in the attached enclosures.
Included in those actions are briefings of all operating crews regarding the PRA vulnerabilities, review of and changes to the Emergency Procedures, validation of the procedures in the simulator, and training of the operating crews'for specific local manual actions that had been identified as required for recovery.
Hr. Bailey proceeded to discuss design modifications being contemplated to minimize or eliminate "the event initiator's and to increase the reliabi'lity,of the non-class auxiliary feedwater system.
These modifications included addition of a high temperature alarm in the DC equipment room, changes to the logic of Hain Steam Isolation Valve (HSIV) and Feedwater Isolation Valve (FWIV) solenoid valves to preclude closure of the MSIVs and FWIVs on loss of DC control power, a change to the failure mode of the train "A" downcomer isolation valve such that it fails open on a'oss of DC pow'er, and the'ddition of alternate DC
~
'
3'ontrol power to the non-class AFW pump breaker.
Current projections indicated that three of the four modifications could be installed in all three Palo Verde units by the end of 1992.
The addition of an alternate DC control power source for the non-class AFW pump was projected to be completed in Units I and 3 by the end of 1992 and in Unit 2 by May 1993.
Mr. Bailey noted that accomplishment of the second and third modifications noted above would reduce the CDF by a factor of 10.
Hr. Levine continued the APS presentation by discussing the Palo Verde safety system performance goals in general and specifically the goals for the AFW system, the emergency AC power system and the High Pressure Safety Injection system.
The noted goals are included in the attached APS slides.
Hr. Levine also discussed the actions being taken specifically to improve the system availability of those systems affected by the PRA vulnerability previously discussed.
Hr. Stevens discussed the actions ongoing for completing the NRC required IPE for Palo Verde.
He discussed how the PRA information was being integrated into engineering, operations and maintenance activities.
Planned future usage of PRA information included outage planning support, procedural and hardware changes for additional risk reduction, maintenance planning and PM recommendations, severe accident management, and incorporation in licensed operator training.
Hr. Simpson continued the discussions by providing the lessons learned from the current PRA effort and the actions being'aken to improve the engineering involvement in plant operations using the PRA.
Hr. Hartin stated that the discussions provided a focus on safety system unavailability.
He recognized that he did not know the right answer but considered that APS should have a safety system availability rationale that is well thought out and managed.
He did not consider that rationale to exist presently.
APS outage management should be based on reliability data and historical information, and should be balanced with the available PRA risk information.
This should also include engineering management in balancing maintenance with the PRA risks involved.
Hr. Hartin encouraged APS to consider ways to communicate the PRA findings and experience to industry and Mr. Conway agreed that some form of communication was appropriate, such as through the INPO Network system.
Hr. Hartin stated that he would like to discuss the safety system availability/PRA vulnerabilities subject again in the next few months when APS could outline a course of action that they considered correct for Palo Verde.
En ineerin Involvement with 0 erations and Maintenance Hr. Simpson discussed several recent issues 'identified at Palo Verde which indicated a need to improve engineering involvement and engineering response to issues.
Mr. Simpson described the expectations of APS management for engineering, their actions already in place to provide engineering, involvement, and actions being taken to further strengthen engineering support functions.
One effort was to heighten the sensitivity to identify and evaluate safety significant issues promptly and when appropriate, escalate these issues to APS management
attention to ensure sufficient resources were provided and that the problem significance is adequately assessed.
Hr. Hartin emphasized the vital role that engineering has in plant operations and that the engineering expectations discussed must have management leadership to effectively cross the traditional institutional boundaries between
'rganizations.
Hr. Simpson acknowledged the comments.
4.
Non-ualit Meldin Discre ancies Hr. Guthrie and Mr. Hauldin provided a verbal report on a non-9 welding problem experienced recently at PYNGS.
The problem included the use of unqualified welders, lack of weld documentation and the use of weld rod on welds that the rod had not been drawn out for.
gA review of the problem determined that the condition did not affect g welds since they were performed under more formal procedures and inspected by qualified
'C inspectors.
Mr. Guthrie enumerated the corrective actions being taken for the non-g welds.
These actions included replacement of unqualified non-g welds identified, verification of welder certifications for future welds, interim gC inspection of non-9 welds, revocation of field inspector qualifications of affected field engineers, review of the weld rod program, and enhancement of training for performance of non-9 modifications.
5.
Closin Remarks Hr. Martin expressed his appreciation for the information and discussion provided during the meeting and encouraged further discussions.
in the next few months regarding the actions taken in response to the PRA and in the area of safety system availability.
Hr.
Conway acknowledged these comment NRC/APS MEETING IVLMCIX15) 1991 PART I - IPE I.
OPENING REMARKS II.
REVIEW OF DOMINANTIPE SEQUENCE AS IDENTIFIED IN THE IPE
~
Systems Impacted
~
Operations Response III.
