ML030870888
| ML030870888 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 11/26/2002 |
| From: | Kendall T Nuclear Management Co |
| To: | O'Brien K NRC/RGN-III |
| References | |
| FOIA/PA-2003-0094, MSSM 92-09, MSSM 92-11, MSSM 92-12 | |
| Download: ML030870888 (20) | |
Text
328 P01 NOV 26 '02 18:04 NMC Committed to Nuclear Excellence POINT BEACH NUCLEAR PLANT FAX TO:
FROM:
DATE:
PAGES:
SUBJECT:
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328 P02 NOV 26 '02 18:04 MSSM 92-11 *"
,' POINT BEACH NUCLEAR PLANT I- W MANAGER'S SUPERVISORY STAFF July 23, 1992 LfrT:M- YRS
- HELD ON JUNE 16, 1992 Page 1 NO:-j-.EPMANENT YRS FILE NO&/
Membme: G. J. Maxfield (Chairan)
W. J. Heofman J. A. Palmer T. J. Koehler J. J. Ekvetacqua T. L Fredrichs R. D. Seizert N. L Hoefert* W. A. Hennig (A)
Guestspg/Vtors:
G. R. Sherwood* P. A. Johnson K C. Kuizckw J. L Sopata*
R. E. Lnk T. J. Jessessky J. F- Anthony J. Gadzala. NRC D. D. Schoon* D. B. Dahleen* F. A. Flerije M. B. Koudelka D. R. Miller* *Part-tIme
- 1. Audlarv Feedwater (AFWM Controller QA Upgrade. Mr. Sopata reported on the project which upgrades AFW pressure conrtrolrs, pressure transmitters, I/P transducers and poestion Indicators for AF-4012/4019 air-operated AFW discharge valves. (See MSSM 92-09 for previous discussions).
The following AFW discharge pressure controllers and mn-reclrcutatlon flow controllers were evaluated:
"* Asco Model HT83025 Solenoid: Alows the solenold-controlled pneumatic mln-reckrcuaton pressure control valve to reposition based upon an electrical differential pressure signal. The solenoid energlzes, allowing Instrument air to open the minl-reclrculation valve, when the asociated AFW pump discharge flow drops below 30 gpm and deenerglzes, bleeding off air, when flow Is greater than 75 gpm. The valve Is designed to fatl shut upon a loss of power or Instrument air.
"* Copes-Vulcan Model 40814 Discharge Control Posftlorw. Repositions the motor-driven AFW pump pneumatic-operated discharge pressure control valve based upon an electrical signal; mitaintinng an AFW discharge pressure of 1200 psig. The valve Is designed to fal open upon a loss of power or Instrument air.
"* Foxboro Model 611GM Dbscharge Pressure Transmitter. Provides an accurate electrical representation of AFW pump discharge pressure to the pressure control loop.
- Foxboro Model 62H-UE Discharge Pressure Transmitter: Controls the electrical signals in the discharge pressure current loop.
0 Foxboro Model M/610A Discharge Pressure Loop Power Supply, Provides power to the discharge pressure current loop.
- Foxbom Model 6gTA-1 Discharge Pressure Control I/P Transducer:. Converts the electrical signal received from the controiler Into a reps air signal.
The above Instruments are required to function propedy to ensure they automatically Initiate AFW flow upon receipt of an actuation signal. Mr. Sopata said that based upon existinr ctalbration and test procedures and an excellent operating htody, the existing equipment will function adequatly In a safety-related application once reclassification and required recommended actions are complete.
328 P03 NOV 26 '02 18:04 O POINT B[ACH NUCLEAR PLANT MSSM 92-11
't"f ':) MANAGER'S SUPERVISORY STAFF July 23, 1992 "HELD ON JUNE 16, 1992 Page 2 Mr. Sopata evaluated the AFW components in accordarme with QP 2-1 "Safety-Related and QA-Scope Classification Upgrade or Downgrade Process." The methodology of EPRI.6652, =Guklelines for the Utilization of Commercial Grade Items In Nuclear Safety-Related Applications" as described In OP 4-2, "rechnlcal Evaluation of Replacement hoems was also used during the evaluation. In accordance with OP 2-1, Mr. Sopata determined that Method 4, which allows for justification of roscoping the Items to QA-Scope based upon the operating performance of the Item, Is the most appropriate method for this upgrade.
