ML13015A004

San Onofre, Unit 2, Response to Request for Additional Information (RAI 16), Regarding Confirmatory Action Letter Response (TAC No. Me 9727)

ML13015A004
Person / Time
Site:	San Onofre
Issue date:	01/10/2013
From:	St-Onge R J Southern California Edison Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
TAC ME9727
Download: ML13015A004 (5)

Text

JSOUTHERN CALIFORNIAEDISONAn EDISON INTERNATIONAL CompanyRichard 1. St. OngeDirector, Nuclear Regulatory Affairs andEmergency PlanningJanuary 10, 201310 CFR 50.4U.S. Nuclear Regulatory CommissionATTN: Document Control DeskWashington, DC 20555-0001Subject:Docket No. 50-361Response to Request for Additional Information (RAI 16)Regarding Confirmatory Action Letter Response(TAC No. ME 9727)San Onofre Nuclear Generating Station, Unit 2References:1. Letter from Mr. Elmo E. Collins (USNRC) to Mr. Peter T. Dietrich (SCE), datedMarch 27, 2012, Confirmatory Action Letter 4-12-001, San Onofre NuclearGenerating Station, Units 2 and 3, Commitments to Address Steam GeneratorTube Degradation2. Letter from Mr. Peter T. Dietrich (SCE) to Mr. Elmo E. Collins (USNRC), datedOctober 3, 2012, Confirmatory Action Letter -Actions to Address SteamGenerator Tube Degradation, San Onofre Nuclear Generating Station, Unit 23. Letter from Mr. James R. Hall (USNRC) to Mr. Peter T. Dietrich (SCE), datedDecember 26, 2012, Request for Additional Information Regarding Responseto Confirmatory Action Letter, San Onofre Nuclear Generating Station, Unit 2Dear Sir or Madam,On March 27, 2012, the Nuclear Regulatory Commission (NRC) issued a Confirmatory ActionLetter (CAL) (Reference 1) to Southern California Edison (SCE) describing actions that the NRCand SCE agreed would be completed to address issues identified in the steam generator tubesof San Onofre Nuclear Generating Station (SONGS) Units 2 and 3. In a letter to the NRC datedOctober 3, 2012 (Reference 2), SCE reported completion of the Unit 2 CAL actions andincluded a Return to Service Report (RTSR) that provided details of their completion.By letter dated December 26, 2012 (Reference 3), the NRC issued Requests for AdditionalInformation (RAIs) regarding the CAL response. Enclosure 1 of this letter provides theresponse to RAI 16.P.O. Box 128San Clemente, CA 92672 Document Control Desk-2-January 10, 2013There are no new regulatory commitments contained in this letter. If you have any questions orrequire additional information, please call me at (949) 368-6240.Sincerely,Enclosures:1. Response to RAI 16cc:E. E. Collins, Regional Administrator, NRC Region IVR. Hall, NRC Project Manager, San Onofre Units 2 and 3G. G. Warnick, NRC Senior Resident Inspector, San Onofre Units 2 and 3R. E. Lantz, Branch Chief, Division of Reactor Projects, NRC Region IV ENCLOSURE ISOUTHERN CALIFORNIA EDISONRESPONSE TO REQUEST FOR ADDITIONAL INFORMATIONREGARDING RESPONSE TO CONFIRMATORY ACTION LETTERDOCKET NO. 50-361TAC NO. ME 9727Response to RAI 16Page 1 RAI 16Reference 1, Section 9.3, page 50 -Provide additional information concerning the "OperationalDecision Making" process and describe how it would be applied if the proposed criterion isexceeded. Provide the procedural action statement.RESPONSEReference 1, Section 9.3 states: "The plant procedure for chemical control of primary plant andrelated systems has been modified to require action if the specific activity of the reactor coolantDose Equivalent Iodine (DE 1-131) exceeds the normal range of 0.5 pCi/gm, which is one-half ofthe TS Limit of 1.0 pCi/gm. In the event that the normal range is exceeded, Operations isrequired to initiate the Operational Decision Making process to evaluate continued plantoperation."Operational Decision Making ProcessThe San Onofre Nuclear Generating Station (SONGS) Operational Decision Making (ODM)process is based on the Institute of Nuclear Power Operations (INPO) 2011 document,"Principles for Effective ODM," which was developed by an industry task force with assistancefrom INPO and