Text

FENOC, Perry Nuclear Power Plant - Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding the Flooding Aspects of Recommendation 2.1 of the Near-Term Task Force (NTTF) Review of Insights from the Fukushima Dai-ichi Ac
	ML15069A056
Person / Time
Site:	Perry
Issue date:	03/10/2015
From:	Harkness E; FirstEnergy Nuclear Operating Co
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	L-15-074
	Download: ML15069A056 (39)
	v • d • e

FENOC' Perry Nuclear Power Plant P.O. Box 97 10 Center Road Perry, Ohio 44081 FirstEnergy Nuclear Operating Company ErnestJ. Harkness 440-280-5382 Vice President Fax: 440-280-8029 March 10, 2015 L-15-074 10 CFR 50.54(f)

ATTN: Document Control Desk U.S. Nuclear Regulatory Commission 11555 Rockville Pike Rockville, MD 20852

SUBJECT:

Perry Nuclear Power Plant Docket No. 50-440, License No. NPF-58 FirstEnergy Nuclear Operating Company (FENOC) Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding the Flooding Aspects of Recommendation 2.1 of the Near-Term Task Force (NTTF) Review of Insights from the Fukushima Dai-ichi Accident On March 12, 2012, the Nuclear Regulatory Commission (NRC) issued a letter titled, "Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3, and 9.3, of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident," to all power reactor licensees and holders of construction permits in active or deferred status. Enclosure 2 of the 10 CFR 50.54(f) letter addresses NTTF Recommendation 2.1 for flooding. One of the required responses is for licensees to submit a Hazard Reevaluation Report (HRR) in accordance with the NRC's prioritization plan. By letter dated May 11, 2012, the NRC placed the Perry Nuclear Power Plant (PNPP) in Category 3 requiring a response by March 12, 2015. The Flood HRR for PNPP is enclosed.

As discussed in the enclosed report, three flood levels (riverine, local intense precipitation and probable maximum storm surge) determined during the hazard reevaluation exceed the current licensing basis (CLB) flood levels. Actions planned to address the reevaluated hazards are also described in the enclosed report.

Perry Nuclear Power Plant L-15-074 Page 2 In accordance with the guidance provided by NRC letter dated December 3, 2012, titled "Trigger Conditions for Performing an Integrated Assessment and Due Date for Response," an integrated assessment is required if flood levels determined during the hazard reevaluation are not bounded by the CLB flood levels. The 10 CFR 50.54(f) letter specifies that the integrated assessment be completed and a report submitted within two years of submitting the HRR. Therefore, FENOC intends to submit an Integrated Assessment Report for PNPP prior to March 12, 2017.

There are no regulatory commitments contained in this letter. If there are any questions or if additional information is required, please contact Mr. Thomas A. Lentz, Manager -

Fleet Licensing, at 330-315-6810.

I declare under penalty of perjury that the foregoing is true and correct. Executed on March Id , 20 15.

Respectfully,

~~-

Ernest J. Harkness

Enclosure:

Flood Hazard Reevaluation Report cc: Director, Office of Nuclear Reactor Regulation (NRR)

NRC Region Ill Administrator NRC Resident Inspector NRR Project Manager

Enclosure L-15-074 Flood Hazard Reevaluation Report (36 pages follow)

FLOODHAZ/ARDREEVALUATIOil REPORT IN RESPONSE TO THE50.5/T(f} INFORUATION REQUESTREGARDING NEAR-TERI'TASKFORCERECOHTENDATION 2.I: FLOODING for ths PERRYHUCLEARPOWERPLANT f 0 Ctnttr Road North Perry,OH {4081 Firret EnergyCorporation 76 SouthMainStreet Akron,OH44308 Preparad by:

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NTTF Recommendation 2.1 (HazardReevaluations): Flooding Revision 0 FirstEnergyCorporation February23,2015 Table of Gontents 1 . P U R P O S.E . ......3 1 . 1 . B a c k g r o u .n d ..........3 1.2. Requested Actions.. ..........3 1.3. Requested Information ...-.-..4

2. SITEINFORMATION ......5 2 . 1 . C u r r e nDt e s i g n Basis.. ..........7 2.1.1. LocalIntense Precipitation (LlP)..... ......7 2.1.2. Flooding in Streams andRivers ......7 2.1.g. DamBreaches andFailures 2.1.4. StormSurgeandSeiche... ...'..7 2.1.5. Tsunami...... .....7 2 . 1 . 6 . l c e - l n d u c eFdl o o d i n g .........7 2.1.7. Channel Migration or Diversion ..,....7 2.1.8. Combined EffectFlood(including \Mnd-Generated Waves) ...........8 2.1.9. LowWater 2.2. Flood-Related Changes to the LicenseBasis ......8 2.3. Changesto theWatershed andLocalAreasinceLicenselssuance .....8 2.4. CurrentLicensing BasisFloodProtection andPertinent Features............8 FloodMitigation

3.

SUMMARY

OF FLOODHATARD REEVALUATION ........9 3.1. Floodingin Streamsand Rivers(Reference PNPP2015a,PNPP2015b,PNPP2015c, PNPP2015d,PNPP2015e,PNPP2015f , PNPP 2015n,PNPP2015r,andPNPP2015s)........10 3.1.1. Basisoflnputs:... ..........11 3.1.2. Computer Software Programs ....-12 3.1.3. Methodology ....12 3.1.4. Results .......16 3.2. DamAssessment (Reference PNPP2015h) 3 . 2 . 1 . B a s i so f I n p u t s . . . . .....18 3.2.2. Computer Software Programs ....18 3.2.3. Methodology ....1I 3.2.4. Results .......1I 3.3. lce-lnduced Flooding (Reference PNPP2015i) ....'..18 3 . 3 . 1 . B a s i so f I n p u t s . . . . ....18 3.3.2. Computer Software Programs .......18 3.3.3. Methodology ...18 3.3.4. Resutts ....'..19 3.4. ChannelMigration or Diversion (Reference PNPP2015i) ...'20 PERRYNUCLEARPOWERPLANT Page1 of 35

NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision0 FirstEnergyCorporation February23,2015 3 . 4 . 1 . B a s i so f I n p u t s . . . . ...20 3.4.2. Computer Software Programs ......24 3.4.3. Methodology ...20 3.4.4. Results ....20 3.5. StormSurge(Reference PNPP2015j,PNPP2015k,PNPP20151, PNPP2A15o,andPNPP 2015p) ...20 3 . 5 . 1 . B a s i so f l n p u t s . . . . ........21 3.5.2. Computer Software Programs ......21 3.5.3. Methodology .....21 3.5.4. Results ....23 3.6. Tsunami Assessment (Reference PNPP2015m). ....24 3 . 6 . 1 . B a s i so f I n p u t s . . . . ....24 3.6.2. Computer Software Programs .......24 3.6.3. Methodology ...24 3.6.4. Results ......25 3.7. Combined EffectFlood(including \Mnd-Generated PNPP2015q)...26 Waves)(Reference 3.7.1. Basisoflnputs.... ....26 3.7.2. Computer SoftwarePrograms ...27 3.7.3. Methodology .....27 3.7.4. Results ......27 3.8. LocalIntensePrecipitation (Reference PNPP20159) .....28 3 . 8 . 1 . B a s i so f I n p u t s . . . . ...28 3.8.2. Computer Software Programs ....... .....28 3.8.3. Methodology ...28 3.8.4. Results .....29

4. COMPARISON WITHCURRENT DESIGN BASIS... .......29

5. INTERIM ANDPLANNED FUTURE ACTIONS .......33

6. REFERENCES ......34 PERRYNUCLEARPOWERPLANT Page2 of 35

NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision 0 FirstEnergyCorporation February 23,2015

1. PURPOSE 1.1. Background In response to the nuclearfueldamageat the Fukushima Dai-ichipowerplantdueto the March 11, 2011 earthquakeand subsequenttsunami,the United States Nuclear Regulatory Commission (NRC)established the NearTerm Task Force(NTTF)to conducta systematic reviewof NRC processes and regulations, and to makerecommendations to the NRCfor its policydirection.The NTTFreporteda set of recommendations thatwereintendedto clarifyand strengthen the regulatory frameworkfor protection againstnaturalphenomena.

On March12,2012the NRCissuedan information requestpursuantto Title10 of the Codeof FederalRegulations, Section50.54(f) (10CFR50.54(0or 50.54(Dletter)whichincludedsix (6) enclosures:

1. NTTF Recommendation 2.1:Seismic

2. NTTF Recommendation 2.1: Flooding

3. NTTF Recommendation 2.3:Seismic

4. NTTF Recommendation 2.3:Flooding

5. NTTF Recommendation 9.3:EP

6. Licensees andHoldersof Construction Permits fn Enclosure2 of the NRC-issued informationrequest(Reference NRCMarch2A12),the NRC requestedthat licenseesreevaluatethe floodinghazardsat their sites againstpresent-day regulatory guidanceand methodologies beingusedfor earlysite permits(ESP)and combined operatinglicensereviews.

On behalfof FirstEnergy NuclearOperating Company(FENOC)for the PerryNuclearPower Station (PNPP), this Flood HazardReevaluation Report(Report)providesthe information requestedin the March 12, 2012 50.54(Dletter;specifically, the informationlistedunderthe "Requested Information" sectionof Enclosure 2, paragraph 1 ('a'through'e').The "Requested fnformation" sectionof Enclosure2, paragraph2 ('a'through'd'),IntegratedAssessment Report, will be addressed separately if the currentdesignbasisfloodsdo not boundthe reevaluated hazardfor all flood-causing mechanisms.

1.2. RequestedActions Per Enclosure 2 of the NRO-issued informationrequest,50.54(0letter,FENOCis requested to performa reevaluation of all appropriate externalfloodingsourcesfor PNPP,including theeffects fromlocalintenseprecipitation (LlP)on the site,the probable maximum flood(PMF)on streams and rivers,lake floodingfrom stormsurges,seiches,and tsunamis,and dam failures.lt is requested thatthe reevaluation applypresent-day regulatoryguidance andmethodologies being usedfor ESPs,combinedoperatinglicensereviews,and calculation reviews includingcurrent techniques, software, andmethods usedin present-day standard engineeringpracticeto develop the floodhazard.The requestedinformation will be gatheredin Phase1 of the NRCstaffstwo-phase processto implementRecommendation 2.1, and will be used to identifypotential "vulnerabilities"(seedefinitionbelow).

PERRYNUCLEARPOWERPI-ANT Page 3 of 35

NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision0 FirstEnergyCorporation February23,2Q15 The NRC prioritization of responsesletter(ReferenceNRC May 2012)identifiesPNPPas a Category3 site.Licensees in thiscategoryareexpectedto reportthe resultsof the reevaluation withinthreeyearsof the March12,201250.54(f)letterissuance.

Forthe siteswherethe reevaluated floodexceedsthe designbasis,addressees are requested to submitan interimactionplan documenting plannedactionsor measuresimplemented to addressthe reevaluated hazards.

Subsequently, addressees shallperforman integratedassessment of the plantto fullyidentify vulnerabilitiesanddetailactionsto addressthem.Thescopeof the integrated assessment report will includefullpoweroperations andotherplantconfigurations thatcouldbe susceptible dueto the statusof the floodprotection features.Thescopealsoincludesthosefeaturesof the ultimate heatsink(UHS)thatcouldbe adverselyaffectedby floodconditions(thelossof UHSfromnon-flood associatedcausesis not included).lt is also requestedthat the integratedassessment addressthe entiredurationof thefloodconditions.

A definitionof vulnerabilityin the contextof Enclosure2 is as follows:Plant-specificvulnerabilities are thosefeaturesimportantto safetythatwhensubjectto an increased demanddueto thenewly calculatedhazardevaluationhave not been shown to be capableof performingtheir intended functions.

1.3. RequestedInformation PerEnclosure 2 of the NRC-issued request50.54(D information letter,the Reportshouldprovide documented results,as well as pertinentPNPPinformation and detailedanalysis,and include the following:

1. Site information relatedto the flood hazard.Relevantstructure,systems,and components (SSCs)important to safetyandthe UHSare includedin the scopeof thisreevaluation, and pertinentdataconcerning theseSSCsshouldbe included.Otherrelevantsite data include thefollowing:

1. Detailedsite information(both designed and as-built),includingpresent-daysite layout,elevationof pertinentSSCs importantto safety,sitetopography,and pertinent spatialandtemporaldatasets;

2. Currentdesignbasisfloodelevations for allflood-causingmechanisms;

3. Flood-related changesto the licensingbasis and any flood protectionchanges (including mitigation) sincelicenseissuance;

4. Changesto thewatershed andlocalareasincelicenseissuance;

5. Currentlicensingbasisfloodprotection and pertinentfloodmitigation featuresat the site;and

6. Additional sitedetails,as necessary, to assessthefloodhazard(e.g.,bathymetry and walkdownresults).

2. Evaluation of the flood hazardfor eachflood-causing mechanism, basedon present-day methodologies and regulatoryguidance.Providean analysisof each flood-causing mechanism thatmayimpactthesite,including LIPandsitedrainage, floodingin streamsand rivers,dam breachesandfailures,stormsurgeand seiche,tsunamis,channelmigration or diversion,and combinedeffects.Mechanisms that are not applicable at the site may be screenedout; however,a justificationshould be provided.A basis for inputs and PERRYNUCLEARPOWERPLANT Page 4 of 35

NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision0 FirstEnergyCorporation February23,2415 assumptions, methodologies and modelsused,includinginputand outputfiles,and other pertinent datashouldbe provided.

