ML14314A512
| ML14314A512 | |
| Person / Time | |
|---|---|
| Site: | Hatch, Point Beach, Arkansas Nuclear, Vermont Yankee, Fort Calhoun  |
| Issue date: | 11/13/2014 |
| From: | NRC/NRR/DIRS/IPAB |
| To: | NRC/NRR/DIRS/IPAB |
| Andrew Waugh (301) 415-5601 | |
| References | |
| Download: ML14314A512 (23) | |
Text
Enclosure 2 Reactor Oversight Process Task Force FAQ Log
- October 22, 2014 NEI99 02FAQ14 02FortCalhounMSPIPage1of5Revised09/8/2014Plant:FortCalhounNuclearStationDateofEvent:12/18/2013(ReactorCritical)SubmittalDate:05/14/2014LicenseeContact:ErickMatzkeTel/Email:402 533 6855ematzke@oppd.comNRCContact:LouisCruzTel/Email:301 415 3982louis.cruz@nrc.govPerformanceIndicator:MS06MitigatingSystemPerformanceIndex(EmergencyACPowerSystems)MS07MitigatingSystemPerformanceIndex(HighPressureInjectionSystems)MS08MitigatingSystemPerformanceIndex(HeatRemovalSystems)MS09MitigatingSystemPerformanceIndex(ResidualHeatRemovalSystems)MS10MitigatingSystemPerformanceIndex(CoolingWaterSystems)SiteSpecificFAQ(AppendixD)?YesFAQrequestedtobecomeeffective:Whenapproved.QuestionSectionNEI9902,Revision07,Guidanceneedinginterpretationand/oradditionalinformation:TheMSPISection(startingonpage32)doesnotprovideguidanceontheprocessinvolvedinreportingperformanceindicatordataforlicenseesthathavestartedupafterhavingbeeninashutdownconditionforanextendedperiodoftime.MSPIvaluesaresensitivetounavailabilityhourswhenthecriticalhoursforaunitarelow,asisthecasewithaplantstartingupafteranextendedshutdown.Inthis,MSPImaynotbeavalidindicationofperformanceandshouldbeconsiderednotvaliduntilsufficientcriticalhoursareaccrued.ThedraftNRCStaffWhitePaperonPerformanceIndicatorValidityduringExtendedShutdownandSubsequentStartup,lastdiscussedattheApril2014ROPWorkingGroupmeetingnotes:"Forplantsthatareinextendedshutdownconditions,theMSPIdataelementscontinuetobereported.Oncethelicenseeanticipatesthatashutdownwillenteranextendedperiod(sixmonths),aFAQshallbesubmittedfortheROPWorkingGrouptodetermineMSPIvalidity.ThelicenseeshallsubmitanadditionalFAQtoestablishMSPIvalidityuponsubsequentstartup."TimelineofsignificanteventsforFortCalhounStation:April,2011-FortCalhounNuclearStationshutdown:26RefuelingOutage.June6,2011-DeclaredaNotificationofUnusualEvent-RisingfloodwatersAugust29,2011ExitedNotificationofUnusualEvent-RiverLevel1003'6"andloweringJune7,2011-1B4ALoadCenterfireDecember,2011-FCSenteredInspectionManualChapter0350.December21,2013-Breakersclosedandextendedoutageended.
NEI99 02FAQ14 02FortCalhounMSPIPage2of5Revised09/8/2014NRCResidentCommentsResidentsInspectorhadnocomments.LicenseePositionFCSwillcontinuemonitoringMSPIandreportingdataelementsonaquarterlybasis.TheperformanceindicatorshallremainN/Auntilreporteddataisexpectedtobeamoreaccuratereflectionofcurrentplantperformance.
