ML16124B162
| ML16124B162 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 05/03/2016 |
| From: | Richard Guzman Plant Licensing Branch 1 |
| To: | Craft W Dominion Nuclear Connecticut |
| Guzman R | |
| References | |
| CAC MF6476 | |
| Download: ML16124B162 (4) | |
Text
1 Guzman, Richard From:
Guzman, Richard Sent:
Tuesday, May 03, 2016 4:28 PM To:
Wanda D Craft (Generation - 6)
Subject:
Re: MPS3 RV Surveillance Capsule Withdrawal Schedule revision
- Wanda,
InresponsetoyourrequestforNRCapprovaloftherevisedcapsulewithdrawalscheduledescribedinyourApril27, 2016,email,theNRCstaffhascompleteditsreviewandhasconcludedthatthereactorvesselmaterialsurveillance capsulewithdrawalscheduleforMIllstonePowerStation,Unit3continuestosatisfytherequirementsofAppendixHto 10CFRPart50andtherecommendationsoftheGALLReportastheyrelatetotheperiodofextended operation.Therefore,theproposedchangeinlocationforthereinstallationofCapsuleYfromthe241°locationtothe 61°locationisacceptable.Asummaryofthestaff'stechnicalevaluationisprovidedbelow.Thisemailofficially transmitsNRCstaffapprovalofthelicensee'sApril27,2016,request.ItwillbeaddedtoADAMSasanofficialagency record.
Pleasecontactmeifyouhaveanyquestions.
RichGuzman Sr.ProjectManager NRR/DORL USNRC 3014151030
SummaryofNRCstaffevaluation
In the NRC letter with enclosed safety evaluation (SE) dated March 15, 2016, the NRC staff approved a revised reactor vessel material surveillance capsule withdrawal schedule for the Millstone Power Station, Unit 3 (MPS3). Capsule Y was withdrawn after 13.8 effective full power years (EFPY) and placed into storage in the spent fuel pool after accruing a neutron fluence of 2.98 x 1019 n/cm2. The withdrawal schedule was changed to allow the reinstallation of standby Capsule Y into the reactor vessel at the 241° location during the Spring 2016 refueling outage. During the MPS3 spring 2016 outage, Dominion Nuclear Connecticut, Inc. (the licensee) notified the NRC staff that the 241° location was obstructed, and therefore, the licensee proposed reinstallation of Capsule Y instead at the 61° location. The 61° and 241° locations have the same lead factor of 3.98. No other changes were proposed to the withdrawal schedule previously approved in the March 15, 2016, NRC SE.
Appendix H to 10 CFR Part 50 includes the requirement of dosimetry monitoring as part of the reactor vessel material surveillance program. In addition, for the period of extended operation for license renewal, NUREG-1801, "Generic Aging Lessons Learned (GALL) Report," Aging Management Program, XI.M31 Reactor Vessel Surveillance, states that programs without in-vessel capsules use alternative dosimetry to monitor neutron fluence during the period of extended operation, as part of the aging management program for reactor vessel
2 neutron embrittlement. The July 2, 2015, submittal stated, "Concurrent reinsertion of Capsule Y will maintain continuous reactor vessel fluence monitoring as required by 10 CFR 50 Appendix H." Since the lead factors are identical in the 61° and 241° locations, the NRC staff determined that the neutron fluence exposures would be essentially identical at both locations. Based on the information in the References listed below and the staff assessment that Capsule Y will experience sufficiently similar neutron fluence conditions at the 61° and 241° locations, the NRC staff concludes that the reactor vessel material surveillance capsule withdrawal schedule for MPS3 continues to satisfy the requirements of Appendix H to 10 CFR Part 50 and the recommendations of the GALL Report as they relate to the period of extended operation. Therefore, the proposed change in location for the reinstallation of Capsule Y from the 241° location to the 61° location is acceptable.
References:
1.LetterdatedJuly2,2015(ADAMSAccessionNo.ML15194A061),supplementedbyletterdatedJanuary28,2016 (ADAMSAccessionNo.ML16034A215)fromDominionNuclearConnecticut,Inc.
