ML14184A782

Relief Request GG-ISI-017, Alternative to Reactor Vessel Internal Structure Examination, Use of BWRVIP Guidelines, B13.10, Categories B-N-1 and B-N-2, Third 10-Year Inservice Inspection Interval

ML14184A782
Person / Time
Site:	Grand Gulf
Issue date:	08/01/2014
From:	Doug Broaddus Plant Licensing Branch IV
To:	Entergy Operations
Wang A
References
TAC MF3678
Download: ML14184A782 (8)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 August 1, 2014 Vice President, Operations Entergy Operations, Inc.

Grand Gulf Nuclear Station P.O. Box 756 Port Gibson, MS 39150

SUBJECT:

. GRAND GULF NUCLEAR STATION, UNIT 1- RELIEF REQUEST GG-ISI-017 FROM ASME CODE, SECTION XI INSERVICE INSPECTION REQUIREMENTS FOR EXAMINATION B13.10 AND ALTERNATIVE USE OF BOILING WATER REACTOR VESSEL AND INTERNALS PROJECT GUIDELINES (TAC NO. MF3678)

Dear Sir or Madam:

By letter dated February 26, 2014, Entergy Operations Inc., the licensee, requested a verbal approval for deferring the examination of the reactor vessel (RV) interior surfaces from the refueling outage (RF0-19) until refueling outage (RF0-20) in the year 2016 at Grand Gulf Nuclear Station, Unit 1 (GGNS). In Relief Request GG-ISI-017, the licensee provided justification for deferring the examination of the RV interior surfaces on the basis of hardship or unusual difficulty as allowed by the provisions set forth in the Title 10 to the Code of Federal Regulations (1 0 CFR) paragraph 50.55a(a)(3)(ii). By letter dated February 28, 2014, in response to a U.S. Nuclear Regulatory Commission (NRC) staff request for additional information dated February 27, 2014, the licensee noted that the original request had incorrectly requested the relief pursuant to 10 CFR 50.55a(a)(3)(i). The examination requirements for the RV interior surfaces are addressed in Section XI of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code), Examination Categories B-N-1, B13.10 for the RV interior surfaces. On March 5, 2014, the NRC staff provided a verbal authorization, as documented in an e-mail to the li.censee dated Ma~ch 6, 2014, confirming the verbal authorization of the deferral of the examinations of the RV interior surfaces until RF0-20.

The NRC staff has reviewed the Relief Request GG-ISI-017 and concludes, as set forth in the enclosed safety evaluation, that the alternatives proposed by the licensee, that deferring the examination of the ASME Code,Section XI, Category B-N-1, B13.10, RV interior surfaces at GGNS, Unit 1, from RFO 19 until RF0-20 does not affect the safety function of the RV and its internal components. Further, complying with the specified requirement would result in hardship or unusual difficulty without compensating an increase in the level of quality and safety.

Therefore, pursuant to 10 CFR 50.55a(a)(3)(ii), the licensee's proposed alternative for GGNS is authorized by the NRC staff for one time only for RF0-19. During the pre-planning stages of the outage activities, the licensee should take into account for the potential malfunction of equipment or a tooi used for lSI inspections. The staff expects that the licensee should take adequate steps to implement a contingency plan in case of any malfunction of the equipment or a tool that is to be used for lSI inspections during future refueling outages.

All other requirements of ASME Code,Section XI, for which relief was not specifically requested and authorized by the staff remain applicable, including the third-party review by the Authorized Nuclear In-service Inspector. Any ASME Code,Section XI, RV interior components that are not included in this request for alternative should be inspected in accordance with the ASME Code,Section XI requirements.

If you have any questions, please contact Alan Wang at 301-415-1445 or via e-mail at Alan.Wang@nrc.gov.

Sincerely,

/ougla~~

Plant Licensing IV-2 and Decommissioning Transition Branch Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-416

Enclosure:

Safety Evaluation cc w/encl: Distribution via Listserv

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELIEF REQUEST GG-ISI-017 FROM ASME CODE, SECTION XIINSERVICE INSPECTION REQUIREMENTS FOR EXAMINATION B13.10 AND ALTERNATIVE USE OF BOILING WATER REACTOR VESSEL AND INTERNALS PROJECT GUIDELINES ENTERGY OPERATIONS, INC.,

