ML18275A105
| ML18275A105 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 09/26/2018 |
| From: | Mark D. Sartain Virginia Electric & Power Co (VEPCO) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 18-289 | |
| Download: ML18275A105 (7) | |
Text
VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 September 26, 2018 United States Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 10 CFR 50.55a Serial No.18-289 NRA/DEA RO Docket Nos.
50-338 License Nos.
NPF-4 VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION ENERGY VIRGINIA)
NORTH ANNA POWER STATION UNIT 1 ASME SECTION XI INSERVICE INSPECTION PROGRAM REQUEST FOR PROPOSED ALTERNATIVE N1-14-CS-002 SNUBBER PROGRAM EXTENSION In accordance with 10 CFR 50.55a(z)(2), Dominion Energy Virginia hereby requests Nuclear Regulatory Commission (NRC) approval of proposed inservice inspection (ISi) alternative N 1-14-CS-002 for North Anna Unit 1. The request is for a proposed alternative to extend the fourth inspection interval for affected snubber program components until December 14, 2020. The request for alternative is provided in Attachment 1.
Approval of the proposed alternative is requested by September 1, 2019 to support the Unit 1 2019 Fall refueling outage. If you have any questions, please contact Ms. Diane E. Aitken at (804) 273-2694.
Sincerely, ~-
Mark Sartain Vice President - Nuclear Engineering and Fleet Support
Attachment:
- 1. Proposed Alternative N 1-14-CS-002 - Snubber Program Extension This letter contains no NRC commitments.
cc:
U.S. Nuclear Regulatory Commission Region II Marquis One Tower Serial No.18-289 Docket No.: 50-338 Request for Proposed Alternative N 1-14-CS-002 Snubber Program Extension Page 2 of 2 245 Peachtree Center Ave., NE, Suite 1200 Atlanta, Georgia 30303-1257 Mr. Marcus Harris Old Dominion Electric Cooperative Innsbrook Corporate Center 4201 Dominion Blvd.
Suite 300 Glen Allen, Virginia 23060 Mr. James R. Hall NRC Senior Project Manager U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 08 B 1-A 11555 Rockville Pike Rockville, Maryland 20852 Ms. K. R. Cotton NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 08 G-9A 11555 Rockville Pike Rockville, Maryland 20852-2738 NRC Senior Resident Inspector North Anna Power Station
Serial No.18-289 Request for Proposed Alternative N 1-14-CS-002 Snubber Program Extension Page 1 of 5 ATTACHMENT 1 PROPOSED ALTERNATIVE N1-14-CS-002 SNUBBER PROGRAM EXTENSION VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION ENERGY VIRGINIA)
NORTH ANNA POWER STATION UNIT 1
N1-14-CS-002 Serial No.18-289 Docket No. 50-338 - Page 2 of 5 Proposed Alternative for North Anna Unit 1 Snubber Program Extension In Accordance with 10 CFR 50. 55a(z)(2)
-- Hardship Without a Compensating Increase in Quality and Safety -
1.0 ASME CODE COMPONENT($) AFFECTED All Class 1, 2, and 3 Snubbers 2.0 APPLICABLE CODE EDITION AND ADDENDA The NAPS 1 applicable Code for the Fourth 10-year lnservice Inspection (ISi) Interval and the ISi program is the 2004 Edition of ASME Code,Section XI with no Addenda (Reference 1 ). NAPS 1 Fourth inspection interval started May 1, 2009 and ends April 30, 2019. This proposed alternative requests an extension of the Fourth inspection interval for affected components until December 14, 2020.
3.0 APPLICABLE CODE REQUIREMENT Subparagraph IWA-2430(b) of ASME Code,Section XI, requires the inspection interval to be determined by calendar years following placement of the plant into commercial service.
Paragraph IWA-2432, "Inspection Program B," specifies that the first inspection interval is 10 years following the initial start of plant commercial service and that each of the successive inspection intervals is 10 years following the previous inspection interval.
Subparagraph IWA-2430(d)(1) states that each inspection interval may be extended as much as one year. The subparagraph also requires that the interval adjustments shall not cause successive intervals to be altered by more than one year from the original pattern of intervals.
4.0 REASON FOR REQUEST By Nuclear Regulatory Commission (NRC) letter dated April 26, 1988 (TAC No. 67585),
the Units 1 and 2 lnservice Testing (1ST) Programs were aligned at the end of the first interval. The current North Anna Power Station (NAPS) Unit 1 and 2 ASME O & M Code (2004 Ed.) Pump and Valve Programs 1ST Intervals end on December 14, 2020.
The NAPS Unit 1 snubber inspection and testing program is currently contained in the NAPS Technical Requirements Manual (TRM) in lieu of ASME Code,Section XI, Article IWF, as approved in Relief Request N1-14-CS-001-R1 (Accession No. ML091350058),
which ends on April 30, 2019. This request for alternative is needed to transition from ASME Code,Section XI and the NAPS TRM with Unit 1 and Unit 2 snubber programs having different ending dates to the NAPS 1ST Program, scheduled to end December
Serial No.18-289 Docket No. 50-338 - Page 3 of 5 14, 2020. Although Unit 1 was shutdown for approximately three months during the Fourth interval because of the seismic event earthquake in 2011, this timeframe is not enough to meet the eight months (4/2019 thru 12/2020) required to align with 10-year inspection interval update.
