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{{Adams
#REDIRECT [[RS-13-098, Response to Request for Additional Information Related to Request for NRC Approval of Relief Requests for Fifth Inservice Testing Interval]]
| number = ML13093A177
| issue date = 04/01/2013
| title = Dresden Nuclear Power Station, Units 2 and 3, Response to Request for Additional Information Related to Request for NRC Approval of Relief Requests for Fifth Inservice Testing Interval (TAC Nos. ME9871 and ME9872)
| author name = Simpson P R
| author affiliation = Exelon Generation Co, LLC
| addressee name =
| addressee affiliation = NRC/NRR, NRC/Document Control Desk
| docket = 05000237, 05000249
| license number = DPR-019, DPR-025
| contact person =
| case reference number = RS-13-098, TAC ME9871, TAC ME9872
| document type = Letter
| page count = 6
| project = TAC:ME9871, TAC:ME9872
| stage = RAI
}}
 
=Text=
{{#Wiki_filter:RS-1 3-098April 1, 201310 CFR 50.55aATTN:Document Control DeskU. S. Nuclear Regulatory CommissionWashington, DC 20555-0001Dresden Nuclear Power Station, Units 2 and 3Renewed Facility Operating License Nos. DPR-19 and DPR-25NRC Docket Nos. 50-237 and 50-249Subject:Response to Requestfor AdditionalInformation Related to Request for NRCApproval ofRelief Requestsfor Fifth InserviceTesting Interval(TAC Nos.ME9871 and ME9872)Reference:Letter from P. R. Simpson (Exelon Generation Company,LLC) to U.S. NRC,"Submittal of Relief Requests Associated with the Fifth Inservice TestingInterval," dated October 30, 2012In the referenced letter, Exelon GenerationCompany, LLC (EGC)requested approval of reliefrequests associated with the upcomingFifth IST Intervalat Dresden Nuclear Power Station,Units 2 and 3.During the NRC's review of the referenced document, the NRC found that additional informationwas required to support its review. The requested information is provided in the attachment tothis letter.There are no regulatory commitments contained within this letter. Should you have anyquestions concerning this letter, or require additional information, please contactMitchel Mathews at (630) 657-2819.Patrick R. SimpsonManager -LicensingExelon GenerationCompany, LLCAttachment: Response to NRC Request for Additional Information,. RS-13-098 April 1, 2013 A TIN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555-0001 Dresden Nuclear Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-19 and DPR-25 NRC Docket Nos. 50-237 and 50-249 10 CFR 50.55a Subject: Response to Request for Additional Information Related to Request for NRC Approval of Relief Requests for Fifth Inservice Testing Interval (TAC Nos. ME9871 and ME9872) Reference: Letter from P. R. Simpson (Exelon Generation Company, LLC) to u. S. NRC, "Submittal of Relief Requests Associated with the Fifth Inservice Testing Interval," dated October 30,2012 In the referenced letter, Exelon Generation Company, LLC (EGC) requested approval of relief requests associated with the upcoming Fifth 1ST Interval at Dresden Nuclear Power Station, Units 2 and 3. During the NRC's review of the referenced document, the NRC found that additional information was required to support its review. The requested information is provided in the attachment to this letter. There are no regulatory commitments contained within this letter. Should you have any questions concerning this letter, or require additional information, please contact Mitchel Mathews at (630) 657-2819. Patrick R. Simpson Manager --Licensing Exelon Generation Company, LLC Attachment: Response to NRC Request for Additional Information 
 
==Attachment==
Response to NRC Request for Additional InformationPage 1 of 5RAI-RV-23H-1:In Relief Request RV-23H, Section 3, "Applicable Code Requirements, " notes that relief isrequested from the requirements of the American Society of Mechanical Engineers (ASME),Code of Operation and Maintenance of Nuclear Power Plants (OM Code), ParagraphsISTC-3300, ISTC-3310, ISTC-5151 (a), (b), and (c), and ISTC-5152. The ASME OM Code alsoprovides inservice testing requirements for solenoid-operated valves in ISTC 5151(d) andISTC-5153. Confirm that no relief is needed from ISTC-5151(d) and ISTC-5153.Exelon Generation Company,LLC (EGC)Response:As stated in proposed Relief Request RV-23H, the affected high pressure coolantinjection (HPCI) system solenoid operated valves 2(3)-2301-32 are not equipped with positionindicators and the valves are completely enclosed; therefore, valve position cannot be verifiedby direct observation.While valve operation cannot be assessed