GRAND GULF NUCLEAR STATION UNIT 1 DOCKET NO. 50-416

1.0 INTRODUCTION

By letter dated February 26, 2014, as supplemented by letter dated February 28, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession Nos. ML14057A685 and ML14059A236, respectively), Entergy Operations Inc., the licensee, requested verbal approval for deferring the examination of the reactor vessel (RV) interior surfaces from the current refueling outage (RF0-19) until refueling outage (RF0-20) in the year 2016 at the Grand Gulf Nuclear Station, Unit 1 (GGNS). In Relief Request GG-ISI-017, the licensee provided justification for deferring the examination of the RV interior surfaces on the basis of hardship or unusual difficulty as allowed by the provisions set forth in the Title 10 to the Code of Federal Regulations (1 0 CFR) paragraph 50.55a(a)(3)(ii). The examination requirements for the RV interior surfaces are addressed in Section XI of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code), Examination Categories B-N-1, B 13.10 forthe RV interior surfaces. On March 5, 2014, the U.S. Nuclear Regulatory Commission (NRC) staff provided a verbal authorization, as documented in an e-mail to the licensee dated March 6, 201,4 (ADAMS Accession No. ML14065A096), confirming the verbal authorization of the deferral ofthe examinations of the RV interior surfaces until RF0-20.

2.0 REGULATORY REQUIREMENTS The inservice inspection (lSI) of ASME Code Class 1, 2, and 3 components is performed in accordance with Section XI of the ASME Code as required by 10 CFR 50.55a(g), except where specific relief has been granted by the Commission pursuant to 10 CFR 50.55a(g)(6)(i). The regulations in 10 CFR 50.55a(a)(3) state that alternatives to the requirements of 10 CFR 50.55a(g) may be used, when authorized by the Commission if: (i) the proposed alternatives would provide an acceptable level of quality and safety or (ii) compliance with the Enclosure

specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.

Pursuant to 10 CFR 50.55a(g)(4), ASME Code Class 1, 2, and 3 components (including supports) shall meet the requirements, except the design and access provisions and the pre-service examination requirements, set forth in the ASME Code,Section XI, "Rules for lSI of Nuclear Power Plant Components," to the extent practical within the limitations of design, geometry, and materials of consth]chon. of the com ponEmts. *The regulations require that lSI examination of components and system pressure tests conducted during each 10-year interval comply with the requirements in the latest edition and addenda of Section XI of the ASME Code incorporated by reference in 10 CFR 50.55a(b), 12 months prior to the start of the 120-month interval,* subject to the limitations and modifications listed therein. The applicable ASME Code of record for the third 10-year lSI interval for GGNS, Unit 1, is ASME Code,Section XI, 2001 Edition through the 2003 Addenda.

3.0 TECHNICAL EVALUATION

3.1 Licensee's Evaluation The Components for Which an Alternative is Requested The ASME Code,Section XI, Class .1, Examination Categories B-N-1, Code Item Number B13.10.

• B 13.10 - Examine accessible areas of the RV interior surfaces during each period using a technique. which meets the requirements for a VT-3 examination, as defined in paragraph IWA-2213 of Section XI of the ASME Code.

These examinations are performed to. periodically* assess the structural integrity ofthe RV interior surfaces. Additional components addressed in ASME Code,Section XI include:

B13.20, Interior Attachments within Beltline Region; B13.30, Interior Attachments Beyond Beltline Region; and B13.40, Core Support Structure.

Licensee's Basis for Requesting Deferral of Reactor Vessel Interior Inspection By letter dated February 26, 2014, the licensee stated that during the RF0-19, while performing the examination of RV interior surfaces, the submersible inspection vehicle did not produce sufficient image quality to satisfy the visual testing (VT-3) standards. This emergent issue did not affect other in-vessel inspections performed during this outage, and this relief request will not bypass ASME or Boiling Water Reactor Vessel Internals Program (BWRVIP) requirements to inspect safety-related system components that are welded to the RV interior surfaces. The licensee stated, in part, that it was

... seeking relief to preclude additional radiological dose to personnel who would be required to inspect over the reactor vessel and to mitigate aggregate risk presented by an additional delay in restoring safety-related equipment The BWRVIP Guideline alternative to ASME Section XI examination B13.1 0 would permit overview inspections of the reactor vessel wall locations adjacent to those

components required to be inspected in accordance with ASME Section XI examinations 813.20, 813.30, and 813.40, or their approved 8WRVIP alternatives, during the next refueling outage [RF0-20] in February to March of 2016.

This request is only applicable to the third 10-year lSI interval commencing on May 31, 2008, and ending on July 1, 2017.

