ML18318A062
| ML18318A062 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 12/10/2018 |
| From: | Hall J Plant Licensing Branch II |
| To: | Stoddard D Virginia Electric & Power Co (VEPCO) |
| Hall J, NRR/DORL/LPLII-1, 415-4032 | |
| References | |
| EPID L-2017-LLL-0021 | |
| Download: ML18318A062 (8) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 December 10, 2018 Mr. Daniel G. Stoddard Senior Vice President and Chief Nuclear Officer Innsbrook Technical Center 5000 Dominion Boulevard Glen Allen, VA 23060-6711
SUBJECT:
SURRY POWER STATION, UNIT NOS. 1 AND 2 - REVIEW OF REACTOR VESSEL MATERIAL SURVEILLANCE CAPSULE WITHDRAWAL SCHEDULES (CAC NOS. MG0098 AND MG0099; EPID L-2017-LLL-0021)
Dear Mr. Stoddard:
By letter dated July 28, 2017, Dominion Energy Virginia (the licensee) made a request to revise the reactor vessel material surveillance capsule withdrawal schedules for the Surry Power Station, Unit Nos. 1 and 2 (Surry), in accordance with the requirements of Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Appendix H, paragraph 111.B.3. Supplemental information was provided in letters dated March 19, June 5, and October 18, 2018.
The licensee has performed new projected neutron fluence calculations that have resulted in revised estimated surveillance capsule neutron fluence values. Based on these revised values, the licensee is requesting U.S. Nuclear Regulatory Commission (NRC) staff approval to revise the withdrawal schedules for Unit No. 1 Capsule Z from 2025 to 2027 and Unit No. 2 Capsule U from 2027 to 2032.
The NRC staff has reviewed the licensee's request and concludes that the proposed changes for the withdrawal schedule of Capsule Z for Surry Unit No. 1 and Capsule U for Surry Unit No.
2 are acceptable and consistent with the requirements of the applicable regulations and guidance found in 10 CFR Part 50, Appendix H, and in the American Society for Testing and.
Materials Standard E185-82, "Standard Practice for Conducting Surveillance Tests for Light-Water Cooled Nuclear Power Reactor Vessels," dated July 1, 1982.
The licensee identified additional planned changes to the Surry reactor vessel material surveillance program in its request. These changes consist of (1) eliminating intermediate capsule relocations for standby Capsule S (Unit No. 1) and standby Capsule Z (Unit No. 2); and (2) adding projected neutron fluence values for the standby capsules beyond end of life (Unit No. 1, Capsules U, S, and Y, and Unit No. 2, Capsules T and Z). These changes were not reviewed by the NRC staff nor addressed in the enclosed safety evaluation because they are associated with the licensee's asset management objectives beyond the currently licensed 60-year operating period.
The NRC staff also notes that the licensee submitted an application for subsequent license renewal (SLR) for Surry Unit Nos. 1 and 2 by letter dated October 15, 2018. That application included additional proposed changes to the surveillance capsule withdrawal schedules for the SLR period. Those proposed changes will be considered as part of the NRC staff's review of the SLR application.
If you have any questions regarding this matter, please contact Mr. Randy Hall at 301-415-4032 or via email at Randy.Hall@nrc.gov.
Docket Nos.: 50-280 and 50-281
Enclosure:
Safety Evaluation cc: Listserv Sincerely, Michael T. Markley, Chief Plant Licensing Branch 11-1 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 REQUEST FOR REVISED REACTOR VESSEL MATERIAL SURVEILLANCE CAPSULE WITHDRAWAL SCHEDULES DOMINION ENERGY VIRGINIA SURRY POWER STATION. UNIT NOS.1 AND 2 DOCKET NOS. 50-280 AND 50-281
1.0 INTRODUCTION
By letter dated July 28, 2017 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML17213A080), Virginia Electric and Power Company (Dominion Energy Virginia, the licensee) requested revision of the reactor vessel material surveillance capsule withdrawal schedules for the Surry Power Station (Surry) Unit Nos. 1 and 2, in accordance with Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Appendix H, "Reactor Vessel Material Surveillance Program Requirements," Section 111.B.3. The licensee also provided supplemental information in letters dated March 19, June 5, and October 18, 2018 (ADAMS Accession Nos. ML18085A159, ML18162A099, and ML18302A121, respectively).