during the quarterly exercise, EGC will comply withthe requirements of ISTC-5151(d) during the functional testing during refueling.With regardsto ISTC-5153, EGC is only requesting relief from the stroke timing requirements inISTC-5153(b). All other ISTC-5153 requirements will be metfor the fifth ISTinterval at DNPS.RAI-RV-23H-1 : Attachment Response to NRC Request for Additional Information Page 1 of 5 In Relief Request RV-23H, Section 3, "Applicable Code Requirements, U notes that relief is requested from the requirements of the American Society of Mechanical Engineers (ASME), Code of Operation and Maintenance of Nuclear Power Plants (OM Code), Paragraphs ISTC-3300, ISTC-3310, ISTC-5151 (a), (b), and (c), and ISTC*5152. The ASME OM Code also provides inservice testing requirements for solenoid-operated valves in ISTC 5151(d) and ISTC-5153. Confirm that no relief is needed from ISTC-5151(d) and ISTC-5153. Exelon Generation Company. LLC IEGC) Response: As stated in proposed Relief Request RV-23H, the affected high pressure coolant injection (HPCI) system solenoid operated valves 2(3)-2301-32 are not equipped with position indicators and the valves are completely enclosed; therefore, valve position cannot be verified by direct observation. While valve operation cannot be assessed during the quarterly exercise, EGC will comply with the requirements of ISTC-5151 (d) during the functional testing during refueling. With regards to ISTC-5153, EGC is only requesting relief from the stroke timing requirements in ISTC-5153(b). All other ISTC-5153 requirements will be met for the fifth 1ST interval at DNPS. 
 
==Attachment==
Response to NRC Request for Additional InformationPage 2 of 5RAI-RV-23H-2:The Section 4.0, "Reason for Request, " second paragraph states that, "Compliance with thequarterly exercising and stroke timing requirements of the Code would require either systemmodifications to replace these valves with ones of testable design, or to purchase non-intrusivetest equipment and develop new test methods and procedures." Please explain why modifyingthe system by replacing these valves with a testable design or purchasing non-intrusive test equipment is not feasible (i.e., cost, planning or new method and procedure).EGC Response:The Dresden Nuclear Power Station (DNPS), Units 2 and 3 design does not include remote lightindication for the 2(3)-2301-32-SO valves. These valves are completely enclosed such that thevalve position cannot be verified by direct observation. Due to the absence of a visible valvestem and light indication, "switch to light" stroke timing cannot be performed. In addition, thereare no known reliable non-intrusive test methods for measuring stroke times for this valveconfiguration.In order to perform stroke timing of these valves, a design change would have to beimplemented. The modification would include: (1) changing the valve design to include positionlimit switches, (2) routing light indication cabling from the plant to the control room, and (3)installing position indication lights in the main control room panels. It is estimated that thismodification would cost in excess of $300,000 per unit. This remote valve indication would beinstalled solely for meeting the American Society of Mechanical Engineers (ASME) Operationand Maintenance (OM) Code requirements and would serve no other operational purpose.A semi-annual exercise of the 2(3)-2301-32-SO valves is currently performed and its associatedlevel switches operate as proven by the receipt of the "HPCI TURBINE EXH DRAIN POT HIGHLEVEL" alarm (i.e., water level increase) and reset (i.e., water level decrease due to the openexercise of valves 2(3)-2301-32-SO). During this same evolution, the valve solenoid is alsoverified actuated (i.e., valve solenoid is magnetized) by use of a small metal object. This testingapproach provides reasonable assurance that the valves function as required.RAI-RV-23H-2: Attachment Response to NRC Request for Additional Information Page 2 of 5 The Section 4.0, "Reason for Request, " second paragraph states that, "Compliance with the quarterly exercising and stroke timing requirements of the Code would require either system modifications to replace these valves with ones of testable design, or to purchase non-intrusive test equipment and develop new test methods and procedures." Please explain why modifying the system by replacing these valves with a testable design or purchasing non-intrusive test equipment is not feasible (i.e., cost, planning or new method and