ML17059C345

Summary of 980924 Meeting with Niagara Mohawk Power Corp in Oswego,Ny Re Proposed Extension to Schedule for Reinspecting Vertical Welds in Core Shroud at Nine Mile Point Nuclear Station,Unit 1.Agenda & Partial List of Attendees Encl

ML17059C345
Person / Time
Site:	Nine Mile Point
Issue date:	11/13/1998
From:	Hood D NRC (Affiliation Not Assigned)
To:	NRC (Affiliation Not Assigned)
References
TAC-M99720, NUDOCS 9811200189
Download: ML17059C345 (26)

Text

I ~

~R RE0ii

+4 po Cy A

C1O I

O~

+~

i

~O

++*++

UNITED STATES NUCLEAR REGULATORY COMMISSION g g~g WASHINGTON, D.C. 20555-0001 November 13, 1998 LICENSEE: Niagara Mohawk Power Corporation FACILITY:

Nine Mile Point Nuclear Station, Unit No. 1

SUMMARY

OF MEETINGS WITH LICENSEE AND PUBLIC ON SEPTEMBER 24, 1998, REGARDING CORE SHROUD REINSPECTION SCHEDULE (TAC NO. M99720)

On September 24, 1998, the NRC staff participated in a meeting with Niagara Mohawk Power Corporation (NMPC and licensee) regarding a proposed extension to the schedule for reinspecting the vertical welds in the core shroud at Nine Mile Point Nuclear Station, Unit No.

1 (NMP1). The meeting, held from 5:00 to 7:00 p.m., was followed by an NRC meeting with the public from 7:30 p.m to 12:15 a.m. on the same subject.

The meetings were held in Snygg Hall at State University of New York in Oswego, New York.

The agenda and a partial list of NRC attendees are given in Enclosure 1. NMPC participants included Messrs. J. Mueller, R. Abbott, C. Terry, R. Smith, and G. Inch. Contractor personnel for NMPC included Dr. M. Manahan, Sr. of MPM Technologies; Dr. S. Ranganath and R. Horn of

'eneral Electric Nuclear Energy; and Messrs. R. Smith, A. Gianuzzi, and R. Matson of Structural Integrity, Inc. Both meetings were well attended by state and local officials, members of the public, various organizations, and local news media.

The purpose of the meeting with NMPC was to review the technical basis for NMPC's request in a letter dated February 27, 1998, and several supplemental submittals, that the NRC consent to extending the schedule for reinspecting the vertical welds in the NMP1 core shroud.

In the February 28, 1998, letter, NMPC concluded that NMP1 can be safely operated with the current operating cycle extended beyond that which NMPC had previously proposed and which the NRC had accepted.

Specifically, NMPC provided a revised crack growth rate basis and a structural margin analysis for extending the 10,600 hot operating hours that the NRC staff approved in a letter dated May 8, 1997, to 14,500 hours0.00579 days <br />0.139 hours <br />8.267196e-4 weeks <br />1.9025e-4 months <br />.

In its letters and during the meeting, NMPC reviewed the basis for the 10,600 hours0.00694 days <br />0.167 hours <br />9.920635e-4 weeks <br />2.283e-4 months <br /> interval and developments since NMP1 restart in May 1997. These developments include the NRC's issuance of a safety evaluation on a slower crack growth rate (2.2 x 10~ in/hr) based on Boiling Water Reactor Vessel and Internals Project (BWRVIP) report, BWRVIP-14, "Evaluation of Crack Growth in BWR Stainless Steel Reactor Pressure Vessel Internals," NRC approval of the NMPC finite element fracture mechanics and limit load analysis of the vertical welds, and the safety assessment of the vertical weld cracking.

NMPC discussed metallurgical evaluations of the two vertical weld boat samples and additional structural margin analyses that have been completed.

NMPC showed that, even at the higher crack growth rate (5 x 10~ in/hr), its supplemental fracture mechanics analysis (performed with BWRVIP-01 guidelines and with credit for uncracked locations) demonstrates that structural margins required by the American Society of Mechanical Engineers Boiler and Pressure Vessel Code are maintained for more than the 14,500 hours0.00579 days <br />0.139 hours <br />8.267196e-4 weeks <br />1.9025e-4 months <br /> of operation.

