ML20021A013

Request for Revision to Reactor Vessel Material Surveillance Capsule Withdrawal Schedule

ML20021A013
Person / Time
Site:	Robinson
Issue date:	02/19/2020
From:	Undine Shoop Plant Licensing Branch II
To:	Catherine Nolan Duke Energy Progress
Hon A
References
EPID L-2019-LLL-0021
Download: ML20021A013 (9)

Text

February 19, 2020 Mr. Christopher Nolan, Vice President Nuclear Regulatory Affairs, Policy &

Emergency Preparedness Duke Energy, LLC 526 South Church Street, EC-07C Charlotte, NC 28202

SUBJECT:

H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT NO. 2 - REQUEST FOR REVISION TO REACTOR VESSEL MATERIAL SURVEILLANCE CAPSULE WITHDRAWAL SCHEDULE (EPID L-2019-LLL-0021)

Dear Mr. Nolan:

By letter dated May 2, 2019, Duke Energy, LLC (Duke Energy or the licensee) requested a revision of the reactor vessel (RV) material surveillance capsule withdrawal schedule for the surveillance program that applies to the H. B. Robinson Steam Electric Plant, Unit 2. This program is required to be designed and implemented in accordance with requirements in Title 10 of the Code of Federal Regulations (CFR), Part 50, Appendix H, "Reactor Vessel Material Surveillance Program Requirements" (henceforth Appendix H). The licensee submitted this programmatic change in accordance with requirements specified in Section III.B.3 of Appendix H. The licensee supplemented its request in the letters dated November 13, 2019, and December 19, 2019.

The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the requested changes to the schedule and concludes that it will continue to meet the RV surveillance capsule withdrawal schedule criteria in American Society for Testing and Materials (ASTM) E185-82, Standard Practice for Conducting Surveillance Tests for Light-Water Cooled Nuclear Power Reactor Vessels, and is in compliance with 10 CFR Part 50, Appendix H. The NRC staff, therefore, concludes that the RV withdrawal schedule, as requested above, is acceptable for implementation. The NRC staffs evaluation of the subject is enclosed.

C. Nolan Please contact Andrew Hon, Project Manager, at (301) 415-8480, if you have questions or comments on this letter.

Sincerely,

/RA/

Undine Shoop, Chief Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-261

Enclosure:

As stated cc: ListServ

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO REACTOR VESSEL SURVEILLANCE PROGRAM WITHDRAWAL SCHEDULE REVISION DUKE ENERGY PROGRESS, LLC H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT 2 DOCKET NO. 50-261

1.0 INTRODUCTION

By letter dated May 2, 2019 (Reference 1), Duke Energy Progress, LLC (Duke Energy or the licensee) requested a revision of the reactor vessel (RV) material surveillance capsule withdrawal schedule for the surveillance program that applies to the H. B. Robinson Steam Electric Plant (HBRSEP), Unit 2. This program is required to be designed and implemented in accordance with requirements in Title 10 of the Code of Federal Regulations (CFR), Part 50, Appendix H, Reactor Vessel Material Surveillance Program Requirements (henceforth Appendix H). The licensee submitted this programmatic change in accordance with requirements specified in Section III.B.3 of Appendix H. The licensee supplemented its request in the letters dated November 13, 2019 (Reference 2), and December 19, 2019 (Reference 3).

Specifically, in this request (as supplemented), the licensee proposes a change to the schedule for withdrawing Surveillance Capsule U in accordance with the licensees activities for implementing the surveillance program. The licensees current surveillance capsule withdrawal schedule was requested on September 28, 2011 (Reference 4) and approved by the U.S.

Nuclear Regulatory Commission (NRC) on December 21, 2011 (Reference 5). The NRC staffs safety evaluation (SE) of the approval letter included the basis the licensees current basis for withdrawing Capsule U at 38.0 effective full power years (EFPY).1 Prior to that, Capsule U was designated for removal at 28.9 EPFY, as approved in NUREG-1785 (Reference 6).

2.0 REGULATORY EVALUATION

2.1 Applicable Regulatory Requirements Appendix H establishes the requirements for designing and implementing RV material surveillance programs.Section I of Appendix H states that the objective of the program is to 1

In the staffs letter of December 21, 2011 (Reference 5), the NRC staff approved the licensees previous basis for removing Capsule U from the reactor pressure vessel (RPV) at 38.0 EFPY or the refueling outage after the capsule has achieved a neutron fluence exposure equal to the peak fluence exposure of the RPV at the end of 80 years of plant operations.