procedure). EGC Response: The Dresden Nuclear Power 8tation (DNP8), Units 2 and 3 design does not include remote light indication for the 2(3)-2301-32-80 valves. These valves are completely enclosed such that the valve position cannot be verified by direct observation. Due to the absence of a visible valve stem and light indication, "switch to light" stroke timing cannot be performed. In addition, there are no known reliable non-intrusive test methods for measuring stroke times for this valve configuration. In order to perform stroke timing of these valves, a design change would have to be implemented. The modification would include: (1) changing the valve design to include position limit switches, (2) routing light indication cabling from the plant to the control room, and (3) installing position indication lights in the main control room panels. It is estimated that this modification would cost in excess of $300,000 per unit. This remote valve indication would be installed solely for meeting the American 80ciety of Mechanical Engineers (A8ME) Operation and Maintenance (OM) Code requirements and would serve no other operational purpose. A semi-annual exercise of the 2(3)-2301-32-80 valves is currently performed and its associated level switches operate as proven by the receipt of the IIHPCI TURBINE EXH DRAIN POT HIGH LEVEL" alarm (Le., water level increase) and reset (Le., water level decrease due to the open exercise of valves 2(3)-2301-32-80). During this same evolution, the valve solenoid is also verified actuated (Le., valve solenoid is magnetized) by use of a small metal object. This testing approach provides reasonable assurance that the valves function as required. 
 
==Attachment==
Response to NRC Request for Additional InformationPage 3 of 5RAI-RV-23H-3:Section 5.0, "Proposed Alternative and Basis for Use, " does not provide any operational history(i.e.,maintenance and reliability data) or note any failures of solenoid-operated valves 2-2301-032 and 3-2301-032. Please provide details of the operational history and informationregarding any failures of these valves for each unit. Also, describe how often the internals forthese valves have been replaced or repaired and note any defects identified duringmaintenance activities, during the fourth ten-year inservice testing (1ST) interval atDresden 2 and 3.EGC Response:A review of the work and Inservice Testing history of these valves did not identify any cases ofthese valves failing to stroke open since they were added to the IST Program scope inNovember 1994. EGC has a preventive maintenance activity to replace these DNPS valvesonce every six years. The valve internals were not repaired or replaced during the fourth ten-year interval. This activity was last performed on March 11, 2013, on Unit 2, and on December8, 2007, on Unit 3. No defects were noted.RAI-RV-23H-4:The Section 5.0, second paragraph, under "Basis for Use," states, in part, that, "failure of thesevalves to perform their safety function would be indicated by the drain pot high level alarmoperation with low pressure steam." (1) Please provide details of any consequences of failuresof the 2(3)-2301-032 valves during normal and emergency operations, and (2) explain whatactions and/or procedures are used if these valves fail to perform their safety function.EGC Response:If the HPCI Drain Pot Steam Trap (i.e., 2(3) 2301-2) fails, then the HPCI drain pot bypass valve(i.e., 2(3) 2301-32) would receive a signal to open to drain condensation to the unit's glandsteam condenser. If both 2301-2 and 2301-32 fail to open, then the exhaust drain pot couldbegin to fill, resulting in an exhaust diaphragm rupture and turbine blade and exhaust line checkvalve damage.Operator actions are currently in place in accordance with DNPS Procedure DAN 902(3)-3 C-11to trip the HPCI turbine if this occurs while the HPCI system is being tested. If an alarm isreceived during the emergency use of HPCI system, then manual trap bypass valve2(3) 2301-50 is opened to drain to the unit's torus, and prevent HPCI system damage.RAI-RV-23H-3: Attachment Response to NRC Request for Additional Information Page 3 of 5 Section 5.0, "Proposed Alternative and Basis for Use," does not provide any operational history (i.e., maintenance and reliability data) or note any failures of solenoid-operated valves 2-2301-032 and 3-2301-032. Please provide details of the operational history and information regarding any failures of these valves for each unit. Also, describe how often the internals for