3. Comparison of currentand reevaluated flood-causing mechanisms at the site.Providean assessment of the currentdesignbasisfloodelevationto the reevaluated floodelevationfor eachflood-causing mechanism. Includehowthe findingsfrom Enclosure 2 of the 50.54(D letter(i.e.,Recommendation 2.1, floodhazardreevaluations) supportthisdetermination. lf the current design basis flood bounds the reevaluatedhazard for all flood-causing mechanisms, includehowthisfindingwasdetermined.

4 . Interimevaluation and actionstakenor plannedto addressany higherfloodinghazards relativeto the designbasis,priorto completionof the integratedassessmentdescribed below,if necessary.

5 . Additionalactionsbeyondrequestedinformation item 1.d taken or plannedto address floodinghazards,if any.

2. SITEINFORMATION PNPPis locatedin LakeCounty,Ohio,approximately sevenmilesnortheast of Painesville. The southernplantsiteboundarylineis 3,100feetfromthe shoreline of Lake Erie on the westside of the site and 8,000feet on the east side (USAR,Section2.4.1.1).Lake Erie is the major hydrologic featureof the location.In the vicinityof the site,the coastalwatershed is drainedby severalsmallstreams(USAR,Section2.4.1.2). Twonameless, parallelstreamsruncloseto the plantarea.The larger(MajorStream)has a drainagebasinof 7.16 squaremilesand runs northwestward within1,000feetof the southwest cornerof the plant.Thesmallerstream(Minor Stream), whichhasa drainageareaof only0.76squaremiles,borderstheplantareato theeast.

The safety-related structuresof the plantare locatedwithinthe drainagebasinof the small stream.Finalgradeelevations in the immediate plantareavaryfrom617 to 620 feet (USGS)

(USAR,Section2.4.2.2). Thefloorsat plantgradearesetat Elevation 620.5feet(USGS)(USAR, Section2.4.2.3). NotethattheUpdatedSafetyAnalysisReport(USAR)presents elevations using a USGSdatumthatis equivalent to the NationalGeodetic VerticalDatum of 1929 (NGVD 29).

Thepresent-day sitelayoutis shownin Figure2.0.1.

PERRYNUCLEAR POWERPLANT Page5 of 35

NTTF Recommendation Flooding

2.1 (HazardReevaluations)

Revision0 FirstEnergyCorporation February23,2015 Figure2.0.1- Present-DaySite Layout PERRYNUCLEAR POWERPLANT Page 6 of 35

NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision0 FirstEnergyCorporation February23,2015 2,1. CurrentDesignBasis The currentdesignbasisis definedin the PNPPUSAR.The followingis a listof flood-causing mechanisms and theirassociatedwatersurfaceelevationsthat wereconsidered for the PNPP currentdesignbasis.

2.1.1. LocalIntensePrecipitation (LlP)

The USARindicates valueof 26.7inchesovera 6-hourperiod,withthe that the precipitation maximumhourlyrainfallof 13.1inchesoccurringduringthe first hour,is utilizedfor the LIP analysis.In the caseof complete blockage of thestormdrainagesystem,the plantsitehasbeen gradedso thatoverlanddrainage willoccurawayfromthe plantsitebuildings andwillnotallow the accumulated stormwaterto exceedElevation 620.5feet(USGS)(USAR,Section2.4.2.3).

2.1.2. Floodingin Streamsand Rivers The USARidentifiesa flow rateof 31,250cubicfeet per second(cfs)for the MajorStreamand 7,000cfsfortheMinorStream(USAR,Section2.4.3).TheMajorStreamwatersurfaceelevation upstreamof the plantaccessroadfor the PMFwas foundto be 624.0feet (USGS)untilthis surfacemet the normaldepthof flow in the existingstream.This watersurfaceelevationwill safelypassbeneaththerailroadbridge(USAR,Section2.4.3.5\. TheMinorStreamwatersurface efevationwasfoundto be 619.5feet(USGS)(USAR,Figure2.4-8).

2.1.3. DamBreachesand Failures The USARidentifiesno impoundments upstreamof the plant.Therefore, dam failureis not includedas a designcondition (USAR, Section 2.4.4).

2.1.4. StormSurgeand Seiche Theprobable maximum meteorologicaleventin LakeErieresultsin a maximum stillwatersurface etevationof 580.5feet(USGS)(USAR,Section2.4.5.2.2). Theprobablemaximum storm(PMS) was assumedto occurovera 72-hourperiod,duringwhichthe windsincreasedfrom 20 miles per hourto the maximumspeedof approximately 103 milesper houroverthe lakeand then decreased to lessthan35 miles hourin the Perryarea(USAR,Section2.4.5.1.3).

per 2.1.5.Tsunami Sincethe site is locatedon LakeErie,an inlandlake,tsunamioccurrence not applicable (USAR,Section2.4.6).

2.1.6. lce-lnducedFlooding lce floodingcannotoccurbecauseof the highbluffsbetweenthe buildings andthe lake.Also, safety-related onshorebuildingsare set backfromthe top of the 4S-foothigh bluffto preclude iceforcesbeinga problem(USAR,Section2.4.7.4).

2.1.7. ChannelMigrationor Diversion Channeldiversionis not applicable to PNPPsinceno coolingwaterchannelsexistfromwhich ffowcouldbe diverted(USAR,Section2.4.9).

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NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision0 FirstEnergyCorporation February 23,2415 2.1.8. CombinedEffectFlood(includingWind-Generated Waves)

\Mndwaveactivity,includingrunup,wasevaluated as partof thesurgeanalysis.Runupoccurring coincidentally with the probablemaximumsetupwouldextendto aboutelevation607.9feet (USGS)on the bluffat the lakeshore(USAR,Section2.4.2.2).

2.1.9. Low Water No wateris takenfromthe MajorStreamor MinorStream.Therefore,low flowsin the streams willnotaffectPNPPoperation.

The UHSfor PNPPis LakeErie.Submerged offshoreintakessupplywaterto the emergency servicewaterpumphouse. All safety-relatedpumpsandequipmentare locatedaboveelevation 586.5feet (USGS)in the emergency servicewaterpumphouse (USAR,Section2.4.10).The emergencyservicewater pumphouseand emergencyservicewater pumpsare designedto provideservicecapacityunderall lakelevelconditions downto 565.26feet(USGS)levelcaused by the probablemaximumsetdownsuperimposed on the minimummonthlymeanlake level (USAR,Section2.4.11.6). Two verticalshaftsconveywaterintothe intaketunnel.The intake headsare coveredwith a velocitycap to prevenUminimize whirlpooling. Withthe invertsof the intakeportsat an averageelevationof 552.65feet (USGS),inflowof sufficientcoolingwateris assured(USAR,Section2.4.11.5).The corresponding waterlevelin theemergency servicewater pumpchamberwouldbe at elevation 562.09feet(USGS).

2.2. Flood-Related Changesto the LicenseBasis Therewereno changesto theflood-related licensebasissincethe initiallicenseissuance.

2.3. Changesto the Watershedand LocalArea since Licenselssuance Thewatershed contributoryto the MajorStreamis determined to be 7.44squaremilesbasedon the mostcurrentdata available(Reference PNPP2015c).The watershedcontributory to the MinorStreamis determined to be 0.69squaremilesbasedon the mostcurrentdataavailable (ReferencePNPP 2015e).Basedon aerialimagesof the watershed,the changesto the watershedincludecommercialdevelopment within the watershedarea, which is a small percentage of the overallwatershedarea.

Thenominaldesignelevation of sitepowerblockbuildings (buildings importantto nuclearsafety) are at elevation620.5feet (USGS) or higher.Reviewof the site CorrectiveActionprogram determined theactuatcurrentelevation of someof the powerblockbuildings areupto 1.5inches lower(PNPPCondition Report2009-68678). The changesto the localareasub-watershed for PNPPincludebuildings that havebeenaddedor removedand securitybarrierupgradesthat havebeenaddedto thesitesincelicenseissuance.

2.4. GurrentLicensingBasisFloodProtectionand PertinentFloodMitigationFeatures The maximumfloodlevelin the designbasisis belowthe sitefinishedfloorelevationof 620.5 feet (USGS).Therefore,no mitigation actionswereinitiatedor takenfor floodingat the site.

While performing this floodingreevaluation, it was discovered that the originalanalysisthat supportsthe MinorStream probable maximumflood in the USAR could not be located.A functionalityassessment was conducted and determined thatthe maximumwaterlevelat the sitebuildings dueto floodingof the MinorStreamdoesnotexceedthe groundfloorelevation of Unit 1 and Unit 2 site buildingsor affectthe abilityto achieveand maintaincold shutdown conditionsfollowing a PMP/PMF event(PNPPCondition Report2013-05625). Nocompensatory actionsare credited.

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NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision 0 FirstEnergyCorporation February 23,2015

3.

SUMMARY

OF FLOODHAZARDREEVALUATION NUREGICR-7046,Design-BasisFtoodEstimationfor SiteCharacterization at NuelearPower Plantsin the tJnitedSfafes of America (ReferenceNUREG/CR-7046), by referenceto the AmericanNuclearSociety(ANS),statesthat a singleflood-causing eventis inadequate as a designbasisfor powerreactorsand recommends that combinations should be evaluated to determine the highestfloodwaterelevation at thesite.ForPNPP,thecombination that produces the highestfloodwaterelevationat the site safety-related structuresis the PMF on the Minor Streamwiththe effectsof coincident windwaveactivity,as providedbelow.

The USARreportselevations corresponding to a USGSdatumthatis equivalent to the NGVD 29 verticaldatum.The recentsitesurvey,UnitedStatesGeological Survey(USGS)topographic maps,and otherreferencedocumentsreportelevationin the NorthAmericanVerticalDatumof 1988(NAVD88). The Lake Erieelevationsare typicallyreferencedto the International Great LakesDatumof 1985(IGLD85).In orderto comparethe reevaluated flood elevations withthe existingdesignbasiselevationsreportedin the USAR,the final pertinent elevations have been convertedto the NGVD29 datum.The conversionfrom NAVD88 to NGVD29 at PNPPis represented as: feet NGVD29 = feet NAVD88 + 0.72feet. The conversionfrom IGLD85 to NGVD29 at PNPPis represented as:feetNGVD29= feetIGLD85 + 0.94feet.

Calculation 50:40.000(ReferencePNPP2015e)definesthe MinorStreammaximumwater surfaceelevationof 623.0feet NGVD29 at PNPPadjacentto the eastsideof the powerblock, whichoccursat the Unit2 TurbineBuilding. Thiselevationis due to an all-season PMFevent.

The maximum watersurfaceelevation is above the sitenominal finished floor elevation of 620.5 feetNGVD29 for a durationof 2 hour2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months sand 15 minutes.

Calculation 50:55.000(Reference PNPP2015q)definesthe coincident windwaverunup,The maximum waverunupelevation of the PMFcoincident withwindwaveactivityis determined by addingthewindwaverunupto thewatersurfacefloodelevation due to the PMF. The maximum waverunupelevation in the vicinityof the powerblockis 628.3feetNGVD29.Thewaverunup elevationsin the vicinityof the powerblockare abovethe sitenominalfinishedfloorelevationof 620.5feetNGVD29.

Calculation 50:42.OOO (Reference PNPP20159)definesthe maximumwatersurfaceelevation resulting fromthe LIPeventadjacentto the entirewestsideof the powerblock.The maximum watersurfaceelevation due to the LIPeventis 621.2feet NGVD29. The LIP maximumwater surfaceelevation is abovethe sitenominalfinishedfloorelevation of 620.5feetNGVD29. Note that becausethe MinorStream drainage area is small relatively (less than 1 squaremile),the PMPappliedto the MinorStreamis equalto the LlP. Therefore the PMF resultsfor the Minor Streamare equivalent to the effectsof the LIPon the eastsideof the power block.

