ML15062A042

Seabrook, Response to Requests for Additional Information for the Review of License Renewal Application- Set 23 (TAC No. ME4028) Relating to the Alkali-Silica Reaction (ASR) Monitoring Program

ML15062A042
Person / Time
Site:	Seabrook
Issue date:	02/23/2015
From:	Dean Curtland NextEra Energy Seabrook
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
SBK-L-15024, TAC ME4028
Download: ML15062A042 (6)

Text

NExTeraoENERGY _February 23, 201510 CFR 54SBK-L-15024Docket No. 50-443U. S. Nuclear Regulatory CommissionAttn: Document Control DeskWashington, DC 20555-0001Seabrook StationResponse to Requests for Additional Information for the Review of theSeabrook Station, License Renewal Application- SET 23 (TAC NO. ME4028)Relating to the Alkali-Silica Reaction (ASR) Monitoring ProgramReferences:1. NextEra Energy Seabrook, LLC letter SBK-L-10077, "Seabrook Station Application forRenewed Operating License," May 25, 2010. (Accession Number ML101590099)2. NRC Letter, Requests For Additional Information for the Review of the Seabrook Station,License Renewal Application- Set 23 (TAC NO. ME4028), November 25,2014 (AccessionNumber ML 14301 A316)In Reference 1, NextEra Energy Seabrook, LLC (NextEra) submitted an application for arenewed facility operating license for Seabrook Station Unit 1 in accordance with the Code ofFederal Regulations, Title 10, Parts 50, 51, and 54.Enclosure 1 contains NextEra responses to the information requested in Reference 2 for RAIsB.2.1.31A-2(a) and B.2.1.31A-7. Within these responses, changes to LRA Appendix A-Updated UFSAR Supplement, and Appendix B -Aging Management Programs associated withthe Alkali-Silica Reaction Monitoring Program are provided. The changes are explained, andwhere appropriate to facilitate understanding, portions of the LRA are repeated with the changehighlighted by strikethroughs for deleted text and bolded italics for inserted text. In someinstances the entire text of a section has been replaced or added. In these cases a note is includedin the introduction indicating the replacement of the entire text of the section.As discussed with the staff in a teleconference on January 30, 2015; NextEra will requireadditional time to fully provide the staff with requested information for the remaining RAIs,which is dependent on ongoing ASR testing. NextEra anticipates providing a response to theremaining RAIs no later than June 30, 2015.NextEra Energy Seabrook, LLC, P.O. Box 300, Lafayette Road, Seabrook, NH 03874 U.S. Nuclear Regulatory CommissionSBK-L- 15024 /Page 2This letter contains no new commitments.If there are any questions or additional information is needed, please contact Mr. Edward J.Carley, Engineering Supervisor -License Renewal, at (603) 773-7957.If you have any questions regarding this correspondence, please contact Mr. Michael OssingLicensing Manager, at (603) 773-7512.I declare under penalty of perjury that the foregoing is true and correct.Executed on February 23, 2015erely'/ Ge-an CurtlandSite Vice PresidentNextEra Energy Seabrook, LLCEnclosure 1 -Seabrook Station License Renewal Application, Response to Requests forAdditional Information -Set 23, RAIs Relating to the Alkali-Silica Reaction(ASR) Monitoring Program for the Seabrook Station License RenewalApplicationcc: D. H. DormanJ. G. LambP. C. CataldoR. A. PlasseL. M. JamesNRC Region I AdministratorNRC Project ManagerNRC Senior Resident InspectorNRC Project Manager, License RenewalNRC Project Manager, License RenewalMr. Perry PlummerDirector Homeland Security and Emergency ManagementNew Hampshire Department of SafetyDivision of Homeland Security and Emergency ManagementBureau of Emergency Management33 Hazen DriveConcord, NH 03305Mr. John Giarrusso, Jr., Nuclear Preparedness ManagerThe Commonwealth of MassachusettsEmergency Management Agency400 Worcester RoadFramingham, MA 0 1702-5399 Enclosure 1 to SBK-L- 15024Seabrook Station License Renewal ApplicationRequests for Additional Information -Set 23Response to RAIs Relating to the Alkali-Silica Reaction (ASR) Monitoring Program for theSeabrook Station License Renewal Application U.S. Nuclear Regulatory CommissionSBK-L-15024 /Page 2B.2.1.31A-2(a)BackgroundIn its response to Request for Additional Information (RAI) B.2.1.3 1A-2, part 4, datedMay 15, 2014, regarding criteria by which the frequency of inspection may be changed, theapplicant stated that there are no plans to change the inspection frequency. However, theapplicant also stated that if the "ASR monitoring results" indicate a need to amend theacceptance criteria or frequency of inspection, it will take such action under the "operatingexperience" program element of the Alkali-Silica Reaction (ASR) Monitoring Program.IssueIt is not clear if the "ASR monitoring results" will be used to increase the inspection interval togreater than the 5-year interval specified in American Concrete Institute (ACI) 349.3R.Changing the inspection frequency for either tier two or tier three structures beyond 5 years mayinhibit the applicant's ability to adequately monitor for expansion due to cracking from reactionwith aggregates.RequestState whether the frequencies of inspection, established within the ASR Monitoring Program(Tier 2 and 3), will be allowed to exceed the 5-year interval generally accepted for concreteinspections per ACI 349.3R. If so, provide a justification for how inspection frequencies,exceeding a 5-year interval, will ensure adequate