NMPC reviewed NMP1's conformance with each of the conditions in the NRC's safety evaluation for BWRVIP-14, including NMP1's coolant chemistry which has been maintained below the Electrical Power Research Institute's guidelines, and neutron fluence which at the remaining ligaments of the vertical welds would remain within the limit of 5 x 10" n/cm'8ii200i89 98iiis I

PDR ADOCK 05000220 P

PDR

~ ~

f I lI h

~

I 'I once the 14,500 hours0.00579 days <br />0.139 hours <br />8.267196e-4 weeks <br />1.9025e-4 months <br /> of operation was reached.

Details of NMPC's presentations are given in their submittals to the NRC staff dated September 30, 1997; January 30, February 27, March 31, April 16 and 30, June 30, and September 21, 1998; and are not repeated here.

presents the viewgraph slides and handouts used by NMPC and its contractors.

The meeting with the public included introductions of local officials and members of various organizations by Ms. Barbara Brown, Legislator of Oswego County. Numerous questions and expressions of concern for shroud integrity were received and discussed by the NRC staff. The public comments expressed a clear preference that the reinspection be performed once the 10,600 hours0.00694 days <br />0.167 hours <br />9.920635e-4 weeks <br />2.283e-4 months <br /> has been reached and a desire for the strongest possible oversight of nuclear reactors by the NRC. The public's preference was based upon the higher assurance afforded by actual observation compared to reliance upon calculations.

One member of the public requested that the NRC determine the maximum allowable deterioration of the shroud and its minimum margins before acting upon NMPC's request; Mr. Hermann of the NRC explained that degraded components are inspected and evaluated at predetermined intervals during service life in order to assure that Code required margins will be met during that pre-analysized period of operation.

Another member of the public stated that a petition opposing the extension request and containing over 300 signatures would soon be sent to the NRC. Ms. Kavanagh and Mr. Caruso of the NRC answered several questions about shroud leakage potential and consequences.

One member of the public was concerned that crack growth would accelerate once leaking commenced due to the effects of chemistry; Dr. Shack (an NRC contractor) responded that experiments have demonstrated that leakage actually slows crack growth rate by diluting or flushing away the chemical deposits within the crack.

Mr. Bajwa responded to questions regarding the NRC's decision process and policies.

Messrs. Doerflein and Norris of NRC Region I addressed certain prior events at the NMP facilities (not.related to the shroud) for which some members of the public expressed concern.

Mr. Lois of the NRC replied to questions regarding the relationship between neutron fluence and intergranular stress corrosion cracking and how the fluence at the NMP1 shroud was measured and calculated.

Asked about the NRC's schedule, Mr. Hood of the NRC stated that the current target date for reaching a decision is November 1, 1998. Several people expressed appreciation for the meeting and requested that more meetings on issues of local concern be held in the future. The NRC staff noted that comments received during the meeting would be considered during the staff's continuing review of the extension request.

Sincerely, Darl S. Hood, Senior Project Manager Project Directorate I-1 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation Docket No. 50-220

Enclosures:

1. Agenda and NRC attendees

2. NMPC and contractor slides cc w/encls: See next page

f ovember 13, 1998 once the 14,500 hours0.00579 days <br />0.139 hours <br />8.267196e-4 weeks <br />1.9025e-4 months <br /> of operation was reached.

Details of NMPC's presentations are given in their submittals to the NRC staff dated September 30, 1997; January 30, February 27, March 31, April 16 and 30, June 30, and September 21, 1998; and are not repeated here.

presents the viewgraph slides and handouts used by NMPC and its contractors.

The meeting with the public included introductions of local officials and members of various organizations by Ms. Barbara Brown, Legislator of Oswego County.

Numerous questions and expressions of concern for shroud integrity were received and discussed by the NRC staff. The public comments expressed a clear preference that the reinspection be performed once the 10,600 hours0.00694 days <br />0.167 hours <br />9.920635e-4 weeks <br />2.283e-4 months <br /> has been reached and a desire for the strongest possible oversight of nuclear reactors by the NRC. The public's preference was based upon the higher assurance afforded by actual observation compared to reliance upon calculations.