Mr. Sopata said the following parts need to be replaced:
0 Mini-Reclrculation Solenoids: These solenoids will be replaced with models that will allow for manual operation. The modification, when Issued, should ensure the replacements are procured and maintained as QA-Scope components. If the available QA-Scope solenoids are not suitable for this application, a solenoid should be commercially dedicated per OP 4-2.
S Foxboro I/1P Pressur Transducers: The presently Installed I/P transduce are obsolete and are no longer repaired because spare parts are not available. QA-Scope I/P transducers suitable for this apprcatlon cannot be procured. A commercial grade I/P transducer will have to be dedicated per OP 4-2.
S Foxbom Pressum Transmitter: The presently Installed pressure transmitters are obsolete.
Replacement parts are sll available onsite: however, new parts am no longer avalable from the vendor. A Spare Parts Equivalency Evaluation Document (SPEED) will be Issued to replace these transmitters.
The remainder of the components were determined to be in a condition to perform their Intended function based on adequate testing and good operating performance. A comprehensive reviow of all spare parts will be completed to ensure the oomponents have been reclassified as QA-Scope. All spare parts that may be used on the affected components must also be rescoped and stocked accordingly.
Mr. Sopata continued by stating a design review of exstIng hardware Indicates the functional requirements of NUREG-0800, -Standard Review Plan IEEE 279-1971, "CrIteria for Protection Systems for Nuclear Power Generating Stations" and NUREC-0737, "Clarification of TMI Action Plan Requirementse for safety-related systems structures and components are met with the following exceptions:
0 P38A&B motor-driven AFW pump existing electrical cabling associated wfth the discharge pressure loop was field verified. Inadequate chanmel Independence (physical separation of cabling) was noted; however, this does not agree with the current data In the CARDS system. The cables from the controllers to the pressure transmitters and I/P transducers are muted through a common raceway. Mr. Sopata recommended rerouting the cables to ensure a single failure will not disrupt the power supplies to the components. He also recommended re-evaluation of the CARDS system because of noted disocpancles.
328 P04 NOV 26 '12 18:04
, POINT BEACH NUCLEAR PLANT MSSM 92-11
"(.,J' MANAGER'S SUPERVISORY STAFF July 23, 1992 HELD ON JUNE 16, 1992 Page 3 0 In our response to NRC Generic Letter (GL) 89-04, 'Guidance on Developing Acceptable Inservice Testing Programs," 52 relIef requests were submitted requesting relief from measuring full stroke test times of valves. VRR-28 requested relief of this testing from AF-4002, AF-4007 and AF.4014 (air operated AFW pump rnlni-recirculation valves) In accordance with ASME Section XI IWV-3413. We maintained that these valves are control valves because they respond to discharge flow and may actually be In a throttled poditon. According to ASME IWV-1200, as control valves they are exempt from testing. The NRC denied our request based on the fact that IWV-1200(b) eaempts only those valves that do not have a required safety function. This is darified In ASME Code Interpretation XI-1-83-69 and NRC GL 89-04, which dictates the valves provide a safety function to dose ensuring full design flow to the steam generators and to open to provide flow for pump protection.
0 A new model solenoid will be Installed that allows manual actuation In order to full stroke test the valves In accordance with ASME Section Xl requirements.
A review of Westinghouse drawings Indicates both control solenoids for 1&2P29 turbine-driven AFW pump minl-reclrculation discharge valves are powered from 125 Vdc distribution panel D1. In order to protect from a single falure (loss of D12), the power supplies should be modified to provide Independent sources of power to both channes The power supplies for P38A&B motor-driven APW pump mnin-recIrculation valve solenoids are powered from D13 and D11. respectively; however, bus Doi supplies power to panels Dli and D12. A loss of D01 would cause the minr-recirculatlon valves for both turbIne-driven and one motor-operated AFW pumps to fal shui This could leave the pumps In an operating condition that may damage them. Mr. Sopata recommended a modification be Initiated to reconfigure the I &2P29 AFW pump mini-recirculation valve solenoids to 125 Vdc distribution panels D31 and 141. This provides a separate source (station battery) of DC power to eact However. if a loss of Instrument air occurred, this would prevent any of the mini-recirculation valves from opening. This could Jeopardize the operation of all four AFW pumps. A possible modification of the controller configuration may also be needed. A solution may be to modify the Instrument air system to provide a backup source to the controllers or to the entire AFW system.
