RS-13-098, Response to Request for Additional Information Related to Request for NRC Approval of Relief Requests for Fifth Inservice Testing Interval

Response to Request for Additional Information Related to Request for NRC Approval of Relief Requests for Fifth Inservice Testing Interval

ML13093A177
Person / Time
Site:	Dresden
Issue date:	04/01/2013
From:	Simpson P Exelon Generation Co
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
RS-13-098, TAC ME9871, TAC ME9872
Download: ML13093A177 (6)

Text

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RS-1 3-098 RS-13-098 10 CFR 10 CFR 50.55a 50.55a April 1, April 1, 2013 2013 ATTN:

A Document Control TIN: Document Control Desk Desk U. S. Nuclear Regulatory Commission U. S. Nuclear Regulatory Commission Washington,DC Washington, DC 20555-0001 20555-0001 Dresden Nuclear Dresden Nuclear Power Power Station, Station, Units Units 22 and and 3 3 Renewed Facility Operating License Nos.

Renewed Facility Operating License Nos. DPR-19 and DPR-19 and DPR-25 DPR-25 NRC Docket Nos. 50 -237 and NRC Docket Nos. 50-237 and 50-249 50-249

Subject:

Response to Response to Request Request forfor Additional Additional Information InformationRelated Related toto Request Request for for NRC NRC Approval of Relief Requests Approval of Relief Requests for Fifth Fifth Inservice Testing Interval Testing Interval (TAC Nos.

(TAC ME9871 and Nos. ME9871 and ME9872)

ME9872)

Reference:

Letter fromP.

Letter from P. R.

R. Simpson Simpson (Exelon Generation Generation Company, Company, LLC) to U. u. S. NRC, NRC, "Submittal "Submittal ofofRelief ReliefRequests Requests Associated Associatedwith with the the Fifth Fifth Inservice Inservice Testing Testing Interval,"dated Interval," datedOctober October 30,2012 30, 2012 In the referenced In the referenced letter, letter, Exelon Exelon Generation Generation Company, Company, LLC LLC (EGC)

(EGC) requested requested approval approval of of relief relief requests associated with the upcoming requests associated with the upcoming Fifth IST Interval at Dresden Fifth 1ST Dresden Nuclear Nuclear Power Power Station, Station, Units Units 2 2 and and 3.

3.

During During the NRC's review of the the referenced referenceddocument, document,the theNRC NRCfoundfoundthat thatadditional additionalinformation information was required to was required supportsupport its review. The The requested information is provided in the requested information is provided in the attachment attachmentto to this this letter.

letter.

There There areare no no regulatory regulatory commitments commitments contained contained within this letter.

within this letter. Should Should you you have haveanyany questions questionsconcerning concerningthis thisletter, letter,or orrequire require additional additional information, please contact information, please contact Mitchel Mathews at Mitchel Mathews at (630)

(630) 657-2819.

657-2819.

Patrick Patrick R.R. Simpson Simpson Manager Manager -- - Licensing Licensing Exelon Generation Exelon Generation Company, Company, LLC LLC

Attachment:

Response

Response totoNRC NRC Request Request forfor Additional AdditionalInformation Information

Attachment Response to NRC Request Request forfor Additional Additional Information Information Page 11 of Page of 5 RAI-RV-23H-1:

RAI-RV-23H-1 :

In Relief Relief Request Request RV-23H, RV-23H, Section Section3,3, "Applicable "ApplicableCode CodeRequirements, Requirements," notes U notesthat thatrelief reliefisis requested from the requirements of of the the American American Society Societyof ofMechanical MechanicalEngineers Engineers (ASME),

(ASME),

Code of Operation and and Maintenance Maintenance of of Nuclear Nuclear Power PowerPlants Plants (OM(OM Code),

Code), Paragraphs Paragraphs ISTC-3300, ISTC-3310, ISTC-3310, ISTC-5151 (a), (a), (b),

(b), and (c),

(c), and ISTC*5152.

ISTC-5152. The The ASME ASME OM OM Code also provides provides inservice inservice testing testing requirements requirements for for solenoid-operated solenoid-operatedvalves valves inin ISTC ISTC5151(d) 5151(d) andand ISTC-5153. Confirm that no relief is needed from ISTC-5151(d)

ISTC-5153. Confirm that no relief is needed from ISTC-5151(d) and ISTC-5153. and ISTC-5153.