Thelackofcriticalhoursforthepast12quartershasandwillcontinuetoskewtheperformanceindicatorsvalidity.Ascriticalhoursareaccrued,performanceandpredictabilitybecomesincreasinglyrepresentativeofactualperformanceofthestation.AsoneofthebasicpremisesofMSPIisthatasinglefailureshouldnotresultinanadverseindicator,thefollowingcriteriawereusedbyFt.CalhounStationtodeterminewhentherewillbesufficientcriticalhourstoavoidafalsepositiveindicator:1. Thereshouldbeatleast4quartersofdatafollowingthestartupfromtheextendedoutage,and2. TheMSPIvalueshouldbeabletotoleratetheworsesinglefailureandunavailabilityequaltoafullLCOCompletiontimeandremainGreen( 1.0E 6/yr)followingstartupfromtheextendedoutage.AplantspecificPWROwnersGroup"What If"toolwasusedtopredictfutureMSPIvaluesusingexpectedplantdata(UnavailabilityandUnreliability).
ThechartsbelowillustratestheimpactfortheEACandRHRsystemsfromhavingafailureandassociatedunavailabilityinthe4 thquarter2014andtheimpactonMSPIasadditionalcriticalhoursareaccrued:
NEI99 02FAQ14 02FortCalhounMSPIPage3of5Revised09/8/2014EACQ12014Q22014Q32014Q42014Q12015MSPI 2.4E 082.7E 073.0E 071.2E 069.2E 07UAI 9.50E 092.86E 073.31E 077.11E 076.92E 07URI 1.49E 08 1.31E 08 3.18E 084.66E 072.32E 07%BaselineCritHrs9.7%18.7%27.8%35.6%45.8%Q12015MSPIdecreasereflectsaFeb2012failuredroppingoutofthe3yearmonitoringperiod.BothDG2YearOverhauls(103hourseach)areincludedin2014estimate.PastMSPIvaluesreflectoriginalestimateforobservedperiod.2.00E 070.00E+002.00E 074.00E 076.00E 078.00E 071.00E 061.20E 061.40E 06Q12014Q22014Q32014Q42014Q12015MSPI UAI URI AssumedFailureandappliedfullLCO EAC NEI99 02FAQ14 02FortCalhounMSPIPage4of5Revised09/8/2014RHRQ12014Q22014Q32014Q42014Q12015Q21015Q32015Q42015Q12016MSPI1.7E 07 1.5E 07 1.5E 071.9E 061.7E 061.4E 061.2E 061.1E 069.9E 07UAI1.92E 07 1.37E 07 1.37E 071.51E 061.35E 061.08E 068.93E 077.66E 076.60E 07URI 1.73E 08 1.05E 08 9.47E 093.52E 073.24E 073.24E 073.25E 073.18E 073.35E 07%BaselineCritHrs9.7%18.7%27.8%35.6%45.8%50.2%59.4%68.5%77.5%Estimatedplannedunavailabilityhoursforeachquarter:7hours.RFO27isscheduledfor45daysduringQ2_2015.2.00E 073.00E 078.00E 071.30E 061.80E 062.30E 06Q12014Q22014Q32014Q42014Q12015Q21015Q32015Q42015Q12016MSPI UAI URI AssumedFailure RHR NEI99 02FAQ14 02FortCalhounMSPIPage5of5 PotentiallyrelevantexistingFAQnumbers:NoneResponseSectionBasedontheresultsofthissensitivitystudy,thefollowingtableidentifieswheneachMSPIshouldbeconsideredvalid:MSPISystemEffectiveDateLimitingCriteriaMS06-EmergencyACPower1 stquarter2015SingleFailureplusassociatedunplannedunavailability(fullLCO)yieldswhiteindicatorin4 thquarter2014butgreenin1 stquarter2015MS07-HighPressureInjectionSystem4 thquarter20144quartersdataMS08-HeatRemovalSystem4 thquarter20144quartersdataMS09-ResidualHeatRemovalSystem1 stquarter2016SingleFailureplusassociatedunplannedunavailability(fullLCO)yieldswhiteindicatorin4 thquarter2015butgreenin1 stquarter2016MS10-CoolingWaterSystem4 thquarter20144quartersdataNRCResponse NEI 99-02 FAQ 14-03 ANO Scram March 31, 2013 Page 1 of 4 Revised 10/14/2014 Plant: Arkansas Nuclear One Unit 2 (ANO-2) Date of Event:
March 31, 2013 Submittal Date:
March 20, 2014 Licensee Contact:
Stephenie Pyle Tel/email:
479-858-4704 / spyle@entergy.com NRC Contact: Matt Young Tel/email:
479-858-3113 / matt.young@nrc.gov Performance Indicator:
IE04 - Unplanned Scrams with Complications (USwC)
Site-Specific FAQ (see Appendix D)?
