ML030800438

Operability Determination 000031, CR 029952, Rev 1

ML030800438
Person / Time
Site:	Point Beach
Issue date:	11/07/2002
From:	Branam T, Ted Carter, Schroeder J, Weber D Nuclear Management Co
To:	Office of Nuclear Reactor Regulation
References
FOIA/PA-2003-0094 PBF-1553, Rev 9
Download: ML030800438 (8)

Text

Poin: Beach "-,c-ear PNant OPER.-ABILITY DETERMINATION PART I OPR IŽ0001 C.AP 029952 REVP 7 ENGINEERING TO COMPLETE THIS BOX WHEN OD ACCEPTED BY DSS SYNOPSIS FOR NIM IFORL-ATION ONLY C-HANMPS Unit(s) 0, 1,2 System AF Equipment ID Vancus

[] Inoperable - does not meet the rmnirmum level of performance.

[] Operable - fully meets performance requirements. No further action required.

Operable But Degraded - or Operable But Nonconforming - meets the minimum required level of performances, compensatory measures ARE required.

Operable But Degraded - or Operable But Nonconforming - meets the rminmum required level of E] performances, compensatory measures are NOT required.

Potential for simultaneous failure of all AFW pumps due to insufficient nmmunum pump flow TITLE (EQUIPMEN-t NUMBER AND DESCRIPTION OF ISSU-E)

Describe the condition.

During a plant transient,a combination of the existingplant design and operating procedures may result in afailure mode of one or more AFW pumps.

When steam generator(SG) levels have been restored to desired levelsfollowing a transient,manual action is requiredto maintain those levels. This manual action could be accomplished by securingthe associatedpump(s), or by reducingflow to match the steaming rate. It could also be accomplishedby completely closing offflow to one or both SGs if desired; this is likely to be the case if the desiredlevel has been exceeded due to overfill, swell, etc. Isolating dischargeflow to the SGs, could result in AFW pump damage due to the potentialinability of the recirculationline to pass the requiredflow to maintainpump operability.This may cause very rapidfailure of these multi-stage high pressurepumps. I

2. Identify the Current Licensing Basis (CLB) functions and performance requirements including.

Tech Spec Reference 375 FSAR Reference 10.2. 7.3.3.4

'NRC Comrrmtment Reference Other 50.59 EVAL 2002-005, FCR 02-027, FCR 02 019 If no CLB function, requirement or commitment is affected, no further action is required. N/A Steps 3, 4 and 5 and proceed with Step 6.

PBF-1553 _z37 Rcvis=on 9 t0/16102 Page 1 of 8 Reterenct NP

TS3 7.5 Th7e AFWIStstem shall be OPERABLE -t'vth one turbine drite-z AFW pump system <per Unit> and r.ýo motor drz'en AF.VF u:mp systems when in modes 1. '. and 3 The bases for this Technical Specificanon stares that "The AFWS~stem autom-,nzcall, supplies f'eeddtater to the steam generators to remove decay heatf-om :ze Reactor Coolant System upon the loss of normalfeedwatersupply".

FSAR Chapter 10 2.1 The AFW svstem shall automaticalli start and deliver adequate AF system flow to maintain adequate generatorlevels during accidents which may resuhd in main steam safety valve ovening including: Loss of Normal Feedwater (LONF)and Loss ofAll AC Power to the Station Auxiliaries (LOA). These accidents are evaluated in detail in sections 14 1. 10 and 14.1.11 respectively.

The AF system is credited vith automatically startingand delivering sufficient AFflow to maintain adequatesteam generatorlevels duringaccidents which requirerapid reactor coolant system cooldown to achieve cold shutdown condition within the limits of the analysis, includingSteam GeneratorTube Rupture (SGTR; FSAR Chapter 14.2.4), and Main Steam Line Break (MSLB: FSAR Chapter 14.2.5).

The AF system shall be capable of isolating the AF steam andfeedwater supply lines from the rupturedgeneratorfollowing a SGTR event.

The AF system also is capableof automaticallysupplying sufficientfeedwater to remove decay heatfrom both units without any reliance on ACpowerfor one hour (station blackout).

In the event ofplantfires, including those that requireevacuation of the control room, the AF system shall be capable of manual initiationto providefeedwater to a minimum of one steam generatorper unit at sufficientflow andpressure to remove decay and sensible heatfrom the reactorcoolant system over the rangefrom hot shutdown to cold shutdown conditions.