One member of the public requested that the NRC determine the maximum allowable deterioration of the shroud and its minimum margins before acting upon NMPC's request; Mr. Hermann of the NRC explained that degraded components are inspected and evaluated at predetermined intervals during service life in order to assure that Code required margins willbe met during that pre-analysized period of operation.

Another member of the public stated that a petition opposing the extension request and containing over 300 signatures would soon be sent to the,NRC.

Ms. Kavanagh and Mr. Caruso of the NRC answered several questions about shroud leakage potential and consequences.

One member of the public was concerned that crack growth would accelerate once leaking commenced due to the effects of chemistry; Dr. Shack (an NRC contractor) responded that experiments have demonstrated that leakage actually slows crack growth rate by diluting or flushing away the chemical deposits within the crack.

Mr. Bajwa responded to questions regarding the NRC's decision process and policies. Messrs. Doerflein and Norris of NRC Region I addressed certain prior events at the NMP facilities (not related to the shroud) for which some members of the public expressed concern.

Mr. Lois of the NRC replied to questions regarding the relationship between neutron fluence and intergranular stress corrosion cracking and how the fluence at the NMP1 shroud was measured and calculated.

Asked about the NRC's schedule, Mr. Hood of the NRC stated that the current target date for reaching a decision is November 1, 1998. Several people expressed appreciation for the meeting and requested that more meetings on issues of local concern be held in the future. The NRC staff noted that comments received during the meeting would be considered during the staffs continuing review of the extension request.

Si

ere, Darl S. Hoo, Senior Project Manager Project Directorate I-1 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation Docket No. 50-220

Enclosures:

1. Agenda and NRC attendees

2. NMPC and contractor slides ccw encls:

See next page DOCUMENT NAME:

G:XNMP1XPUBMEET2.SUM To receive a copy of this document, indicate in the box:

"C" - Copy without attachment/enclosure "E" - Copy wit attachment/enclosure "N" - No copy OFFICE PM:PDI-1 E

LA:PDI-D:PDI-1 NAME DHood/rsl SLI t SBsjws DATE 11/

/98 11/

98 11/

/98 Official Record Copy

f K l I

L I'J

'1 I

1 f (

tl fl

DISTRIBUTION:

I

~Hard Co (w/all enclosures)

Docket File PUBLIC PDI-1 R/F OGC ACRS E-Mail (w/enclosure 1 only)

S. Collins/F. Miraglia G. Holahan B. Boger J. Zwolinski S. Bajwa D. Hood S. Little B. Sheron G. Lainas R. Wessman R. Hermann W. Koo K. Wickman K. Kavanagh L. Lois R. Caruso E. Sullivan

,N. Sheehan, L. Doerflein, Rl C. Cowgill, Rl,

I r

f, t

'l 1

I

Niagara Mohawk Power Corporation CC:

Mr. John H. Mueller Chief Nuclear Officer Niagara Mohawk Power Corporation Nine Mile Point Nuclear Station Operations Building, Second Floor P.O. Box 63 Lycoming, NY 13093 Regional Administrator, Region I

U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Mark J. Wetterhahn, Esquire Winston 8 Strawn 1400 L Street, NW Washington, DC 20005-3502 Supervisor Town of Scriba Route 8, Box 382 Oswego, NY 13126 Gary D. Wilson, Esquire Niagara Mohawk Power Corporation 300 Erie Boulevard West

Syracuse, NY 13202 Warren Bilanin, EPRI Task Manager 3412 HillviewAvenue Palo Alto, CA 94303 Robin Dyle, Technical Chairman BWRVIP Assessment Task Southern Nuclear Operating Company Post Office Box 236 40 Inverness Center Parkway Birmingham, AL 35201 Nine Mile Point Nuclear Station Unit No. 1 Resident Inspector U.S. Nuclear Regulatory Commission P.O. Box 126 Lycoming, NY 13093 Charles Donaldson, Esquire Assistant Attorney General New York Department of Law 120 Broadway New York, NY 10271 Mr. Paul D. Eddy State of New York Department of Public Service Power Division, System Operations 3 Empire State Plaza Albany, NY 12223