Enclosure

monitor for changes in the fracture toughness properties of ferritic materials that are included in the beltline of the reactor pressure vessel (RPV) due to exposure of the materials to a neutron irradiation and thermal environment.Section III.B in Appendix H establishes the requirements for the design of the surveillance program and for implementing capsule withdrawals and performing material testing in accordance with the program.

Section III.B.1 of Appendix H requires the design of the surveillance program and the surveillance capsule withdrawal schedule to meet the requirements specified in the edition of American Society for Testing and Materials (ASTM) Standard Practice E185 that is current on the issue date of the American Society of Mechanical Engineers (ASME) Code to which the RV was purchased. Appendix H permits later editions of ASTM E185 to be used for these objectives, but only for editions up to and inclusive of ASTM E185-82 (Reference 7).

Section III.B.1 of Appendix H also requires that, for each capsule withdrawal, the procedures for performing tests of capsule specimens and for reporting test results must meet the requirements of ASTM E185-82 to the extent practical for the configuration of the specimens in the capsules.

The provisions in Section III.B.2 of Appendix H establish specific requirements for placing the surveillance capsules inside of the RV cavity. The rule requires the capsules to be located at positions so that the capsule irradiation history duplicates (i.e., to the extent practical within the physical restraints of the system) the neutron spectrum, temperature history, and maximum fluence experienced by the RV at the inside surface of the vessel. Appendix H states that if capsule holders are used and attached to the vessel wall or vessel cladding, construction and inspection of the attachments and attachment welds must be done in accordance with the requirements of the licensees ASME Section III and Section XI editions of record. Appendix H also requires the design and location of the capsule holders to permit for insertion of replacement capsules. Appendix H permits use of accelerated irradiation capsules in addition to the normal number of capsules that are required by Appendix H.

The provisions in Section III.B.3 of Appendix H require a proposed RV surveillance capsule withdrawal schedule to be submitted with a technical justification and to be approved by the staff prior to implementation. Paragraph IV.A of Appendix H states that Each capsule withdrawal and the test results must be the subject of a summary technical report to be submitted, as specified in §50.4, within one year of the date of capsule withdrawal, unless an extension is granted by the Director, Office of Nuclear Reactor Regulation.

2.2 Current Licensing Basis for Complying with the Requirements of Appendix H The licensee defines its licensing basis for designing and implementing the surveillance program in Section 5.3.1.5, Material Surveillance, of the updated final safety analysis report (UFSAR) for the reactor unit. The UFSAR states the design and implementation of the current program complies with the requirements in Appendix H and the criteria in ASTM Standard Practice E185-82. The UFSAR clarifies that the licensee has removed five capsules (i.e.,

Capsules S, Z, V, T, and X) in accordance with the program and has tested the material specimens in four of these capsules (i.e., Capsules S, V, T, and X), with the latest test results for all capsule test results being summarized in WCAP-15805 (Reference 8).2 2

Table 7-1 in WCAP-15805 clarifies that Capsule Z was inadvertently removed from the RV, but at the time of developing the WCAP report, it was unconfirmed whether Capsule Z had been re-installed into the RV or placed in the spent fuel pool of the unit.

The UFSAR also indicates that there are three remaining capsules in the RV (i.e., Capsules U, Y and W). Of these capsules, the UFSAR indicates that the Capsule U is currently scheduled to be withdrawn from the RV when 38.0 EPFY have elapsed at a neutron fluence of 7.84 x 1019 n/cm2, which is the projected neutron fluence equivalent to the peak RV inner surface at 80 calendar years (66 EFPY). The UFSAR states that Capsule Y and W are standby capsules for the program.

3.0 TECHNICAL EVALUATION

The staff reviewed the following sources:

(a) Duke Energy Letter dated May 2, 2019 (Reference 1),

(b) Duke Energy dated November 13, 2019 (Reference 2),

(c) Duke Energy dated December 19, 2019 (Reference 3),

(d) UFSAR Section 5.3.1.5, (e) Section 3.1.2.3.6 of NUREG-1785, (Reference 6),

(f) WCAP-15805 (Reference 8), and (g) Relevant correspondence from the licensee or issued by the staff that either relate to the surveillance program for HBRSEP Unit 2 or that provide relevant neutron fluence information for either the RV or the surveillance capsules (References 4, 5, and 9).