COMPENSATORY ACTIONS TAKEN OR PLANNED IV.
IPE MODIFICATION(S)SCOPE AND SCHEDULE V.
SAFETY SYSTEM UNAVAII.VILITYGOALS VI.
PRA PROGRAM AT PALO VERDE t
VII-CHRONOLOGY OF EVENTS IN IPE PROJECT
~
Strengths and Weaknesses
~
Corrective Actions VIII. LESSONS LEARNED W. F. Conivay J. A. Bailey J. M. Levine J. A. Bailey J. M. Levine C. R. Stevens C. R. Stevens E. C. Simpson SHORT BREAK ART II - ENGINEERING COUPLED WITH OPERATIONS 8c MAINTENANCE L
EXPECTATIONS OF PV MANAGEMENT II.
ACTIONS TAKENIN 1990 & 1991 III.
FUTURE EFFORTS TO ENHANCE DAY-TO-DAY SUPPORT BY ENGINEERING AT PVNGS IV.
PROPOSED APPROACH TO ENHANCE TECHNICALISSUE MANAGEMENT E. C. Simpson E. C. Simpson E. C. Simpson E. C. Simpson
DOMINANTIPE SEQUENCE TWO SCENARIOS IDENTIFIED DURING THE PERFORMANCE OF THE LEVEL I PROBABILISTIC RISK ASSESSMENT. EACH LEAD TO A CDF VALUE OF 4X10 PER REACTOR YEAR. ASSUMING NO OPERATOR RECOVERYACTIONS.
THE DOMINANTSCENARIOS BOTH INVOLVETHE LOSS OF A CLASS lE DIRECT CURRENT BUS INITIATEDBYTWO SEPARATE MECHANISMS:
I.
LOSS OF ALLVENTILATIONTO THE DC EQUIPMENT ROOMS RESULTING INTHE FAILUREOF THE BALI'ERY CHARGERS AND VITALINVERTERS CAUSED BY HIGH TEMPERATURE.
2.
ELECTRICALFAULTOR COMPONENT FAILUREIN THE DC DISTRIBUTIONSYSTEM.
LOSS OF THE 'A'RAIN DOMINATED THIS CLASS OF EVENT SCENARIOS SINCE FOUR OF FI'W SOURCES OF FEEDWATER'WOULDBE DISABLED UPON LOSS OF THE DC DISTRIBUTIONPANEL. (SEE EVENT SEQUENCE).
LOSS OF CHANNELA 125V DC SCENARIO
~
DC POWER LOST TO THE FOLLOWING:
NON-CLASS AFW PUMP MOTOR BREAKER CONTROL TRAINA AFWGOVERNOR CONTROL AUXILIARYFEEDWATER TRIP ANDTHROTTLE VALVE AFA-HV-54 TRAINA AFW ISOLATIONVALVEAFA-UV-37 TRAINA AFW REGULATOR VALVEAFA-UV-32 TRAINA AFW STEAM SUPPLY VALVESSGA-UV-134 AND SGA-UV-138
~
MSIV's ANDF%WS FAST CLOSE
~
100 PERCENT LOADREJECT: RCS TEMPERATURE INCREASES AND RCS PRESSURE INCREASES.
"~
REACTOR WILLTRIP ON HIGH PRESSURIZER PRESSURE.
~
PRIMARYSAFETIES WILLLIFT.
~
ITIS POSTULATED THATTHE REMAININGB TIGON AFWPUMP IS UNAVAILABLEELIMINATINGALLSOURCES OF FEEDWATER (%TIHOUT OPERATOR ACTION).
~
STEAM GENERATORS WILLBOILDRYIN APPROXIMATELY30 MINUTE V MCC IE.PHA M35 I
I I
25KVA,480 ~ 12OV VOLTAGE REGVLATOA10 z2%
IE.PNA401 1800 AH 125V DC BATTERY
'A'E PKA-F11 BATTERY 400A CHARGER 'A'25VDC IENKAAII IE.PHA.M33 BATCHGR 400A
'AC'25VDC IE4KA4(IS le (T BATTERY CHARGER
'C'E4KC4(13 300A 125VDC 1140AM 125M Dc BATTERY
'C'E P KG+13 125 VDC POWER SYSTEM LOAD GROUP
480V MCC 490V MCC IE.FHA M35 IE PHA.M31 25KVA,480 ~ 12OV VOLTAGE REGULATDAIalw(
IE PNC V27 I
I 480V MCC IE PHA M35 125V OC CONTROL NC)
ll HC CENtER E PKA M41 HC)
NC)
NC)
Hc)
CONTROL CENTER NC)
IE.P C4143 125V DISTAIBUTIOHPANEL IE PKA432I '
(KSTRIBUTIONPANEL IE.PKC4123 480V. 30. 25KVA INVEAtEAIE PKC4(43 480V. 30 25KVA STARIEA STAATFA IE PKC4(43 120 V. 10 I
25KVAINVERTER A IE.PHA411 HO MANUALTRANSFERSW(UNITIt STATIC TRANSP EA SW (UNITS 2 d 3)
I I
)
120VAC UNGROUNDED I
IaVITALINSTRUMENT
)
(KSTRIBUTIONPANEL
120 V. 10 25KVAINVEATEA
'A'E.PNA HII MANUALTRANSFER SW(UNIT I)
StATC T RAN SF ER SW (UNITS 2 d 3t I
(
I UNGROUNDED 120VAC I
laVITALINSTRUMENT (KSTRIBUTIOHPANEL SHUTDOWHCLG tSOLVALVE 14 SIC.VV'
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COMPENSATORY MjMSUPZF)
I.