U.S nuclear utility managers and executives.SONGS ODM procedure provides the Operations Shift Manager (SM) and station leadership aframework for making decisions in response to degraded conditions to address long termprotection of the public, plant personnel and station assets. Two scenarios are addressed bythe ODM process: Type 1 off-normal conditions and Type 2 degraded conditions that fall belowthe action thresholds defined in license documents or may not be defined in existingprocedures.The ODM process provides checklists with specified considerations the SM uses to ensure athorough review of the degraded condition is performed and documented. A list of stakeholdersis included to facilitate involvement of required subject matter experts and personnel. Thepurpose of these lists is to provide an established format to address trends, assessments, risks,plant conditions, regulatory commitments, and impacts of the degraded condition to ensure thehealth and safety of the public. The ODM process results in operational decisions,implementation plans and thresholds to trigger actions.Establishment of Administrative Limit for RCS DE 1-131 Activity LevelChemistry procedure, "Units 2/3 Chemical Control of Primary Plant and Related Systems," hasbeen revised to lower the Reactor Coolant System (RCS) DE 1-131 limit from 1.0 pCi/gm to0.5 pCi/gm. The Technical Specification (TS) limit for DE 1-131 is 1.0 pCi/gm. As a defense indepth action included in the Unit 2 return to service plan, if DE 1-131 exceeds the Normal RangeLimit of 0.5 pCi/gm, Chemistry personnel will perform sampling for DE 1-131 once every fourhours until the level is less than 0.5 pCi/gm. In addition, Chemistry personnel are directed tonotify the on-shift Operators to initiate a Type 1 0DM evaluation to determine other appropriateactions to be taken. For this off-normal condition, the ODM will be performed to determine theimpact of the increasing levels of DE 1-131 and involve senior station management in evaluatingcontinued plant operation. If DE 1-131 exceeds 0.5 pCi/gm for greater than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, a plantshutdown to Mode 3 will commence with Tavg less than 500°F within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> (as required byTSs when DE 1-131 exceeds 1.0 pCi/gm). The procedural actions, frequency, and range areshown in the table below.Page 2 Using the ODM process, the SM obtains data from (1) Chemistry Department representativesas to the nature of the increasing DE 1-131, (2) Nuclear Fuels group concerning the condition ofthe nuclear fuel pins that would be the source of the increased activity, and (3) engineeringpersonnel regarding the condition of the steam generators. Based on the input from thestakeholders, the SM confers with Station Management to decide future actions, including apotential plant shutdown prior to being procedurally required.Chemistry Procedure RCS Activity Level Action StatementParameter Frequency Normal Comments/Corrective ActionRangeITS SR 3.4.16.2Mode 1 requirement for non-transient sample is onceWeekly per 14 days.TS 3.4.16VERIFY within 2 to 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> following a thermal powerchange -15% of the rated power within a one-hourperiod.IF DE 1-131 EXCEEDS the Normal Range (< 0.5DE 1-131, pCi/gm), THEN send a Memo to Operations requestingDE 1-11, < a Type 1 0DM be performed to continue plantpCi/gm -0.5 operation considering Steam Generator health."TS 3.4.16 pCi/gmIF DE 1-131 EXCEEDS the Normal Range Limit (5 0.5SR 3.4.16.2 With >15% pCi/gm ), THEN SAMPLE and analyze the RCS everypower four hours until < 0.5 pCi/gmchange/hourNOTE: Actual Tech Spec Limit is > 1.0 pCi/gm,however, TS required Actions shall be performed at> 0.5 pCi/gmIF DE 1-131 is > 0.5 pCi/gm for greater than 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />sOR greater than the limits of Figure 3.4.16-1 at anytime, THEN be in Mode 3 with Tavg <5000F within 6hours.Page 3