these valves have been replaced or repaired and note any defects identified during maintenance activities, during the fourth ten-year inservice testing (1ST) interval at Dresden 2 and 3. EGC Response: A review of the work and Inservice Testing history of these valves did not identify any cases of these valves failing to stroke open since they were added to the 1ST Program scope in November 1994. EGC has a preventive maintenance activity to replace these DNPS valves once every six years. The valve internals were not repaired or replaced during the fourth year interval. This activity was last performed on March 11, 2013, on Unit 2, and on December 8,2007, on Unit 3. No defects were noted. RAI-RV-23H-4: The Section 5.0, second paragraph, under "Basis for Use, " states, in part, that, "failure of these valves to perform their safety function would be indicated by the drain pot high level alarm operation with low pressure steam." (1) Please provide details of any consequences of failures of the 2(3)-2301-032 valves during normal and emergency operations, and (2) explain what actions and/or procedures are used if these valves fail to perform their safety function. EGC Response: If the HPCI Drain Pot Steam Trap (Le., 2(3) 2301-2) fails, then the HPCI drain pot bypass valve (Le., 2(3) 2301-32) would receive a signal to open to drain condensation to the unit's gland steam condenser. If both 2301-2 and 2301-32 fail to open, then the exhaust drain pot could begin to fill, resulting in an exhaust diaphragm rupture and turbine blade and exhaust line check valve damage. Operator actions are currently in place in accordance with DNPS Procedure DAN 902(3)-3 C-11 to trip the HPCI turbine if this occurs while the HPCI system is being tested. If an alarm is received during the emergency use of HPCI system, then manual trap bypass valve 2(3) 2301-50 is opened to drain to the unit's torus, and prevent HPCI system damage. 
 
==Attachment==
Response to NRC Request for Additional InformationPage 4 of 5RAI-RV-23H-5:The Section 5.0, third paragraph, under"Basisfor Use, " states that, "Following discussions withthe manufacturer regarding valve design and application, it was decided to disassemble,examine and repair or replace these valves every third operating cycle." Please provide (1) thebasis for this activity to be performed every third operating cycle, and (2) the criteria forselecting between repair and/or replacement of the valve during this activity.EGC Response:EGC has elected to replace the DNPS valve 2(3)-2301-32 on a six year interval, due to costsaving and dose concerns. The six-year replacement schedule has proven to be adequate forthis valve and its application based on the history discussed in the response to RAI-RV-23H-3above. The criteria for selecting between repair and/or replacement of the valve are based onperformance, cost of repair versus replacement and dose concerns.RAI-RV-02C-1Will the alternative to ASME OM Code Mandatory Appendix 1, Section 1-1320, proposed byRelief Request RV-02C for testing of the Dresden Units 2 & 3 Main Steam SafetyValves(MSSVs)fully meet all requirements of ASME OM Code Case OMN-17? For instance,the referenced letter mentions compliance with OMN-17 paragraphs (a), (b), and (d) butcontains no information regarding compliance with paragraphs (c) and (e).EGC Response:Paragraph (c) of Code Case OMN-17 states:(c) Requirements for Testing Additional Valves.Additional valves shall be tested inaccordance with the following requirements.(1)For each valve tested for which the as-found set-pressure (first test actuation)exceeds the greater of either the plus/minus tolerance limit of the Owner-established set-pressure acceptance criteria or +/-3% of valve nameplate set-pressure, two additional valves shall be tested from the same valve group.(2)If the as-found set-pressure of any of the additional valves tested inaccordance with subpara. (c)(1) exceeds the criteria noted therein, then allremaining valves of that same valve group shall be tested.