Yes FAQ to become effective
- October 30, 2014 Question Section
NEI 99-02 Guidance needing interpretation (include page and line citation):
Pg H-4 Line s 27, 28, 29 Since all PWR designs have an emergency feedwater system that operates if necessary, the availability of the normal or main feedwater system as a backup in emergency situations can be important for managing risk following a reactor scram.
Pg H-5 Line s 3, 4, 5 Condenser vacuum, cooling water, and steam pressure values should be evaluated based on the requirements to operate the pumps and may be lower than normal if procedures allow pump operation at that lower value.
Event or circumstances requiring guidance interpretation:
ANO-2 Loss of a Condenser Vacuum due to Transfer to Startup Transformer #2 (SU 2) In determining if a scram i s complicated/uncomplicated, the guidance asks "Was main feedwater unavailable or not recoverable using approved plant procedures during the scram?" (emphasis added)
The question fails to include the phrase "normal or" as stated in H-4 above. The intent is to determine if a backup feedwater source is available should Emergency Feedwater (EFW) fail.
The NEI 99
-02 guidance use s the term Auxiliary Feedwater (AFW) interchangeabl y with EFW. ANO-2 has two EFW pumps and has installed a low power feedwater system referred to as AFW. The ANO AFW pump (2 P-75) and its connections to the EFW and the main feedwater (MFW) header s has called into question whether it is a "normal or main Feedwater system as a backup in emergency situations" an d an "electric-driven main feedwater pump".
NEI 99-02 FAQ 14-03 ANO Scram March 31, 2013 Page 2 of 4 Revised 10/14/2014 Beginning March 31, 2013
, ANO-2 has experience d the loss of condenser vacuum due to the transfer of the offsite power sources to Startup Transformer #2 (SU2) on t wo separate occasions.
Since SU2 is share d between the two unit s at ANO , SU2 power feed to 4160V switchgear 2A-2 breaker and SU2 power feed to both 6900V switchgear 2H-1 and 2H-2 are maintained in pull-to-lock per procedure OP-2107.001 , Electrical System Operation (normal configuration).
This avoids a challenge to the millstone relay setpoints should both ANO units transfer to SU2 simultaneously. In both events SU2 automatically powered 4160 V switchgear 2A
-1 successfully, which in turn provided offsite power to safety bus 2A
-3. Switchgear 2A-1 remained energized throughout the event
- s.
ANO-2 has two offsite power sources: SU2 and Startup Transformer #3 (SU3). When available (i.e., not removed from service for maintenance, testing, or grid conditions), SU3 is the preferred source of offsite power following a reactor trip. This is because SU3 is not shared between the two ANO units and, therefore, no load shedding is required for transfer to SU3. A reactor trip with SU3 available will automatically result in MFW being reduced to a single MFW pump (both MFW pumps are high capacity steam
-driven pumps), which is driven to minimum speed and respective valves driven to minimum positions (referred to a reactor trip override or RTO). The MFW system is subsequently manually secured and the electric-driven AFW pump placed in service to maintain hot standby conditions or to support plant cooldown. When AFW is available, all plant startups and shutdowns are performed with AFW as the preferred source.
The AFW pump is capable of supplying sufficient feedwater flow to remove decay heat up through ~4% reactor power
. The AFW pump is tested quarterly in accordance with Supplement 8 of procedure OP
-2106.006, Emergency Feedwater System Operations.
When SU3 is unavailable, switchgear 2A
-1 loads are transferred to SU2 as described above. However, the two circulating water pumps necessary to maintain condenser vacuum are powered from 2H
-1 and 2H-2, which are not automatically transferred to SU2. SU2 continues to supply power to vital buses and some no n-vital equipment, although the AFW pump is also initially load
-shed if in operation.