A seismic walkdown was perforned of the AFW system to address NRC GL 81-14, "eIsmic Quafication of Auxiliary Feedwater Systems" to determine If the system Is sslsmically qualified. Noted discrepancies from the walkdown were corrected as of 1985. A second prellminary walkdown was performed this month to ensure the existing equipment still meets seismic standards. No gross seismic Inadequacies were found; however, two concerns were noted:
a Control room cabinets IC105 through 1Cl14 are Improperly bolted per the Seismic Qualification Users Group (SQUG) methodology. CR 92-3W was Issued to address this problem.
0 The solenoids and positioners for the mnklI.recurc*ation valve controllers am mounted on the valve operators. The SQUG generic Implementation procedure requires the solenold, operator and positloner be evaluated together as one unit (or box). The solenoids faMed the procedures distance criteria; however, due to the relatively smam-sized solenoid, further acceptance criteda may demonstrate the arrangement is adequate.
Mr. Sopata said that as his recommencations are preliminary, no action by the staff Is necessary at this time. He will present his final report containing recommendations needing to be acted upon by the next MSS meeting (see MSSM 92-12).
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328 P0G NOV 26 '02 18:05
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I m1M3M tJ-Uz MANAGER'S SUPERVISORY STAFF June 17, 1992 MEEi'NG HELD MAY 19,1992 Page 3 Mr. Gopeta wN be worling with Mr. Rooma an MR 89-127, Train Specif Power Sifs for P04012 and PC-4o1. The modicaton requt reroutes power ppins to the APW discharge vWe wotralkn to the sawm Iatnimuit bUs as their respective loop pmwe suppiese The afore mentioned action aef being tralc2d we IK M LER 1-0./1, OP 2.1, "'SafeWysaa an OX-$cope Clasafllstion Upgrade or Downfgrade ProcWu, requlre MWia approval The staff concurred with Mr. 8opmla's request to continue with t projec. Mr. RMib~eher amaoed form OP 2-1.1.
- 5. WrLaN. Ieing.*Lo Enmta . Mr. Bir, n prom Wd memo PBLE *-O:2 from Mr. Wlczew f H*Iburmon NUS, dad May 14, 192_ He explained til 1i I&C procedure are on hold pending resolution of T84reatd questions.
Mr. Brmnmn qLeod If "n when an LO should be entered for wulous redundant paranmter montoring.
The1 z affecayondd en adilni v 1CO be entere bocau the NRC rcoimmend nterlng a 00 dufnganytesting. The LC10ho dmain In effect,for the dutiono the pmedum Astatementshoud be added to the procedure to Inlud*e LOO electlnO UrInL TS Section 16.6 "Inrmweaiaon Systu, wl be fot-Awed to Regulatry Mfah for iclusion as a TS cang.., Mr. Branam tramnmitted this dwe to Mr. P**mno v P 9205.
,M The ppmed Change Is asfollow&
"B. I&C relay function t"V equired by Technical Speoftatione Table 16.4.1 may be performed on.lne durng pow peratons1 , WAed acmain to the mquireet Mhovn In Table 1&3.5-2 ithrough 15.3.5-4 Automatlc actuation funcion of teste Insomnxnetallon and conrml alieN not be declared incpabl of pokxm-'g their related eupot wdonms prowvidingths
- 1. The entire teg be completed within one MAhl.
- 2. l mrtmamon and rontrolsaWe restored to seuv wice nt one &hW
- 3. No instumenttion mid controls wre disomered to be inoperaWl.
In accordace lwth TB 15.85.1 .5c, the "tarrecoImN=d approval d the prposed TS chang. This also qpmdkes the I&C procedures t we an olid.
BEG g laga.e mnmarxii RmnumL Mk. Wkinge disussed BEG r9 Um.mKM4 from the UI1OR outage schedule, detaled In memo P3M 92.0454 dated May , 1992. Mem. Milen and Becks conducted an oftage schedule review risk assesunent prior to the outage. They mode 18 wowr- . tsru mG#baed on a review of Revision D af the schedule.