(3)The Ownershall evaluate the cause and effect on system capability of valvesthat fail to comply with the set-pressure acceptance criteria established insubpara. (c)(1), or the acceptance criteria for other required tests (e.g.,acceptance of auxiliary actuating devices, compliance with Owner's seattightness criteria).Based upon this evaluation, to address any generic concerns,Attachment Response to NRC Request for Additional Information Page 4 of 5 RAI-RV-23H-S: The Section 5.0, third paragraph, under "Basis for Use, If states that, "Following discussions with the manufacturer regarding valve design and application, it was decided to disassemble, examine and repair or replace these valves every third operating cycle. /J Please provide (1) the basis for this activity to be performed every third operating cycle, and (2) the criteria for selecting between repair and/or replacement of the valve during this activity. EGC Response: EGC has elected to replace the DNPS valve on a six year interval, due to cost saving and dose concerns. The replacement schedule has proven to be adequate for this valve and its application based on the history discussed in the response to above. The criteria for selecting between repair and/or replacement of the valve are based on performance, cost of repair versus replacement and dose concerns. RAI-RV-02C-1 Will the alternative to ASME OM Code Mandatory Appendix I, Section 1-1320, proposed by Relief Request RV-02C for testing of the Dresden Units 2 & 3 Main Steam Safety Valves (MSSVs) fully meet all requirements of ASME OM Code Case OMN-17? For instance, the referenced letter mentions compliance with OMN-17 paragraphs (a), (b), and (d) but contains no information regarding compliance with paragraphs (c) and (e). EGC Response: Paragraph (c) of Code Case OMN-17 states: (c) Requirements for Testing Additional Valves. Additional valves shall be tested in accordance with the following requirements. (1) For each valve tested for which the as-found set-pressure (first test actuation) exceeds the greater of either the plus/minus tolerance limit of the established set-pressure acceptance criteria or +/-SOlo of valve nameplate pressure, two additional valves shall be tested from the same valve group. (2) If the as-found set-pressure of any of the additional valves tested in accordance with subpara. (c)(1) exceeds the criteria noted therein, then all remaining valves of that same valve group shall be tested. (3) The Owner shall evaluate the cause and effect on system capability of valves that fail to comply with the set-pressure acceptance criteria established in subpara. (c)(1), or the acceptance criteria for other required tests (e.g., acceptance of auxiliary actuating devices, compliance with Owner's seat tightness criteria). Based upon this evaluation, to address any generic concerns, 
 
==Attachment==
Response to NRC Request for Additional InformationPage 5 of 5the Owner shall determine the need for testing in addition to the minimum testsspecified.EGC will comply with paragraph (c) of Code Case OMN-17 during the fifth IST interval.Paragraph (e) of Code Case OMN-17 states:(e) Disassembly and Inspection.Each valve shall have been disassembled andinspected in accordance with subpara. (d) above prior to the start of the 72-mo testinterval.Disassembly and inspection performed prior to the implementation of this CodeCase may be used.EGC removes a partial complement of the DNPS MSSVs each refueling outage and ships themto an ASME OM Code-certified vendor to perform as-found testing prior to resumption of electricpower generation. The vendor also performs the inspection, refurbishment, and as-left testingthat meet the maintenance requirements specified in subparagraph (d) of OMN-17. All MSSVsfor each unit are refurbished in this manner every 72 months. For these reasons, the proposedalternative complies with paragraph (e) of Code Case OMN-1 7.Attachment Response to NRC Request for Additional Information Page 5 of 5 the Owner shall determine the need for testing in addition to the minimum tests specified. EGC will comply with paragraph (c) of Code Case OMN-17 during the fifth 1ST interval. Paragraph (e) of Code Case OMN-17 states: (e) Disassembly and Inspection. Each valve shall have been disassembled and inspected in accordance with subpara. (d) above prior to the start of the 72-mo test interval. Disassembly and inspection performed prior to the implementation of this Code Case may be used. EGC removes a partial complement of the DNPS MSSVs each refueling outage and ships them to an ASME OM Code-certified vendor to perform as-found testing prior to resumption of electric power generation. The vendor also performs the inspection, refurbishment, and as-left testing that meet the maintenance requirements specified in subparagraph (d) of OMN-17. All MSSVs for each unit are refurbished in this manner every 72 months. For these reasons, the proposed alternative complies with paragraph (e) of Code Case OMN-17. 
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