,Mr. F. William Valentino, President New York State Energy, Research, and Development Authority Corporate Plaza West 286 Washington Avenue Extension Albany, NY 12203-6399

AGENDA September 24, 1998 Meeting Regarding Inspection of Core Shroud Vertical Wetds at Nine Mile Point Nuclear Station Unit 1 I. NRC SESSION WITH NIAGARAMOHAWKPOWER CORPORATION (NMPC) 5:00 NRC Opening Remarks Darl Hood Purpose Introduction of Participants 5:05 Background 5:10 NMPC's Review of Request to Extend Core Shroud Inspection Interval Robert Hermann Richard Abbott et al.

Introduction Core Shroud Boat Sample Tests and Evaluations Application of BWRVIP-14 to Unit 1 Core Shroud Weld Cracks Conclusions 6:30 NRC Questions/Commerits 7:00 Break II. NRC SESSION WITH PUBLIC 7:30 NRC Opening Statements 7:35 Questions/Comments from Audience 9:30 NRC Closing Remarks Darl Hood Singh Bajwa Encl osure 1

NRC ATTENDEES Office of Nuclear Reactor Regulation, Rockville, MD:

Singh S. Bajwa Director Project Directorate I-1 Darl S. Hood Senior Project Manager Project Directorate I-1 Robert A. Hermann Senior Level Advisor-Materials Science Materials and Chemical Engineering Branch Division of Engineering-William H. Koo Senior Materials Engineer Materials and Chemical Engineering Branch Division of Engineering Ralph Caruso Section Chief Reactor Systems Branch Division of Systems Safety and Analysis Kerri A. Kavanagh Reactor Systems Engineer Reactor Systems Branch Division of Systems Safety and Analysis Dr. Lambros Lois Senior Reactor Systems Engineer

~

Reactor Systems Branch Division of Engineering Region I, King of Prussia, PA:,

Lawrence T. Doerflein Chief, Project Branch 1

Division of Reactor Projects Barry S. Norris Senior Resident Inspector Nine Mile Point Nuclear Station Neil A. Sheehan Senior Public Affairs Officer Public Affairs Staff NRC Contractor:

Dr. William J. Shack Associate Division Director of the Energy Technology Division Argonne National Laboratory

4

l IIJ arf NIACARAMONAIVKPOWER CORPORATION lIIJ NINE MJLE PDINT NUcLEARSTATfoN UhYTI Rllll-Agellda NRC/NMPC Nine MilePoint Unit 1 Core Shroud Meeting September 24, 1998 Opening Remarks J H. Mueutr Introductions I.

. R. B. Abbott Purpose

..ILB. Abbott Background.

C.D. Terry Results olEvduation........................G.

Inch R Horn M. hfandtan Results olStructurd Margin Assessment.......G.

Inch Conclusion.

ILB. Abbott RlS Meeting Purpose

~ Present supplemental information applied as basis for extending shroud reinspection NMPI shroud metallurgical, fluence, and crack growth assessment submitted February, 1998

- NMP1 supplemental shroud structural margin analysis submitted April,1998

- Neutron transport analysis - September, 1998

~ Applicabilityof BWRVIP-14 II@

Background

~ 'Ihe BWRVIPdeveloped industry standardized shroud inspection, evaluation and repair criteria which were approved by the NRC

~ Unit 1 shroud horizontal welds preemptively repaired in 199S

~ Allvertical welds inspected in 1997 consistent with BWRVIPcriteria for repaired shrouds

~ Cracks were observed andboat samples removed for metallurgical evaluation llew

Background

~ April1997,NMPC provided Justification, consistent with BWRVIP41 guidelines, lor IOAOO hours olhot operation

~ May 8, 1997, NRC issued an SER allowing operation lor IOAOO hours prior to reinspection of the vertical welds

~ February 27, 1998, the NMPC submittal retiuesttd to extend operation from IOAOO hours to 14500

hours, based upon metdlurgical evduation and resstssmennt of crack growth rates forwelds V9 and VIO