Mr. Winget sad the majority o the reommendations hae been meolved: however, Mr. Relsenbiuecher requested the follawin open itms be placed on the NPD comr*mnmt trucing system to ensure resolution:
SMody the step In OP40 which ilrects Uagou of the tan codoers to allow keepn the tan coolers In service m rendumd kw y Is anticipated. This woud.. the coolers more roeely avabable In the mMent they ~ needed. Alo, clarity the tormn~tlogy "sevice water out df containmnent' - coukd be Consirued-- to mean service m~ter inside containrmit, which Isnot the case fsdprsuilm
328 P07 NOV 26 '02 18:06 POINT BEACH NUCLEAR PLANT MSSM 92-12 tMANAGER'S SUPERVISORY STAFF Attachment D MEETING Page 5 Mr. Guokas said the modification would be completed within 30 days. He said based upon the low probability of a seismic event during the 30 day period, his engineering Judgement was the existing cabfnet welds and design would not result In damage of the equitpent In the avent of an SSE.
The staff agreed with the recomrnendaton Mr. Guokas presented as a result of the englneedng evaluation.
Auxiliary Foeodater fAPFW) Controer QA Upgrade. Mr. Sopama presented his final recommendations and action items for the AFW controller QA upgrade. (See MSSM 92-09 and 92-11 for previous discussions&)
Mr. Sopata recommended the foilowing action Items be pursued:
0 Perform a modification to the cabling for the I/P transducers and the pressure transmitters associated with discharge pressure control valves AF-4012 and AF-4019 to route the cabling via separate raceways. Update CARDS. This was assigned to Ske Construction and Engineering.
a Perform a modification to the power supplies for the minklrculatlon pressure control valves IAF.4002 and 2AF-4002 to power them from D31 and D41. Update CARDS. This was assigned to Electrical Systems Engineerlng.
0 Evaluate the cabnet associated with the discharge pressure loop power supply cabinets 1C105 and 2C105. (CMTRK CRS92-WS0/)
e Evaluate the existing Instrument air system for seismic adequacy. Ifthe system Isfound to be seismically Inadequate, a modification request wil be needed to address the feasIblity of providing a backup supply to the AFW system components. This was assigned to Nuclear Safety.
a Perform a caculation showing seismic adequacy of the rnml-recirculalion control solenoids. This was assigned to Nuclear Safety.
- Modification requests92-091.92.092 and 92.0-3 were Issued to replace the control solenoids for 1&2AF-4002, AF-4007 and AF-4014, the m~ni-recirculatlon valves, to dcow for manual full stroke testing.
0 Prepare appropriate documentation (SPEED or MR) to ensure I/P transducers for the AFW discharge pressure control loops for P38A&B be commercially dedicated for use In the AFW system.
This was assigned to SQA/l&C.
- Prepare appropriate documentation (SPEED OR MR) to replace P38A&B AFW pressure control loop pressure transmitters. This was assigned to SQA/I&C.
9 Perform a comprehensive review of all spare parts Issues to ensure all spare parts that could be used on affected AFW components are propedy scoped and stocked In the storeroom. This was assigned to SQA.
6 Update the 0-List/CHAMPS equipment database to reflect the AFW upgrade. This was assigned to CPS.
0 Update Appendbc 8 of the NPD Policy Manual to reflect the AFW upgrade. This was assigned to Oualty Support.
The staff accepted Mr. Sopata's recommendadons. AN the Items are being tracked as part of the QA status upgrade project by Mr. Sopata. Mr. Maxe approved form OP 2-1.1 nuthorizing the upgrade.
328 P08 NOV 26 '02 18:06 LIARY FEEDWATER SYSTEM (AFW) DBD-01 DESIGN BASIS DOCUMENT RevisIon 0 CoNSIN ELECTRIC NUCLEAR POWER DEPARTMENT 4/4194 10.5.110 Instrument & Controls Procedure ICP 6.59, Condensate Storage Tank Level &Service Water Pressure Transmitter, Revision 0, 11/01/90.
10.5.111 WE Nuclear Power Department Quality Assurance Policy Manual, Revision 9, dated 311/91.
10.5.112 WE Internal Memo, NPM-91-0368, Hoynacki to Frieling, Krieser, Lipke, Maxfield, and Newton, dated 3/5/91.
10.5.113 PBNP Modification Request M-55, Change Feedwater Check Valve AF-100 and AF-10].
10.5.114 PBNP Modification Request 86-123, Change the Operator's Gear Ratio on 2MS-2019 and 2020.
10.5.115 PBNP Modification Request 87-25, Change the Operatorls Gear Ratio on 1MS-2019 and 2020.
10.5.116 PBNP Administrative Control Policies and Procedures Manual, PBNP 8.4.1, Secondary Water Chemistry Monitoring Program, Revision 16, 11/2/90.