3.1 Proposed Surveillance Capsule Withdrawal Schedule Change In the letter of May 2, 2019, the licensee requested staff approval to change the time for withdrawing Capsule U from the RV in accordance with the following basis defined in the submittal:

Capsule U will be withdrawn at 41.3 effective full-power years (EFPY) or during the scheduled outage after the 80-year peak vessel fluence is reached, but prior to 57.1 EFPY.

3.2 Licensees Basis and Justification for the Proposed Withdrawal Schedule Change The licensee stated that the changes to the withdrawal time for Capsule U are justified based on the guidance or regulatory criteria established in the following document sources:

(a) Aging Management Program (AMP) Chapter XI.M31 in NUREG-1801, Revision 2 (GALL Report, Reference 9), (b) ASTM Standard Practice E185-82, and (c) the guidelines in Electric Power Research Institute (EPRI) Materials Reliability Program (MRP) Report No. MRP-326 (Reference 10).

The licensee indicated that the change to the withdrawal schedule for Capsule U is necessary to accommodate a migration to 24 month operating cycles and a design change that eliminates partial length shield assemblies in the reactor design for the unit, which were reflected and

accounted for in the staffs approval of the year 2018 license amendment request for P-T limit curves effective to 46.3 EFPY (References 11 and 12).

3.3 Assessment of Proposed RPVMSP Withdrawal Schedule Change for Capsule U The staff verified that changing the capsule withdrawal schedule to 41.3 EPFY will increase the projected neutron exposure of the capsule at the time of removal from a projected fluence exposure of 7.84 x 1019 n/cm2 (E > 1.0 MeV) to a projected fluence exposure of 8.09 x 1019 n/cm2 [E > 1.0 MeV]).

However, the licensees proposed schedule in the May 2, 2019 letter (Reference 1) would also permit the licensee to remove Capsule U at alternate times, and more specifically at any plant outage at or after 41.3 EPFY but prior to 57.1 EFPY. The staff noted that this added withdrawal provision would permit considerable latitude in defining exactly when Capsule U would be removed. The staff also noted that this type of caveat was not included in the licensees previous withdrawal schedule change request for Capsule U, which was request by Duke Energy in Reference 4 and established the current withdrawal schedule for the capsule at 38.0 EPFY, and which was approved in Reference 5.

As a result, the staff noted that the added provision in May 2, 2019 letter might not comply with the requirement in Section III.B.3 of Appendix H because it would allow the licensee to remove the capsule at any outage up to 57.1 EFPY and did not propose a definitive time for removing Capsule U. Duke Energys responded to the NRC staffs request for additional information (RAI) on November 13, 2019 (Reference 2) and amended on December 19, 2019 (Reference 3). The supplements amended its request criterion for withdrawing Capsule U to eliminate the phrase but prior to 57.1 EFPY to state:

Capsule U will be withdrawn at 41.3 effective full-power years (EFPY) or during the scheduled outage after the capsule achieves a neutron fluence exposure equal to the peak, projected inside surface fluence for the reactor pressure vessel at 80-years operation.

The staff finds that the new withdrawal schedule for Capsule U is acceptable for implementation because it will comply with the requirements in Appendix H. Once Capsule U has been withdrawn from the RV in accordance with the revised schedule approved in this safety evaluation, testing of the specimens in the capsule is subject to the post-removal testing requirements specified in Section III.B.1 of Appendix H and the staffs reporting requirements for submitting the reactor pressure vessel surveillance material test results to the Director, Office of Nuclear Reactor Regulation, as specified in Section IV of Appendix H.

4.0 CONCLUSION

The staff finds that Duke Energy requested withdrawal schedule change for Capsule U, as amended in the letter of December 19, 2019, is consistent with Appendix H for the withdrawal of Capsule U. The staff also finds that the proposed withdrawal schedule change for Capsule U, as amended in the letter of December 19, 2019, complies with the requirements of Section III.B.3 in Appendix H. Based on these findings, the staff approves the licensees request and Duke Energy is authorized to withdraw Capsule U in accordance with the following withdrawal schedule requirement:

Capsule U will be withdrawn at 41.3 EFPY or during the scheduled refueling outage after the capsule achieves a neutron fluence exposure equal to the peak, projected inside surface fluence for the reactor pressure vessel at 80-years operation.

5.0 REFERENCES

1. Serial Letter No. RA-19-0145 from Mr. Chris Nolan, Duke Energy Company, to the NRC Document Control Desk, Revision to Reactor Vessel Surveillance Capsule Withdrawal Schedule, May 2, 2019. (ADAMS Accession No. ML19122A012).