Company. LLC (EGC)

Exelon Generation Company, IEGC) Response:

As stated in in proposed proposed Relief Relief Request RequestRV-23H, RV-23H, the the affected affected high high pressure pressurecoolant coolant injection (HPCI) injection (HPCI)system system solenoid solenoid operated valves valves 2(3)-2301-32 2(3)-2301-32 are are not notequipped equippedwith with position position indicators and the valves are completely enclosed; therefore, valve position the valves are completely enclosed; therefore, valve position cannot be verified cannot be verified by direct observation.

While valve While valve operation operation cannot be be assessed assessedduring duringthethequarterly quarterlyexercise, exercise,EGC EGCwillwillcomply complywith with the requirements requirementsof ofISTC-5151(d)

ISTC-5151 (d) during during thethefunctional functional testing testingduring duringrefueling.

refueling.

ISTC-5153, EGC With regards to ISTC-5153, EGCisisonlyonlyrequesting requestingrelief relieffrom fromthethestroke stroketiming timingrequirements requirementsinin ISTC-5153(b).

ISTC-5153(b). AllAll other ISTC-5153 requirements ISTC-5153 requirements will be met for the fifth IST interval 1ST interval atat DNPS.

Attachment Response to NRC Request for Additional Information Information Page Page 22 ofof 5 RAI-RV-23H-2:

The Section 4.0, "Reason for for Request, second paragraph states that, Request, " second that, "Compliance "Compliance with withthe the quarterly exercising and stroke timing requirements of of the Code Code would would require require either eithersystem system modifications to replace these valves with ones of of testable testable design, design, or ortoto purchase purchase non-intrusive non-intrusive test equipment and and develop develop newnew test methods methods andand procedures."

procedures." Please Please explain explain why why modifying modifying the system by replacing these valves with a testable design or or purchasing purchasing non-intrusive non-intrusive testtest equipment is not feasible (i.e., cost, planning or new method new method and and procedure).

EGC Response:

The Dresden Nuclear Nuclear Power Station8tation (DNPS),

(DNP8), Units 2 and 3 design design does doesnot notinclude includeremote remotelight light indicationfor indication forthe the2(3)-2301-32-80 2(3)-2301-32-SOvalves. valves.These These valves valves areare completely completely enclosed enclosed such that the valve position valve position cannot cannot be verified verified by bydirect directobservation.

observation. Due to the absence absenceof ofaavisible visible valve valve stem and light and light indication, "switch to light" stroke timing cannot "switch to light" stroke timing cannot be be performed. In In addition, there addition, there are no known reliable non-intrusive test test methods methods forfor measuring measuring strokestroketimes timesfor forthis this valve valve configuration.

In order In order to to perform performstroke stroketiming timingofofthese thesevalves, valves,aadesign design change change would would have to be implemented. The Themodification modification would include:

include: (1)

(1) changing changing the valve design design toto include include position position limit switches, (2) routing light indication cabling from the limit switches, (2) routing light indication cabling from the plant to the plant to the control room, and (3) and (3) installing position installing position indication indicationlights lightsininthe themain maincontrol controlroomroompanels.

panels. ItIt is is estimated estimated that this modificationwould modification wouldcost costininexcess excess ofof $300,000

$300,000 per unit.

unit. This This remote remotevalvevalve indication indication would would bebe installed solely for installed for meeting meeting the American Society 80ciety of Mechanical EngineersEngineers(ASME)(A8ME) Operation Operation and Maintenance (OM) Code requirements and would serve no (OM) Code no other other operational operational purpose.

purpose.

A semi-annual A semi-annual exercise of the the 2(3)-2301-32-80 2(3)-2301-32-SO valvesvalves is is currently currently performed performed and and its its associated associated level switches operate operate as proven by the receipt of the IIHPCI TURBINE EXH DRAIN POTHIGH as proven by the receipt of the "HPCI TURBINE EXH DRAIN POT HIGH LEVEL"alarm LEVEL" alarm(Le.,

(i.e.,water waterlevel levelincrease) increase)and andreset reset(Le.,

(i.e.,water waterlevel leveldecrease decrease due due to the open exercise of valves 2(3)-2301-32-80).

2(3)-2301-32-SO). During this same During this same evolution, evolution, the valve solenoid is also verifiedactuated verified actuated (Le.,

(i.e., valve valve solenoid solenoid isis magnetized) magnetized) by by use use of aa small metal object.

object. This This testing testing approach provides reasonable reasonable assurance assurancethat thatthe thevalves valvesfunction function as asrequired.

required.