10.5.117 PBNP Modification Request 88-99 (including MR 88-99*A, *B, *C, *D), AFW Pump Mini Recirc Flow Enhancement.
10.5.118 PBNP Modification Request IC-274 (CANCELED), Modify the Control Scheme of AFW Pump Recirc Flow Control Valves to keep valves normally open.
10.5.119 PBNP ISI Testing Program Background Document, Rev. 3, (Appendix B).
10.5.120 PBNP Modification Requests85-213 and 85-214, Anticipated Transient Without Scram Mitigating System Actuation Circuit (AMSAC) 10.5.121 MSSM 90-23 10.5.122 PBNP Background Document BG.EOP-3,'Rev. 13.
10.5.123 AOP-10A, "Control Room Inaccessibility", Rev 12. 10/7/91 10.5.124 Deleted.
10.5.125 SPEED 91-002, "Ashton-Crosby Relief Valve, Model GC-32, 100 psig set pressure, Crosby Drawing G-31436-1".
10.5.126 PBNP Modification Request M-623, TDAFWP Cooling Water Modification for Independence from AC Power.
10.5.127 PBNP Modification Request M-624, TDAFWP Cooling Water Modification for Independence from AC Power.
Page 10-15
328 P09 NOV 26 '02 18:06 LIARY FEEDWATER SYSTEM (AFW) DBD-01 DESIGN BASIS DOCUMENT Revision 0 CONSIN ELECTRIC NUCLEAR POWER DEPARTMENT 4/4/94 FUNCflONS COMPONENT COMPONENT FUNCTIONS Section 4.8 Component I) Service AF-4007,4014 AFW Pump Recirc Flow Control Valves (AOV) l/2AF-4002 Safety-Related Functions
- 1. These valves shall open automatically and remain open to provide a recirculation flowpath from AFW pump discharge to the CST when flow in the AFW discharge line is insufficient to prevent pump damage. (REF 10.5.117J
- 2. These valves shall close automatically to prevent the unnecessary diversion of AFW pump discharge during high-flow conditions where adequate pump discharge flow Is removing pump heat.
- 3. These valves shall passively maintain the AFW system pressure boundary integrity.
Augmented Quality Functions
- 1. 1/2 AF-4002 shall be capable of being manually "gagged" in the open position to ensure minimum pump recirculation flow to Turbine-Driven AFW Pumps during plant fires. [Reference 10.2.59]
Non-Safety Functions
- 1. These valves shall close automatically after the AFW pump is secured (and remain clQsed) to prevent a flowpath of MFW backleakage to the CST. Under such abnormal conditions, this flow would defeat the function of existing temperature instrwments (located in the discharge line) to indicate the bacileakage condition. [REF 10.5.118]
Page 4-79
328 PI1 NOV 26 '02 18:07 P LIARY FEEDWATER SYSTEM (AFW) DBD-01 DESIGN BASIS DOCUMENT Revision 0 CONSIN ELECTRIC NUCLEAR POWER DEPARTMENT 414/94 COMPONENT PARAMETERS
SUMMARY
Section 4.8 (continued)
Component ID Servic AF-4007,4014 AFW Pump Recirc Flow Control Valves (AOV) l/2AF-4002 PARAMETER VALUE REFFRTO PERFORMANCE REQUIREMENTS
- 1. Controls 4.8.1 Automatic Open/Shut Manual Handwheel Open/Shut
- 2. Operating Differential Pressure 4.8.2 Specified "Available DIP" 195 psid Specified "Maximum D/P" (4007,4014) 1410 psid Specified "Maximum D/P" (4002) 1440 psid
- 3. Design Flow at the "Available D/P" 4.8.3 AF-4007, 4014 80 gpm 1/2AF-4002 >100 gpm
- 4. Position 4.8.4 Normal Position Closed Failure Position Closed
- 5. Operational Requirements Gagged Open during Plant Fires 4.8.5 OTHER DESIGN REQUIREMENTS
- 6. Material Stainless Steel 3.15
- 7. Design Code Unspecified 10.6.95 2.2
- 8. Design Pressure, Temperature 1410 psig 10.6.95 100 F
- 9. Valve Type Globe 10.6.95
- 10. Operator Air Loading Pressure 45 psig 10.6.95 Page 4-80
328 P11 NOU 26 '02 18:07 LoARY FEEDWATER SYSTEM (AFW) DBD-01 V DESIGN BASIS DOCUMENT Revision 0 CONSIN ELECTRIC NUCLEAR POWER DEPARTMENT 4,4/94 COMPONENT PARAMETER WORKSHEET Section 4.8.1 CoMponent ID AF-4007,4014 AFW Pump Recire Flow Control Valves (AOV) 1/2AF-4002 A. Parameter Controls B. Value Automatic