~ April 30,

1998, NMPC subrnltted results of supplemtntd structural margin assessment ol weld s V4, V9 and VIO, consistent withBWRVIP41 Biddance, to lurther support operation lot 14~

hours

~ On June 8, 1998. the NRC Issued an SER on BWRVIP-14 which is directly applicable to the NMPI eral king Rlmt Basis ofthe Vertical Weld 10,600 Hour Inspection Interval

~

1007 lruptction ofall accessible vtrtkal and horiaontal welds consistent withBWRVIP41 and BWRVIP47

~ Finite element Unear Ehsdc Fracture Mtdiantcs fLEFM) andysls of V9 and VIOpart through wall cracks based on lracrure toughntss of ttsoksl Ztn) consistent withBWRVIP41 evduation guktttints

~ UmltLoad Analysis for V4,VIS. and VI6

~ Optratktg bittrval was defrned based on CGR cl SO x 10'n/br

~ No credit lothortacntal weld Inttgrtty

~,Part through wall cracking assumed at locations where Ur

'I ttae~~ltg~nt

~ Optratt withillEPRI water chtmtsuy guidelines

~ Complete boat sample evduattons Enclosure 2

I

~

~

Ilail Actions Since April1997 Inspection and Evaluation

~ NRC approved the NMPC fin)te element fracture mechanics and hmit load analysis of the vertical weids and the safety assessment of the venicai weld cracking

~ NMPC has operated well below the EPRI water chemistry guideline commitment (conductivity c3 eg/cm, sulfate>>E ppb, chloride >>5ppb)

- avg. conductivity 0/)y6 >>S/cm

- avg. sulfate 2.01 ppb, avg. chloride <05 ppb

~ NMPC completed detaitedmetaUurgicai evduauans ofthe vertical weld boat samples

~ Additional structural margin analysis completed

~ The NRC issued BWRVIP-14 SER which supports lower CCR IllllBasis ofthe Vertical Weld 14,500 Hour Inspection Interval

~ Metallurgical and fluence evaluations justify14~

hours based upon lower CGR.'

PLEDGE analysis CGR confirms 2.2 x 1(ys in/hr with significant margin

- Cracking confirmed as IGSCC, consistent with basis of BWRVIP-14

- Analysis satisfies the BWRVIP-14 SER conditions

>> Fluence willremain below 5x10 n/cmr

~ Supplemental structural analysis which satisfies BWRVIP41 analysis guidelines justifies greater than 14500 hours at the assumed 5 x 10 s in/hrCGR Nlmt Vertical Weld Boat Sample Evaluations

~ Two bolt eunpics removed

~

Boat selnface eehR/It cepected ICSCC chvacueieocs Crack txaud in hart affected aae>> 0IAE)

- Eorfece read work

- No entanetve crack tip~~ endeclan>>nt ar Erabi dlopao t cherecurieoc oflrreduoan effacu

~

Rauhe confirm trrsirbiE(wiOdn.t inch)

~ Ran lu can/am aeceUent no>>riel deathly

~

Tensile peapcniee aee canuucnt whh ieadleiian ofnuecriel in 0>> 2 e IO>> n/arne ranEe

~

Boat sample baled fluence n>>eeoecmcens. confirm out analytic ptebct'xm ofvcnical weld peak nocn<<are c<<e>>eveove

~ Meunotrephy and other n>>eeoran>>nu cansnn aeceemmcnt of

~ Candor)an: Venice 1 weld b ICSCC which ie typical ofBWRc<<e shroud crec4nS with no observed evidence of fired)anon effects IIN NRC SER Crack Growth Assessment

~

NRC SKR>>ecol fane S. 1181 on the SWRVIP Itcreek Sea>>threw annaoeree the\\ e>> oeee eteaeahee we anatole a>>hect ea lolleevnw end o>>

laaaenna eanrkoane:

fetnaaan Weu eetelh, eire eev eve@de%I In eVeonnea O>> receiver

~ Seana oan iecanle chaw no eep>>n ee eeneal west NMt1 encl)en review>>I Iebnceoan peeaoaee (MPM>>trot)