Specifically, the licensee proposed to delay the withdrawal of Capsule Z of Unit No. 1 from 2025 to 2027 and delay the withdrawal of Capsule U of Unit No. 2 from 2027 to 2032.
2.0 REGULATORY REQUIREMENTS The regulations and guidance pertinent to this request include:
10 CFR Part 50, Appendix H, Section I, which starts, in part:
The purpose of the material surveillance program required by this appendix is to monitor changes in the fracture toughness properties of ferritic materials in the reactor vessel beltline region of light water nuclear power reactors which result from exposure of these materials to neutron irradiation and the thermal environment. Under the program, fracture toughness test data are obtained from material specimens exposed in surveillance capsules, which are withdrawn periodically from the reactor vessel.
Enclosure 10 CFR Part 50, Appendix H, Section 111.B.1, which states, in part:
The design of the surveillance program and the withdrawal schedule must meet the requirements of the edition of ASTM E 185 that is current on the issue date of the ASME [American Society of Mechanical Engineers] Code to which the reactor vessel was purchased. Later editions of ASTM E 185 may be used, but including only those editions through 1982.
10 CFR Part 50, Appendix H, Section 111.B.3, which states, in part:
A proposed withdrawal schedule must be submitted with a technical justification as specified in § 50.4. The proposed schedule must be approved prior to implementation.
NRC Administrative Letter 97-04, "NRC Staff Approval for Changes to 10 CFR Part 50, Appendix H, Reactor Vessel Surveillance Specimen Withdrawal Schedules," published September 30, 1997, which states, in part:
3.0 3.1 The Commission found that while 10 CFR Part 50, Appendix H, 11.B.3 requires prior NRC approval for all withdrawal schedule changes, only certain changes require license amendments as the process to be followed for such approval. Specifically, those changes that do not conform to the ASTM [American Society for Testing and Materials] standard referenced in Appendix H (ASTM E-185, Standard Practice for Conducting Surveillance Tests for Light-Water Cooled Nuclear Power Reactor Vessels) will require approval by the license amendment process, whereas changes that conform to the ASTM standard require only staff verification of such conformance.
NRC STAFF EVALUATION Licensee's Proposal, Surry Unit No. 1 In its submittal for Surry Unit No. 1, the licensee proposes to alter the current withdrawal schedule for Capsule Z from 2025 (neutron fluence = 6.31 x 1019 n/cm2 (E > 1 MeV)) to 2027 (neutron fluence = 6.35 x 1019 n/cm2 (E > 1 MeV)). The capsule withdrawal information was provided in Table 4.1-12 of the submittal.
3.2 Licensee's Proposal, Surry Unit No. 2 In its submittal for Surry Unit No. 2, the licensee proposes to alter the current withdrawal schedule for Capsule U from 2027 (neutron fluence = 5.95 x 1019 n/cm2 (E > 1 MeV)) to 2032 (neutron fluence = 7.26 x 1019 n/cm2 (E > 1 MeV)). The capsule withdrawal information was provided in Table 4.1-13 of the submittal.
3.3 NRC Staff Review Reactor vessel material surveillance capsules are withdrawn and tested periodically as designated in the withdrawal schedule. Appendix H requires that the proposed schedule be approved prior to implementation.
ASTM E185-82 defines "end of life (EOL)" as the design lifetime in terms of years, effective full power years (EFPY), or neutron fluence. Table 1 in ASTM E185-82 lists the minimum recommended number of surveillance capsules and their withdrawal schedule. ASTM E185-82 clarifies that the timeframe for withdrawal of surveillance capsules identified in Table 1 is based on effective full-power years of the vessel with a design life of 32 EFPY. The NRC staff noted that the withdrawal schedule provided in Table 1 of ASTM E185-82 is an example based on a 40-year design life and is not applicable to vessels with a design life greater than 40 years.