' Open Pump On, Discharge Flow < Reqd Mfini-Flowl
' Close Pump On, Discharge Flow > Reqd Mini-Flow1 Manual Handwheel Open/Shut C. Source I. MR 88-99 [REF 10.5.117]
- 2. WE Internal Memo response to IEN 84-06 [REF 10.5.5]
- 3. MR IC-274 [REF 10.5.118]
- 4. MSSM 84-28 [REF 10.5.8]
D. Backgmround/Reason As stated in the Source 1: "To ensure this minimum flow [70 gpm] is met, the setpoints for the valve's [AF 4007, -4014] controlling instrumentation will be adjusted so that the mlni-recirc valve is open when flow in the discharge line is less than 80 gpm". Also, Source 1 adjusted the automatic operating setpoints of 1/2AF 4002 accordingly:
l/2AF-4002 145 GPM (increasing) Valve Close
- 110 GPM (decreasing) Valve Open REF 10.5.117 states that, "after each AFW pump is up to rated speed and flow [as sensed by the discharge flow instrument], a shut signal is sent to its associated mini-mire valve which shuts after a 3-minute delay".
The time delay is activated whenever a signal is generated to close the valve. Source I suggests two bases for this time delay function:
(1) the delay prevents the system from "hunting" for its operating point, and (2) the delay allows pump heat removal during pump coastdown.
'These automatic controls are required to function only when the associated pump is running (as indicated by a closed MDAFWP breaker or open steam-admission valve to the TDAFWP).
Without this feature, these valves would be open when the AFW system was In its normal standby lineup. The automatic control signals to close these valves are delayed 3-minutes.
Page 4-81
328 P12 NOV 26 '02 18:07 LoIARY FEEDWATER SYSTEM (AFW) DBD-01 DESIGN BASIS DOCUMENT Revision 0 tMCONSIN ELECTRIC NUCLEAR POWER DEPARTMENT 4/4194 COMPONENT PARAMETER WORKSHEET Section 4.8.1 (continued)
These two bases compete with the performance objectives of IEN 84-06 to prevent water hammer in AFW discharge piping. Sources 2 and 3 suggested that the coastdown control feature described above did not provide an "abrupt change" in differential pressure to ensure good seating of the discharge check valves.
Source 4 would have allowed operators to defeat this time delay function (to allow better valve seating), but it was cancelled in lieu of improvements to the check valve design.
Another detriment of the time delay is its effect on pump runout analyses. The time delay aisntains an additional discharge path for the AFW pumps upon startup and increases pump output. This effect has been evaluated in Source 1.
Page 4-82
328 P13 NOV 26 '02 18:07 LoARY FEED WATER SYSTEM (AFW) DBD-01 DESIGN BASIS DOCUMENT Revision 0 CONSIN ELECTRIC NUCLEAR POWER DEPARTMENT 4/4/94 COMPONENT PARAMETER WORKSHEET Section 4.8.2 Component IM Service AF-4007,4014 AFW Pump Recirc Flow Control Valves (AOV)
I2IAF-4002 A. Parameter Operating Differential Pressure B. Value Specified "Available D/P" 195 psid Specified "Maximum D/P" (4007,4014) 1410 psid Specified "Maximum D/P" (4002) 1440 psid C. Source 1. AOV Spec M-181 [REF 10.6.95]
D. Background/Reason This valve was originally specified with an "available" differential pressure of 195 psig, which was used in the vendor's design to achieve the design flowrate of 30 gpm specified on the original valve specification
[Source 1].
This valve was originally specified with a "maximum" differential pressure of 1410 psig for the recirc valves on the motor-driven AFW pumps, and 1440 psig on the turbine-driven AFW Pump recin valves. These values are probably derived from the values of shutoff head on each pump 1305 psig (MDAFWP) and 1340 psig (TDAFWP) plus a maximum suction pressure of 90 psig attributable to the maximum operating pressure of the Service Water System.