ACTIONS TO 1VEHGATEINITIATIONOF THE EVENTOR REDUCE ITS PROBABILITYOF OCCURRENCE.
A.
THE POLICYFOR ENTERING ANACTIONSTATEMENT TO PERFORM VOL~iARYMAJI~NANCE WAS'SSUED.
E.
THE CUIUIENTPEEVENTIVE MAINTENANCETASKS FOR THE A'LVZLIARYFEEDWATER SYSTEM %ERE REVIEWEDTO REDUCE SYSTEM UNAVAILABILITY DUETDPIAIINKD MAINTENANCE.THE DIESEL GENERATOR AM)CLASS 120V AC AI'K)DC SYSTEMS WILLBE REVIEWS OVER THE NEXTSIX WEEKS. CHANGES TO THE PROGtudr1'WILL BE IvLV3EEXPEDITIOUSLYBASED ON THERESULTS OF THEREVIEW'.
C MONITORINGOF TEMPERATUREINTHEDC EQUIPMENTROOMS WAS STARTED TO PROVIDE EAIU.YIDEN.HFICATIONOF ONE OF THE SCENARIO INITIATORS,LOSS OF HVAC. EQUIPMENT WAS STAGED TO PROVIDE TEMPORARYVENTILATIONIN THE EVENTHVACIS LOS r I
"II.
A'ONS TO ENHANCERECOVERY FROM THE EVENT ONCE IT IS INITIATEDE A.
NIGHTORDERS WHIRWRIITSN FOR EACH UNITTO BRIEF THEMON THERESULT OF THE PRA AND WHATSOME RECOVERY ACTIONS WOULDBE.
B.
THEEMERGENCYPROCEDURZS WEREREVIEWEDTO DEIERMINETHE ACTUALOPERATDR RESPONSE TO THIS SCENARIO AIIDDEIERMRKTHE
~ S OF THE PROCEDURAL DIRECIIDN.
C REVISIONS TO THEEMERGENCY PROCEDURE WERE MMIETO ENHIINCETHEIREFFECITFENFES.
1.
THE PATHTHROUGHTHE PROCEDURES WAS S"Q~MLINEDTO PROVIDEAMORE DIRECT PATH TO THE APPROPRIATE RECOVERY STEPS.
2.
SPECIFIC DIRECTIONWAS ADDEDTO THE PROCEDURE FOR RECOVERY OPERATIONS THATWKKNOT PREVIOUSLYINCLUDED.
D THENEWPROCEDUIKS WILLBE VALIDATEDON THE SIMULATORAM)ACTUALTESTING INUNIT T&KK
E JPMs WILLBE DEVELOPED FOR SPECIFIC LOCAL MANUALACTIONS THATAREREQUIIMDFOR RECOVER e
PROPOSED DESIGN MODIFICATIONADDRESS TWO ASPECTS OF THE EVENT SCENARIO:
1.
M1NIMIZINGOR ELIMINATINGEVENTINITIATORS:
~
MMMIZINGTHE PROBABILITY OF LOSING THE DC EQUIPMENT PANEL AS A
RESULT OF A
HIGH TEMPERATURE IN THE DC EQUIPMENT ROOMS.
~
ELIMINATING THE PLANT TRANSIENT WHICH INITIATES AS A RESULT OF THE CLOSURE OF THE MSIV'S ANDFQtIV'S.
2.
INCREASING THE RELIABILITYOF THE NON-CLASS AUXILIARY FEEDWATER SYSTEM
~
PROVIDING ADDITIONALFLOWPATHS FOR MAKEUP WATER TO THE STEAM GENERATORS THROUGH THE DOWNCOMER LINES TO EACH STEAM GENERATOR.
~
ALLOWINGCONTINUED REMOTE OPERATION OF THE NON-CLASS.