2.SafetyEvaluationdatedMarch15,2016(ADAMSAccessionNo.ML16067A234
3.EmailfromW.CrafttoR.GuzmandatedApril27,2016
From:"WandaDCraft(Generation6)"<wanda.d.craft@dom.com>
Subject:
[External_Sender]MPS3RVSurveillanceCapsuleWithdrawalSchedulerevision Date:27April201616:08 To:"Guzman,Richard"<Richard.Guzman@nrc.gov>
- Rich, InlettersdatedJuly2,2015andJanuary28,2016,DNCrequestedNRCreviewandapprovalofarevisiontothe surveillancecapsulewithdrawalscheduleforMPS3.TheNRCapprovedtherevisedwithdrawalscheduleinaletter datedMarch15,2016.
DNCplannedtoreinstallstandbyCapsuleYintothereactorvesselfromthespentfuelpoolduringthespring2016 refuelingoutage.CapsuleYwasscheduledforreinsertionatthe241°locationbutcouldnotbereinsertedtheredueto theobstructioncausedbytheliftrigfortheupperinternals.Thisobstructionlimitedtraveloftherefuelbridgeand therefore,restrictedaccesstothe241°specimenguides.DNCproposestorevisethecapsulewithdrawalschedulefor reinsertionofCapsuleYatthe61°location,whichhasthesameleadfactorasthe241°location.Nootherchangesare proposedtothewithdrawalschedulepreviouslyapprovedintheMarch15,2016NRCsafetyevaluation.
3
Theproposedrevisiontothereactorvesselsurveillancecapsulewithdrawalscheduleisshownbelow.
Proposedrevisionstothecapsulewithdrawalscheduleareshownwithadditionsinbold,italicizedtextanddeletionsare shownwithstrikethrough.
Proposed Millstone Unit 3 Reactor Vessel Surveillance Capsule Withdrawal Schedule CAPSULE LOCATION LEAD FACTOR(a)
REMOVAL /
INSTALLATION TIME (EFPY)(b)
FLUENCE (n/cm2,E>1.0MeV)(a)
U 58.5° 4.06 1.3 4.00 x 1018(c)
X 238.5° 4.35 8.0 1.98 x 1019(c)
W 121.5° 4.22 13.8 3.16 x 1019(c, d)
Y(e)(f) 241° 3.98 13.8 Footnote (i)
Y(f) 61° 3.98 Footnote (i)
V(e) 61° 3.98 Storage Z(g) 301.5° 4.22 23.4 5.37x 1019(h)
- a. Updated in Capsule W dosimetry analysis.
- b. Effective Full Power Years (EFPY) from plant startup.
- c. Plant specific evaluation.
- d. This fluence is not less than once or greater than twice the peak end of license fluence, and is approximately equal to the peak vessel fluence at 63 EFPY.
- e. Capsules Y and V were withdrawn after 13.8 EFPY (EOC 10) and placed into storage after accruing 2.98 x 1019 n/cm2 fluence.
- f. Capsule Y was reinserted into its original location (24161°) at EOC 17 (approximately 23.4 EFPY).
- g. Capsule Z was withdrawn at 23.4 EFPY (EOC 17) after accruing approximately 5.37 x 1019 n/cm2 fluence. Dosimetry analysis was performed and the test specimens placed into vendor storage for future testing.
- h. This projected fluence is greater than once and less than twice the projected 72 EFPY and 90 EFPY peak vessel fluence.
- i. Capsule Y is installed for fluence monitoring during the operating license in accordance with ASTM E 185-82.
4 Thanksforyourreviewandwearelookingforwardtodiscussingthiswithyouinacalltomorrow.WewillneedNRC approvaloftherevisedcapsulewithdrawalschedulepriortoenteringMode2,whichiscurrentlyexpectedtooccuron May9th.Ifyouhaveanyquestions,pleaseletmeknow.Thanks.
Wanda D. Craft Nuclear Licensing and Operations Support Dominion Resources Services, Inc (804) 273-4687 tie-line 730-4687
CONFIDENTIALITY NOTICE: This electronic message contains information which may be legally confidential and or privileged and does not in any case represent a firm ENERGY COMMODITY bid or offer relating thereto which binds the sender without an additional express written confirmation to that effect. The information is intended solely for the individual or entity named above and access by anyone else is unauthorized. If you are not the intended recipient, any disclosure, copying, distribution, or use of the contents of this information is prohibited and may be unlawful. If you have received this electronic transmission in error, please reply immediately to the sender that you have received the message in error, and delete it. Thank you.