Page 4-83
328 P14 NOV 26 '02 18:08
,A=LIARY FEEDWATER SYSTEM (AFW) DBD-01 O DESIGN BASIS DOCUMENT Revision 0 WCONSIN ELECTRIC NUCLEAR POWER DEPARTMENT 4/4/94 COMPONENT PARAMETER WORKSHEET Section 4.8.3 Component ID Service AF-4007,4014 AFW Pump Recirc Flow Control Valves (AOV) 1/2AF-4002 A. Pgarametr Design Flow at the "Available DIP" B. Valu.e AF-4007, 4014 80 gpm It2AF-4002 >100 gpm C. Source 1. MR 88-99 [REF 10.5.117]
D. Background/Reason These valves do not "control flow" by virtue of throttle-control capabilities, but rather, they open or close (at prescribed setpoints of AFW flow) to initiate or secure flow through the recirculation line. The amount of recirculation flow is determined by the flow resistance in the line, which is predominantly controlled by the restricting orifice.
Source 1 established the design flow through valves 4007 and 4014 as 80 gpr. This value of flow is based on the recirculation line design, and provides 10 gpm margin above the minimum recirculation value required by the Motor-Driven AFW Pump (70 gpm). Source I established the design flow through valves 1/2AF 4002 as 125 gpm, which provides an approximate 25 gpm margin to the minimum recirculation value required by the Turbine-Driven AFW Pump (100 gpm). Source 1 installed new valves to accommodate the increased design flow of the recirculation lines.
Page 4-84
328 P15 NOV 26 '02 18:08 LIARY FEEDWATER SYSTEM (AFW) DBD-01 DESIGN BASIS DOCUMENT Revision 0 NSIN ELECTRIC NUCLEAR POWER DEPARTMENT 414/94 COMPONENT PARAMETER WORKSHEET Section 4.8.4 Component ID Service AF-4007,4014 AFW Pump Recirc Flow Control Valves (AOV) l/2AF-4002 A. parmterer Position B. Value Normal Position Closed Failure Position Closed C. Source 1. WE Caic N-87-041 [REF 10.4.3]
- 2. MR 88-99 [REF 10.5.117]
- 3. MR IC-274 [REF 10.5.118]
D. Backrfound/Reason Failure Position Although no documented basis has been found for the selection of an air-operator in this application (as opposed to motor-operator), several facts support the design requirement to have an operator which falls to the closed position. Since this valve has a safety function to close, and a less significant function to open (long-term pump protection) it is most reliable therefore to have the valve fail (upon loss of power or instrument air) to the closed position. THIS INFORMATION HAS BEEN DERIVED LOGICALLY, BECAUSE NO DOCUMENTED BASIS COULD BE FOUND. THEREFORE, THE ABOVE IS PROVIDED FOR INFORMATION ONLY.
Interestingly, Source 1 concludes that "adequate minimum pump flow will exist for all auxiliary feed pumps under all design basis conditions with an assumed failure of the pneumatic recirculation control valves". This evaluation, however, did not consider the potential for instrument air loss (causing recirc valve closure) in combination with the single active failure (i.e., the associated discharge MOV fails shut).' The "worst case" recirculation flow would occur if the air-operated recirc valve(s) and the air-operated discharge valve(s) failed in the closed position.
Failure of one of these valves in the n position would cause a reduction in AFW System flow to the steam generators during an accident; however, the value of flow-reduction is
'This concern is based on the NUREG-0800 assumption that all non-safety grade equipment may fail to its worst-case condition in addition to one limiting safety grade failure. In this case, such an assumption would result in no flow through the pump. As NUREG-0800 has not been incorporated into the PBNP licensing basis, this combination of failures appears to fall outside the system design and licensing basis.
Page 4-85 I7
328 P1G NOV 26 '02 18:08 A=LIARY FEEDWATER SYSTEM (AFW) DBD-01 W DESIGN BASIS DOCUMENT Revision 0 M19CONSIN ELECTRIC NUCLEAR POWER DEPARTMENT 4/4/94 COMPONENT PARAMETER WORKSHEET Section 4.8.4 (continued) bounded by the single failure condition created if the TDAFW Pump fails to start [Source 2].
Normal Position In the AFW System is in a standby lineup, these valves are normally closed to limit backleakage (from MFW) to the CST. As discussed in Source 3, allowing such leakage would mask the failure of AFW discharge check valves by allowing flow and keeping AFW piping temperatures and pump suction pressures below levels that would otherwise be indicative of a problem.