AUXILIARY FEEDWATER PUMP BY INCREASING THE RELLQ3ILITY OF THE BREAKER CONTROL POWE MINIMIZINGOR ELIMINATINGEVENT INITIATORS DC E UIPMENTROOM HIGH TEMPERATURE ALARM SCOPE ADD A HIGH TEMPERATURE ALARM FOR EACH OF THE FOUR DC EQUIPMENT ROOMS, WHICH ALARMS IN THE MAINCONTROL ROOM.
TECHNICALISSUES TO ADDRESS REQUH&MENTFOR IE VS NON IE SYSTEM CHANNELREDUNDANCY(IF IE SYSTEM)
NUMBERANDLOCATIONOF TEMPERATURE SENSORS ALARMINGSTRATEGIES TRENDING REQUII&MENTS SCHEDULE (SEE ATTACHED).
THE DCP CAN BE ISSUED BY AUGUST 18, 1991.
.INSTALLATIONSHOULD NOT REQUHK A UNIT OUTAGE, BUT MAYREQUIRE A SYSTEM OUTAGE FOR FINALTIE-INS.
TO ENSURE THIS CAN BE COMPLETED WI'M LE%LE RISK TO AN OPERATING UNIT,THE PLANIS TO INSTALLTHIS DCP FIRST IN UNIT 2 DUIUNGTHE 2R3 OUTAGE IN THE FALLOF 1991.
IF NO PROBLEMS ARE IDENTIFIED, THIS MODIFICATIONWILLBE INSTALLEDIN KQTS 1 AND 3 BY THE END OF 199 DC EQUIPMEN't ROONl HIGH TEMPERATURE ALARMSYSTEM (OPTION "A")
DC EQUIP. ROOM 'A" DC EQUIP. ROOM "8" DC EQUIP. ROOM "C" OC EQUIP. ROOM '0" TS TS TS TS TS TS TS TS TS = TEMPERATURE SWITCH LOCALANNUNCIATOR PANEL CONTROL BUILDING PLAN @ EL.
100'C EQUIPMENT ROOM HIGH TEMPERATURE TROUBLE ALARM ANNUNCIATORPANEL CONTROL ROOM
I
DC EQUIPMENT ROOM HIGH TEMPERATURE ALARMSYSTEM (OPTION "B")
OC EQUIP. ROOM "A" DC EQUIP. ROOM 'B'
DC EQUIP. ROOM "C" DC EQUIP. ROOM "D" TS TS TS TS TS TS TS TS TS = TEMPERATURE SNITCH CONTROL BUILDING PLAN5 EL1OO'LANT COMPUTER DC EQUIPMENT ROOM H!GH TEMPERATURE TROUBLE ALARM ANIIUNCIATORPANEL CONTROL ROOM
~,
Typica! Normal Ventilation To DC Equipment Room HJ-AO)
1400 CFM~
HJ-A03 Switchgear Room 1400 CFM DC Equip. Room Battery Room
PCR-9013H J018 DC Equipment Room High Temperature Alarm Projected Schedule (1991}
MARCH APRIL MAY JUNE JULY AUGUST SEPTEMBER OCTOBER NOVEMBER
11 td
1
15
29 d
20
3
17
1 S
22
5
19
2
16
30
14 2f 2S
11 tS
2 Develop design options bsue PO for system hardware OCP preparation
- Cl
- bsue DCP Rev. A E3 Constructablllty watkdown Technical review OBA meeting CD bsue DCP Rev. 0 U2 Aefuellng Outage
MINIMIZINGOR ELIMINATINGEVENT INITIATORS MSIV iVFAILAS-IS ON LOSS OF DC POWER SCOPE CHANGE THE MSIV AND F%M LOGIC AND SOLENOID VALVES SUCH THATA LOSS OF DC CONTROL POWER WILL NOT CAUSE A CLOSURE OF THE MSIVANDF%V/. THIS CAN BE ACCOMPLISHED BY CHANGING THE DEENERGIZE TO OPEN SOLENOID IN EACH TRAINTO AN ENERGIZE TO OPEN AND-POWERING EACH THROUGH A NORMALLY OPEN CONTACTVERSUS NORMALLYCLOSED CONTACT.
TECHNICALISSUES TO ADDRESS DESIGN BASIS (GDC)
SAFETY ANALYSIS APPENDIX R SCHEDULE
~ THE DCP CAN BE ISSUED BY OCTOBER 1, 1991, ASSUMING THE ABOVE ISSUES CAN BE READILY RESOLVED.
INSTALLATION WILL REQUIRE A UNIT OUTAGE. AS A RESULT, THIS MODIFICATION-WILL BE INSTALLED AS FOLLOWS: UNIT 2 - 2R3 (FALL 1991), UNIT 1 - 1R3 (SPRING 1992), UNIT3 - 3R3 (FALL1992).