Details regarding the withdrawal schedule of surveillance capsules are provided in Sections 7.6.2 and 7.6.3 of ASTM E185-82. More specifically, Section 7.6.2 states, in part, that the capsule withdrawal schedule should be set so that the exposure of the final capsule does not exceed twice the EOL vessel inside surface peak neutron fluence.
Surry Updated Final Safety Analysis Report (UFSAR) Section 4.1.5, "Service Life," states that reactor vessel design is based on the transition temperature method of evaluating the possibility of brittle fracture of the vessel material as a result of operations and that the service life of the reactor coolant system components, as required by the ASME Code, Section Ill, for Class "A" vessels, is established for the 60-year design life.
For Surry Unit No. 1, the currently scheduled withdrawal date for Capsule Z is 2025. This corresponds to a neutron fluence of 6.31 x 1019 n/cm2 (E > 1.0 MeV), which is 1.38 times the peak 60-year neutron fluence of 4.57 x 1019 n/cm2 (E > 1.0 MeV). The licensee has proposed changing the withdrawal date for Capsule Z to 2027. The corresponding change in neutron fluence for this capsule would be 6.35 x 1019 n/cm2 (E > 1.0 MeV), which is 1.39 times the 60-year neutron fluence. Even with this change, the capsule is scheduled to be withdrawn before twice the EOL neutron peak fluence is reached, per ASTM E185-82.
For Surry Unit No. 2, the approved surveillance capsule withdrawal schedule identifies Capsule U for withdrawal in 2027 at a neutron fluence of 5.95 x 1019 n/cm2 (E > 1.0 MeV), which is 1.19 times the peak 60-year fluence of 5.01 x 1019 n/cm2 (E > 1.0 MeV). If the capsule withdrawal is delayed from 2027 until 2032, the corresponding neutron fluence on the capsule would increase to 7.26 x 1019 n/cm2 (E > 1.0 MeV), which is 1.45 times the peak 60-year neutron fluence. Even with this change, the capsule is scheduled to be withdrawn before twice the EOL peak neutron fluence is reached, per ASTM E185-82.
The previous proposed surveillance capsule withdrawal schedules to address the period of extended operation were submitted by letter dated October 26, 2009 (ADAMS Accession No. ML092990570), as supplemented by letters dated September 13, 2010, and January 3, 2011 (ADAMS Accession Nos. ML102570804 and ML110040077, respectively), in accordance with 10 CFR Part 50, Appendix H, Section 111.B.3. As stated in the October 26, 2009, submittal, The proposed schedules were developed to accommodate the 60-year license period for Surry Units 1 and-2 and to satisfy the requirements and guidance of ASTM E-185-82, "Standard Practice for Conducting Surveillance Tests for Light-Water Cooled Nuclear Power Reactor Vessels," dated July 1, 1982, and the GALL [Generic Aging Lessons Learned] Report for surveillance capsule withdrawal and testing.
The NRC staff approved the revised 60-year schedules in the safety evaluation dated January 31, 2011 (ADAMS Accession No. ML103000386) and stated:
[T]he NRC staff found that the revised surveillance capsule WSs [withdrawal schedules] for Surry, Unit Nos. 1 and 2 satisfy the requirements of ASTM E185-
- 82. Therefore, the NRC staff concludes that the licensee's modified surveillance capsule WSs for Surry, Unit Nos. 1 and 2 are acceptable for implementation and satisfy the requirements of Appendix H to 10 CFR Part 50 for the 60-year extended license period.
The revised schedules were included in the Surry U FSAR, Tables 4.1-12 and 4.1-13, "Surveillance Capsule Withdrawal Schedule for Surry Unit 1," and "Surveillance Capsule Withdrawal Schedule for Surry Unit 2," respectively.