The methodology usedin the floodingreevaluation for PNPPis consistent with the following standards andguidancedocuments:

o NRCStandard ReviewPlan,NUREG-0800, revisedMarch2007(Reference NUREG-0800) o NRCOfficeof Standards Development, Regulatory -

Guides,RG 1.102 "FloodProtection for NuclearPowerPlants",Revision1, datedSeptember 1976(Reference NRCRG 1.102) and RG 1.S9-"Design BasisFloodsfor Nuclear Power Plants",Revision 2, datedAugust 1977(Reference NRCRG 1.59)

. NUREG/CR-7046, "Design-Basis FloodEstimationfor Site Characterization at Nuclear Power Plants in the United States of America,"dated November2011 (Reference NUREG/CR-7046)

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NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision0 FirstEnergyCorporation February23,2015 o NUREG/CR-6966, "Tsunami HazardAssessment at NuclearPowerPlantSitesin theUnited Statesof America",datedMarch2009(Reference NUREG/CR-6966)

. "AmericanNationalStandardfor Determining DesignBasisFloodingat PowerReactor Sites",datedJuly28, 1992(Reference ANSI/ANS-2.8-1992)

. NEI Report12-08,"Overview of ExternalFloodingReevaluations" (Reference NEIAugust 2012) o NRC JLD-ISG -2012-06, "Guidance for Performing a Tsunami,Surgeor SeicheFlooding HazardAssessment", Revision 0, datedJanuary4,2013(Reference JLD-ISG-2012-06) o NRC JLD-lSG-2013-01, "Guidancefor Assessmentof FloodingHazardsdue to Dam Failure",Revision 0, datedJuly29, 2013(Reference JLD-lSG-2O13-01)

Thefloodhazardreevaluation, includinginputsandmethodology, arebeyondthe currentPNPP designand licensebasis.Consequently, the analytical resultsprojectbeyondthe capability of the currentdesignbasis.The followingprovidesthe flood-causing mechanisms and their associated watersurfaceelevations thatareconsidered in the PNPPfloodhazardreevaluation:

3.1. Floodingin Streamsand Rivers(ReferencePNPP2015a,PNPP2015b,PNPP2015c, PNPP2015d,PNPP2015e,PNPP2015f,PNPP20{5n,PNPP2015r,and PNPP2015s)

The PMF in riversand streamsadjoiningthe site is determinedby applyingthe probable maximumprecipitation (PMP)to the drainagebasinin whichthe site is located.Becausethe watersheds analyzedaresmall,the representative PMPis pointprecipitation. Thisis identical to the LlP.Furthermore, the proximity of the MinorStreamto PNPPcreatesa condition wherethe MinorStreamfloodingbasedon pointprecipitation PMPis identical to the LIP analysisfor the MinorStreamandthe adjacentSSCs.

The PMFis basedon a translation of PMPrainfallin thewatershed to floodflow.The PMPis a deterministic estimateof the theoretical maximumdepthof precipitation that can occurat a certaintimeof year for a specifiedareaat a particulargeographical location.A rainfall-to-runoff transformation function, as wellas runoffcharacteristics, basedon thetopographic anddrainage systemnetworkcharacteristics andwatershedproperties, are neededto appropriately develop the PMFhydrograph. The PMFhydrograph is a timehistoryof the discharge andservesas the inputparameter for otherhydraulic modelsthatdevelopthe flowcharacteristics, including flood flowandelevation.

The PMFis a functionof the combined eventsdefinedin NUREG/CR-7046 for floodscausedby precipitation events.

Alternative 1 - Combination of:

. Meanmonthlybaseflow o Mediansoilmoisture Antecedent or subsequent rain:the lesserof (1) rainfallequalto 40 percentof PMPand (2)a 500-yearrainfall a TheAll-Season PMP o Wavesinducedby Z-yearwindspeedappliedalongthe criticaldirection Alternative 2 - Combination of:

. Meanmonthlybaseflow PERRYNUCLEARPOWERPLANT P a g e1 0 o f 3 5

NTTF Recommendation 2.1 (HazardReevaluations): Flooding Revision 0 FirstEnergyCorporation February 23,2015

. Snowmelt fromthe probable maximumsnowpack

. A 1O0-year, snow-season rainfall o Wavesinducedby Z-yearwindspeedappliedalongthe criticaldirection Alternative3 - Combination of:

o Meanmonthlybaseflow

. Snowmelt froma 1O0-year snowpack

. Snow-season PMP

. Wavesinducedby 2-yearwindspeedappliedalongthe criticaldirection 3.1.1. Basisof Inputs:

Theinputsusedin the PMP,snowmelt, andPMFanalysesarebasedon thefollowing:

All-SeasonPMPAnalysisand Cool-seasonPMPwith SnowmeltAnalysis

. PNPP,MajorStream,andMinorStreamwatershed locations;

. Probable MaximumPrecipitation Study for the Stateof Ohio; o Site-specific,all-season PMPpointrainfallshortdurationestimates determined using a storm-based approachin accordance with NOAAHydrometeorological Reportsand theWorldMeteorological Organizationapproach;

. Site-specific, cool-season PMP pointrainfallestimatesdeterminedusinga storm-based approachin accordancewith NOAA Hydrometeorological Reportsand the WorldMeteorological Organizationapproach; o The 100-year,all-seasonpoint rainfallestimatesfrom the NationalOceanicand Atmospheric Administration (NOAA)Precipitation FrequencyDataServer,andratioof cool-season to all-seasonrainfalldepthsdeterminedfrom the regionalRainfall Frequency Atlasof the Midwest; o Dailysnowdepthanddensityby monthfor Ohio,datais downloaded fromNOAA;and

. Snowmeltrate (energybudget)equationsand constantsare basedon U.S.Army Corpsof Engineers (USACE) Engineering ManualEM-111A-2'1406.

PMFAnalysis-Hydrologic and HydraulicAnalysis

. PNPP,MajorStream,andMinorStreamwatershed locations, areas,boundaries and configurations; o Precipitation andassociated snowmelt,as applicable, for the subjectwatershed area; a Baseflow:Historic flowratedatacollectedby USGSat gauge04212100 on the Grand River,whichis usedto determinethe baseflow for the MajorStreamand Minor Stream; a Sitetopography developed fromaerialphotogrammetry; O Digitalterrainmodel(DTM)developed fromsitetopography; a Manning's roughness coefficientsare based on a visual assessmentof aerial photography andselected usingstandard applicableengineering guidance references; and Sitedataforthe raillinebridgecrossing the MajorStream.

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NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision 0 FirstEnergyCorporation February 23,2015 3.1.2. ComputerSofhryare Programs PMPand Snowmeltanalysis

. ArcGlSDesktop10.1 o MicrosoftExcel o SPAS9.5 PMFanalysis

. AutoCADCivil3D 2012

. ArcGlSDesktop10.0

. ArcGlSDesktop10.1

. HEC-HMS 3.5

. HEC-RAS 4.1

. HEC-GeoRAS 10.1 o MicrosoftExcel 3.1.3. Methodology Thesite-specific PMPanalysisincluded thefollowingsteps:

o An extensivestormsearchto identifystormswhichcouldbe usedfor PMPstudiesin the region.

. Largestprecipitation eventswhichwere determinedto be transpositionable to the PNPPsitewerethenmaximized in-placeandtranspositioned to the site.

Site-Specific, All-SeasonPMP All the stormsevaluated in the previousPMPstudiesin the region,andconsidered to be transpositionable to the PNPPsitewereevaluated. Thisresulted in 20 events thatwere evaluated to determine the shortduration1-hourdepthfor the site-specific, all-season PMP.Ten of thesestormswerepreviously analyzedin Hydrometeorological ReportNo.

33 andHydrometeorological ReportNo.51 by the National WeatherService(NWS)and the USACE.The remaining1O were analyzed for the Probable MaximumPrecipitation Studyfor the Stateof Ohio.

Eachstormis thenmaximized by an in-placemaximization factorto represent whatthe storm would havelooked like had the atmospheric conditionsand moisture availablefor rainfallproductionbeenat maximumlevelswhen the stormoccurred versus what was actuallyobserved. The in-placemaximized valuesfor eachstormare thenadjustedto transposethe storm from its originallocationto the PNPP site. The transposition calculation adjustsfor differences in availablemoistureat the site versusthe original stormlocation.The ratiosto determinesub-hourly increments in Hydrometeorological ReportNo. 52, are appliedto the resultingsite-specific,1-hour PMP estimateto determine 5-, 15-,and3O-minute durationestimates.

Site-Specific, Cool-Season PMP A site-specific, cool-season depth-area-durationrelationshipis developed for durations from 1 to 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months sand areasizesfrom 1 to 20,000squaremiles.In addition,hourly temperature, dewpoint,andwindspeedtimeseriesaremaximized for cool-season PMP for input parameters of associated snowmelt. Ten extreme rainfallstorms that occurred from Octoberto May withinthe GreatLakesregionare identified. Althoughthe cool-seasonmonthsareOctoberthroughAprit,stormsduringthe month Maythatrepresent of PERRYNUCLEAR POWERPLANT Page 12 of 35

NTTF Recommendation 2.1 (HazardReevaluations): Flooding Revision0 FirstEnergyCorporation February 23,2015 cool-season characteristics are includedin the analysisfor determining the site-specific, cool-season PMP SPASsoftwareanalysisis completed for threestormsthatwerenot analyzedpreviously by the NWS or USACE,or occurredafter the publicationof the hydrometeorological documents. The moisturecontentof eachstormis maximized to providethe upperlimit rainfallestimation for eachstormat the location where it occurred.Themaximized storms are then transpositioned from the originalstorm locationto PNPP to the extent supportableby similarityof topographicand meteorological conditions.Maximum precipitation values,adjustedfor in-placemaximization and transposition factors,are enveloped to definethe cool-season PMP.

The PMFanalysisincludes thefollowing steps:

. Delineatewatershedand sub-watersheds and calculatesub-watershed areasfor inputintothe USACEHEC-HMS rainfall-runoff hydrologic computer model.

. Determine rainfall.

. EstimateHEC-HMSrainfall-runoff model input parameters:NationalResources Conservation Service(NRCS)unithydrograph method.

o Adjustunithydrograph to accountfor the effectsof nonlinear basinresponse.

. PerformPMFsimulation withPMP input using HEC-HMS model withno precipitation losses.

o Estimatewater surfaceelevationusing HEC-RASunsteady-state modelby using runoffhydrograph fromthe HEC-HMS modelas an input.

WatershedDelineation Forthe purposesof the hydrologic modelingeffort,the MajorStreamis evaluatedusing onewatershed. TheMinorStreamwatershedis subdivided intothree(3)sub-watersheds (theMinorStreamsouthof the site,the MinorStreamand site areacontributing to the MinorStreamat the lateralswalebetweenthe two coolingtowers,and the unnamed tributaryeastof the site)basedon the topography of the site.

Rainfalland Snowmelt Eachatternative containsrainfalldefinedeitherbytheall-season PMP(Alternative 1),the 1O0-year, cool-season rainfall(Alternative 2), or the cool-season PMP (Alternative 3).

Eachrainfalleventis considered to be a72-hourdurationevent.Notethatan antecedent rainfalloccurspriorto the all-season PMP.Becauseof the smalldrainageareasof the MajorStreamand MinorStreamand the 72-hourdry periodbetweenthe antecedent stormand the PMPevent,the streamsreturnto baseflowconditions priorto the PMP event.Therefore,the antecedent stormis determined to have no influence on the PMP storm.Theall-season eventincorporates no rainfallrunofflosses.

Snowmelt is includedin thetwocoolseasonalternatives. Alternative 2 includes snowmelt fromthe probable maximumsnowpack. Alternative 3 includes snowmelt from the 100-yearsnowpack. Forrain-on-snow conditions dew point temperature and wind speed are obtained fromthesite-specific PMPanalysis. Thebasinwindcoefficient is conservatively assumedto maximize snowmelt.

Thesnowpackis assumedto be at its maximumat the onsetof rainfalleventsandcover theentirewatershed. Soilis assumed to be frozenwithno precipitation lossesduringthe cool-season monthsof OctoberthroughApril.Forthe probable maximumsnowpack, the snowpack depthis assumed to providecontinuous snowmelt for theentiredurationof the coincident rainfallevent.

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NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision 0 FirstEnergyCorporation February 23,2015 AlternativeI -All-Season PMP The all-season PMPis determined by usingthe site-specific PMPestimates definedby the PMPstudyfor the Stateof Ohio(Reference ODNR2013)for durations from6to72 hours.The PNPPsite-specific analysisdefinesthe PMPestimates for t hourand sub-hourlyincrements. lntermediate S-minuteincremental PMPdepthsare determined for pointprecipitation (1 squaremile).

Thetemporaldistribution of the PMPis arrangedin accordance with recommendations in HMR-52,whereinindividual rainfallincrements decreaseprogressively to eitherside of the greatestrainfallincrement. Varioustemporaldistributions for eachrainfallscenario arethenevaluated to furthermaximizethe runoff.Front,onethird,center,twothirds,and end-loading temporaldistributions are considered in an effortto capturethe distribution thatmaximizes runoff.