MSIV/FWIVFail-As-Is Projected Schedule (1991)
MARCH APRIL MAY JUNE JULY AUGUST SEPTFMBER OCTOBER NOVEMBER
11
25
8
22
8
20
3
17
1
15
29
12
26
9
23
7
21
4
18
2 ( "m'>M 4'>> 'A>>>>>>>A ". '<r ~
'Safety Analysis
'Y>>'>>>>:>'9?5 Append R C on structablllty walkdown Technical:
5'>: ',(c >+'>5 >>>e>> >o'A,.'z.>'c"':
cx>>: >>'?>> zY(>("c'r?>>>>(+>>'shR'>4:" '.>
Prspare DCP DRB meeting c?"..4c'?'?:..>>>>>>.
Q~>(>>)A ~ ( +4k'>>'>?4?0>>>>'>>?(>>>>>>
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Prepare DCN8 It SDCNs leave Rev. 0 A>A>>:>>4,>kg'>> '.$ >>>">> N
>.?,,p',> Q> Y(Q>> ("r>>'>
- Prepare required evaluations If checkllst8
.>>?'>?>>(<>>>> )('v..>'P.PN5>>.N?'>K).
'P0:..4'jNN
~ Prepare descrlptlon of work
>?'>, YG >>>>> c(>? (? '?.INES'c':"(>>
4>>v 4 ~c> "le Procure englneerlng long lead time materials
INCREASING THE RELIABILITYOF THE NON-CLASS AFW SYSTEM TRAINA DOWNCOMER ISOLATIONVALVESFAILOPEN SCOPE CHANGE THE FAILURE MODE OF THE TIMIN A DOWNCOMER ISOLATIONVALVESTO FAILOPEN ON A LOSS OF DC POWER. THIS WILLREQUIRE CHANGING SOLENOIDS FROM DE-ENERGIZE TO OPEN TO ENERGIZE TO OPEN.
TECHNICALISSUES APPENDIX R SCHEDULE (SEE ATTACHED)
THE DCP CAN BE ISSUED BY SEPTEMBER 16, 1991.
INSTALLATION WILL REQUII& A UNIT OUTAGE. AS A
" RESULT, THIS MODIFICATION WILLBE INSTALLED AS FOLLOWS: UNIT 2 - 2R3 (FALL 199.1), UNIT 1 - 1R3 (SPRING 1992), UNIT3 - 3R3. (FALL1992).
PCR 90-13-SG-081 Train A. Downcomer Fail Open on Electrical Failure Projected Schedule (1991)
MARCH APRIL MAY JUNE JULY AUGUST SEPTEMBER OCTOBER NOVEMBER
11
25
8
22 29.8
20
3
17
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'IS
29
12
28
9
23
7
21
4
18
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Prepare DCP Prepare OCNS/SDCNs dw<:. xe'%~K Prepare evaluation It checklist Prepare Safety AnalysIs (50.59)
50.59 Review
. <!(~%5'im. <<<'.+;c>".'~s ':<>>re<:"..'0."
- Prepare descrlptlon of work:
<&.<><<
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Prepare BOM Technical ID Review Comment resolution Approval Issue R89. 0 Order material 5 delivery
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INCREASING THE RELIABILITYOF THE NON-CLASS AFW SYSTEM NON-ESSENTTAL AFW PUMP BREAKER CONTROL POWER SCOPE PROVIDE ALTERNATE DC CONTROL POWER TO THE NON-CLASS AUXILIARY FEEDWATER PUMP BREAKER.
PRELIMINARY CONCEPTUAL DESIGN INDICATES THAT PROVIDING CONTROL POWER FROM EITHER OF TWO REDUNDANTSOURCES OF "A"CHANNELDC POWER, WITH POWER TRANSFER POSSIBLY OCCURRING AUTOMATICALLYFROM THE PREFERRED SOURCE TO THE BACKUP SOURCE WILLPROVIDE THE BEST SOLUTION.
TECHNICALISSUES TO ADDRESS ALTERNATESOURCES OF POWER AUTOMATICVS. MANUALTRANSFER SUPPLY ALTERNATEPOWER TO OTHER COMPONENTS LOCATIONOF AC-DC CONVERTER SCHEDULE (SEE ATTACHED)
BE ISSUED BY DECEMBER 1,
1991.
iNSTALLATION WILL REQUII& A UNIT OUTAGE. AS A RESULT, THIS MODIFICATION WILL BE INSTALLED AS FOLLOWS: UNIT 1 - 1R3 (SPRING 1992), UNIT 3 - 3R3 (FALL 1992), UNIT2 - 2R4 (SPRING 1993).
PCR 90-13-AF-016 CONCEPTUAL DESIGN (R1)..
EXlSTING:
BATTERY 125 VDC CONTROL CENTER DC DISTRIB.