By letter dated October 18, 2018, the licensee provided the following detailed information regarding Capsule Z for Surry Unit No. 1, and Capsule U for Surry Unit No. 2:
For Unit 1, Capsule Z is being withdrawn in 2027 (when the capsule fluence reaches 6.41 x 1019 n/cm2 [E > 1 MeV]). The peak 60-year EOL vessel fluence is 4.57 x 1019 n/cm2 [E > 1 MeV]. This [capsule] fluence value (in 2027) is greater than the vessel peak fluence at 60 years, and is also below twice the 60-year reactor vessel peak fluence.
For Unit 2, Capsule U is being withdrawn in 2032 (when the capsule fluence reaches 7.31 x 1019 n/cm2 [E > 1 MeV]). The peak 60-year EOL vessel fluence is 5.01 x 1019 n/cm2 [E > 1 MeV]. This [capsule] fluence value (in 2032) is greater than the vessel peak fluence at 60 years and is also below twice the 60-year reactor vessel peak fluence.
This information is summarized in the following table:
Estimated Capsule Fluence -
"Last" Capsule - Between 1x to 2x of Proposed 60-Year EOL Fluence (i.e., Footnote E in Peak 60-Year Withdrawal
.ASTM E185-82)- Proposed Plant EOL Fluence Schedule Withdrawal Schedule Surry Unit No.
4.57 E19 6.41 E19 n/cm2 1
n/cm2 (Capsule Z)
Satisfied by Capsule Z Surry Unit No.
5.01 E19 7.31 E19n/cm2 2
n/cm2 (Capsule U)
Satisfied by Capsule U Based on its review of the licensee's proposed capsule withdrawal schedules for Capsule Z for Surry Unit No. 1, and Capsule U for Surry Unit No. 2, the NRC staff finds the exposure of these capsules (i.e., last capsule for 60-year design life) does not exceed twice the EOL vessel inside surface peak fluence, consistent with ASTM E185-82, Section 7.6.2.
NRC Administrative Letter 97-04 informed licensees that changes to their facility reactor vessel material surveillance capsule withdrawal schedules, as specified in 10 CFR Part 50, Appendix H, that conform to the applicable ASTM standard require only staff verification of such conformance. Based on the information in the application and the supplemental letters dated July 28, 2017, March 19, 2018, and October 18, 2018, the NRC staff finds the licensee has demonstrated that its proposed withdrawal schedules fulfill the provisions in ASTM E 185-82, specifically for Capsule Z (Unit No. 1) and Capsule U (Unit No. 2), for the 60-year design life of Surry Unit Nos. 1 and 2.
The additional changes described in the licensee's submittal dated July 28, 2017, were not reviewed by the NRC staff nor addressed in this safety evaluation because they are associated with the licensee's asset management objectives beyond the currently licensed 60-year operating period. Also, any proposed capsule withdrawal schedule changes relating to the Surry subsequent license renewal application, dated October 15, 2018 (ADAMS Accession No. ML18291A842), will be considered as part of the NRC staff's review of that application.
4.0 CONCLUSION
Based on the above evaluation, the NRC staff concludes that the revised surveillance capsule withdrawal schedules for Capsule Z for Surry Unit No. 1, and Capsule U for Surry Unit No. 2 satisfy the requirements of ASTM E185-82 as they relate to the current 60-year operating period. The NRC staff further concludes that the licensee's modified surveillance capsule withdrawal schedules for Capsule Z for Surry Unit No. 1, and Capsule U for Surry Unit No. 2, are acceptable for implementation and satisfy the requirements of 10 CFR Part 50, Appendix H, for the current 60-year license term. Therefore, the NRC staff approves these revised surveillance capsule withdrawal schedules.
Principal Contributor: 0. Yee Date: December 10, 2018
SUBJECT:
SURRY POWER STATION, UNIT NOS. 1 AND 2 - REVIEW OF REACTOR VESSEL MATERIAL SURVEILLANCE CAPSULE WITHDRAWAL SCHEDULES (CAC NOS. MG0098 AND MG0099; EPID L-2017-LLL-0021)
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