Alternative2 - ProbableMaximumSnowpackand 100-YearGool-Season Rainfall

\l/hilesnowpackcan be determined directlyfromthe snowdepth,adequatedata is not available to extrapolate any historical observations up to the magnitude of the probable maximumevent.To maximize snowmelt contribution, the probable maximum snowpack is conservatively assumednotto depleteduringthe durationof the coincident rainfall.

The 1O0-year, cool-season rainfallis determined forthe PNPPlocationanda durationof 72-hoursusingprecipitation frequencyestimatesdefinedby NOAAAtlas 14 guidance and applyingregionalseasonalguidance.NOAAAtlas 14 providesall-seasonpoint precipitation rainfallestimatesvia the NOAAprecipitation frequencydata server.The NOAAAtlas14 valuesare adjustedto reflectcool-season rainfallratherthanall-season rainfall.

The 100-year,cool-seasonrainfallis equivalentfor all the cool-seasonmonths.

Furthermore, the maximizeddew point temperatureand wind speed time series determined bysite-specific analysisis applicable to allcool-season months.To maximize snowmeltat eachtimestep,the dew point temperature and wind speed are reordered to matchthe 72-hourtemporaldistributions of the rainfall.

Alternative3 - 1O0-Year Snowpackand Cool-SeasonPMP A 10O-year snowdepthis calculated by performing a statisticalanalysisbasedon the historicaldataobtainedfromthe NOAANationalClimaticDataCenterdailysnowdepth records.A Fisher-Tippett Type l (FT-l)distribution frequencyanalysisis performedto determine the maximumsnowdepth with an annual exceedance probability of 1 percent (i.e. 100-yearsnow depth)for each monthfrom OctoberthroughApril. The FT-l distributionis applicablefor long-termstatisticalanalysesand specifically for extreme valuecalculations. The maximumsnowpackbulk densityis appliedto determinethe available snowwaterequivalent. Themaximum100-year snowpack occursin Marchand is combined withthesite-specific, cool-season PMP.To maximize snowmelt at eachtime step,the dew point temperatureand wind speed are reordered to match the 72-hour temporaldistributions of the rainfall.

HydrologicModel(HEC-HMS)

ThePMFis thefloodresulting fromthe72-hour duration all-season PMPor a combination of cool-season rainfallandsnowmelt. Thetemporaldistribution of the PMPis determined in accordance with the recommendations in HMR-52,whereinindividualincrements decrease progressively to eithersideof the greatest increment.Front,one-third,center, two-thirds, and end-loading temporaldistributions are consideredin an effortto capture PERRYNUCLEAR POWERPLANT Page14of 35

NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision0 FirstEnergyCorporation February 23,2015 the distributionthatmaximizes runoff.Becauseof the smalldrainageareasof the Major StreamandMinorStreamandthe 72-hourdry periodbetweenthe antecedent stormand the PMPevent,the antecedent stormis determined to haveno influence on the PMP storm.

USACEHEC-HMShydrologicsoftwareis used to convertrainfallto runoff.A rainfall hyetographis appliedto the MajorStreamwatershedand each sub-watershed of the MinorStreamandtransformed to runoffusingunithydrograph methodology. Generally, a unit hydrograph is developedusinghistoricaldata obtainedfrom variousrain and streamgaugesin the watershed. The MajorStreamand MinorStreamwatersheds are ungauged. Thus,no historical observations are availableto use as a basisto createa unit hydrograph. Therefore,a syntheticunit hydrographis developed.NRCS unit hydrographmethodology is usedfor rainfall-to-runofftransformation.

ANSI/ANS-2.8-1992 suggests thatbaseflowshouldbe basedon meanmonthlyflow.As meanmonthlyflowis notavailable for the MajorStreamor MinorStream,the baseflow is approximated basedon the meanmonthlyflowin an adjacentwatershed. The USGS gaugestationon the GrandRivernearPainesville, OH is used.TheGrand River is in the samehydrologic unitas the MajorStreamand MinorStreamand hassimilarwatershed characteristics.Therefore,it is an acceptable approachto usethe baseflow information for the GrandRiveras the basisfor estimationof the baseflow for MajorStreamand MinorStream.

To conservatively maximizerunoff,no precipitation lossesare incorporated intothe all-seasonPMFalternative analysis.Additionally, lossesare incorporated no precipitation intothe cool-season PMFalternatives dueto the assumption thatthe groundis frozen.

The unit hydrographs for the MajorStreamwatershedand eachsub-watershed of the MinorStreamare modifiedto accountfor the effectsof nonlinearbasinresponsein accordance with NUREG/CR-7046. The peakof eachunithydrograph is increased by one-fifthand the time-to-peakis reducedby one-third. The remaining hydrograph ordinatesare adjustedto preservethe runoffvolumeto a unit depthoverthe drainage area.

HydraulicModel(HEC-RAS)

The unsteadyflowsimulation modulewithinthe USACEHEC-RASsoftwareis usedto transformthe resultingflow hydrographs from the controllingalternativeinto a water surface elevationhydrographunder unsteadyflow conditions.For referenceand comparison, allthreealternatives areevaluated withthe HEC-RASmodel.

Channelandfloodplain geometry for the MajorStreamandthe MinorStreamis modeled by developing crosssectionsof the streams.The crosssectionsare placedat locatlons that definegeometriccharacteristics of the streamand overbanks.Crosssectionsare also placed at representative locations wherechangesoccurin discharge, slope,shape, and roughness, as well as at hydraulicand inlinestructures (e.9., bridges culverts).

Streambanks,blockedobstructions, andineffective flowareasare also incorporated into the HEC-RASmodel.

Threecrossingsare incorporated intothe MajorStreammodel.The plantaccessroad includesa culvertand is modeledusingtopographic surveydataand USARdata.The upstream raillinebridgeis modeledusingtopographic surveydataandsiterecords. The upstreamsecondaryaccessroadis includedas an inlinestructureand all flow overtops the road.

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NTTF Recommendation 2.1 (HazardReevaluations): Flooding Revision0 FirstEnergyCorporation February23,2015 One crossingis incorporated intothe MinorStreammodel.The downstream Lockwood Roadcrossingis modeledas an inline structure and all flowovertops the road.

The PMF flow hydrographs obtainedfrom the time-seriesoutflowresultsof the HEC-HMSmodelsareenteredintothe HEC-RAS models. A bounding waterlevelin LakeErie is usedas a downstream boundarycondition for the HEC-RAS softwareprogram.The HEC-RAS modelis evaluated fortheall-season PMF (Alternative 1)andthecool-season PMF(Alternative 2 andAlternative 3).

3.1.4. Results MajorStream The MajorStreamis not directlyadjacentto PNPPsafety-related structures.However, overtopping at the raillinebridgestructureresultsin overflowfromthe MajorStreamthat contributes to floodingeffectsin the MinorStreamandthe LIParea.

The Alternative 1 PMF is the controlling combination and is a resultof the all-season PMP,Theone-third, center,andtwo-thirds temporaldistributions produceidentical peak resultsandthemaximumwaterlevels.Themaximumwatersurfaceelevation overtopping the raitlinebridgestructure is 630.9feetNGVD29,witha maximum flowof 30,100cfsat the bridge.The resultingmaximumwaterlevelsfor the MajorStreamare not adjacentto the powerblock.

Overtopping of the rail line causesbackwaterto accumulateand flow towardthe site throughtwo accesspointsof the secondaryaccessroad.The peakflowthroughthe two accesspointsis74cfs.Thisflowis incorporated intothe LIPareaanalysis by combination withrainfallrunofffor the areadirectlysouthof the plant.

Backwateralsooverflowsthe secondaryaccessroadfurtherto the east.The peakflow intothe MinorStreamwatershedis 1754cfs. Thisflow is incorporated intothe Minor Streamanalysisby application directlyto the upstream crosssectionof theMinorStream hydraulic model.

Alternative 2 doesnot overtopthe raillinebridgestructure and no overflowto the Minor Streamor LIP areaoccurs.The one-third,center,and twothirdstemporaldistributions produceidenticalpeak resultsand the maximumwater levels.The maxlmumwater surfaceelevation at the raillinebridgestructure is 621.1feetNGVD29 witha maximum flowof 9,500cfsat the bridge.

Alternative 3 doesnot overtopthe rail linebridgestructureand no overflowto the Minor Streamor LIP areaoccurs.The one-third, center,and two-thirds temporaldistributions produceidenticalpeak resultsand the maximumwater levels.The maximumwater surfaceelevation at the raillinebridgestructure is 623.1feetNGVD29 witha maximum flowof 14,900cfsat the bridge.

The all-season PMF is determined to be the controlling PMF scenario.An additional combinedeffectanalysis,includingthe effectsof wind wave activity,is performedas discussed in Section3.7.The contribution to LIP flooding incorporated is into the analysis discussed in Section3.8.

MinorStream Overtopping flowfromthe MajorStreamwatershedis addedto the HEC-RASmodeling for the Alternative 1 PMF.Overtopping flowfromthe MajorStreamwatersheddoesnot occurfor Alternative 2 or Alternative3.

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NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision 0 FirstEnergyCorporation February 23,2015 The Alternative1 PMF is the controlling combination and is a resultof the all-season PMP.Theone-third, center,andtwo-thirds temporaldistributions produceidentical peak resultsand the maximumwaterlevels.The maximum water surface elevationoccurs at the Unit2 TurbineBuildingand is 623.0feetNGVD29. The maximum flowovertopping LockwoodRoaddownstream is 5,300cfs.Alternative1 peakfloodingoverflows the Minor Streamchannelbanksandcontributes to LIPfloodingonthewestsideofthepowerblock.

For Alternative2, the one-third,center,and two-thirdstemporaldistributions produce identicalpeak resultsand the maximumwater levels.The maximumwater surface elevationoccursat the Unit2 TurbineBuilding andis 620.6feetNGVD29.Themaximum flow overtopping LockwoodRoaddownstream is 1,000cfs.Alternative2 peakflooding overflowsthe MinorStreamchannelbanksand contributes to LIP floodingon the west sideof the power block.

For Alternative3, the one-third, center,and two-thirdstemporaldistributions produce identicalpeak resultsand the maximumwater levels.The maximumwater surface elevationoccursat the Unit2 TurbineBuilding andis 621.1feetNGVD29.Themaximum flow overtopping LockwoodRoaddownstream is 1,600cfs.Alternative3 peakflooding overflows the MinorStreamchannelbanksand contributes to LIPfloodingon the west sideof the powerblock.

The all-season PMF(Alternative1) is determined to be the controlling PMFscenario.

The maximumwatersurfaceelevationsat eachsafety-related structureadjacentto the MinorStreamfloodingand the durationof floodingabovethe nominalfinishedfloor elevationof 620.5feetNGVD29 areprovidedin Table1. An additional combined effect analysisis performed as discussed in Section3.7.The contribution to LIP floodingis incorporated intothe analysisdiscussed in Section3.8.

TableI - MinorStreamFloodingElevationsand Durationsat PNPP MaximumWater SurfaceElevation Flood Duration above Structure (feetNGVD29) 620.5 feet (NGVD 29)

Unit2 TurbineBuilding 623.0 2 hour2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months s15 minutes Building Unit2 Auxiliary 622.9 2 hour2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months s10 minutes Unit2 ReactorBuilding 622.3 t hour10 minutes lntermediateBuilding 622.2 t hour10 minutes Unit1 ReactorBuilding 622.2 t hour10 minutes Unit1 Auxiliary Building 622.2 t hour10 minutes Unit1 TurbineBuilding 621.1 40 minutes PERRYNUCLEARPOWERPLANT Page17of 35

NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision 0 FirstEnergyCorporation February 23,2015 3.2. DamAssessment(ReferencePNPP2015h) 3.2.1. Basisof Inputs Inputsusedfor the damassessment evaluation include:

o PNPP,MajorStream,andMinorStreamwatershed locations.

. USGStopographic quadrangle maps.

o The USACENationalInventoryof Dams(NlD) databaseis usedto identifyany watershed dams.

3.2.2. ComputerSoftwarePrograms

. None 3.2.3. Methodology ThePNPPMajorStreamandMinorStreamwatershed locations areapproximated using USGS topographic quadrangle maps. The USACE NID database is reviewed to determine thatno damsarelocatedin the MajorStream or Minor Stream watersheds.

3.2.4. Results No damsarelocatedin the combined watershed of the MajorStreamandMinorStream.

Therefore, damfailureis notapplicable.

3.3. lce-lnduced Flooding(Reference PNPP2015i)

As identified by NUREG/CR-7046, icejamsandicedamscanformin riversandstreamsadjacent to a site,and mayleadto floodingby two mechanisms:

. Collapse of an icejam or an icedamupstream of the sitecanresultin a dambreach-like floodwavethatmaypropagate to the site;and o An icejam or an ice dam downstream of a site may impoundwaterupstreamof itself, thuscausinga floodvia backwater effects.