PANEL E-PKA-M41 E-PKA-D21 BATTERY CHARGER
"A" CHANNEL DC DISTRIBUTIONSYSTEM 803S TO AFH.PO E-PBA-S03 4.16KV SWITCHGEAR
PCR 90-'i 3-AF-0't 6 CONCEPTUAL DESIGN (R1)
'
CHANGE TO BATTERY 125 VDC CONTROL CENTER DC DISTRIB.
PANEL (~v.p pgA 1 <<cy E-PKA-M41 E-PKA-D21 BATTERY CHARGER FEJ3 FROM EITHER MCC E-PHA-M33 OR M35 h~My>~p;.j 480v MOTOR CONTROL CENTER E-PHA-M31 6<gQ
)35; Qwh<<I<.<l<
~~">>~AGNEW,iQUIPSlEhfTk,CABLE>=:-,-,....<
SO3S TO AFN-PO Note 1 - To circuit breaker PBA-SO3S control circuit.
E-PBA-S03 4.16KV SWITCHGEAR
.
PCR 90-13-AF-016 Non-Essential Auxiliary Feed Pump Breaker Control ProjeCted Schedule (1991)
MARCH APRIL MAY JUNE
11
25
8
22
8
20
3
17
JULY AUGUST SEPTEMBER OCTOBER NOVEMBER
15
29
12
26
9
23
7
21
4
18
2 Ucenslng Interface Prepare baltery charger specs C3 Meeting to flnallze conceptual deslgn-
-
-3 Spec review OCN preparation
- C~
~
~ Evaluate bids DCP preparation Procure battery charger Issue Rev. A Cross dlsclpllne review C3 Conslructsblllty walkdown Constructablllty walkdown/
comment Incorporation Technical review E3 DRB meeting DRB comments Incorporation OCP Issue Rev. 0:
SUMMARY. OF PRA MODIFICATIONS ALLFOUR DESIGN CHANGES ARE ACTIVELYBEING DEVELOPED A RANEZNG IN PRIORITY OF THE IMPORTANCE TO MITIGATION OF THE EFFECTS OF THE IDENTIFIED IPE VULNERABIL1TYIS (%TIH OPERATOR ACTION):
1.
MSIV/FVGVFAILAS-IS ON LOSS OF DC POWER 2.
TRAINA DOWNCOMER ISOLATIONVALVESFAILOPEN 3.
NON-ESSE%I'IAL AFW PUMP BREAKER CONTROL POWER 4.
DC EQUIPMENT ROOM HIGHTEMPERATUIKALARM THE SCHEDULES FOR IMPLEMENTATION OF THESE MODIFICATIONS PROJECT THAT THREE OF THESE FOUR (1., 2.,
AND4.) WILLBE INSTALLEDINALLTHREE UNITS BYDECEMBER 1992. THE FINAL MODIFICATION (3.) WILL BE INSTALLED IN KtITS 1 AND 3 BYDECEMBER 1992 ANDINKGT 2 BYMAY1993.
BY COMPLETING THE FIRST TWO, THE CDF IS SIGNIFICANTLY IMPPROVE PVNGS SAFETY SYSTEM PERFORMANCE GOALS SYSTEM 1991 1995 GOAL GOAL PER TRAIN PER TRAIN 1990 PVNGS INDUSTRY PEf<FORMANCE MEDIAN AUXILIARYFEED%ATER SYSTEM EMERCENCYACPOWm SYSTEM
'.2%
2.5%
2.0%
2.0%
U1 - 5.7%
U2 - 3.4%
U3 - 2.4%
Ul - 3.0%
U2 - 2.5%
U3 - 4.2%
1.4%
1.9%
HIGHPRESSURE SAFETY INJECTION 1.0%
1.0%
U1 - 15%
U2 - 0.4%
U3 - 1.3'7o 0.8%
ASS LP )ING THE REVISED PM PROGRAM FOR AF IS IN PLACE ANDCORRECTIVE O'IAINTENANCEIS THE SAME AS 1990, TI-IEUNAVAILABILITYESTIMATEDFOR THE SYSTEM IS APPROXIMATELY2.0%.
AUXILIARYFEEDWATER SYSTEM Safety System Performance Indicator (SSPI)
UNIT2 UNlT3 Goal SSPI 1990 Qtr. 4 SSPI 1990 (1 YR.) SSPI 3 YR. SSPI 0.032 0.020
<0.057>
<0.039>
0.032 0.012
<0.034>
<0.046>
0.032 0..021 0.019 0.0244
% CM/ST/PM
% CM/ST/PM
% CM/ST/PM 68/1/31 31/2/67
-
44/5/51 UNIT 1 DOMINANTCONTRIBUTORS Replaced defective relay.