Attachment Response to NRC Request Request for Additional Information Information Page 33 of Page of 5 RAI-RV-23H-3:

Section 5.0, "Proposed "Proposed Alternative Alternativeand andBasisBasisforforUse, Use," " does does not not provide provide anyanyoperational operationalhistoryhistory (i.e., maintenance and and reliability reliability data) data) or or note note any any failures failures of of solenoid-operated solenoid-operated valves valves 2 2301-032 and and 3-2301-032. Please Pleaseprovide providedetails detailsof ofthe the operational operational history historyandand information information regarding any failures of of these valves for each unit. unit. Also, Also, describe describe how how often often thethe internals internals forfor these valves have been replaced or or repaired repaired and and note note anyany defects defects identified identified during during maintenance activities, maintenance activities, during during the the fourth fourthten-year ten-yearinservice inservicetestingtesting(1ST)

(1ST) interval intervalat at Dresden 2 and and 3. 3.

EGC Response:

A review of A review ofthethe work workandand Inservice Inservice Testing Testing history history of ofthese these valves did did not identify identify any any cases cases of of these valves these valves failing failing to stroke open since since they they were were added addedto tothe theIST 1STProgram Programscopescopeinin November 1994. EGC EGC hashasaapreventive preventivemaintenance maintenanceactivity activity to replace these these DNPS DNPS valves valves once every every six years. The Thevalve valveinternals internalswere werenot notrepaired repairedororreplaced replacedduring duringthe thefourth fourthten-ten-year interval. This This activity activity was last performed on March 11, 2013, on Unit 2, 2, and on December 8, 2007, on Unit 3.

8,2007, 3. No No defects defects were were noted.

noted.

RAI-RV-23H-4:

The Section 5.0, The 5.0, second paragraph, under under "Basis "Basis for Use,"

Use, " states, in part, that, "failure"failure of of these these valves to perform their safety safety function wouldwould be indicated indicated by by the the drain drain pot pot high level level alarm alarm operation with low pressure steam." (1) (1) Please Please provide provide details details of of any any consequences consequences of of failures of the 2(3)-2301-032 valves during normal of normal and and emergency emergency operations, operations, and and (2)

(2) explain explain whatwhat actions and/or and/or procedures procedures are used used ifif these these valves valves failfail to to perform perform their their safety safety function.

function.

EGC Response:

Ifthe If the HPCI HPCI DrainDrain Pot Pot Steam Steam Trap (i.e.,

(Le., 2(3) 2301-2) fails, then the the HPCI HPCI drain pot pot bypass bypassvalvevalve (i.e., 2(3)

(Le., 2(3) 2301-32) would would receive receive a signal to open open to to drain drain condensation condensationto tothe theunit's unit'sgland gland steam condenser.

condenser.IfIfboth both2301-2 2301-2and and2301-32 2301-32fail fail to to open, open, thenthen the the exhaust exhaustdrain drain pot pot could could begin to fill, resultingininan fill, resulting anexhaust exhaust diaphragm rupture and turbine blade blade and and exhaust exhaustline linecheck check valve damage.

valve Operator actions Operator actions are arecurrently currentlyin in place placeininaccordance accordancewith withDNPS DNPSProcedure ProcedureDAN DAN902(3)-3 902(3)-3C-11C-11 trip the to trip the HPCI turbine ififthis HPCI turbine thisoccurs occurs while whilethe the HPCI HPCIsystemsystem isis being being tested.

tested. IfIf an alarm alarm isis received during the the emergency use use ofof HPCI HPCI system, then then manual manual traptrap bypass bypassvalvevalve 2(3) 2301-50 is opened to to drain drain to the unit's unit's torus, andand prevent prevent HPCI HPCI system system damage.

damage.

Attachment Response to NRC Request for Additional Information Information Page Page 44 of of 55 RAI-RV-23H-5:

RAI-RV-23H-S:

The Section 5.0, thirdthird paragraph, under under "Basis for Use, If" states states that, that, "Following discussions discussions with with the manufacturer manufacturer regarding valve design and and application, itit was was decided decided to to disassemble, disassemble, examine and repair or replace replace these these valves valves every third third operating operating cycle.

cycle."/J Please Please provide provide (1) (1) the the basis for this activity activity to to be performed performed everyevery third third operating operating cycle,cycle, and and (2)

(2) the the criteria criteria for for selecting between repair repair and/or and/or replacement replacement of of the the valve valve during during this this activity.

activity.