3.3.1. Basisof Inputs

. USACEicejam database.

o Sitetopography.

. Bridge geometry(upstreamand downstreamof PNPP) using site topography andsiterecords.

3.3.2. ComputerSoftwarePrograms

. MicrosoftExcel 3.3.3. Methodology PerNUREG/CR-7046, ice-induced floodingis assessed by reviewingthe USACEicejam databaseto determine the mostseverehistorical eventsthathaveoccurred.No historical recordsareavailable for the MajorStreamor the MinorStream.Thenonexistence of ice jam recordsis explainedby the absenceof stream monitoringstationson the two streams.Basedon icejam occurrences recordedfor riverswithinadjacentwatersheds, it is determined thaticejam eventsarepossible.

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NTTF Recommendation 2.1 (HazardReevaluations): Flooding Revision0 FirstEnergyCorporation February23,2015 The maximumice jam is determined by selectingthe historiceventthat producedthe maximumflood stage relativeto the normalwater surfaceelevation n a t that location.

Regardless of the specificconditions that produced the historic flood stage at a specific location,thefullheightis conservatively assumedto represent the ice jam.

icejam dataforthe adjacentwatersheds Historical for the GrandRiverandtheAshtabula Riverare considered. Althoughno recordsare available for the actualheightof the ice jams,the maximumrecordedstageis usedto representthe ice jam. The ice jam is transposed to the siteandcompared withotherfloodingcausingmechanisms.

3.3.4. Results The maximumreportedicejam stagein the regionalvicinityof PNPPis estimated to be 18feet.Forthe MinorStream,no significant upstream crossings or structures are present that couldfacilitatesignificantice jam formation.The only upstreamaccessroadis an unimprovedroad with a low profileand a small drainagestructure.The elevation characteristics of the areaat thatdrainagestructureindicatein the unlikelyeventan ice jam did occur,it wouldbe limitedto lessthan2 feetin height.Furthermore, any icejam and subsequent failurewouldonlyreleasea flow rateat the maximumcapacityof the smalldrainagestructure. By qualitative comparison, the PMFanalysisincludesrainfall runoffcontribution fromthe entiredrainagearearesultingin a peakflowratemagnitudes greaterthanthe capacityof a smalldrainagestructure. Any upstreamicejam collapseis bounded by thePMFanalysis.

The only downstreamlocationon the MinorStreamconduciveto an ice jam is at LockwoodRoad.The assumedtransposition of the maximumicejam wouldproducea maximumwatersurfaceelevationof 608.7feetNGVD29 (608feetNAVD88).Assuming theculvertat LockwoodRoadis completely blocked,anycoincident flowwouldeventually overtop LockwoodRoad. The PMF analysisfor Minor Stream assumesthe Lockwood Road culvert is completely blocked and the PMF overtops the road. Therefore,by qualitativecomparison with the PMF analysis,any downstreamice jam flooding is bounded by thePMFanalysis.

Forthe MajorStream,the upstream raillinebridgehasa clearheightof greaterthan20 feetfromnaturalgradeto the bottomof the lowchord.Theassumedtransposition of the maximumestimated 18 feeticejam wouldallownormalflowsovertopping the icejam to flowthroughtheremaining bridgeopeningbelowthe lowchord.ThePMFanalysis the for MajorStreamresultsin overtopping of the rail line bridge.Any ice jam failureat this locationwouldbe transposed downstream to the plantaccessroad.

The accessroad includesa largeellipticalculvert35'-11"by 23'-5".Basedon site topography the clearheightis approximately 18 feet abovethe normalwatersurface elevition.Assumedtransposition of the maximumestimated18 feet ice jam would producea maximum watersurfaceelevation belowthe plantaccessroad.Assuming the culvertat the plant access road is completelyblocked, any coincident flow would eventually overtopthe plantaccessroad.The PMFanalysisfor MajorStreamresultsin overtopping of the plantaccessroad.Therefore, by qualitative comparison withthe PMF analysis,anyicejam floodingis boundedby the PMFanalysis Thedownstream sedimentcontrolstructureis the onlyotherlocationpossiblyconducive to an ice jam. The assumedtransposition of the maximumice jam wouldproducea maximumwatersurfaceelevationof 604.7feetNGVD29 (604feetNAVD88).Theresults of the PMFanalyses for the MajorStreamexceedthe estimated icejam elevation.

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NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision 0 FirstEnergyCorporation February23,2015 lce-inducedfloodingat PNPP is boundedby the PMF analyses,and no further considerationis required.

3.4. GhannelMigrationor Diversion(ReferencePNPP2015i)

NUREG/CR-7046 indicates historicalrecordsand hydrogeomorphological datashouldbe used to determine whetheran adjacent channel, stream,or riverhasexhibited thetendency to migrate towardsthe site.

3.4.1. Basisof Inputs

. OhioDepartment of NaturalResources geologymap surficial

. USGStopographic quadrangle maps,including aerialimages 3.4.2. GomputerSoftwarePrograms o None 3.4.3. Methodology Surficialgeologyalongwith historicand currenttopographic quadranglemaps that includeaerialimagesare reviewed to examinethe condition andalignment of riversand streamsovertime.

3.4.4. Results The surficialgeologymap indicatesthe area in the immediatevicinityof PNPP is characterized by layersof sand,silt and clay,and till or clayeyto silty till over shale bedrock.Thischaracterization represents the entirewatershedof the MinorStreamand the majorityof the MajorStream.The upstreamportionof MajorStreamis characterized by additionalareasof sandandgravelor clayeyto siltytill overshalebedrock. Alluvium or organicmaterial, whichare moresusceptible to erosion,are not presentin the Major Streamor the MinorStreamwatersheds.

Topographic mapsfor the yearsof 1905(Reprinted 1943),1960(Revised1992),1994, and 2010 are reviewedto assesshistoricchannelmigration. The MinorStreamwas rerouted as part of the plant construction.These modificationshave remained unchanged. Thetopographic and aerialimagesprovideno evidenceof oxbows,braided streams,or alluvialfansthatcouldindicatea potential for channelmigration of the Major Streamor the MinorStream.

Thestreamsin thevicinityof PNPPdo notexhibitcharacteristics of channelmigration.

3.5. StormSurge(ReferencePNPP20151, PNPP2015k,PNPP20151, PNPP20{5o' and PNPP20{5p)

ProbableMaximumStormSurse(PMSSl In accordance with JLD-ISG-2012-06, all coastalnuclearpowerplantsitesand nuclearpower plantsitesadjacentto coolingpondsor reservoirssubjectto potentialhurricanes, windstorms and squatllinesmustconsiderthe potential for inundation fromstormsurge and waves. JLD-ISG-2012-06 alsosuggests thatfor the stormsurgehazardassessment, storm historical events in the regionshouldbe augmented by a synthetic stormparameterized to accountfor conditions moreseverethanthoseinthehistorical recordsandconsidered reasonablypossible onthebasis of technical reasoning.

PERRYNUCLEAR POWERPLANT Page 20 of 35

NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision0 FirstEnergyGorporation February23,2015 3.5.1. Basisof Inputs Theinputsusedin PMSSanalysisarebasedon thefollowing:

. windand pressurefielddatafromNOAAfor the GreatLakeRegion Historical o Probablemaximum windstorm (PMWS)

. LakeEriebathymetry fromthe NOAAgeophysical database

. Supporting GISdata 3.5.2. ComputerSoftwarePrograms

. ArcMap10.1

. Deft3D softwaresuite (Delft3D-FLOWDelft3D-WAVE,Delft3D-RGFGRID, and Delft3D-QUICKIN)

. lGLD85HeightConversion Tool

. R Computer Language 2.15.1

. MicrosoftExcel 3.5.3. Methodology Several physicalprocessescontributeto the generationof a storm surge. The contributionof windto a stormsurgeis oftencalledwind setup.\Mnd blowingoverthe watercausesa shearstressthatis exertedon the surfaceof the water,pushingwaterin thedirectionof thewind.Atmospheric pressure gradients areanotherforcingmechanism that contributesto changesin water level, as water is forcedfrom regionsof high atmospheric pressuretowardregionsof low atmospheric pressure.

Thefollowing describesthe methodologies usedin the PMSScalculation:

Developmentof the PMWS The PMWSstorm-basedapproachis specificto the characteristics of the site. Past extremeeventsin a region areanalyzed and considered transpositionable. As partof the PMWS,differentstormtypes(suchas synoptic,squall line, and hybrid)that impactedthe GreatLakesregionareconsidered in orderto determine thestormevent thatwillgenerate themaximum surgeandseiche.Eachstorm'sinputparameters are quantifiedandplotted basedon the locationof low/highpressurecenters,concurrent wind/pressure fields,and howtheyevolvethroughtimeandspace.

Mostof the synopticstormsoccurin association with deepareasof low pressurewhich movethroughthe regionfrom southwestto northeast.The generalsynopticpatternis one in whichthe deep area of low pressureresultsin a very strongpressuregradient forcebetweenits low pressurecenterand a corresponding regionof higherpressureto the northor west.The largerthe gradientbetweenthe two systems overa givendistance is,the strongerthe resultingwinds.

Squallline (or derecho)events createa widespreadstraight-linewindstormthat is associatedwith a fast-movingband of severe thunderstorms. These winds have produced someof the highestinstantaneous gustson record,but lastforonlya shorttime (lessthan30 minutes)at a givenlocation.The shortdurationof theseevents,as they quicklytraversea givenlocation,meanstheywill not controlthe PMSS.Further,these eventsdo not occurwithindeep low pressuresystemsor remnanttropicalsystems' Therefore, theirwindand pressuredataare not combinedwiththe otherstormtypesin thisanalysis,as thiswouldresultin a PMWSthatis not physically possible.

PERRYNUCLEARPOWERP].ANT Page21 of 35

NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision 0 FirstEnergyCorporation February 23,2015 Althoughdeep tow pressuresystemsoften producethe longestdurationlarge-scale winds,otherstormtypesalsoproducestrongwindsoverthe region.In rarecases,land-fallingtropicalsystemsalongtheGulfCoastor AtlanticSeaboard moveinlandacrossthe Appalachians or up the Mississippi and Ohio Rivervalleys.By the time thesestorms reachthe GreatLakesregion,they are no longertropicalsystems,but insteadhave transitionedintoextra-tropical cyclones.Theirgeneralcirculation andcenterof deeplow pressurepersists.Muchlikethe deeplowpressurescenariopreviously discussed, strong and persistent winds can result. The remnants of HurricaneHazel (October 1954) and HurricaneSandy (October 2012)areclassicexamples of this storm type.This storm scenarioprovidedsomeof the strongestwindsfromthe northwestthroughthe northeast directions overLakeErie(withdurations of 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months sor more).

Delft3DGalibration The Delft3Dhydrodynamic modelis set up usingthe Delft3Dsoftwaresuite.The wave setupcontribution to the total stormsurgevaluesare modeledby couplingthe Delft3D-WAVEandDelft3D-FLOW surgemodels.Thegeneralapproach to stormsurgemodeling usingcoupledDelft3D-FLOW andDelft3D-WAVE modelsconsistsof thefollowingsteps:

o Developing the bathymetric datasetandmodelgridmeshfor the lakesystem; o Assembling inputfilesfor atmospheric forcing(windandpressure fields);

. Assembling inputfilesfor initialwaterlevel,boundary conditions,andthe physical andnumerical parameters of the model; Assemblingmeasuredwater levelsand wave data for modelcalibrationand verification; Testingand refiningthe initialmodelsetup; I Validating the modelfor historical extremestormevents;and o Assessingmodelsensitivity to variousfactorsandadjustable parameters suchas bottomfrictionandwinddragcoefficient.

The Delft3Dmodel is calibratedbased on historicaldata obtainedfrom NOAA meteorological andwaterlevelrecording stationslocatedin the LakeErieregion.

Reviewof historicaldatashowsthatvariouspartsof LakeErieresponddifferently to any one particularstorm.The stormthat producesextremewaterlevelsin one part of Lake Eriemightnot,and probablydoesnot,produceextremelevelsin otherparts.Therefore the numberof calibration and validationstormsselected,to assessmodelprediction accuracy,coveredall parts of the lakeshoreline.

Calibration and verification of the coupledDelft3D-FLOW and Delft3D-WAVE modelsis performedby a timeseriescomparison of measuredandpredicted/modeled stormsurge valuesat differentwater levelrecordingstationson Lake Erie.A similartime series comparison is alsoperformed for waveheights.

The Delft3Dmodelsare calibratedusingextremehistoricwind and pressuredatafrom multiplemeteorological andwaterlevelrecording stations.Calibrationandverification of the coupled Delft3D-FLOWand Delft3D-WAVE models demonstrates that the hydrodynamic modelis capableof computing the stormsurgeandseichedynamics for LakeErie,as well as the significant wave heightsand periodsat PNPPfrom PMWS events.

