ML17080A038
| ML17080A038 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 03/27/2017 |
| From: | James Danna Plant Licensing Branch 1 |
| To: | Nazar M NextEra Energy Seabrook |
| Poole J C, NRR/DORL/LPLI, 415-2048 | |
| References | |
| CAC MF9260 | |
| Download: ML17080A038 (11) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Mr. Mano Nazar President and Chief Nuclear Officer Nuclear Division NextEra Energy Seabrook, LLC 15430 Endeavor Drive Mailstop: NT3/JW Jupiter, FL 33478 March 27, 2017
SUBJECT:
SEABROOK STATION, UNIT NO. 1 -RELIEF FROM THE REQUIREMENTS OF THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS BOILER AND PRESSURE VESSEL CODE (CAC NO. MF9260)
Dear Mr. Nazar:
By letter dated February 6, 2017 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 17038A265), as supplemented by letter dated February 8, 2017 (ADAMS Accession No. ML 17039A925), NextEra Energy Seabrook, LLC (the licensee) submitted Relief Request RA-17-002 to the U.S. Nuclear Regulatory Commission (NRC) for the use of alternatives to certain American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI requirements at Seabrook Station, Unit No. 1 (Seabrook). Pursuant to Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(z)(2), the licensee requested to use an alternative on the basis that complying with the specified requirement would result in hardship or unusual difficulty, without a compensating increase in the level of quality and safety. Specifically, the licensee requested to perform a temporary repair of a leaking service water pipe. On February 8, 2017 (ADAMS Accession No. ML 17040A008), the NRC staff verbally authorized the use of Relief Request RA-17-002 to perform temporary repair of service water piping at Seabrook until either the end of the next refueling outage in Spring 2017, or the flaw progresses outside the encapsulated area such that the pipe wall thickness is below 0.077 inches, whichever occurs first. The NRC staff determined that complying with the ASME Code requirement would result in hardship or unusual difficulty, without a compensating increase in the level of quality and safety. Accordingly, the NRC staff concluded that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(z)(2) and is in compliance with ASME Code requirements. The enclosed safety evaluation documents the technical basis for the NRC staff's verbal authorization. All other ASME Code,Section XI requirements for which relief was not specifically requested and approved remain applicable, including third-party review by the Authorized Nuclear lnservice Inspector.
M. Nazar If you have any questions, please contact the Project Manager, Justin Poole, at 301-415-2048 or by e-mail to Justin.Poole@nrc.gov. Docket No. 50-443
Enclosure:
Safety Evaluation cc w/enclosure: Distribution via Listserv Sincerely, n ,,....---, " 'c i ) ") /\/VvL--,
- L/ C/l.--v1/\..-A../ James G. Danna, Chief Plant Licensing Branch I Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELIEF REQUEST RA-17-002 REGARDING TEMPORARY REPAIR OF SERVICE WATER PIPING NEXTERA ENERGY SEABROOK, LLC, ET AL.* SEABROOK STATION, UNIT NO. 1 DOCKET NO. 50-443
1.0 INTRODUCTION
By letter dated February 6, 2017 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 17038A265), as supplemented by letter dated February 8, 2017 (ADAMS Accession No. ML 17039A925), NextEra Energy Seabrook, LLC (the licensee) requested relief from the requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, IWA-4412, at Seabrook Station, Unit No. 1 (Seabrook). The licensee submitted Relief Request RA-17-002 to the U.S. Nuclear Regulatory Commission (NRC) to perform a temporary repair of a leaking service water pipe. Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(z)(2), the licensee submitted Relief Request RA-17-002 for a temporary repair of leaking service water piping on the basis that complying with the specified ASME Code requirement to repair the degraded piping would result in hardship or unusual difficulty, without a compensating increase in the level of quality and safety. On February 8, 2017 (ADAMS Accession No. ML 17040A008), the NRC staff verbally authorized the use of Relief Request RA-17-002 to perform temporary repair of service water piping at Seabrook until either the end of the next refueling outage (OR18) in Spring 2017 or the flaw progresses outside the encapsulated area such that the pipe wall thickness is below 0.077 inches, whichever occurs first. The NRC staff determined that complying with the ASME Code requirement would result in a hardship or unusual difficulty, without a compensating increase in the level of quality and safety. The NRC staff also determined that the proposed alternative is technically justified and provides reasonable assurance of the structural integrity of the affected piping. Accordingly, the NRC staff concluded that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(z)(2) and is in compliance with the ASME Code requirements. This safety evaluation documents the technical basis for the NRC staff's verbal authorization.