FSAR 10.2.2 This section states that each pump has an AOVcontrolled recirculationline back to the condensate storagetanks to ensure minimum flow to prevent hydraulic instabilitiesand dissipatepump heat.

FSAR 10.2.3 Based on the operatingcharacteristicsof the minimum recirculationflow control scheme, a portion of the AFpumps dischargewill be automaticallyrecirculatedbacklto the CSTsfor approximately 45 seconds after the pump starts. The 45 second time delay in closing the recirculationline control valves is incorporatedin the design to providefor pump stability and cooling during coastdown.

FSAR 7.3.3.4 If a loss of instrument airoccurs or an Auxiliary FeedwaterPump minimum flow recirculationvalvefails closed, manual operatoraction is requiredto prevent the potentialfailure of the pump(s). By procedure,the operatorwill either secure the running pump(s) or maintainforwardflow through the still runningpump(s) to prevent pump damage that could be caused by overheating.

Backup pneumaticsupplies are provided to all AFpump minimum recirculationvalves.

These backup supplies are sized to provide adequate time for operators to either maintain minimumflow through the runningpump(s) to secure the unneeded pump(s) if necessary to restore instrument ab; or to use the manual gag on each valve to provide minimum recirculationflow.

PBF-1553 Revisio g 10/16i02 Page 2 of 8 RP::rcnc" NP 5 3 7

Aggregate Reiei*: [dent:uf related issues b', re,,,e,, otfactx'e ODs for the same p':stem inciudng as apphcable their comrpensatoqy measures Historical ODs can also be mciuced in this re.e, at the discreton of the Engineer. The re', iewv of the act,%e ODs and their compensator: measures is to ensure there is no conflhct between the related conditions. e., conflicmig assumptiors or cormensatorv measures H No related issues exist Related AR Number CR 01-.3,648 impact Review of the condition describedin section I ofthis OD indicates a potentialforthe loss of aflowpathfor the MDAFWPs mirroringthat described in OD CR 01-3648. OD CR 01-3648 describes a condition where an Appendix Rfire in Fire Areas A01-B, A02, A23N and A23S, could result in the loss of MDAFPflowpath due to afire initiatedauto-startof an MDAFP with a coincident loss of off-site power and instrument air. In each of thefire areas listed above, a MDAFP is relied upon as the means of deliveringAux Feedwaterto at least one Steam Generatorfor at least one or both Units to support decay heat removal from the RCS. This condition occurs due to afire initiated trip of the Main Feedwater Pumps or start signal to the creditedMDAFP. This auto-startsignal generatedby this condition opens the associatedrecirculationvalve and motor operateddischarge valve(s) for the steam generatorto be supplied AF. Due to fire damage, the motor driven dischargevalve may fail to open and the mini-recircvalve may fail closed due to a loss of instrument airsupply.

The difference in the conditions describedin OD CR 01-3648 and this OD is the failure mechanism of the MQDAFP recirculationline, however thefailure mechanism for the MDAFPs is the same. The condition described in this OD, as it pertainsto Appendix R, is bounded by that described in OD CR 01-3648 because the initiatingevent is essentially the same for both conditions, i.e., auto-startof the MWDAFP and loss of control of the motor operateddischarge valve(s)for the steam generatordue to fire damage. The loss of instrument airdescribed in OD CR 01-3648 is equivalent to the recirculationline failure describedin this OD because loss of instrument airis assumedfor all Appendix R fires and the failure describedby this OD could appy to allfire initiatedstarts of the MDAFPs. Therefore,failure of the MDAFPs as described in OD CR 01-3648 is the same for this condition and Appendix R operabilityconclusion of OperableBut Nonconforming also remains the same.

Related AR Number CR 01-3595 Impact:

Closed. Concerns postulated failure of the recirculation line AOV. This is a related issue but it does not unpact this OPR.

Related AR Number Impact:

Review additionally, as applicable, these items to help clarify current plant conditions These items may have impact on the SSC performance.

Active Temporary Operating Procedure Changes None Applicable PBF.1553 Revision9 10/16&02 Page 3 of 8 R.-'erence- NP 5 3 7

Ac::ve Terporar. Modifications None Aohlicabie Modifications cu-entty being installed None Apnhcable Recent Work Orders None Apolicable A poroved DC",ý's None Applicable Recently Performed Inservice Testing IT-10 4 Evaluate the CLB functions and performance requirements identified in Step 2 against the as-found condition and the related issues identified in Step 3. The evaluation must identify the extent to which the SSC is capable of performing its identified CLB funcnon. Document the evaluation After the automatic initiation of AF in response to an analyzed event, operatorsare requiredto manually cqontrol AFflow based on SG levels (FSAR 7.3.3.4). Manual control may include shutting pump dischargevalves resulting in pump operation strictly on recirculationflow. Due to the potential inabilityof the recirculationline to pass the requiredflow to maintainpump operability, the AF system may not be able to perform its CLB functions.