PERRYNUCLEARPOWERPLANT Page22 ot 35

NTTF Recommendation 2.1 (HazardReevaluations): Flooding Revision0 First EnergyCorporation February23,2015 PMSS The calibratedDelft3Dmodelis usedto determinethe PMSS.The historicwind and pressurefielddata is replacedwith candidatePMWSevents,and the modelis run to determine the criticalPMWS.

JLD-lSG-2012-06 andANSI/ANS2.8-1992requiretheantecedent (pre-storm) waterlevel equalto the 1O0-year maximumrecordedwaterlevelto be appliedas the initialstorm surgemodelstillwaterlevel.The 1O0-year waterlevelof 575.6feetNGVD29 (574.6feet IGLD85) is usedas the initialcondition/antecedent waterlevelin all the Delft3D-FLOW models.Sincethe probable minimumlowwaterlevelat PNPPcouldoccurat a timewhen the monthlymeanlakelevelis at the long-termmeanlow probablelevel,the antecedent waterlevelfor lowwaterevaluation is setto the long-term lowprobablelevelat LakeErie, whichis equalto 568.9feetNAVD29 (568feet IGLD85).

Varioustopographic featuresaffectthe stormsurgepropagation towardsPNPP.Thesite is locatedon the bluffsadjacentto the shoresof LakeErie.Thebluffsat the sitearemore than40 feetabovethe 100-yearwaterlevelof the lake.

MaximumHistoricaland 2S-yearStormSurge The historical maximumstormsurgeis the largestof the determined yearlymaximum stormsurgeheights.The historicat maximumstormsurge height is used in combined floodingscenarios as discussed in Section3.7.

Storm surgesare calculatedfrom monthlydata as the differencebetweenmonthly maximumandmonthlymeanbasedon guidanceprovidedby USACE.TheLogPearson Typelll distribution is thecommonly accepted frequency procedure for annualmaximum waterlevels.A frequency analysison theyearlymaximumstormsurgeheightsobtained from the Fairportand Erie stationsis performedusing a Log Pearsonlll statistical analysis.The 25-yearstormsurgeheightis usedin combined floodingscenarios.

3.5.4. Results Simulations of all the candidatePMWSeventsshowedthat the criticalPMWSeventis the transpositioned September 1989windstormeventmaximized overthe PNPPsite.

Thisstormis the mostintenseof all the PMWSeventswith a maximumwind speedof 106 miles/hour and is alignedalongthe north-south direction.The maximumPMSS resultingfromthis PMWSeventproduceda maximumwatersurfaceelevationof 582.6 feet NGVD29, which is well belowthe site. Wave runupeffectsare evaluatedwith combined floodingscenarios as discussed in Section3.7.

Surge,Seiche,and Resonance Resultsshowthat the levelof the rise due to a seicheis significantly less than the calculated surgeheight.For this reason,seichesare not the controlling floodeventat PNPP.

Resonance generatedby wavescan causeproblemsin enclosedwaterbodiessuchas harborsand bayswhenthe periodof oscillation of the waterbodyis equalto the period of theincoming waves.However, thePNPPsiteis notlocatedin anenclosed embayment.

Additionalty,the period of oscillationof Lake Erienear the PNPP siteis determined to be in the rangeof 11 to 15 hours1.736111e-4 days 0.00417 hours 2.480159e-5 weeks 5.7075e-6 months .Thisis much greater thanthat of the peak spectral period of the incidentshallowwaterstormwaves.Consequently, resonance is not a detriment at PNPPduringthe criticalPMWSevent.

PERRYNUCLEAR POWERPLANT Page23 of 35

NTTF Recommendation 2.1 (HazardReevaluations): Flooding Revision0 FirstEnergyCorporation February23,2415 ProbableMinimumLow WaterLevelresultingfrom the PMWS Simulations of all the candidatePMWSstormeventsshowthatthe criticalPMWSevent thatwoutdresultin probabte minimumlowwaterlevel(drawdown) is thetranspositioned November1998stormeventmaximized overthe PNPPsite.Thisstormhad the most intensesoutheasterly windsof the examinedstormevents,witha maximumwindspeed of 93 miles/hour. The probableminimumlowwaterelevation (drawdown) associated with the transposed November1998storm produces a probable minimum low water levelof 563.0feetNGVD29 nearthe PNPPsite.The invertsof the PNPPintake portsare at an averageelevationof 552.65feet NGVD29.

3.6. TsunamiAssessment(ReferencePNPP2015m)

NUREG/CR-6966 identifies thatearthquakes, landslides, and volcanoescan initiatetsunamis, with earthquakesbeing the most frequentcause. Dip-slipearthquakes(due to vertical movement)are more efficientat generatingtsunamisthan strike-slipearthquakes (due to horizontalmovement). To generatea majortsunami,a substantial amountof slip and a large ruptureareais required. Consequently, onlylargeearthquakes withmagnitudes greaterthan6.5 generateobservable tsunamis.

3.6.1. Basisof Inputs o NationalCenterfor Earthquake Engineering Research (NCEER)database

. NaturalResources Canadaseismicity data

. NOAAnaturalhazardstsunamidatabase

. NOAAnaturalhazardsvolcanodatabase o OhioDepartment of NaturalResources (ODNR)seismicity data o USGSearthquake hazards program database 3.6.2. GomputerSofhrarePrograms

. None 3.6.3. Methodology As identifiedby NUREG/CR-7046, tsunamiassessment is referenced to NUREG/CR-6966andNOAATechnical Memorandum OAR PMEL-136. In addition,the morerecently issued NRC guidance,JLD-lSG -2012-06, also addresses tsunami assessment.

However,JLD-ISG -2012-OO providesguidanceon detailedtsunami modeling and is beyondthe scopeof thisassessment. Technical Memorandum OARPMEL-136 reflects a similartsunamiscreening assessment described by NUREG/CR-6966.

TheNUREG/CR-6966 screening assessment is basedon a regional screening anda site screening. The regionalscreening consistsof researching historicalrecordsfor tsunami recordsand the potentialfor tsunami-generating sources.The site screeningevaluates thesitebasedonthehorizontal distancefroma coast,thelongitudinal distance measured alonga river,and the grade elevation in comparison to the effects of a tsunami. This assessment approachis basedon a reviewof historical records and databases.

NUREG/CR-6966 identifiesthat tsunamis are generatedby rapid, large-scale disturbances of a bodyof water.The mostfrequentcauseof tsunamisis an earthquake; however,landslides andvolcanoes can alsoinitiatetsunamis.Becauseof the tsunami-generationsequenceassociated withearthquakes, dip-slipearthquakes (dueto vertical movement) aremoreefficientat generating tsunamisthanstrike-slip earthquakes (dueto horizontalmovement). Furthermore,to generatea majortsunami,a substantial amount PERRYNUCLEARPOWERPLANT Page24 of 35

NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision 0 FirstEnergyCorporation February 23,2415 of slipand a largeruptureareais required.Consequently, onlylargeearthquakes with magnitudes greaterthan6.5generateobservable tsunamis.

As partof the assessment, the NOAAnaturalhazardstsunamidatabaseis usedto review historicaltsunamieventsand associatedrunupsfor the eastcoastof the UnitedStates andCanada.Of the totalevents,therewere7 tsunamieventsthatproduced14 runups occurring in the GreatLakesregionfrom1755to 1954.TheUSGShazardfaultdatabase findingsare reviewedfor strongearthquakes or the verticaldisplacements necessary to inducea tsunami.Additionally, the USGSearthquakehazardsprogram,the NCEER database,and the NaturalResourcesCanadadatabaseare reviewedfor historical earthquakes in the region.

ODNRdata is atsoreviewedfor earthquake-generated tsunamiand landslide-induced tsunami.Lastly,the NOAA naturalhazardsvolcanodatabaseis reviewedto assess volcanoes in the LakeErieregion.

3.6.4. Results According to ODNR,an earthquake-generated tsunamiin LakeEriewouldrequirea very large earthquakeon the order of magnitude7.A or greaterand significantvertical displacement. Historically,in the LakeErie region,the largestearthquakes are in the magnitude 5.0range.Preliminary analysisof post-glacial sediments in the regionhasnot yieldedevidenceof a largeearthquake in the last few thousandyears.Furthermore, earthquakesin the region,for which sufficient data are available,show primarily horizontalrather than verticalmovement,which is not as conduciveto tsunami generation.

Tsunamiscan alsobe generatedby the downslopemovementof a verylargevolumeof rockor sediment, eitherfroma rockfallabovethe wateror froma submarine landslide.

Althoughlargeamountsof unconsolidated sedimentsare washedinto Lake Erie each year when shorelinebluffsare undercutby wave action,these masseslack sufficient volumeand rapidcollapseto displacea volumeof waterthatwouldcreatea tsunami.

LakeErie also has a very gentlebottomprofile,particularly in the westernand central basins.The easternbasinhassteeperslopes, but not steep enough for a largeamount of sediment to suddenly flowdownslope in a submarine landslide.

The NOArAnsturalhazardstsunamidatabaseidentifiesonly two occurrences of non-seiche (or non-wind-induced) tsunami events in the Great Lakes region. The two occurrences yieldedslightor smallwaveeffects.

The USGSEarthquake HazardsProgramfaultdatabasecontainsno knownQuaternary faults currentfaults)in thisregionbecausegeologists (or havenotfoundanyfaultsat the Earth'ssurface.Consequently, no potentialexistsfor strongearthquakes or the vertical displacement necessary to inducea tsunami.Variousearthquake databases, including the USGSEarthquake HazardsProgramearthquake database, the NationalCenterfor Earthquake Engineering researchcatalog,and NaturalResourcesCanada,identifythat the largesteventsin thevicinityareno greaterthanmagnitude 5.0.

Lastly,no volcanoes arelocatedin the LakeErie accordingto the NOAAnatural hazardsvolcanodatabase.

Tsunamiis not the controllingfloodeventat PNPP.

PERRYNUCLEARPOWERPLANT Page25 of 35

NTTF Recommendation 2.1 (HazardReevaluations): Flooding Revision 0 First EnergyCorporation February23,2015 3.7. GombinedEffectFlood(includingWind-Generated Waves)(ReferencePNPP20{5q}

Evaluation of floodscausedby precipitation eventsis coveredin AppendixH.1of NUREG/CR-7046.Thethreealternatives areaddressed in floodingon streamsandrivers(Section3.1),which identifiesthe resultingwater surface elevations.Combinedeffect floodingevaluatesthe component of addedwavesinducedby 2-yearwindspeedalongthe criticaldirection.

Evaluation of floodsalongthe shoresof enclosedbodiesof wateris coveredin AppendixH.4.1 of NUREG/CR-7046 andincludes onealternative:

Combinationof:

Probablemaximum surgeandseichewithwind-wave activity.

The lesserof the 100-yearor the maximumcontrolledwater level in the enclosed bodyof water.

Three alternativesare specifiedin AppendixH.4.2 of NUREG/CR-7046 for streamside locationsof enclosedbodies of water. Each of the alternativesconsideredhas three components to thewatersurfaceelevation.

contributing Alternative 1 - Gombination of:

The lesserof one-halfof the PMF or the 500-yearflood; Surge and seiche from the worst regionalhurricaneor windstormwith wind-wave activity;and The lesser of the 100-yearor the maximumcontrolledwater level in the enclosed body of water.

a Alternative 2 - Combination of:

PMF in the stream; A 2S-yearsurge and seichewith wind-waveactivity;and The lesser of the 1OO-year or the maximumcontrolledwater level in the enclosed body of water.

o Afternative3 -Gombinationof:

- A Z5-yearfloodin the stream;

- Probable maximumsurgeandseichewithwind-waveactivity;and

- The lesserof the 100-yearor the maximumcontrolled waterlevelin the enclosed bodyof water.

3.7.1. Basisof Inputs Inputsinclude thefollowing:

. MajorStreamall-season PMFandHEC-RASmodeling fromCalculation50:38.000

. MajorStreamcool-season PMFandHEC-RAS modeling fromCalculation50:39.000 o MinorStreamall-season PMFandHEC-RASmodeling fromCalculation50:40.000 o MinorStreamcool-season PMFandHEC-RAS modeling fromCalculation50:41.000 o PMSSfromCalculation 50:47.000 o Waveparameters for LakeErieat PNPPfromCalculation 50:47.000

. 1OO-year or maximumcontrolled water levelin LakeErie fromCalculation50:46.000

. LakeEriehistorical maximum surgefromCalculation 50:46.000 o LakeErie2S-yearsurgefromCalculation 50:46.000

. Z-yearwindspeed

. Sitetopography PERRYNUCLEAR POWERPLANT Page 26 of 35

NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision0 FirstEnergyCorporation February23,2015 3.7.2. GomputerSofhrvare Programs

. ArcGlSDesktop10.1 o HEC-GeoRAS 10.1 o HEC-RAS 4.1

. MicrosoftExcel 3.7.3. Methodology Eachcombination includescoincident wind-wave activity.Coincident wind-wave activity is determined for the criticalfloodingcombination usingthe USACE guidance outlined in USACECoastatEngineeringManual.Windsetupis the effectof horizontalstresson the watersurface.Runupis the maximum elevation of waveuprushabovestillwater level.