Implemented PCPs, performed movats and equipment qualification tasks on CTAHV001 and 004, AFAHV0054.
Monthly removal ofcondensate from AFAP01, turbine driven pump.
UNIT2 Rework governor.
Implemented PCPs, performed movats and equipment qualification tasks on CTAHV001 and 004, Monthly removal of condensate from AFAP01, turbine driven pump.
UNIT3 Implemented PCPs, performed movats and equipment qualification tasks on AFAHV00. -'.
Monthly removal ofcondensate from AFAP01, turbine driven pump.
< )Denotes goal exceeded
A.
IPE 1. Approach 2. Status 3. Results B.
INTEGRATIONOF PRA INTO PV ACTIVITIES 1. PRA Issue Reporting A Resolution 2. Ongoing Usage of PRA 3. Potential Future Activities
1.
A roach
~ Detailed Fault Trees and small Event Trees
~ Plant - specific Support System Initiators
'i.e., Loss of a DC bus)
- APS Engineers performed most analysis
~ Mainframe - IBMand SETS computer pro-gram
~ Level IIusing MAAPprogram to analyze se-vere accident phenomenology
~
Cross - discipline support received during de-velopment of PRA models
2.
Status
~ Level I PRA near completion witlidesign changes incorporated into the PRA models
~ Level Iiongoing. Consultants are on-site to support on-the-job training activities
~ PRA %'orkstation 3.
Results a.Dominant scenarios
~ Loss of a DC bus
~ Complete loss of Uentilation to DC Equip-ment Rooms b.Other Significant Scenarios
B. INTEGRATIONOF PRA INTO ENGINEERING, OPERATIONS R MAINTENANCEACTIVITIES 1.
PRA issue Re ortin & Resolution Reporting Criteria (consistent with GL88-20)
~ Functional Sequences
> 10 per Rx.-
yr.
Functional Sequences
> 5% total CDF
~ Functional Sequences contribute to a con-tainment bypass frequency o 10 "per Rx-yr.
Failure Data Trendin Pro ram
~ Looks at component failures for trends as well as impact to PRA Reliability Centered Maintenance Pro-ram(PM Task Force Safety System Unavailability Pro ram
2. On oin Usa eofpgA Design Change Package Input and Review.
Impact to core melt risk as well as design change reliability.
~ Chairman of DRB is department head.
I Support JCOs, EERs, MNCRs, PRS, etc.
Support Resolution of NRC/INFO Require-
- ments, i.e., NRC Info.Notice Evaluation Monitor, trend, and report on unusual safety system nnavaiiabiiity (Anx Feed, HPSI, EDGs). Identify availability targets and review PM activities to ensure safety system availabili-ty.
E-Plan scenario development support Support SSFI, 50.59, nuclear hazard insur-ance, No Significant Hazard Evaluation i
~
'
3. Planned Future Activities Outage Planning Support (SlD Risk)(Simiiar to SONGS Program)
Identify future procedural and hardware changes for additional risk reduction to achieve 10 per Rx-yr CDF.(APS Management Directive)
Integrate PRA results into maintenance plan-ing and PM recommendations. Identify risk sensitive components for mainter'ance organi-.
zation usage. (Similar to SONGS Program)
Severe Accident Management Incorporate PRA insights into Licensed Oper-ator Trainiag Program.
"
Tech Specs changes Provide reliabilityand risk analysis to support big picture. issue resolution and decision mak-ing.
EDG SBO Compliance Program (Deveio pment Stage)
PRA EFFORT LESSONS LEARNED POSITIVE
~
PRA BEING DONE WITHAPS DIRECTS
~
GAVE PRESENTATIONS TO OPERATIONS, NED,EED, STANDARDS, LICENSING, ANDMANAGEMENT.
TRAININGHELD FOR QA.
~
PRA/DESIGN TIGER TEAM
~
QA DEPT. FOCUSED AUDITINGOY PKA EQUIPMENT
~
ENGINEERING GIVINGCAREFUL CONSIDERATION TO MODS
~
PRA INFLUENCE ON REWRITE OF EOP'S
~
ON-LINEMAINTENANCERECOGNIZED AS IMPACT TO CORE MELTRISK
NEGATIVE:
~
ENGINEERIiNG COULD HAVEBEEN MORE EXPEDI-TIOUS ONCE MODS WERE APPROVED
~
NO COMPENSATORY MEASURES
ENGINEERING COUPLED WITH OPERATIONS AND MAINTENANCE Ex ectations of Palo Verde P
Mana ement:
~
Act on developing regulatory and safety issues to ensure timely prioritization and resolution of these issues to ensure the highest level of plant safety and regulatory compliance.
~
Promote an attitude that does not accept mediocrity, accepts individual accountability, report problems and learns from the experience of others.
~
It is the expectation that Engineering organization involvement will lead to improved operational and regulatory performance.