By design and as discussed previously , unavailability or a lockout of S U3 result s in the loss of non-vital circulating water pumps and the subsequent loss of condenser vacuum. In relation to the aforementioned ANO events, the loss of condenser vacuum initially results in the loss of MFW pump (high exhaust pressure
). Procedures provide the necessary instructions to defeat the load shed relay for the AFW pump if EFW is lost or to support plant cooldown as needed. In addition , procedures provide the necessary instructions to restart the MFW pump without vacuum if both EFW and AFW become unavailable. Either of these backup options to EFW can be accomplished within approximately 30 minutes and prior to Steam Generator dry-out (reference NEI 99
-02, H1.5).
During the subject ANO events, no equipment malfunctions occurred that would have prevented at least one of the backup options from being utilized if needed. The AFW pump can be supplied directly from the Condensate Storage Tanks, does not rely on condenser vacuum or portions of the MFW system, and is the normal and preferred feedwater source to support plant cooldown, heatup, hot standby conditions, and startup (Emergency Operating Procedure (EOP) OP
-2202.002, Reactor Trip Recovery, Step 12, among all the relevant EOPs, Abnormal Operating Procedures (AOPs), and Normal Operating procedures, place 2P
-75 pump in service as the preferred source).
All necessary features which support operation of 2P
-75 remained available.
NEI 99-02 FAQ 14-03 ANO Scram March 31, 2013 Page 3 of 4 Revised 10/14/2014 Applicable procedure steps from reactor trip through completion of restarting a MFW pump without condenser vacuum were reviewed and qualitatively timed. The timing was reviewed by Operations personnel including SRO's responsible for simulator training. GE input was obtained which qualitatively confirmed MFW pump capability to operate with no condenser vacuum for several hours. ANO
-2 Reactor Coolant System parameters were stabilized in the subject scram event in less than 30 minutes, upon the establishment of natural circulation cooling. Plant stabilization via natural circulation cooling would not be delayed if MFW pump restart had been required.
If licensee and NRC resident/region do not agree on the facts and circumstances, explain: With respect to feedwater sources, Entergy has determined the scram to be uncomplicated because at least one or more "normal or main" feedwater sources remained available as backup to the EFW system, as designed. The aforementioned timing and flow path through relevant procedures was provided to the ANO NRC Resident inspector.
In addition, GE provided information, based on engineering judgment, regarding the operation of the MFW pump under a loss of vacuum condition. Based on the information provided, the ANO NRC Resident Inspectors and associated NRC Regional personnel have verbally concurred that a MFW pump could likely have been recovered within 30 minutes and, therefore, the subject scrams should be considered uncomplicated.
Potentially relevant FAQs:
FAQ 481 (10-02) significantly revised Section 2.1 of NEI 99
-02 Rev 7 on August 31, 2013. FAQ 467 response: "availability of feedwater beyond 30 minutes and whether consideration of the scram response time window remains an appropriate marker for judging a complication to recovery from an unplanned scram
"
5 Response Section Proposed Resolution of FAQ:
Due to the plant design of ANO-2 , the response to the guidance question: "Was main feedwater unavailable or not recoverable using approved plant procedures during the scram?" Should be "NO" provided that the MFW and/or A FW pump wa s available for use within an estimated 30 minutes in both events.
NEI 99-02 FAQ 14-03 ANO Scram March 31, 2013 Page 4 of 4 Revised 10/14/2014 If appropriate, provide proposed rewording of guidance for inclusion in next revision:
Because this FAQ is site
-specific, no wording changes are proposed with regard to NEI 99-02. This FAQ concludes that the ANO
-2 Auxiliary Feedwater pump provides an appropriate electric-driven backup feedwater capability to the ANO
-2 safety-related Emergency Feedwater system.
PRA update required to implement this FAQ?
No MSPI Basis Document update required to implement this FAQ?