H.4.1Gombination Probablemaximumsurgeand seicheis discussedIn Section3.5. \Mndwaveactivity includeswave height,wind setup,and wave runup.Wave heightand wind setupare includedas partof the PMSSdeveloped usingDelft3Dmodel.Waverunupis determined in accordance withUSACEguidanceon the shoreline and bluffslopesadjacent to Lake Erie.

H.4.2CombinationAlternatives As a boundingapproach, the maximumLakeEriewaterlevelfromall threealternatives, includingthe initialwaterleveland surgeeffects,is usedas the downstream boundary condition for MajorStreamand MinorStreamflooding,and combinedwith the PMFfor eachstream.lt is determined thatthe maximumLakeEriewaterlevelhasno significant effecton the PMFanalyses. The MajorStreamandMinorStreamHEC-RASmodelsare updatedand the resultsare compared to the H.1 Combination resultsto determine the boundingcombination for windwaveactivity.The 2-yearwind speedis appliedto the longestfetchlengthbasedon the inundation areaof the PMF.Waveheightand wind setupare determined in accordance with USACEguidance.Significant waveheightis usedto determine waverunupin accordance withUSACEguidanceon verticalwalls.

3.7.4. Results The H.4.1 Combination maximumwater surfaceelevationis 582.6feet NGVD 29, includingwindsetup,andoccurswestof the powerblockalongtheshoreline bluffslopes.

The maximumeffectsdueto windwaveactivityoccurat a location just east of the power block along a sectionof shorelinewith steeperbluff slopes.Wave actionanalysis concludes thata maximumwaverunupof 27.5 feet maybe generated on the shoreline bluffslopes.The PMSSmaximumwatersurfaceelevationat this locationis 581.7feet NGVD29. The maximumwaverunupelevation duringthe controlling PMSSis equalto 609.2feetNGVD29,whichis well below the site.

The maximumcombinedwatersurfaceelevationfor the MajorStreamand the Minor StreamarethePMFresults. Thebounding H.4.2Combination includes thePMFfor Major StreamandMinorStreamutilizing the PMSSas a downstream boundary condition. This resultsin maximumwatersurfaceelevations equal to the PMF resultsfor the Minor Stream.For the MajorStreamthe maximumwatersurfaceelevationsare equalto the PMFresultsupstreamof the plantaccessroad.Downstream of the plantaccessroadare slightvariances.However,the resultingwaterlevelsare maintained withinthe Major Streamwatershedboundaries awayfromthe powerblockand well belowthe nominal PERRYNUCLEARPOWERPLANT Page 27 of 35

NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision 0 FirstEnergyCorporation February 23,2015 finishedfloorelevationof PNPPsafety-related structures.Therefore,the variancesare minimal.

The MajorStreamis not directlyadjacentto PNPPsafety-related structures. Therefore, windwaveactivityhasno specificconsequence.

The maximumPMFwatersurfaceelevation for the MinorStreamas shownin Table1 is 623.0feet NGVD29. Waveactionanalysisconcludes thata maximumcombinedwind setupand wave runupof 5.3 feet may be generatedon the verticalfaceof the power blockstructures. The maximumwaverunupelevation duringthe controlling floodingfor the MinorStreamandeastsideof the powerblockis equalto 628.3 feetNGVD 29.

3.8. LocalIntensePrecipitation(ReferencePNPP20159)

The LIP is an extremeprecipitation eventat a given location.The effectsof the LIP are evaluatedfor the westsideof the powerblock.The effectsof the LIP on the eastsideof the powerblockare identical to the MinorStreamreevaluation. The LIPevaluation is performed in accordance withNUREG/CR-7046.

3.8.1. Basisof Inputs

. Site topography

. Site-specific,all-seasonPMP o Combinedprobablemaximumsnowpacksnowmeltand 1O0-year, cool-season rainfall

. Combined1OO-year snowpacksnowmeltand site-specific, cool-season PMP

. Contributionflow from MajorStream all-season PMF o Contributionflow from MajorStreamcool-seasonPMF

. Contributionflow from MinorStreamall-seasonPMF o Contributionflow from MinorStreamcool-seasonPMF 3.8.2. GomputerSoftwarePrograms

. ArcGlSDesktop10.1

. HEC-HMS 3.5

. MicrosoftExcel 3.8.3. Methodology The LIP is equalto the all-season, pointprecipitationPMPor the comblnedeffectsof cool-season snowmelt and The rainfall. three alternativesforthe PMFarealsoevaluated for the effectsof the LlP.Theduration of the LIP event is 72-hours. The all-season and coot-season alternatives are evaluated using5-minuteincrements for various temporal distributions to maximizerunoff.Front,onethird,center,two-thirds, and end-loading temporaldistributions are consideredin an effort to capturethe distribution that maximizes runoff.

Thesite is subdivided intofour (4) sub-basinareasbasedon the topography of the site.

USACE HEC-HMS hydrologicsoftware is used to convert rainfall to runoff. A rainfall hyetograph is applied to the sub-basin areas and transformed to runoff usingunit hydrograph methodology. No historical observations are availableto use as a basisto createa unithydrograph. Therefore, a synthetic unithydrograph is developed. NRCSunit hydrographmethodology transformation.

is usedfor rainfall-to-runoff PERRYNUCLEARPOWERPLANT Page 28 of 35

NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision 0 FirstEnergyCorporation February 23,2015 The entire roof drainage is assumedto be contributingto the surface runoff.

Conservatively, no precipitation lossesare incorporated intothe analysis.Naturallyfor the site area,baseflow is zero.Activeand passive drainage systemcomponents (e.9.,

pumps,gravitystormdrainsystems,smallculverts,and inlets) were considered non-functionator cloggedduringthe LIP event, per Case 3 in NUREG/CR-7046. No adjustment of the unithydrographs is madeto accountfor the effectsof nonlinearbasin response,becausethe unit hydrographs are developedto conservatively maximizethe response time.

The sub-basinareasare modeledas reservoirsusingUSACEHEC-HMShydrologic softwareandan elevation-area relationship. The reservoirareasare modeledwithbroad crestedweir flow to accountfor outflowlocationsand barrierstructures.Split flow betweenreservoirareasis modeledas an auxiliaryconnectionbetweenthe reservoir areas.Overflowcontributions from the MajorStreamand MinorStreamare addedas applicable. Outflowfromthe modeldrainsnorthtowardLakeErie.

3.8.4. Results Forthe all-season PMPevent(Alternative 1),the one-third, center,twothirds,andend-loadingtemporaldistributions produceidenticalpeak resultsand the maximumwater levels.The maximumwatersurfaceelevationalongthe entirewest side of the power blockfor Alternative 1 is 621.2feetNGVD29.

Basedon the resultsfor Alternative1 onlythe centertemporaldistribution is evaluated for the combined probable maximumsnowpack and 1OO-year cool-season rainfallevent (Alternative 2). The maximumwatersurfaceelevationalong the entirewest side of the powerblockfor Alternative 2 is 620.0feet NGVD29.

Based on the resultsfor Alternative1 only the centertemporaldistributionis evaluated for the combined1OO-year snowpackand cool-seasonPMP event (Alternative3). The maximumwater surfaceelevationalongthe entirewest side of the powerblockfor Alternative 3 is 620.2feetNGVD29.

The all-seasonPMP event (Alternative 1) is determined to be the controllingLIP scenario.The maximumwatersurfaceelevationsat safety-related structuresalongthe westsideof the powerblockis 621.2feetNGVD29.Thedurationof floodingabovethe nominalfinishedfloorelevation is t hour3 minutes.

Coincident wind wave activitycombinedwith the LIP is not designated by NUREG-CR/7046.Additionally, site obstructions, includingstructuresand barrierblocks,and shallowwater depths of floodingon the west side of the power block preclude development of significantfetchlengthandsubsequent waveconditions.

4. COMPARISON WITHCURRENT DESIGNBASIS The reevaluated maximumwatersurfaceelevations due to the riverineflooding(PMFfor the MajorStreamand Minor Stream, including the combined effectsof windwaveactivity), LlP,and lakeflooding(PMSS)exceedthe currentlicensing basis.

For riverineflooding,the currentdesignbasisincorporates superseded guidance, whichdoes notexaminesub-hourly PMPincrements, temporaldistributions, or theeffectsof nonlinear basin response. In addition,recentsitetopography is used for the hazard reevaluation.

PERRYNUCLEARPOWERPLANT Page29 of 35

NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision 0 FirstEnergyCorporation February 23,2015 Forlakeflooding, the currentdesignbasisassumesthe surgeactsonlyin onedirection. A site-specificwind and pressurefield is developedas part of the reevaluation. Morerecentstorms providethe controlling windfor reevaluated surgefloodingat PNPP.

As previously indicated, the PMSSmaximumstillwater surfaceelevationexceedsthe design basiselevation of 580.5feetNGVD29 by a maximumvalueof 2.1feet.The UHSfor PNPPis Lake Erie.Althoughthe designbasisis exceeded,the PMSS Stillwatersurfaceelevation remainsbelowthe safety-related pumpsand equipmentlocatedaboveelevation586.5feet NGVD 29 in the emergencyservicewater pumphouse. Additionally,the PMSS minimum stillwatersurfaceelevationis lowerthanthe designbasisof 565.26feet NGVD29 by 2.3 feet.

However,previousevaluationdetermined thatthereis adequatenet positivesuctionheadand submergence of the emergency servicewaterpumpsfor a resulting elevation as low as 559.0 feet NGVD29 (Reference PNPP2004).The maximumsurgerunupexceedsthe designbasis elevationof 607.9feetNGVD29 by a maximumvalueof 1.3feet.However, the maximumeffects of the PMSSeventare maintained on the bluffsadjacentto LakeErie. The sitegraderemains higherthanthe maximumeffectsof the PMSSevent. Therefore, the resulting beyonddesign basisPMSSeffectsare inconsequential structures.

to safety-related For LIPflooding,the currentdesignbasisreducesthe peakrainfallintensity to accountfor the roofdrainage systemandaltowa build-upof six inchesof rainfalldepthovertheentireplantsite.

Additionally,runoffcoefficients (losses)are incorporatedintothe analysis.As partof the hazard reevaluation, recentsitetopography is used,andno creditis takenfor lossesor the roofdrainage system.Furthermore, the hazardreevaluationincorporatesoverflowcontributions from the adjacentMajorStreamandMinorStreamwatersheds.

Thecomparisons of existingandreevaluated floodhazardsareprovidedin Table2.

PERRYNUCLEARPOWERPLANT Page30 of 35

NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision0 FirstEnergyCorporation February 23,2015 Table2 - Comparisonof Existingand Reevaluated FloodHazardsat PNPP Flood-Gausing Mechanism DesignBasis Comparison Flood HazardReevaluationResults FloodingIn MaiorStream Not MaiorStream streamsand PMFElevation is bounded. All-seasonPMFElevation is 630.9 rivers 624.0feet NGVD Exceeds feetNGVD29 (at raillinebridge).

29 (at railline current bridge). designbasis All-Season PMFFlowis 30,100cfs.

for both PMFFlowis Major Cool-Season PMFElevation is 623.1 31,250cfs. Streamand feet NGVD29.

Minor Cool-season is not Stream. Cool-season PMFFlowis 14,900cfs.

evaluated.

MinorStream MinorStream All-seasonPMFElevation is 623.0 PMFElevation is feetNGVD29.

619.5feet NGVD

29. All-seasonPMFFlowis 5,300cfs.

PMFFlowis 7,000 Cool-season PMFElevation is 621.1 cfs. feet NGVD29.

Cool-season is not Cool-season PMFFlowis 1,600cfs.

evaluated.

Dambreaches No upstream Bounded Damassessment no indicates andfailures impoundments. watersheddams.

Stormsurge Watersurface Not Watersurfaceelevationis 582.6feet elevation is 580.5 bounded. NGVD29.

feetNGVD29. Exceeds current Lowwater designbasis. Lowwaterelevationis 563.0feet elevation is 565.26 NGVD29.

feet NGVD29.

Seiche Thisflood-causing Bounded Boundedby stormsurge.

mechanism is not described specifically for the sitein the USAR.