NAPS Units 1 and 2 will transition the snubber programs to the 1ST Programs in accordance with the ASME O & M Code of record (currently 2012 Ed.), which includes Subsection ISTD, "Preservice and lnservice Examination and Testing of Dynamic Restraints (Snubbers) in Light-Water Reactor Nuclear Power Plants." Transitioning the snubber programs for Units 1 and 2 at different times, NAPS 1 on May 1, 2019 and NAPS 2 on December 14, 2020, would require a significant amount of administrative activity (e. g., administrative procedure changes, reconciliation of ASME O & M Code differences, technical procedure changes, etc.), without enhancement of quality and safety. Additionally, the Snubber Programs would not be aligned with the rest of the 1ST Program. This request for alternative is to extend the existing TRM snubber program requirements through the NAPS 1 Fall 2019, refueling outage N1 R27, which will continue to accomplish the intended program requirements of ASME O & M Code, Subsection ISTD until full conversion of NAPS Units 1 and 2 to ASME O& M Code, Subsection ISTD requirements with the Fifth interval update of the NAPS 1ST Programs by December 14, 2020. Performance of the TRM snubber program requirements during previous intervals has continued to verify the reliability and safety of the affected snubber components.
5.0 PROPOSED ALTERNATIVE AND BASIS FOR USE Dominion proposes to extend the Unit 1 Fourth inspection interval by approximately 8 months past the Cod_e-allowed one-year extension, from April 30, 2019 to December 14, 2020, for only the snubber program components identified in this request. At that time, the Unit 1 snubber program will be managed under the Fifth Interval lnservice Testing (1ST) Program ASME O&M Code, Subsection ISTD requirements.
This proposed alternative for the snubber program encompasses the total number of Unit 1 snubbers inspected as safety-related:
326 small bore (8" bore and less) 12 large bore (Attached to Steam Generators).
and takes into consideration the similarities between existing TRM snubber program requirements and ASME O&M Code, Subsection ISTD requirements, delineated in Reference 1. A summary of some requirements from Reference 1 are summarized below.
Visual Inspection Serial No.18-289 Docket No. 50-338 - Page 4 of 5 TRM 3.7.5, Table 3.7.5-1, a. Visual Inspection, Column A, Extend Interval, indicates that if the number of unacceptable snubbers is equal to or less than the number in column A (based on snubber population), the next inspection interval may be twice the previous interval but not greater than 48 months.
This schedule / table matches ASME O & M Code, Subsection ISTD, Table ISTD-4252-1 (both O&M Code, 2004 Ed. and 2012 Ed.) for inspection surveillance requirements.
Operational Readiness Testing The TRM requires a representative sample of small bore snubbers (using the expression 35[1 +c/2], where c=1 is the allowable number of small bore snubbers not meeting functional test acceptance requirements) be functionally tested.
Currently, using this formula, NAPS functional testing groups include 55 to 60 snubbers. The acceptance criteria includes a provision that each snubber activate in a restraining action within the specified range of velocity or acceleration and the release rate be within the specified range in compression and tension.
The above test criteria is in agreement with ASME O & M Code, Subsection ISTD-5210, 'Test Parameters' {both 2004 Ed. and 2012 Ed.).
The scope expansion requirements for functional test failures in the TRM and ASME 0 & M Code, Subsection ISTD are also similar.
Service Life Monitoring The Service Life Monitoring requirements for snubbers as depicted in the TRM are the same as ASME O & M Code, Subsection ISTD-6000 and Non-mandatory Appendix F. The requirements allow for individual evaluations based on environment, etc. Although the service life monitoring requirements are the same, the current Service Life Monitoring for NAPS 1 is based on a Technical Evaluation of a maximum 14 years snubber seal life rather than performing distinct seal life evaluations/calculations which could possibly extend the seal life. Therefore, using Service Life Monitoring requirements based on Technical Evaluation rather than distinct seal life evaluations/calculations is considered more conservative.
The snubber surveillance requirement I schedule for RFO N1 R27 will continue the requirements of the TRM for the representative sample of the snubber population for the functional test group. As discussed above, NAPS functional test groups contain 55 snubbers. The ASME O & M Code, Subsection ISTD-5260, gives the option of using either a 10% sample Testing Plan or the 37 sample Testing Plan. In reference to the snubber population for Unit 1, both of these options are similar in number. The
Serial No.18-289 Docket No. 50-338 - Page 5 of 5 current TRM functional test group scheduled for testing is, therefore, more conservative than either of these sample Testing Plans.
6.0 DURATION OF PROPOSED ALTERNATIVE This request is applicable to the NAPS 1 ISi program for the Fourth 10-year inspection interval, which will be extended until the start of the North Anna Unit 1 1ST program Fifth 10-year inspection interval (expected to be December 15, 2020).
7.0 REFERENCES
- 1. NRC Letter dated June 10, 2009 (Accession No. ML091350058), "Safety Evaluation for North Anna Power Station, Unit 1, Fourth 10-Year lnservice Inspection and Testing Interval for Snubber Visual Examination and Functional Testing, Relief CS-001 (TAC No. MD9957)."
- 2. NRC Letter dated April 26, 1988 (Accession No. ML8805120171 ), "Issuance of Exemption to 10 CFR Part 50.55a(g)(4)(ii) for the North Anna Power Station, Unit No.
1 (NA-1) (TAC No. 67585)."