~
Enhance the proactiveness of the Engineering organization to anticipate the needs and resolve issues before they are identified through plant events.
~
Engineering must develop a more questioning and probing attitude to ensure indepth root cause review and thorough corrective action implementation.
~
The Operations and Maintenance organizations are expected to involve the Engineering organization in the resolution of technical problems and create a culture that endorses and implements recommendations and direction provided by the Engineering organization.
I Engineering must present a common position and voice (i.e.
System Engineer) when interfacing with the plant staf ACTIONS TAKEN TO ACHIEVE EXPECTATIONS All Engineering functions were brought under one organization.
Day-to-day direction and priorities of the Site Engineering and Technical Support organizations are established by the Vice President Nuclear Production.
Established onsite Design Engineering organization to support Site Technical Support and plant staff.
Realigned and restructured the Procurement Engineering organization with sufficient permanent APS personnel to provide support to operating units.
Engineering personnel are being assigned to the Maintenance
"shops to provide day-to-day engineering support.
Bi-weekly meetings are being held between the Engineering Managers.
The Plant Modifications Committee (PMC) is now chaired by the Director, Site Technical Suppor Actions Taken To A'chieve Expectations Page 2 Walkdowns of systems are being done by Design and Systems Engineers.
Transferred the Nuclear Analysis Department to Site Nuclear Engineering and Construction to focus the EQ activities, PRA efforts and NPRDS Program on day-to-day plant and engineering activities.
Established a Project Management Organization for Capital Projects.
This group has assumed many of the Project activities previously handled by the System Engineers.
Restructured the Nuclear Engineering Department by eliminating a layer of management and narrowing the scope of responsibility.
Filled all critical management positions within Engineering and Construction including Director, Nuclear Engineering and Director, Site Nuclear Engineering and Construction.
Redirected the Configuration Management and Design Bases Program at Palo Verde.
Established dedicated organization to accomplish this effort, with a focus on the end users at Palo Verde versus Nuclear Engineerin Actions Taken To Achieve Expectations Page
Defined and issued uniform Standards and Expectations for the Engineering and Construction group.
Defined roles and responsibilities of all organizations within the Engineering and Construction group.
Focus was placed on the Engineering organizations.
Site Technical Support, Design Engineering and Procurement Engineering attend the daily Unit Management Meetings..
There has been an assignment of a unit liaison engineer to each of the units.
The liaison engineer establishes unit priority for engineering work on a daily basis.
'stablished Component Engineers to create specialist on plant
"equipment.
This relieves the System Engineer from details and allows him to concentrate on system performance and monitoring.
The Component Engineers are our "vendor experts".
Established Weekend Duty Manager and Supervisor assignments to ensure continuity of support over the weekends and holidays.
Engineering was made a key element of the war room concept for outage management.
This has been extremely successful in the Unit 1 ST Outag FUTURE EFFORTS TO ENHANCE SUPPORT BY ENGINEERING AT PVNGS Establish a culture and increased sensitivity to the need to identify and evaluate operational and safety significant issues in a timely manner.
Included in this task is proper notification or escalation to senior management of significant operational or safety issues (condition reporting process).
Established a "Common Focus" for Engineering. A performance planning session was held the weeks of February 25, 1991 and March 11, 1991 to transform this "Common Focus" into a set of goals, objectives, performance standards and performance indicators for 1991.
The Palo Verde Business Plan is a critical element and focal point of this effort.
Define the requirements and scope of the performance monitoring program for equipment and develop a plan (Business Plan 3.D.8).
Establish the predictive maintenance program through implementation of departmental and maintenance procedures (Business Plan 3.C.4).
'OV Program (Business Plan 1.C.1.2).
Future Efforts To Enhance Support By Engineering at PVNGS Page 2 Develop and implement standard engineering specifications for corrective maintenance (Business Plan 3.C.3).
r Develop a
common engineering work management system (Business Plan 3.D.6).
Develop meaningful measures of station backlogs and reduce by the percent assigned in Task Plans (Business Plan 3.B.6).
Evaluate the Region V Engineering Managers Guidelines on proactive Engineering and integrate applicable portions at PVNGS (Business Plan 3.D.I).
"Identify and evaluate tlte various typ'es of engineering requests received and establish realistic resolution time frames (Business Plan 3.D.2).
Continue developing and implementing a process to measure the quality of selected engineering products (Business Plan 3.D.S).
Future Efforts To Enhance Support By Engineering and PVNGS Page
Evaluate existing conQguration management programs and processes to identify areas needing improvement (Business Plan 3.H.1).
Implement Design Basis Program per schedule (Business Plan 3.H.2).
Prepare and issue Safety Function and Shutdown Logic Diagram per CM Plan (Business Plan 3.H.3).
I