Measures taken include heightened Operatorawareness of the potentialfor pump damage (briefings with on-coming shift personnel), temporary information tags posted on the AFWpump flow controls. Revisions to operatingprocedures that will alert the Operatorto the limitations of the AFWsystem with respect to minimum AFWpump flow are completed. The revisions will ensure that AFW Minimum Flow Requirements are maintainedor the affected AFWpump is secured.

NEMA guidelines states that motor driven pumps may be startedtwicefrom an initial standby condition with no restrictions.After the initialstarts, NEMIA MG-1 recommends subsequent starts after "all conditions affecting operation have been thoroughly investigatedand the apparatushas been examinedfor evidence of excessive heating."

This guidance encompasses situations where the load or prime mover may have experienced afault which causes a failure to start or run; excessive temperaturesare not expected with the equipmentfunctioning normally. Additional starts therefore are allowed and not expected to cause machinefailure. It should be recognized that a minimum of 3 starts of a motor driven AFpump are allowed in thefirst 15 minutes of operation.An additionalone or two starts is allowed provided the run time is at least 15 minutes between these later starts.Motor startingnameplate information directs that after initialstarts the motor may be restartedif run time has exceeded 15 minutes or it has been securedfor 60 minutes. Excessive consecutive startingwill decrease overall motor life. Starting duty limitations areprovided by the manufacturerto provide the longest possible motor life.

The AOP SG control band is 29% to 65%. This represents an approximatevolume of 5000 gallons. At a steaming rate of50 gpm, a motor driven pump start would be requiredevery 50 minutes to control level within halfof the control band. At maximum pump flow rate of 200 gpm, the pump would be operatedfor 16 minutes to recover the level lost while the pump was secured. Since the operationof thepumps will meet the NEMA criteriaestablished,the pump motor will not fail as a result of repetitive starts.

The pump motors are suppliedfrom Westinghouse DB-50 Air Circuit Breakers. Vendor information indicates an in-rush, non-fault duty cycle of 750 breakeroperations. The recommended operating conditionsare a frequency of operation not to exceed 20 per 10 PBF-1 553 Revsion 9 10/16W02 Page 4 of 8 Reference NP 5 3 7

minutes or 30 per hour. Since the MDAFPs are only used during startup, shutdo;rn (including SG chemical additions) and requiredsystem test ng, the number of breaker operationsare well below these operating limits 1fan operatoris required to secure and restartpumps during a transient,the actuons would be performed at a frequency of operation much less than the recommended valuefor the entire transient.

There are no starting c;cle limitations on the turbine driven AFW pumps The turbine vendor was contacted and verified that no duty cycle concerns existfor this pump assembly. The steam supply MOVs are rated/or5 minutes of operation every hour which corresponds to five open/shut cycles. With a maximum steaming rate of 75 gpm, it would take approximately 33 minutes to steam off halfof the control band (2500 gallons). The nameplate guidanceformotors and valves is based on manufacturers' recommendations for long life and are consideredconservative. Therefore, operation of the valve will not be degraded.

The recommendations of this OperabiltyDeterminationis to consider the AF system OPERABLE but NON-CONFORMiTNG. The potential Non-Conformancepertains to the FSAR statement of the minimum recirculationflow path ensuringminimum flow is available.

Note. If the SSC is determined to be inoperable based on this evaluation, mark Step 5 N/A and continue with Step 6.

5. Evaluate the need for compensatory measures. Complete with input from DSS.

D Degraded or nonconforming, however, no compensatory measures are required.

Degraded or nonconformng The folowmg compensatory measures are REQUIRED in order to maintain operability.

If Compensatory Measures are not required go to Step 6.

Compensatory measures must be in place prior to OD final approval by the DSS Affected Unit (I OR 2 OR 0) 0 Describe the Compensatory Measure (what needs to be performed):

As an immediate compensatory measure, a briefing of all responsible on-shift Reactor Operationsstaff should be conducted describingthe concern and appropriateresponses:

1. If dischargeflow cannot be maintainedper the applicable operatingprocedure(s) without exceeding desired SG level, secure the associatedpump(s) and re-start again later when (if) needed.