Tsunami This flood-causing Bounded Tsunamiassessment indicates a slight mechanismis possibility in of tsunamis the Great identifiedas not Lakesregion.However,the seismicity applicablein the in the regionsuggestsno potential USAR. existsfor strongearthquakes or the verticaldisplacement necessary to induce a tsunami.

substantial PERRYNUCLEAR POWERPLANT Page 31 of 35

NTTFRecommendation 2.1 (HazardReevaluations) : Flooding Revision 0 FirstEnergyCorporation February 23,2415 Table2 - Comparisonof Existingand Reevaluated FloodHazardsat PNPP(Continued)

Flood-Causing Mechanism DesignBasis Comparison Flood HazardReevaluationResults lce-induced Thisflood-causing Bounded lce-inducedfloodingis boundedby the flooding mechanism is all-seasonPMF event.

identified as not plausible in the USAR.

Channel Thisflood-causing Bounded Channeldiversion is notcharacteristic migration or mechanism is for adjacentstreams.

diversion identified as not applicable in the USAR.

Combinedeffect Waverunupon Not Waverunupon LakeErieshoreline flood(including LakeErieshoreline bounded. bluffsis 609.2feet NGVD29.

wind-generated bluffsis 607.9feet Exceeds waves) NGVD29. current Maximum waverunupelevation in the designbasis.

vicinityof the power block is 628.3 feet

\Mndwaveeffects on streamsis not NGVD29.

described in the USAR.

LIP Maximum water Not Maximumwatersurfaceelevationis surfaceelevationis bounded. 621.2feet NGVD29.

620.5feetNGVD Exceeds

29. current desiqnbasis.

Plantmonument elevations, usedas a basisfor plantdesign,havebeenreportedto havean approximate 0.21feet uncertainty with respectto the 2012Sanborntopographic survey,being the surveybasisof floodingevaluations. The approximate 0.21 feet uncertainty ls in excessof the estimated0.11feettolerance of the 2012Sanbornsurvey.The0.11 feet tolerance accounts for surveyaccuracyas well as for the accuracyof the conversionbetweenNAVD88 to NGVD 29 datums.The0.21feetuncertainty shallbe considered in addition to thestated0.72feetonsite conversionbetweenthe NADV88 andNGVD29 datums.Thus,accounting for an additional 0.21 feetof waterdepthat elevations listedherein.However,sincethe Reportshowsthatfloodlevels exceedthe designbasisfloodlevels,the conclusion significantly of thisreportis unchanged, an interimactionplan has beendetermined necessary. The interimaction plan as stated in the followingsectionwillaccountfor thisdiscrepancy andthe powerblockbuildingsettlement of up to 1.5inchesdiscussed in Section2.3,withinthe listedmodifications as wellas in allfinaldesign basisconditions.

PERRYNUCLEAR POWERPLANT Page32 of 35

NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision0 FirstEnergyCorporation February23,2015

5. INTERIM AND PLANNEDFUTURE ACTIONS TheFlooding HazardReevaluation Reportevaluated theapplicable floodinghazardsfor PNPP.

Four of the postulatedreevaluated flood hazardevents (riverineflooding,lake flooding, combinedeffects,and LIP)resultedin maximumfloodwaterelevations higherthanpreviously calculated for PNPP.Thesepostulated floodingeventsare considered beyonddesignbasis eventsanddo notconstitute an operabilityconcern.The PMSSeventandthe combinedeffects for waverunupon the LakeErieshoreline resultsareinconsequential. Therefore, no interimor futureactionsare plannedfor thisevent.

The interimaction plan is an engineeringchangepackageand supportinganalysesto demonstrate maximumwatersurfaceelevations will not resultin floodingof plantbuildings important to nuclearsafety.An engineering changepackagehas beeninitiatedto implement designchangesto theMajorStreamandtheMinorStreamto addressthedesignbasiscondition describedin the functionalityassessment(PNPP ConditionReport 2013-05625)and accommodate the beyonddesignbasisevents.Althoughthe functionality assessment removes someof the conservatism appliedin the originalevaluation, the resultsfor the MinorStreamon the eastsideof the powerblockandthe LIPresultson the westsideof the powerblockwere equalto or less than the nominalfinishedfloor elevationof PNPPsafety-related structures.

Therefore, no additional interimactionsarenecessary.

The designchangeswill ensurethat all flow will be maintained withinthe Major Stream watershed boundaries andwithinthe banksof the MinorStream. Because the MajorStreamis not immediately adjacentto safety-related structures,the resulting water levelsin the Major Streamare inconsequential. However,overflowfromthe MajorStream is a contributor to Minor Streamwatertevels.Therefore, flowneedsto be maintained withinthe Major Stream watershed boundaries.

Theengineering changepackageincorporates removalof a portionof the existingabandoned rail lineembankment crossingthe MajorStream.Removalof the embankment allowsgreater conveyance of flow in the overbanksof the MajorStream,preventing flowfromovertopping the railline.Furthermore, the secondaryaccessroadis raisedto preventany remainingbackwater fromovertopping the road.Thismodification resultsin the concentration of MajorStreamrunoff to be carrieddownstream to LakeErie,ratherthan contributing to runoffto otherareasof the site.Thetechnical basisof the MajorStreammodifications incorporates analysisof site-specific PMP as input,no precipitation losses,unit hydrograph rainfall runoff analysis,includingthe etfectsof nonlinear basinresponse, andone-dimensional unsteady state hydraulic modeling.

Theengineering changepackageincorporates an upstream diversion of the MinorStream.The diversionchanneldivertsrunofffloweastaroundthe outsideof the securitybarriersand north directlyto LakeErie.A bermis designed adjacentto thediversion channelbetweenthechannel and the site.UnderPMFconditions the bermwill maintainall floodwaterawayfromthe site.

Thesemodifications significantly reducethe runoffflowreceivedby the MinorStream,resulting in the designbasiswaterlevelsof 619.5feetNGVD29.Withthe designbasiswaterlevels,the combinedeffectwind wave activityrunupon the powerblockis no longerapplicable. The technical basisof the MinorStreammodifications incorporates analysisof Hydrometeorological No.33 PMPas input,no precipitation losses,unithydrograph rainfallrunoffanalysis, including the effectsof nonlinearbasin response,and one-dimensional unsteadystate hydraulic modeling. Hydrometeorological No.33 PMPis determined to boundsite-specific PMP.

Thesechangeswill resultin eliminating the overflowcontributions fromthe MajorStreamand the MinorStreamto other areasof the site. Therefore,only the precipitation for the LIP contributes to flooding.Supporting the engineering changepackage,the interimactionplan includes completion of an LIPanalysis to determine the maximum watersurfaceelevation. Also, the evafuation will addressthe 0.21feetdatumdiscrepancy, discussedin Section4, andthe PERRYNUCLEARPOWERPLANT Page33 of 35

NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision0 FirstEnergyCorporation February23,2015 powerblockbuildingsettlement of up to 1.5inchesdiscussed in Section2.3.The resultsof this analysiswillbe incorporatedintothe engineering changepackage.

6. REFERENCES (ANSI/ANS-2.8-1992) ANS,AmericanNationatStandard for Determining DesignBasrsFlooding at Power ReactorSr'fes,Preparedby the AmericanNuclearSocietyStandardsCommittee WorkingGroupANS-2.8,1992.

(JLD-ISG-2013-01) NRC,Guidancefor Assessment of FloodingHazardsdue to Dam Failure, Revision 0, July2A13.

(JLD-ISG -2012-06)NRC,Guidance for Performinga Tsunami, Surgeor SeicheFlooding Hazard Assessment, Revision0, January2013.

(NEfAugust2012)NEl, Report12-08,Overviewof ExternalFloodingReevaluations, August 2012.

(NRCMarch2012)NRC,LettertoLicensees, RequestforInformation Pursuantto Title10of the Codeof FederalRegulations 50.54(0Regarding Recommendations 2.1,2.3,and9.3of theNear-TermTaskForceReviewof Insights fromthe Fukushima Dai-ichiAccident,March12,2012.

(NRCMay 2012)NRC,Letterto Licensees, of ResponseDue Datesfor Request Prioritization for Information Pursuantto Title 10 of the Code of FederalRegulations 50.54(f)Regarding FloodingHazardReevaluations for Recommendation 2.1 of the Near-Term TaskForceReview of lnsightsfromthe Fukushima Dai-ichiAccident,May 11,2012.

(NRC RG 1.59)NRC,DesrgnBasisFloodfor NuclearPower Plants,RegulatoryGuide Revision 2, 1977.

(NRCRG 1.102)NRC,Ftood Protection for NuclearPower Plants,Regulatory Guide1.102, Revision 1, 1976.

(NUREG-O8OO) NRC,NUREG-0800, Standard ReviewPtanfor the Reviewof SafetyAnalysis Reporfs for NuclearPower Ptants:LWR Edition- Sde Characterisficsand Site Parameters (Chapter2), ML070400364, March2007.

(NUREG/CR-7046) NRC,NUREG/CR-7046, PNNL-20091 , Design-Basis FloodEstimationfor SiteCharacterizationat NuclearPower Ptantsin the UnitedSfafes of America,ML11321A195, November 2011.

(NUREG/CR-6966) NRC,NUREG/CR-6966, TsunamiHazardAssessmentat Nuclear Pawer PtantSifesin the lJnitedSfafesof America,NationalTechnical InformationService,March 2009.

(ODNR2013)OhioDepartment of NaturalResources, ProbableMaximumPrecipitation Study for the Sfafeof Ohio,preparedby AppliedWeatherAssociates, LLC, February2013.

(PNPP2OO4) FENOCCalculation P45-081,Evaluation of Nef PositiveSuctionHead(NPSH) and SubmergenceRequirements for the Emergency Service Water(ESW SysfemPumps, Revision 0.

(PNPP2015a)FENOCCalculation 50:36.000, PNPPSde-Specific All-SeasonPMP,Revision 0.

(PNPP2015b)FENOCCalculation 50:37.000, PNPPSde-specific Cool-season PMP,Revision 0.

PERRYNUCLEAR POWERPLANT Page34 of 35

NTTFRecommendation 2.1 (HazardReevaluations): Flooding Revision0 FirstEnergyCorporation February23,2015 (PNPP 2015c) FENOCCalculation50:38.000,PNPPMajor StreamAll-SeasanProbable MaximumFlood,Revision0.

(PNPP2015d)FENOCCalculation 50:39.000,PNPPMajor StreamCool-Season Probable MaximumFlood,Revision0.

(PNPP 2015e) FENOCCalculation50:40.000,PNPPMinor StreamA//-SeasonProbable MaximumFlood,Revision0.

(PNPP20150 FENOCCalculation 50:41.000,PNPPMinor StreamCool-Season Probable MaximumFlood,Revision0.

(PNPP20159)FENOCCalculation50:42.000,PNPP Effectsof Local lntensePrecipitation, Revision0.

(PNPP2015h)FENOCCalculation 50:43.000, PNPPDamsAssessmenf, Revision0.

(PNPP 2015i) FENOC Calculation50:44.000,PNPP lce Jam and Channel Assessmenf,Revision0.

(PNPP2015j)FENOCCalculation 50:45.000, PNPPWindClimatology, 0.

Revision (PNPP2015k)FENOCCalculation 50:46.000, PNPPSurgeand SeicheScreemng, Revision 0.

(PNPP20151) FENOCCalculation 50:47.000,PNPPSurgeand SeicheAnalysis, Revision0.

(PNPP2015m)FENOCCalculation 50:48.000,PNPPTsunami Assessment,Revision0.

(PNPP2015n)FENOCCalculation 50:52.000, PNPPRainfallRunoffGISAnalysis,Revision0.

(PNPP2015o)FENOCCalculation 50:53.000, PNPPSurgeand SeicheG/S Analysis,Revision 0.

(PNPP2015p)FENOCCalculation 50:54.000, PNPPSurgeand SeicheCalibration,Revision0.

(PNPP2015q)FENOCCalculation 50:55.000, PNPPCombinedEvents, 0.

Revision (PNPP2015r)FENOCCalculation 50:59.000,PNPPSde-SpecificAll-SeasonSub-Hour ProbableMaximumPrecipitationAnalysisfor 1-10SquareMiles,Revision0.

(PNPP2015s)FENOCCalculation 50:60.000, Cool-Season PNPPSife-Specific Probable Maximum(rainfall)PrecipitationAnalysis,Revision0.

(USAR)PerryNuclearPowerPlant,UpdatedSafetyAnalysisReport,Revision17.

PERRYNUCLEARPOWERPLANT Page35 of 35

v t e Letter Sequence Response to RAI
TAC:MF6099, (Open)
Initiation Acceptance... Administration Questions Answers 10 March 2015 11 December 2015 Results Approval... Other: ML15153A145
MONTHYEAR2015-03-10 [Table View]

L-15-074, FENOC, Perry Nuclear Power Plant - Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding the Flooding Aspects of Recommendation 2.1 of the Near-Term Task Force (NTTF) Review of Insights from the Fukushima Dai-ichi Ac

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L-15-074, FENOC, Perry Nuclear Power Plant - Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding the Flooding Aspects of Recommendation 2.1 of the Near-Term Task Force (NTTF) Review of Insights from the Fukushima Dai-ichi Ac

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