2.0 REGULATORY EVALUATION
The regulation at 10 CFR 50.55a(g)(4) states, in part, that ASME Code Class 1, 2, and 3 components (including supports) shall meet the requirements, except the design and access provisions and the preservice examination requirements, set forth in ASME Code,Section XI, to Enclosure the extent practical, within the limitations of design, geometry, and materials of construction of components. Seabrook is currently in the third 10-year inservice inspection interval and complies with ASME Code,Section XI, 2004 Edition, no addenda. The regulation at 10 CFR 50.55a(z) states, in part, that alternatives to the requirements of 10 CFR 50.55a(g) may be used when authorized by the NRC if the licensee demonstrates that (1) the proposed alternatives would provide an acceptable level of quality and safety or (2) compliance with the specified requirements would result in hardship or unusual difficulty, without a compensating increase in the level of quality and safety. Based on the above, and subject to the following technical evaluation, the NRC staff finds that regulatory authority exists for the licensee to request the use of the alternative and the NRC to authorize the proposed alternative.
3.0 TECHNICAL EVALUATION
3.1 Licensee's Proposed Alternative On January 21, 2016, with the plant in 100 percent power, the licensee observed through-wall leakage from a portion of the service water piping. The affected piping is moderate energy, ASME Code Class 3, service water pipe 1-SW-1827-001-153-24 on the inlet to the "A" primary component cooling water heat exchanger (1-CC-E-17-A). The pipe is 24-inch nominal pipe size (NPS) with a nominal wall thickness of 0.375-inch and is made of SA-106, Grade B, carbon steel. The detected flaw is located in a Belzona-lined spool upstream of the heat exchanger inlet isolation valve SWV-14, adjacent to field weld FW-1827-F0905. Field weld FW-1827-F0905 is in a transition location between cement-lined and Belzona-lined piping, which is covered internally by a WEKO seal. The leak rate at the time was approximately 12 drops per minute. Based on a best effort ultrasonic testing (UT) examination, the licensee initially estimated a wall thinning area of 1. 75 inches axial by 2.5 inches circumferential. Subsequently, the licensee identified the flaw area as being 0.72 inches axial by 0.953 inches circumferential. There was no visual sign of a through-wall hole.Section XI of the ASME Code specifies Code-acceptable repair methods for flaws that exceed Code acceptance limits for piping that is in service. Specifically, IWA-4412 states that defect removal shall be accomplished in accordance with the requirements of IWA-4420. A Code repair is required to restore the structural integrity of flawed ASME Code piping, independent of the operational mode of the plant, when the flaw is detected. The licensee stated that Seabrook Technical Specification (TS) 3/4.7.4, "Service Water System/Ultimate Heat Sink," requires that the service water system be operable with an operable service water pump house and two service water loops with one operable service water pump in each loop. Performing an ASME Code repair at the flaw location during power operation would require that the "A" train of service water system be taken out of service. While the TSs provide 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for repair, doing so would result in the loss of one train of cooling water during the repair timeframe. The licensee stated that the isolation and draining of the "A" train of service water piping during operation is complex and would expend a significant portion of the 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> allowed. The licensee considered that shutting down the plant towards the end of a fuel cycle creates undue and unnecessary stress on plant systems, structures, and components to perform a Code repair versus using the proposed temporary non-Code repair to be a hardship. In lieu of an ASME Code repair and removal of the defect, the licensee proposes a temporary, non-ASME Code repair of installing an encapsulation covering the flaw at the leaking pipe location. The encapsulation consists of a 6-inch NPS weldolet, weld neck flange, and blind flange as depicted in Figure 1 of the application. The technical basis of the temporary repair is as follows. Flaw Sizing and Characterization When the full circumference of the pipe was inspected in accordance with ASME Code Case N-513-3 "Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping,Section XI, Division 1," in addition to the through-wall flaw location, the licensee discovered 14 additional indications. The licensee observed that all 15 indications are essentially aligned in an axial band around the pipe that extends approximately 4.0 to 4.5 