No NRC Response The NRC staff used the following reference from NEI 99
-02 during the review of this FAQ:
Pg H-4 Line s 27, 28, 29 "Since all PWR designs have an emergency feedwater system that operates if necessary, the availability of the normal or main feedwater system as a backup in emergency situations can be important for managing risk following a reactor scram.
" For this event, ANO proposes that backup to EFW could have been provided in two ways: (1) using AFW, or (2) restarting MFW without condenser vacuum. The staff's review was focused on the licensee's ability to recover MFW, since NEI 99
-02 highlights the importance of having normal or main feedwater available as a backup to EFW in emergency situations.
NEI 99-02 does not discuss the applicability of AFW as a backup to EFW under the Unplanned Scrams with Complications PI.
The staff reviewed the licensee's procedures for restarting MFW without condenser vacuum and agrees that MFW could likely have been recovered within 30 minutes.
The staff also recognizes that the Reactor Cooling System parameters were stabilized in less than 30 minutes, and that the MFW pump could operate without condenser vacuum for several hours, according to the information provided in this FAQ.
The staff concludes that this event does not count in the Unplanned Scram with Complications PI.
The staff proposes to consider revising the language in NEI 99
-02 to clarify the applicability of AFW as backup to EFW in emergency situations under the scope of the Unplanned Scrams with Complications PI.
FAQ 14-XX (Proposed)
Reporting New Siren System Data Page 1 of 2 Revised 07/14/2014 Plant: Southern Nuclear Operating Company
- Hatch Date of Event:
Submittal Date:
April 30, 2014 Contact: Charles Brown Tel/email:
205.992.7421 NRC Contact:
Tel/email:
Performance Indicator:
EP03, Alert and Notification System Reliability Site-Specific FAQ (Appendix D)?
Yes FAQ requested to become effective
- when approved
. Question Section NEI 99-02 Guidance needing interpretation (include page and line citation):
Revision 7 (Clean Copy), page 58:
19 Data Reporting Elements 20 The following data are reported: (see clarifying notes) 21 22 -tests during the previous quarter 23 -tests during the previous quarter Event or circumstances requiring guidance interpretation:
How does a plant initially report alert and notification system reliability for a new siren system where there were no sirens previously?
What is the NRC resident inspector's position?
The guidance is unclear on start
-up of this indicator. Therefore, the SRI seeks clarification from the ROP Working Group.
Potentially relevant existing FAQ numbers None. Response Section Proposed Resolution of FAQ
- In initiating EP03 reporting data for a new siren system (where there were no sirens previously), data is entered over the 12 month period starting from the implementation date of April 1, 2014. Each quarter results will be submitted in accordance with NEI 99
-02 Rev 7. Zeroes are entered for the trailing quarters until four quarters of data have accumulated.
NRC Response The staff agrees with the proposed resolution for this FAQ, upon incorporation of the following revision:
In initiating EP03 reporting data for a new siren system (where there were no sirens previously), data is entered over the 12 month period starting from the implementation date of April 1, 2014. Each quarter results will be submitted in accordance with NEI 99-02 Rev 7. Zeroes areZero should be entered for the trailing 12 month quarters quarterly average until four quarters of data have accumulated.
FAQ 14-XX (Proposed)
Reporting New Siren System Data Page 2 of 2 Revised 07/14/2014 Starting April 1, 2014, the licensee will submit the EP03 PI quarterly results in accordance with NEI 99
-02 Rev. 7. The EP03 PI will be valid once four quarters of data have been accrued.
This resolution is consistent with the approach previously discussed in the ROP Working Group on the validity of the EP03 PI for new plants at a new site (the proposed approach was initia l l y discussed in the December 1, 2011 ROP Working Group public meeting (Accession No. ML11350A092
)).
FAQ 14-XX (Proposed)
Point Beach Alert & Notification System Page 1 of 2 1 0/22/201 4 Plant: Point Beach 1 and Point Beach 2 Date of Event: November 1, 2014 Submittal Date: October 10, 201 4 Licensee Contact: Gerard D. Strharsky Tel/email: 920-755-6557/gerard.strharsky@nee.com NRC Contact:
James Beavers Tel/email: 630-829-9760 Performance Indicator: Alert and Notification System Reliability (EP03) Site-Specific FAQ (Appendix D)?