The licensee further stated that it was requesting the approval of the proposed alternative to ASME*Section XI examination 813.10 on the basis that there have been no reported failures resulting from previous VT-3 inspections performed on the RV interior surfaces at the GGNS and that the use of the 8WRVIP guidelines discussed above will provide an acceptable level of quality and safety. Therefore, in February 26, 2014, submittal, the licensee requested the NRC staff to approve the subject request under the provisions of 10 CFR 50.55a(a)(3)(ii).

3.2 NRC Staff Evaluation The NRC staff reviewed the information provided by the licensee in its submittal dated February 26, 2014. Examination of the accessible areas of the RV interior surfaces during each period using a technique which meets the requirements for a VT-3 examination was required per the ASME Code,Section XI. Previous examinations of the RV interior surfaces, revealed no indications, and as such, there is no known active aging degradation in the RV interior surfaces.

In its submittal dated February 26, 2014, the licensee stated that deferral of the examination of the RV interior surfaces would minimize the radiological dose to personnel. The NRC staff reviewed the licensee's basis provided in the February 26, 2014, submittal and determined that additional information was required with respect to the deferral of the examinations of the RV interior surfaces until the next refueling outage in 2016: Even though the approval of this deferral is beneficial in reducing the radiological exposure to the personnel, the NRC staff was concerned that the licensee did not have a contingency plan to cover the inspection activities when it encountered inspection equipment failure during the RF0-19. The lack,of preplanning could potentially delay the required timely inspections. Therefore, on February 27, 2014 ADAMS Accession No. ML14059A157), the NRC staff issued a request for additional information (RAI). The license responded to this RAI by letter dated February 28, 2014.

In RAI-1, the licensee was requested to provide the date of, and the findings of, the previous 8-N-1 inspections, specifically addressing the following issues: Distortion or displacement of parts; loose, missing, or fractured fasteners; foreign material, corrosion, erosion, or accumulation of corrosion products; wear; and structural degradation. In its letter dated February 28, 2014, the licensee stated that with the exception of one relevant indication (a gouge) located above top guide plate. between feed water sparger a.nd vessel flange, there were no aforementioned indications.on the RV interior surfaces. According to the licensee, this gouge was made during the feedwater sparger replacement modification and it is not a service-induced defect. Since there have been no detected changes in the dimensions of the gouge, the licensee concluded that there are no aging degradation mechanisms that are active on the RV interior surfaces.

• In RAI-2, the NRC staff stated that in its submittal dated February 27, 2014, the licensee did not provide adequate technical basis for hardship or unusual difficulty for deferring the RV interior

examination of the RV interior surfaces until RF0-20. Specifically, in RAI-2, the NRC staff requested that the licensee provide the following:

a. A discussion on the specific causes of hardship, or unusual difficulty, in support of an evaluation under 10 CFR 50.55a(a)(3)(ii). Specifically, address ALARA [as low as reasonably achievable] concerns (including personnel exposure estimates), or creating significant hazards to plant personnel.

b. An estimate with respect to the tote~l radiological exposure to the personnel (in man-rem) if manual inspections were to be performed in lieu of submersible inspection vehicle on the reactor vessel interior surfaces I

during [RF0-19].

c. The survey data that will elaborate the radiation and contamination levels of the Mark Ill containment at GGNS .. It is our understanding that the radiation levels at the re-fueling floor of the Mark Ill containments is low.

d. Information on the availability of alternate or backup equipment that could produce sufficient image quality to. satisfy the VT-3 standards during

[RF0-19].

In its response to RAI-2, the licensee stated that the examinations of the RV interior surfaces*

would pose a hardship due to an increase in the length of the time, a minimum of 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br />, required to complete the examinations. This would result in an increase in radiological exposure to personnel by 397 millirem without adding any benefit to safety and quality. The licensee further stated that there is no active aging degradation in the RV interior surfaces and as such no aging effects were identified thus far in the RV interior surfaces. The licensee further stated that there was no other alternative or any back-up inspection method that was available to perform VT-3 examination of the RV interior surfaces. Based on the above, the licensee requested the NRC staff to grant relief from the visual inspection of the RV interior

. surfaces during the RF0-19. This scheduled inspect!pn '{Viii. be conducted during RF0-20 in the year 2016.