inches downstream of the field weld FW-1827-F0905. Of the 14 additional locations, the licensee identified only two locations to have wall thickness below the ASME Code-required minimum thickness. These two areas are not through wall and have remaining wall thickness of 0.089 inches (flaw area 0.47 inches axial by 0.33 inches circumferential) and 0.117 inches (flaw area of 0.118 inches axial by 0.33 inches circumferential), respectively. The licensee stated that the location around the pipe of the single through-wall flaw and the location of the two other non-through-wall flaws do not need to be combined as a single equivalent flaw based upon Code Case N-513-3. The pipe wall surrounding these indications has a minimum wall thickness of 0.328 inches. To disposition the indications, the licensee calculated three minimum pipe wall thickness values based on three different pressures. First, the licensee calculated an ASME Code-required minimum pipe wall of 0.105 inches based upon a system design pressure of 150 pounds per square inch (psi). Second, in accordance with Code Case N-513-3, the licensee calculated a required minimum pipe wall thickness of 0.120 inches based upon a maximum operating pressure of 171 psi. The basis for the 171 psi value is a cooling tower pump operating at shutoff head in response to an emergency or a faulted event. Third, the original analysis assumed the pump shutoff head was 325 feet, which was subsequently reduced to 250 feet, or 107 .2 psi. Neglecting the elevation difference between the pump discharge and the leak location, the maximum pressure the leak would experience in a shutoff condition is 107.2 psi. Using a value of 110 psi, the licensee calculated a required minimum pipe wall of 0.077 inches in accordance with Code Case N-513-3. The licensee stated that based upon the UT examination, the flaw appears to be localized corrosion from seawater, resulting from a loss of the pipe liner. All are characterized as internal diameter initiated, non-planar indications, with three characterized as flaws because they are below the ASME Code-required minimum pipe wall. The licensee stated that the only degraded area with a wall thickness less than 0.077 inches is the leaking through-wall flaw location and is the subject of the proposed repair. Flaw Evaluation The licensee performed a flaw evaluation in accordance with Code Case N-513-3, with the through-wall flaw size assumed to be the bounding area of 1.75 inches by 2.5 inches. The licensee concluded that structural integrity of the affected pipe is maintained. In accordance with Code Case N-513-3, the licensee performed augmented inspections. Considering the discovery of the 15 indications aligned in an axial band adjacent to a field weld with an installed WEKO seal, the augmented sample size will include locations potentially susceptible to the same condition. The licensee stated that the typical corrosion rate used in the Seabrook service water piping evaluations is 30 mils per year (mpy) under system flow conditions. The position of the Type "D" WEKO seal is over the centerline of the field weld FW-1827-F0905. The axial length of the ethylene propylene diene monomer (EPDM) rubber portion of the seal is 11.125 inches. Considering the approximate 4-inch location from the field weld centerline, the UT identified indications reside under the EPDM portion of the seal. This explains the relative consistency of the indications all being 4 inches downstream of the field weld. The licensee stated that considering the 30 mpy wall loss applied over 57 days, the Code Case N-513-3 derived required wall of 0.077 inch will not be challenged at the two non-through-wall locations having thicknesses of 0.089 inches and 0.117 inches, respectively. Likewise, while further degradation will occur within the bounding area, the surrounding area wall will not be violated during the duration of the proposed, temporary non-Code repair. The licensee stated that to provide further assurance, a 6-inch weldolet has been selected for use. The sizing of the weldolet (6-inch nominal) was based upon the identified wall thickness of the piping and its installation position with respect to the bounded flaw size (1.75 inches by 2.5 inches). The weldolet will be welded to piping verified to be of a thickness of 0.328 inch or better. The typical corrosion rate used by Seabrook is 30 mpy. To proactively address the corrosion potential within the bounded area, a factor of 4 is applied, resulting in a rate of 120 mpy. Although the installation duration is less than 1 year, the licensee used 120 mils as the corrosion rate between the date of the flaw discovery to Spring 2017. The resulting pipe wall under the weldolet and weldment on the date of refueling outage OR18 will, therefore, be reduced from 