~ eee apeeewa inace>>ance wnh Erat SWR weiee eheneeoy Sveaeoe>>e

- NSC~NMPIT~SP>>u>>

o ~~wertat Swaeonee Cack op eence Oeeeoiey ie eethney laos then 2) O>> /ee >>lace eprt>>eau Oe enon>>eel enety>>e NMtl one)ye>> ehawe eoeee oeeew e/ ena eeeee

>>eleve enn 2S tel /eeCCENE4ISOI at>>1th CENE.S2LSOOASOOQ)

Aveea lees then 5 e IO>>n/ce>>e eetee ee>>ere IIN NMPC Crack Growth Assessment Summary

~

2veL>>ihne based anboch CE PIEDCE enaetet aed O>> BWRVIP IS ranchman

~

EveL>>naca coen)arran V>> Ieceaee which erlea pate>>net creak Sn>>nb re>>

Venial wdd reek)net end lebnaeilan eoeeeee (SWRVIP la, NMPI

~>>eire n)

- NMPIapeeeonachnnineyittenineu)

- Canoekn paemoet INMpl deu end SWR de u)

- M enu)nota i~ms<<i~)

(S i~tedeu.CEdna,SWRvtt.tt)

~

Candeekeev.

- PILOCE P~CCRN<<bd IM2eto in/h

- Ure a( 22 e 1or in/he boo>>de pent>>eed CCR (tace<<ar 2)

/attica oan of22 e I olin/Letvppane ~ cyde Sno>>e Sun 2S enaeohe Sobeunoet meeaae eebu lllI Role ofIrradiation Effects on NMP1 Shroud

~ GE presentation (Dr. R. Horn) 2 2

, 1

4 Illll Effects ofIrradiation an Shroud Cracking tiltComparison ofBoat Sample Data

~ High fluence can contribute to the susceptibility of the material

- Can produce chromium depletion at gram boundaries

- Sensitization can be found outside ofthe weld HAZ

~ Cracking willexhibit additional features:

- Significant grain fallout

- Significant crack branching inhigher fluence regions

~ Irradiation willilso produce significant hardening of the base material

~KFoct Ruenor Craciinn in Non seirsitirsrt Msisrisi Scrifcsnt Gran Fssnra Crack 8rrnrcriiro Siorifcsni srosri ino 8x tty Yss Yes Yes Yes savsrt c3 x tty No No No No Ill Summary

~ 'Ihe NMplshroud boat samples allowed a comparison with the earlier evaluation, performed on a boat sampk from another shroud, irradiated to higher fluence

- Locsticns ofscruiYiration r

- Cracking morphology

~

- Base mucnst chsrscwistics

~ Unit 1 crack evaluation indicates no bradi ation effects

- Limited lcwb ofbise mstcriat hardening

- No significant grain fallout

- No significant crack banching

- Cracking correlated withrcginns of wckt induced rcruittraticn

- Ptucncc wai below kvcliwhere barbsticn cffccu Nc imponani 11N NMP1 Shroud Neutron Transport Analysis

~ MPMTechnologies, Inc.

Presentation (Dr. M.P. Manahan, Sr.)

lilt Analysis ofBoat Sample Dosimetry Data

~ Two boat samples were cut from the shroud at the end of cycle 12

- IDsurface of V9 26.4 inches above midplane (peak IDmeasured fluence = 3.49 x IlPn/cm2)

OD surface of V10 83 inches below midplane (peak OD measured fluence = 1.42 x IlPn/cm2)

~ Dosimetry data taken at three depths within each boat sample Analysis ofBoat Sample Dosimetry Data (continued)

~ Analysis by Framatome in January, 1998 using cycle 7 transport data showed a discrepancy between the Fe and Nidosimeters

~ Analysis of the 210 degree surveillance capsule'osimetgy in May,1998 by MPMusing a mid-cyde 12 transport analysis showed a similar discrepancy

~ In May, 1998 MPMsuggested that a large flux drop through cycle 12 would explain the discrepancy

I!ill Boat Sample Analysis Results Ilail Neutron Flux Calculations

~ Through cycle analysis has resulted in close agreement between Fe and Ni dosimeters

~ Average ratio of the fluxes from Ni to those from Fe are 0.991 with a standard deviation of 3.3%

~ Calculations at the boat sample locations have been shown to be conservative by comparison with the measured fluxes Analyses Include:

~ R-e, R-Z, and R calculations for 5 cyde

'2 representative power profiles (15 transport calculations)

~ Uncertainty Analysis RlE NMP-1 R-8 Geometry IllCalculated Fast Fluence to Welds V9 and V10 at End ofCycle 13 tl OSOEo20 4$0EO20

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

4SOEOSO

$20EO20 y 1$0EOSO oe IOOEOSO OSOEelt OSOEICO

~100 40 0, 20 100 A)NIDNNttoo Ottoftool $040Noo EOttetol)

~ leer Nllee

~ OaON Otfeae VO ol ECC 12

~

v)OOIEOC 12 VtSONtett olel)eel VSO oleaeoel Igg Calculated Fast Fluence to Weld H4at Endo C cle13 Neutron Transport Results for Shroud fields leaattoa

~ OOEe20 2 SOEo20 SOOEOSO e 2$ 0EO20 o

2002o20 1$0EOSO IOOEOSO

~ OOEel ~

OOOEOOO 0

10 20

$0 40 OO et etvltlol Aoo4 14oltool)

~tAletovtteo ~

~ ove t lotto Io

<<ON leaoafeattaa NI N!

N)

II$

NO ~

Nl Vatvlo 10 Starter Ooloo rett

~I Not~la

• Io ~ 4 N float t4I

~I ~I 1 ~ ~I

~1 ~ It

~IILI~

~ I~leo

~Il~ ~ 1 loco

~o<4 te ~I%tat II4 I INII I~.$ 1 I~ $ ~

I~.'ll I~.II Ill~

IO Clair IS

~oet rl ~ II lleeoao looser S.lee I ~

't.lee lt I 4al ~

Ieo 1 ~

Skoal ~

$4eal I I )to I ~

S,Ital)

) ~

I~

Cl<N $ $

'eat rl ~ II ftaaae ~

rotter>

I atoll

'I 4el ~

Static I )toll t leall

~ lee) ~

) leal ~

I4olt

~ la I~

Ieev we eave

~

aa aeaeelrevawvaaeettta\\at 4

4

'I

~

~

Qp

~ IM 4

Mlitt

~

I WN Wl Ml tMlth ht

~l

~ h

~ M 4

~t~

~ tl MtM 4

IIJI I 4W 4 tl~

~

~

~

4

~MM4 Illw lh IW MP htttw

~\\

~MMthtl~ 4 Ih lhtl 4oIW 4 W>>t

~MI4IWI

~I 4 44

~Mt

' MII t

~ ll IWI 4

~ I 4 4W IWtMlt

~<<l It

~ II It thhll

~ttt SIN Neutron Transport ResultsforV9/V10 at End ofCycle 13 gag Summary and Conclusions

~ 'Ihrough cycle transport calculations for cycle 12 have brought the Fe and Nidosimeter measured fluxes into agreement

~ 'Ihe calculated fluences at the boat sample locations exceed the measured values by 16% indicating that the calculations at the shroud are conservative

~ The peak fluence to the V9 and V10 remaining ligaments willnot exceed 5.0 x 1(Pn/cd at 14~

EFPH past the end of Cycle 12 NSl Supplemental Structural Margin Analysis

~ The follow up supplemental fracture echanks analysts, demonstrates that the required ASMEcode required margins are maintained, formore than NAOhours, even assuming a CGR of5 x 10s fn/hr

- Analysis consistent with BWRVP41 guidelines

- Credit taken for uncracked locations conrumed by both volumetric inspections (VI)and visual inspections (EVT-1)for V9 and V10

- Credit taken forfar side detectian capability of UTas qualised by BWRVlp43for V4 weld

- V4, V9 and V10limitload evaluations show signLEcant marg m Concluding Remarks

~There is substantial basis for reduced crack growth rate

~Fluence effects are not significant

~Structural analysis demonstrates inspection interval of 14,500 hrs is justified without reducing CGR

~r

~

~

EVALUATED CRACK GEOMETRIES ORIGINAL ANALYSIS SUPPLEMENTAL ANALYSIS 8.97' 6.31'.73'.15'1.88'8.83'

0

~"

1'

~

F III a,

C t'