2. Serial Letter No. RA-19-0421 from Mr. Chris Nolan, Duke Energy Company, to the NRC Document Control Desk, Response to Request for Additional Information (RAI)

Regarding Reactor Pressure Vessel (RPV) Surveillance Capsule Removal, November 13, 2019. (ADAMS Accession No. ML19317D072).

3. Serial Letter No. RA-19-0460 from Mr. Chris Nolan, Duke Energy Company, to the NRC Document Control Desk, Revised Response to Request for Additional Information (RAI)

Regarding Reactor Pressure Vessel (RPV) Surveillance Capsule Removal, December 19, 2019. (ADAMS Accession No. ML19353C963).

4. Serial Letter No. RNP-RA/11-0038 and Licensing Request from Mr. R. Rogaski, Carolina Power and Light Company, to the NRC Document Control Desk, H. B. Robinson Steam Electric Plant, Unit No. 2, Docket No. 50-261, Renewed License No. DPR-23, Revision to Reactor Vessel Surveillance Capsule Removal Schedule, September 28, 2011.

(ADAMS Accession No. ML11276A002).

5. NRC Letter and Safety Evaluation to Carolina Power and Light Company (i.e., to Mr. R. J. Duncan, II, Vice President of HBRSEP), H. B. Robinson Steam Electric Plant, Unit No. 2 - Request for Revision to Reactor Vessel Material Surveillance Capsule Withdrawal Schedule (TAC No. ME7533), December 21, 2011. (ADAMS Accession No. ML11349A026).

6. NRC NUREG-1785, Safety Evaluation Report Related to the License Renewal of H.B.

Robinson Steam Electric Plant, Unit 2, Section 3.1.2.3.6, Reactor Vessel Surveillance Program, March 2004. (ADAMS Accession No. ML040990702).

7. American Society for Testing and Materials (ASTM) Standard Practice E185-82, Standard Practice for Conducting Surveillance Tests for Light-Water Nuclear Power Reactor Vessels, July 1, 1982.

8. Westinghouse Electric Company Non-Proprietary Class 3 Technical Report No. WCAP-15805, Analysis of Capsule X from the Carolina Power and Light Company H. B. Robinson Unit 2 Reactor Vessel Material Surveillance Program, March 2002 (ADAMS Accession Nos. ML021190313 and ML021190357).

9. NRC NUREG-1801, Revision 2, Generic Aging Lessons Learned Report for Nuclear Power Plants, Chapter XI.M31, Reactor Vessel Surveillance, December 2010. (ADAMS Accession No. ML10349A026).

10. Electric Power Research Institute (EPRI) Materials Reliability Program Report No. MRP-326, Materials Reliability Program: Coordinated PWR Reactor Vessel Surveillance Program (CRVSP), 2011. (ADAMS Accession Nos. ML12040A314 and ML12040A315).

11. Serial Letter No. RNP-RA/17-0082 from Mr. E. J. Kapopoulos, Jr., Duke Energy Company, to the NRC Document Control Desk, License Amendment Request to Revise Technical Specification 3.4.4, RCS Pressure and Temperature (P/T) Limits, February 7, 2018. (ADAMS Accession No. ML18038B289).

12. NRC Letter and Safety Evaluation to Duke Energy Progress, LLC (i.e., to Mr. E. J. Kapopoulos, Jr., Site Vice President of HBRSEP), H. B. Robinson Steam Electric Plant, Unit No. 2 - Issuance of Amendment No. 260 Regarding Request to Revise Technical Specification Reactor Coolant System Pressure and Temperature Limits to Reflect 24-Month Fuel Cycles (EPID L-2017-LLA-0033), August 15, 2018.

(ADAMS Accession No. ML18200A042).

Principal Contributor: James Medoff, NRR/DNLR/NVIB Date: February 19, 2020

ML20021A013 (Safety Evaluation)

• ML20015A052 OFFICE NRR/DORL/LPL2-2/PM NRR/DORLLPL2-2/LA NRR/DEX/EVIB/BC*

NAME AHon BAbeywickrama HGonzalez DATE 01/22/2020 01/22/2020 01/13/2020 OFFICE NRR/DORL/LPL2-2/BC NRR/DORL/LPL2-2/PM NAME UShoop AHon DATE 02/19/2020 02/19/2020