• The NRC staff reviewed the licensee's technical basis for deferring the visual inspection of RV interior surfaces until RF-20 and concluded the following:

( 1) Based on the previous inspections that were conducted over the years at GGNS, there were no reportable indications in the RV interior surfaces with the exception of one relevant indication (a gouge) located above top-guide plate between feed water sparger and vessel flange. Since this gouge was introduced during the replacement of feed water sparger, it can be concluded that the presence of the gouge is not related to any active aging degradation mechanism and subsequent inspections of the gouge did not reveal any growt.h, (2) No evidence of corrosion, erosion, or accumulation of corrosion products; wear; and structural degradation was identified on these surfaces. Based on this observation, the NRC staff concluded that the proposed alternative provides

reasonable assurance of structural integrity because there is no active aging degradation mechanism in the RV interior surfaces. Hence, the RV interior surfaces are less likely* to experience any aging degradation during the operating cycle between 2014 to 2016, and, (3) The licensee provided adequate technical basis for hardship, or unusual difficulty in its relief request for the deferment of the inspections of the RV interior surfaces. Specifically, the licensee stated that deferring the inspections until RF0-20 would result in the reduction in radiological exposure to personnel by 397 millirem without adding any benefit to safety and quality.

In the absence of any active aging degradation on the RV interior surfaces, the NRC staff concludes that deferring visual inspections of the RV interior surfaces until RF0-20 will not result in any degradation in these surfaces. In addition, the NRC staff concludes that deferring the examinations of the RV interior surfaces until RF0-20 does not compromise the structural integrity, safety, and functionality of the RV internal components at GGNS. Therefore, under the provisions allowed by 10 CFR 50.55a(a)(3)(ii), the NRC staff authorizes the licensee to defer the visual examination of the RV interior surfaces that is consistent with the requirements of ASME Code,Section XI, Category B-N-1, 813.10 at GGNS, until RF0-20 in 2016.

4.0 CONCLUSION

Based on the information provided in the licensee's submittals dated February 26, 2014, and February 28, 2014, the NRC staff concludes that deferring the examination of the ASME Code,Section XI, Category B-N-1, 813.10, RV interior surfaces at GGNS until RF0-20 in 2016 does not affect the safety function of the RV and its internal components. Further, complying with the specified requirement would result in hardship or unusual difficulty without compensating an increase in the level of quality and safety. Therefore, under the provisions allowed by 10 CFR 50.55a(a)(3)(ii), the NRC staff authorizes the licensee's request to defer the visual examination of the RV interior surfaces until 2016. This relief request for deferring the visual inspections of the RV interior surfaces is approved for one time only and it is valid only for RF0-19 at GGNS. The NRC staff expects that the licensee should take adequate steps to implement a contingency plan in case of any malfunction of the equipment or a tool that is to be used for lSI inspections during future refueling outages.

All other requirements of ASME Code,Section XI, for which relief was not specifically requested and authorized by the staff remain applicable, including the third-party review by the Authorized Nuclear lnservice Inspector. Any ASME Code,Section XI, RV interior components that are not included in this request for alternative should be inspected in accordance with the ASME Code,Section XI requirements.

Principal Contributor: Ganesh Cheruvenki Date: August 1, 2014

All other requirements of ASME Code,Section XI, for which relief was not specifically requested and authorized by the staff remain applicable, including the third-party review by the Authorized Nuclear In-service Inspector. Any ASME Code,Section XI, RV interior components that are not included in this request for alternative should be inspected in accordance with the ASME Code,Section XI requirements.

If you have any questions, please contact Alan Wang at 301-415-1445 or via e-mail at Alan.Wang@nrc.gov.

Sincerely,

/RAJ Douglas A. Broaddus, Chief Plant Licensing IV-2 and Decommissioning Transition Branch Division of Operating React_or Licensing Office of Nuclear Reactor Regulation Docket No. 50-41 6 1

Enclosure:

Safety Evaluation cc w/encl: Distribution via Listserv DISTRIBUTION:

PUBLIC LPL4-2 r/f RidsAcrsAcnw_MaiiCTR Resource RidsNrrDeEvib Resource RidsNrrDoriDpr Resource RidsNrrDorllpl4-2 Resource

• RidsNrrLAJBurkhardt Resource RidsNrrPMGrandGulf Resource RidsRgn4MaiiCenter Resource GCheruvenki, NRR/DE/EVIB ADAMS Accession No.: ML14184A782 NRR-028 *SE via email OFFICE NRR/DORULPL4-2/PM NRR/DORULPL4-2/LA NRR/DE/EVIB/BC NRR/DORULPL4-2/BC NAME AWang JBurkhardt SRosenberg* DBroaddus DATE 07/23/14 07/23/14 06/24/14 08/01/14 OFFICIAL AGENCY RECORD