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328 P17 NOV 26 '82 18:08 RLIARY FEEDWATER SYSTEM (AFW) DBD-01 DESIGN BASIS DOCUMENT Revision 0 CONSIN ELECTRIC NUCLEAR POWER DEPARTMENT 414/94 COMPONENT PARAMETER WORKSHEET Section 4.8.5 Component lID Service AF-4007.4014 AFW Pump Recirc Flow Control Valves (AOV) 1/2AF-4002 A. Parameter Operational Requirements B. Value Gagged Open during Plant Fires C. Source 1. Fire Protection Evaluation Report [REF 10.2.59]
- 2. AOP-1OA, "Control Room Inaccessibility" [REF 10.5.123]
D. BackgroundReason According to the text of the Safe Shutdown Analysis of the PBNP Fire Protection Evaluation Report [Source 1], valves 1/2 AP-4002 shall be manually "gagged" in the open position to ensure minimum pump recirculation flow to Turbine-Driven AFW Pumps during fires requiring Control Room evacuation. Spurious closure caused by control circuit damage could lead to pump damage if the AFW pump is started with its discharge valve closed. Refer to Source 2 for implementation of these requirements.
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328 P18 NOV 26 '02 16:09 koIARY FEEDWATER SYSTEM (AFW) DBD-01 WDESIGN BASIS DOCUMENT Revision 0 CONSIN ELECTRIC NUCLEAR POWER DEPARTMENT 4/4/94 COMPONENT FUNCTIONS Section 4.15 ComlDonent ID Sorvice RO-4008,4015 AFW Pump Recirculation Line Orifice 1/2R0-4003 Safety-Related Functions I. These orifices shall provide passive flow resistance in the recirculation Una of each AFW pump; thereby establishing the required mini-recirc flow and the pressure drop from AFW pump discharge pressure to CST pressure. These orifices must provide adequate flow to prevent low-flow instabilities and excessive fluid temperature rise in the AFW pumps.
- 2. These orifices shall limit the recirculation flow in the event that the recirculation control valve fails to close during the AFW operation response to an accident [REF 10.5.117].
- 3. These orifices shall passively maintain the AFW system pressure boundary integrity.
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328 P19 NOU 26 '02 18:09 LIARY FEEDWATER SYSTEM (AFW) DBD-01 DESIGN BASIS DOCUMENT Revision 0 CONSIN ELECTRIC NUCLEAR POWER DEPARTMENT 4/4/94 COMPONENT PARAMETERS
SUMMARY
Section 4.15 (continued)
Component I) Service R0-4008,4015 AFW Pump Recirculation Line Orifice 1/2RO-4003 PARAMETER VALUE REFER TO PERFORMANCE REQUIREMENTS 1- Design Flow 4.15.1 TDAFWP Orifice 100 gpm MDAFWP Orifice 70 gpm OTHER DESIGN REQUIREMENTS
- 2. Design Code Unspecified 2-2 Page 4-107
328 P20 NOV 26 '02 18:09 tLoIARY FEEDWATER SYSTEM (AFW) DBD-01 Revision 0 W DESIGN BASIS DOCUMENT 4/4/94 WISCONSIN ELECTRIC NUCLEAR POWER DEPARTMENT COMPONENT PARAMETER WORKSHEET Section 4.15.1 Component ID Service RO-4008,4015 AFW Pump Recirculation Line Orifice 1/2RO-4003 A. Parameter Design Flow B. Value TDAFWP 100 gpm MDAFWP 70 gpm C. Soure 1. IEB 88-04 and WE Responses [REF 10.2.61, 10.2.62, 10.2.63]
- 2. MR 88-99 [REF 10.5.117]
- 4. WE Calc N-91-32 [REF 10.4.21]
D. Background/Reason In response to the NRC IEB 88-04 concerns [Source 1], WE committed to increase the miniflow capacity of the AFW pumps to the flow rates recommended by the pump manufacturer. Source 2 upgraded the recirc orifice capacity to meet the AFW Pump minimum recirculation flow requirements stated in section 4.1.3.
Source 3 determined that test data provided the following flow indications through the MDAFWP recirculation lines:
Pump P-38A 86.gpm Pump P-38B 88.3 gpm Source 4 estimated the effect of the increased recirculation line size on flow rates to the steam generators if the recirc valve stuck open. The calculation showed that minimum steam generator flow rate will still be achieved in these conditions.
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