2. Revise OperatingProceduresas appropriateto prevent reducingflow of operating AFWpumps below the minimum requirements.

3. Install tags,placards,or otherwisepost the pertinent information at the controls (in the Control Room and locally)for the associatedAFW pumps.

4. Emphasize verifying a minimum of50 (75) gpm flow through a motor (turbine) driven PBF-1553 Revision 9 10/16,02 Page 5 of 8 Referenc. NP 5 3 7

pump when reducIng flow as stated in the EOPfoldout page Basis which indicates the Compensatory Measure maintains operability By verifying minimum pump flow requirements,the continued avazlability of the AFW pumps is ensured. Minimum pumpflow maintainshydraulicstabiliýv, removes pump heat and increase the life of the pump If the minimum flow requirement cannot be maintained,then the pump will be secured to prevent damage. Repenitive operation of a motor driven or turbine drzien AFpumpfor SG level control has been determined to be acceptable.

Implementation Mechanism (Procedure number, Temp -Modnumber. etc):

As determined appropriateby Operations.

Plant condition(s) or mode(s) of operation which require the Compensatory Measure:

Modes 1, 2, and 3 (modes in which decay heat removalfrom the SGs is necessary and requiredcapabilityper ITS.

Under what conditons may the Compensatory Measure be terminated?

Engineeringevaluation or modification to restore thefunction of the recirculationlines.

6. Prepared By:

X . -1 /- A Date/Time: IJ Name (Print) / Signature Engineering Manager Approval of Evaluation and Proposed Compensatory Measure (if applicable) 7Z3 7 -'O 1I -M( 1 / , ;; --- -- Date/Time:_ _ _ _ _ _

Name (Print) / Signature / v" l-e

'e'.,*

7. SRO Review of Operability Documentation:

El Inoperable - does not meet the minimum level of performance.

El Operable - fully meets performance requirements. No further action required.

[] Operable But Degraded - or Operable But Nonconforming - meets the minimum required level of performances, compensatory measures ARE required.

El Operable But Degraded - or Operable But Nonconforming - meets the minimum required level of performances, compensatory measures are NOT required.

Evaluation Accepted Evaluation and Compensatory Measures Accepted.

PBF-1553 Revision 9 10/16/02 Page 6 of 8 Reference NP 5 3 7

L- Compensatory Measures Verified m Place D N-P 10.1 1. LCO Tracking Log updated to include new items t

Name (Prnt); S&,,ature Route OD package to in-box in WCCfor processing. Packageincludes originalPar:L all attachments, and relatedcondition report PBF-1553 Revision 9 10/16/02 Page 7 of*8 Reference NP 5 3 7

OPERABILITY DETERMINATIO-N OPR Unit5()

CAP __stem _

REV CHAMPS ID 1 SOBD condition which requires compensatory measures Li OBD condition which does NOT require compensator. measures.

Tidke (Eculcrenv ID and Descnotion of rssue PART [I CORRECTIVE ACTION PL.kN, SCHEDULE AND JUSTIFICATION (30 days to complete)

For those Operable But Degraded or Nonconforming items, what action(s) need to be done to restore the condinon to its "fully operable" or -fully qualified" status"

> Also consider any compensatory measures in place and what needs to be done for their removal.

2. Provide a schedule for completion of the action(s) listed in question 1. This schedule represents the earliest available opportunity to perform the corrective actions, allowing reasonable time for planning, scheduling, design, procurement, etc.

3. List the date of the next refueling outage for the affected Unit(s). PBI: PB2:

4. Li All actions required to bring this degraded or non-conforming issue back to fully operable will be completed prior or concurrent with the next refueling outage as indicated in Step 3. N/A Step 5 and obtain approval.

Li All actions required to bring this degraded or non-conforming issue back to fully operable will NOT be completed prior or concurrent with the next refueling outage as indicated in Step 3. COMPLETE Step 5 and obtain approval.

5 Please provide justification for this schedule based on:

> the amount of time required for design, review, and approval of the corrective action,

> procurement for replacement or repair,

> availability of specialized equipment to perform the repair,

> the need to be in hot or cold shutdown to implement the corrective action,

> or other factors that constrain the corrective action schedule.

Prepared by: Date/Time:

Name (Print) / Signature Engineering Manager Approval: Date/Time:

Name (Print) / Signature PBF-1553 Revmston 9 10/16102 Page 8 of 8 Reference NP 5 3 7