EGC Response:

Response

EGC has elected elected to to replace replace the theDNPS DNPSvalvevalve 2(3)-2301-32 2(3)~2301 ~32 on on aasix six year yearinterval, interval, due dueto to cost cost saving and dose concerns. The Thesix-year six~year replacement replacement schedule schedule has hasproven proven to to bebe adequate adequatefor for this valve and its application application based on on the the history history discussed discussedininthe theresponse responsetotoRAI-RV-23H-3 RAI~RV-23H-3 above. The Thecriteria criteria for for selecting between repair repair and/or replacement replacement of of the valve are based basedon on performance, cost of repair repair versus versus replacement and dose doseconcerns.

concerns.

RAI-RV-02C-1 RAI-RV-02C-1 Will the alternative to ASME ASME OM OM Code Code Mandatory MandatoryAppendix Appendix1,I, Section Section 1-1320, proposed by 1-1320, proposed by Relief Relief Request Request RV-02C for testing of of the Dresden Dresden UnitsUnits 22 && 33 Main Main Steam Steam Safety Safety Valves (MSSVs) fully meet meet all requirements of ASME OM Code Case OMN-17? For Forinstance, instance, the referenced letter mentions compliance with OMN-17 paragraphs (a), (b),

OMN-17 paragraphs (a), (b), and (d) but and (d) but contains contains no no information information regarding regarding compliance compliancewith withparagraphs paragraphs(c) (c)and and(e).(e).

EGC Response:

Response

Paragraph (c) of of Code Code Case Case OMN-17 OMN-17 states:

states:

(c) Requirements Requirements for for Testing Testing Additional AdditionalValves.

Valves. Additional valves valves shall shall bebe tested tested in in accordance accordance with with thethe following following requirements.

requirements.

(1) For each each valve valve tested tested for for which the as-found set-pressure set-pressure(first (first test testactuation) actuation) exceeds exceedsthe thegreater greaterofofeither eitherthetheplus/minus plus/minustolerance tolerancelimitlimitofofthe theOwner Owner--

established established set-pressure set-pressureacceptance acceptancecriteria criteriaoror+/-3%+/-SOloof of valve valve nameplate nameplateset- set-pressure, two additional pressure, two additional valves shall be tested from the same be tested from the same valve group.valve group.

(2) If the as-found set-pressure If the set-pressure of ofany anyof of the theadditional additional valves valves tested testedinin accordance accordancewith with subpara.

subpara. (c)(1)

(c)(1) exceeds exceedsthe thecriteria criterianoted notedtherein, therein,thenthenallall remaining valves of that that same valve group shall be be tested.

tested.

(3) The The OwnerOwner shall evaluate the cause causeand andeffect effectononsystem systemcapability capability of of valves valves that fail to comply with the set-pressure acceptance criteria fail to comply with the set-pressure acceptance criteria established in established in subpara. (c)(1),(c)(1), oror the acceptance acceptancecriteria criteria for for other required required teststests (e.g.,

(e.g.,

acceptance acceptanceofofauxiliaryauxiliary actuating devices, devices,compliance compliancewith with Owner's Owner's seat seat tightness tightnesscriteria).

criteria). Based Based upon upon this this evaluation, to address any generic concerns, concerns,

Attachment Response to NRC Request for Additional Information Information Page 55 of Page of 5 the Owner shall determine determine the the need needforfortesting testingininaddition addition toto the theminimum minimum tests tests specified.

EGC will comply with will comply with paragraph paragraph (c)

(c) of of Code CodeCaseCaseOMN-17 OMN-17during duringthethefifth fifthIST 1STinterval.

interval.

Paragraph (e) of Code Case OMN-17 states:

(e) Disassembly and and Inspection.

Inspection. Each valve valve shall shall have have been been disassembled and inspected in in accordance accordance with with subpara.

subpara. (d)(d) above aboveprior prior to to the the start start of of the the 72-mo 72-mo test test interval. Disassembly and and inspection inspection performed performed prior prior to to the the implementation implementation of of this Code Code Case may be used.

EGC removes a partial EGC partial complement of the DNPS MSSVs each refueling refueling outage and ships ships them them to an ASME ASME OM Code-certified vendor to perform as-found testing prior OM Code-certified prior to resumption of of electric electric power generation. The Thevendor vendoralso alsoperforms performsthe theinspection, inspection,refurbishment, refurbishment,and andas-left as-lefttesting testing that meet meet the the maintenance maintenancerequirements requirementsspecified specifiedininsubparagraph subparagraph(d) (d)ofofOMN-17.

OMN-17. All All MSSVs MSSVs for each for each unit are refurbished unit are refurbished ininthis thismanner mannerevery every72 72months.

months. For For these these reasons, the proposed proposed alternative complies withwith paragraph paragraph (e)(e)of of Code CodeCase CaseOMN-1 OMN-17. 7.