Yes, Appendix D page D
-1 FAQ requested to become effective
- At the beginning of the first full reporting period after Point Beach assumes full responsibility for all sirens in the overlap area
. Question Section
NEI 99-02 Guidance needing interpretation (include page and line citation):
Page D-1, Lines 20-22: 20 Some provisions in NEI 99
-02 may differ from the design, programs, or procedures of a particular 21 plant. Examples include (1) the overlapping Emergency Planning Zones at Kewaunee and Point 22 Beach and (2) actions to address storm
-driven debris on intake structures.
Page D-1, Lines 27
-42: 27 Kewaunee and Point Beach 28 29 Issue: The Kewaunee and Point Beach sites have overlapping Emergency Planning Zones (EPZ).
30 We report siren data to the Federal Emergency Management Agency (FEMA) grouped by criterion 31 other than entire EPZs (such as along county lines). May we report siren data for the PIs in the 32 same fashion to eliminate confusion and prevent 'double reporting' of sirens that exist in both 33 EPZs? Kewaunee and Point Beach share a portion of EPZs and responsibility for the sirens has 34 been divided along the county line that runs between the two sites. FEMA has accepted this, and 35 so far the NRC has accepted this informally.
36 37 Resolution: The purpose of the Alert and Notification System Reliability PI is to indicate the 38 licensee's ability to maintain risk
-significant EP equipment. In this unique case, each neighboring 39 plant maintains sirens in a different county. Although the EPZ is shared, the plants do not share 40 the same site. In this case, it is appropriate for the licensees to report the sirens they are 41 responsible for. The NRC Web site display of information for each site will contain a footnote 42 recognizing this shared EPZ responsibility.
Event or circumstances requiring guidance interpretation:
Point Beach Nuclear Plant (PBNP) has concluded negotiations for taking responsibility of siren maintenance and operation from Kewaunee for the remaining sirens in the area of overlap of Emergency Planning Zones between the respective sites. That transition is expected to occur sometime after November 1, 2014, with FEMA formal approval shortly thereafter. Consequently, the site
-specific FAQ documented in NEI 99
-02, Rev 7, Page D
-1, Lines 27 through 42
, will no longer apply after that transition occurs
.
FAQ 14-XX (Proposed)
Point Beach Alert & Notification System Page 2 of 2 1 0/22/201 4 PBNP has historically, obtain ed ANS siren performance and maintenance records and data from KPS for the purpose of monitoring and recording all required information related to overlapping siren performance. As a result of previously approved FAQ 13
-04, Point Beach had also been recording the performance information related to those sirens in the comments section of CDE.
If licensee and NRC resident/region do not agree on the facts and circumstances explain The content of this FAQ has been reviewed with NRC Region III Emergency Preparedness Inspector, who indicated that he concurs with the facts and circumstances as provided.
Potentially relevant existing FAQ numbers FAQ 13-04. (The text of Appendix D first appears in NEI 99
-02, Revision 1, published April 2001.)
Response Section
Proposed Resolution of FAQ Beginning with the first full quarter in which Point Beach is responsible for maintenance of the sirens formerly in the overlap area, the site specific FAQ governing reporting of the shared sirens between Point Beach and Kewaunee should be rescinded.
If appropriate, provide proposed rewording of guidance for inclusion in next revision.
Revise Page D
-1, Lines 21
-22, as follows:
20 Some provisions in NEI 99
-02 may differ from the design, programs, or procedures of a particular 21 plant. For E example s , include (1) the overlapping Emergency Planning Zones at Kewaunee and 22 Point Beach and (2) actions to address storm
-driven debris on intake structures.
Delete section of NEI 99
-02 discussing the site specific condition (Page D-1, Lines 27 through 42) in its entirety, as it will no longer be applicable.
If appropriate, provide proposed rewording of guidance for inclusion in next revision.
PRA update required to implement this FAQ? No MSPI Basis Document update required to implement this FAQ?
No NRC Response (To be determined)