0.328 inches to 0.208 inches (0.328 -0.120 = 0.208). The licensee stated that the predicted future wall thickness of 0.208 inches exceeds the Code-calculated minimum; therefore, structural integrity of the repair will be maintained. The licensee noted that the inside diameter of the weldolet of 6.6875 inches bounds the major axis dimension of the bounding flaw (2.5 inches) and actual measured flaw (0.953 inches) such that further corrosion will not affect the integrity of the repair. Design The design pressure and temperature of the service water piping system is 150 psi and 200 degrees Fahrenheit (°F). Normal operating pressure is 75 psi, and normal operating temperature is 65 °F maximum and 35 °F minimum. The repair components, weldolet, weld neck flange, and blind flange design conform to these temperature and pressure requirements. The existing 24-inch diameter piping is constructed from SA-106 Grade B carbon steel material. The weldolet is constructed from ASME SA-105 material and meets the ASME Code, Section Ill, ND requirement for branch connections. The branch connection will meet the ASME Code, Section Ill, ND requirements for fabrication. The licensee noted that the addition of a weldolet results in the application of a stress intensification factor of 4.05. The licensee stated that application of this factor on the existing pipe stress levels does not impact the piping system qualification, since the resulting stress increases have been reviewed and found to remain within ASME Code, Section Ill. The licensee stated that the weight of the encapsulation components is 80.2 pounds. The pipe support adjacent to the defective area is 1827-SG-03. The licensee has reviewed the pipe support design documentation and has concluded that the existing pipe support scheme can accommodate the weight addition of 80.2 pounds. Installation The pre-installation nondestructive examination (NOE) requirements for the weldolet consist of the verification of ASME material and the verification of proper weld joint fit-up. The licensee stated that it will remove water from the weld area via suction or wiping prior to welding the weldolet to the pipe, as necessary. The licensee will perform welding using a qualified procedure that meets the requirements of the ASME Code,Section IX, "Qualification Standard for Welding and Brazing Procedures, Welders, Brazers, and Welding and Brazing Operators," for an open root, full penetration weld. The licensee stated that impact to the Belzona lining on the inside surface of the subject pipe attributed to the heat from welding the weldolet will be minimal based on past experience at Seabrook. The EPDM rubber material in the WEKO seal has a rated service temperature of 150 degrees Celsius (°C) (302 °F). Because the pipe will be water-filled during installation, minimal damage to the WEKO seal is anticipated. In addition, any lining or seal damage would exist for only 2 months until refueling outage OR18, when the weldolet will be removed, plus any corrosion in this area would be observed by the UT examination. After welding, the licensee will perform a final visual and penetrant testing examination of the final weld. The post-installation NOE requirements consist of a VT-2 for leakage in accordance with ASME Code,Section XI, IWA-5000. The acceptance criteria are in accordance with the original construction code and/or the ASME Code, Section Ill, ND requirements. The NOE methods performed will meet the ASME Code,Section XI, IWA-4500 requirements. Extent of Condition In accordance with Code Case N-513-3, the licensee performed augmented inspections and detected 14 other areas in the vicinity of the leaking pipe location. Post-Repair Monitoring The licensee stated that it will perform (a) periodic UT inspections of no more than 30-day intervals around the installed weldolet to identify wall loss propagating outside the encompassed area, (b) periodic UT inspections of no more than 30-day intervals to identify further wall loss at the two indication areas identified above, and (c) daily walkdown of the repaired area. The licensee stated that the proposed temporary repair will remain in place until the next refueling outage (OR 18) and that the relief request will expire at the end of the refueling outage scheduled for Spring 2017. The licensee further stated that should the ongoing non-destructive examinations identify that the flaw progresses outside the encapsulated area to the point that the Code minimum thickness of 0.077 inches is challenged, the relief request would expire and the impact on system operability will be assessed. 3.2 NRC Staff Evaluation The NRC staff evaluated the proposed alternative based on the applicable provisions of ASME Code Case N-513-3 and the 2004 Edition of ASME Code,Section XI, as follows.