aging-management of ASR-affected structures.NextEra Energy Seabrook Response to RAI B.2.1.31A-2(a)The ASR Monitoring Program augments the Structural Monitoring Program in which theinspection frequencies were established based on the recommended guidelines contained inchapter 6 of ACI 349.3R-96.The frequencies of inspection of Tier 3 and Tier 2 areas currently specified in the ASRMonitoring Program may change based on trending, however the inspection frequencies will notexceed the 5-year frequency specified in the Structures Monitoring Program for HarshEnvironment Areas.Inspection frequencies for Mild Environments are discussed below in response to RAIB.2.1.31A-7RAI B.2.1.31A-7BackgroundLRA Section B.2.1.31 A, dated May 16, 2012, states under the "Monitoring and Trending"program element that "newly discovered areas exhibiting visual signs of ASR are identifiedduring routinely performed Structural Monitoring Program inspections." LRA Section B.2.1.31states that periodic visual inspections are performed at a frequency determined by thecharacteristics of the environment in which the structure is found. LRA Section B.2.1.31 further U.S. Nuclear Regulatory CommissionSBK-L-15024 /Page 3states that for structures in a harsh environment, inspections are performed on a 5 year basiswhereas for structures in a mild environment, inspections are performed on a 10 year basis. Theapplicant's response to RAI B.2.1.31-5, dated February 3, 2011, describes what is defined as aharsh environment and lists the frequency of visual inspections for the structures within thescope of license renewal, based on the structure category defined in ACI-349.3R.IssueASR has been observed throughout the site in concrete structures exposed to variousenvironments. Considering that the ASR Monitoring Program augments the StructuresMonitoring Program and ASME Section XI, Subsection IWL Program, and that "newlydiscovered" areas requiring monitoring for ASR progression will be identified during routineinspections in accordance with these programs, the staff is concerned that the frequency ofinspection for structures in a mild environment, i.e., 10 years, may not identify "newlydiscovered" areas in a manner that would provide for adequate monitoring and trending.RequestThe staff requests that the applicant:1. State whether the ten-year inspection frequency is adequate for identifying new locationsaffected by ASR in structures exposed to a mild environment, and if so, provide the basiswhy the 10-year frequency will provide for adequate monitoring and trending, during theperiod of extended operation.2. If these structures in a mild environment will be monitored at a frequency other than thatoriginally described in the License Renewal Application (LRA), state the new inspectionfrequency and provide the basis for its determination.NextEra Energy Seabrook Response to RAI B.2.1.3 1A-71. Per the Structural Monitoring Program a Harsh Environment is defined as:"...an area subjected to outside ambient conditions, high moisture, wet or humidity, veryhigh ambient temperatures or frequent large cycling of temperatures (includingfreezing/thawing), frequent exposure to caustic materials, or extremely high radiationlevels. "The Structural Monitoring Program defines and classifies a Mild Environment as an area that isnot a Harsh Environment.Based on the definition above ASR is not expected to be discovered in concrete structuresexposed to a Mild Environment as a Mild Environment lacks the sufficient moisture needed toproduce an Alkali-Silica Reaction. Accordingly, the 10-year inspection frequency is appropriate U.S. Nuclear Regulatory CommissionSBK-L-15024 /Page 4for monitoring and trending other concrete degradation mechanisms for structures exposed toMild Environments such as those described in ACI 349.3R-96 and ACI 201.1R-92.2. To date the progression of ASR degradation has not been detected in a concrete structure locatedin a mild environment, therefore, the structures in a Mild Environment will continue to bemonitored on a 10 year frequency as originally described in the LRA.Note: Inspection frequencies increase when a deficiency is found in an area for all Environments(deficiencies include but are not limited to ASR).Based on the above definition of what constitutes a Harsh Environment, LRA Section B.2.1.31(Structures Monitoring Program), has been revised as follows:The Seabrook Station Structures Monitoring Program includes periodic visual inspection ofstructures and structural components for the detection of aging effects specific for that structure.These inspections are completed by qualified individuals at a frequency determined by thecharacteristics of the environment in which the structure is found. A structure found in a harshenvironment is defined as one that is in an area that is routine! subject to outside ambientconditions, very high temperature, high moisture or humidity, frequent large cycling oftemperatures, frequent exposure to caustic materials, or extremely high radiation levels. Forstructures in these harsh environments, the inspection is conducted on a five year basis (plus orminus one year due to outage schedule and two inspections within ten years). Structures notfound in areas qualifying as a harsh environment are classified as being in a mild environment,and are inspected on a ten year basis (plus or minus one year due to outage schedule and twoinspections within twenty years).