Flaw Sizing and Characterization The NRC staff finds that the licensee has used encoded UT to measure the wall thickness of the affected area of the subject pipe. Based on information provided, the NRC staff acknowledges that the degradation is a non-planar through-wall flaw, not a crack, and that the degradation mechanism of the defect is localized corrosion caused by seawater. The NRC staff finds that the licensee has satisfied the flaw sizing and characterization requirements of paragraphs 2(a) and 2(b) of Code Case N-513-3. Flaw Evaluation The licensee performed a flaw evaluation to demonstrate the structural integrity of the repaired pipe from the date of flaw discovery to the Spring 2017 refueling outage, when the licensee will perform an ASME Code repair on the subject piping. The licensee's flaw evaluation is based on (a) the predicted bounding final flaw size with respect to the diameter of the encapsulation, (b) the thickness of the pipe wall underneath the encapsulation with respect to the minimum ASME Code-required pipe wall thickness, and (c) the stability of the predicted final flaw size using the methodology in accordance with ASME Code Case N-513-3 and ASME Code,Section XI, Appendix C. The NRC staff notes that the 6.6875-inch inside diameter of the weldolet is larger than the bounding final flaw length of 2.5 inches with sufficient margin; therefore, the encapsulation covers sufficient metal such that the structural integrity of the pipe will be maintained. Based on independent calculations, the NRC staff verified the licensee's calculated three minimum pipe wall thickness of 0.077, 0.105, and 0.120 inches based on various pressures in accordance with Code Case N-513-3 and ASME Code, Section Ill. Of the three, the NRC staff finds the licensee's use of 0.077 inches as the required minimum wall thickness acceptable for regulatory purposes because this value was calculated based on the maximum operating pressure. The NRC staff finds the licensee's plan to install the weldolet to pipe wall thickness of 0.328 inch or better to be acceptable. However, degradation may continue to occur inside the pipe after encapsulation is installed. To estimate the corrosion rate, the licensee applied a factor of 4 to the normal corrosion rate of 30 mpy to obtain a corrosion rate of 120 mpy. The licensee assumed that the pipe wall thickness under the encapsulation (weldolet and attachment weld) will be reduced by the corrosion rate of 0.120 inches from the date of the repair to the Spring 2017 refueling outage. The licensee predicted that the pipe wall under the encapsulation will be reduced to 0.208 inches (0.328 -0.120). The estimated pipe wall thickness of 0.208 inch exceeds the Code minimum of 0.077 inches; therefore, the NRC staff finds that in terms of metal loss, the licensee has demonstrated that the structural integrity of the repaired pipe will be maintained. The NRC staff notes that the licensee used the linear elastic fracture mechanics method in accordance with ASME Code,Section XI, Appendix C, Article C-7000, to demonstrate flaw stability. The NRC staff finds that the licensee has applied proper loading, load combination, and structural factors in the fracture mechanics calculations. The licensee demonstrated that the bounding axial flaw of 1.75 inches, and the bounding circumferential flaw of 2.50 inches, will be stable between the date of flaw discovery until the Spring 2017 refueling outage. The NRC staff finds that the structural integrity of the subject pipe will be maintained based on the licensee's fracture mechanics calculations.
The NRC staff notes that as a defense-in-depth measure, the relief request will expire if the ongoing UT identifies that the flaw progresses outside the encapsulated area to the point that the ASME Code minimum thickness of 0.077 inches is challenged. Design The NRC staff notes that the weight of the encapsulation, 80.2 pounds, is not significant as compared to the 24-inch subject pipe. In addition, a pipe support is located adjacent to the defective area. The NRC staff finds that because the proximity of the existing pipe support, the additional encapsulation weight of 80.2 pounds should not affect the pipe stress significantly. The NRC staff notes that the addition of a weldolet results in the application of a stress intensification factor of 4.05. The NRC staff determined that application of this factor on the existing pipe stress levels should not affect the final piping stresses because the weight and size of the encapsulation are not significant as compared to the 24-inch main pipe. In addition, the adjacent pipe support will sustain the loads from the encapsulation. The NRC staff finds that the resulting pipe stresses should satisfy ASME Code, Section Ill. The NRC staff finds that the weldolet, weld neck flange, and blind flange design conforms to the design temperature and pressure requirements. The NRC staff further finds that the material of the encapsulation is compatible with the subject pipe material and satisfies ASME Code, Section Ill, ND requirements for branch connections. The NRC staff finds that (a) the encapsulation is designed to satisfy ASME Code, Section Ill, ND requirements for fabrication, (b) the acceptance criteria for the design are in accordance with the requirements of the original construction code and/or ASME Code, Section Ill, ND, and (c) the NOE methods performed will satisfy the requirements of ASME Code,Section XI, IWA-4500. Installation The NRC staff finds it acceptable that the licensee will ensure that the surface of the pipe is dry and, therefore, suitable for welding. The licensee will also ensure that weld joint fit-up is acceptable prior to welding. Therefore, the NRC staff finds that the licensee's pre-installation evaluation is acceptable. The NRC staff finds that following the welding requirements of ASME Code,Section IX, is acceptable. The NRC staff finds that the licensee's proposed VT-2 visual examination and penetrant testing examination of the final weld is acceptable because these examinations satisfy the requirements of ASME Class 3 components. Extent of Condition The NRC staff finds that the licensee has satisfied the extent of condition inspection requirement in accordance with Section 5 of Code Case N-513-3 because it has performed an augmented examination and detected 14 other areas of wall thinning at subject piping. According to the licensee, those 14 areas still satisfy the required minimum wall thickness and are acceptable for service.
Post-Repair Monitoring The NRC staff finds that the licensee's proposed daily walkdown and periodic UT inspections of no more than 30-day intervals to monitor the encapsulation of the flaw area are acceptable. The NRC staff finds that the proposed monitoring requirement is consistent with paragraphs 2(e) and 2(f) of Code Case N-513-3 and is adequate to observe any potential leakage. Hardship Justification The NRC staff recognizes that an ASME Code repair of the subject pipe will lead to the unavailability of the "A" train service water system. This will eliminate the defense-in-depth in the system design of two trains. In addition, the ASME Code repair may exceed the required limiting condition of operation required by the plant TSs, which would result in a plant shutdown. The NRC staff finds that a plant shutdown near the scheduled refueling outage would place the systems and components in an undue and unnecessary stressed, transient condition. The NRC staff has determined that performing an ASME Code repair as compared to the proposed temporary repair would result in hardship or unusual difficulty, without a compensating increase in the level of quality and safety. In summary, the NRC staff finds that the licensee has demonstrated the structural integrity of the repaired pipe by (a) the flaw evaluation, (b) the margin between the encapsulation diameter and the predicted final flaw size, (c) periodic monitoring of the repaired pipe location, and (d) the required minimum wall thickness of 0.077 inches. Therefore, the NRC staff finds that Relief Request RA-17-002 will provide reasonable assurance that the structural integrity of the subject service water piping and its intended safety function will be maintained until the end of the next refueling outage (OR 18) in Spring 2017.
4.0 CONCLUSION
As set forth above, the NRC staff concludes that the proposed alternative provides reasonable assurance of structural integrity of the subject service water piping. The NRC staff has determined that complying with IWA-4412 of the ASME Code requirement would result in hardship or unusual difficulty, without a compensating increase in the level of quality and safety. Accordingly, the NRC staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in 1 O CFR 50.55a(z)(2) and is in compliance with ASME Code requirements. Therefore, the NRC staff authorizes the proposed alternative in Relief Request RA-17-002 in accordance with 10 CFR 50.55a(z)(2) for Seabrook until the end of the next refueling outage (OR18) in Spring 2017, or the flaw progresses outside the encapsulated area such that the pipe wall thickness is below 0.077 inches, whichever occurs first. All other ASME Code,Section XI requirements for which relief was not specifically requested and approved remain applicable, including third-party review by the Authorized Nuclear lnservice Inspector. Principal Contributor: J. Tsao Date: March 27, 201 7 M. Nazar
SUBJECT:
SEABROOK STATION, UNIT NO. 1 -RELIEF FROM THE REQUIREMENTS OF THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS BOILER AND PRESSURE VESSEL CODE (CAC NO. MF9260) DATED MARCH 27, 2017 DISTRIBUTION: Public LPL 1 R/F RidsACRS_MailCTR Resource RidsNrrDorlLpl1 Resource RidsNrrDeEpnb Resource RidsNrrLALRonewicz Resource RidsNrrPMSeabrook Resource RidsRgn1 MailCenter Resource JTsao, NRR JBowen, OEDO ADAMS A ccess1on N b um er: ML 17080A038 OFFICE NRR/DORL/LPL 1/PM NRR/DORL/LPL 1/LA NRR/DE/EPNB/BC* NAME JPoole LRonewicz DAiiey DATE 03/22/2017 03/21/2017 02/20/2017 *b 1y e-ma1 NRR/DORL/LPL 1/BC NRR/DORL/LPL 1/PM Joanna JPoole 03/27/2017 03/27/2017 OFFICIAL RECORD COPY