ML15147A016
| ML15147A016 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 05/19/2015 |
| From: | Mark D. Sartain Virginia Electric & Power Co (VEPCO) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 15-245 | |
| Download: ML15147A016 (6) | |
Text
10 CFR 50.55a VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 May 19, 2015 United States Nuclear Regulatory Commission Serial No.15-245 Attention: Document Control Desk NAPS/JHL RO Washington, D.C. 20555 Docket No.
50-338 License No.
NPF-4 VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION)
NORTH ANNA POWER STATION UNIT I ASME SECTION XI INSERVICE INSPECTION PROGRAM PROPOSED INSERVICE INSPECTION ALTERNATIVE NI-14-SPT-006 In accordance with 10 CFR 50.55a(a)(3)(ii), Dominion hereby requests Nuclear Regulatory Commission (NRC) approval of proposed inservice inspection (ISI) alternative N1-14-SPT-006. The reactor coolant pressure boundary pipe segment described in this request is a portion of the auxiliary pressurizer spray line, which is not normally pressurized.
This alternative would allow an ASME Section Xl, Table IWB-2500-1 and IWB-5221 system leakage test, with isolation valve 1-CH-HCV-1311 in the normally closed position, as an alternative to the system leakage test requirements of IWB-5222(b) for this piping segment.
The request for alternative NI-14-SPT-006 is provided in Attachment 1.
Dominion requests approval of the proposed alternative by May 31, 2016. If you have any questions, please contact Mr. Jay Leberstien at (540) 894-2574.
Sincerely, Mark Sartain Vice President Nuclear Engineering This letter contains no NRC commitments.
Attachment
- 1. Proposed Inservice Inspection Alternative - NI-14-SPT-006 in Accordance with 10 CFR 50.55a(a)(3)(ii)
Serial No.15-245 Docket No. 50-338 Request for Alternative N 1-14-SPT-006 Page 2 of 2 cc:
U.S. Nuclear Regulatory Commission Region II Marquis One Tower 245 Peachtree Center Ave, NE Suite 1200 Atlanta, Georgia 30303-1257 Mr. J. E. Reasor, Jr.
Old Dominion Electric Cooperative Innsbrook Corporate Center 4201 Dominion Blvd.
Suite 300 Glen Allen, Virginia 23060 NRC Senior Resident Inspector North Anna Power Station Ms. K. R. Cotton NRC Project Manager-Surry U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 08 G-9A 11555 Rockville Pike Rockville, Maryland 20852-2738 Dr. V. Sreenivas NRC Project Manager-North Anna U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 08 G-9A 11555 Rockville Pike Rockville, Maryland 20852-2738
Serial No.15-245 Docket No. 50-338 Request for Alternative N1-14-SPT-006 Proposed Inservice Inspection Alternative NI-14-SPT-006 In Accordance with 10 CFR 50.55a(a)(3)(ii)
Virginia Electric and Power Company (Dominion)
North Anna Power Station Unit I
Serial No.15-245 Docket No. 50-338 Request for Alternative N1-14-SPT-006 REQUEST FOR ALTERNATIVE NI-14-SPT-006 Proposed Alternative in Accordance with 10 CFR 50. 55a(a)(3)(ii)
-Hardship or Unusual Difficulty without Compensating Increase in Level of Quality or Safety-
- 1. ASME CODE COMPONENTS AFFECTED The Code component associated with this request is the Class 1 Nominal Pipe Size (NPS) 2" Auxiliary Spray Piping, which is part of the extended Class 1 Reactor Coolant Pressure Boundary (RCPB) that requires pressurization once each 10-year inspection interval.
1.1 Category and System Details:
Code Class:
Class 1 System:
Chemical and Volume Control System Examination Category:
B-P Item Number:
B15.10 1.2 Component Descriptions:
NPS 2" Auxiliary Spray Piping Segment Boundary (valve-to-valve) from 1-CH-HCV-1311 to 1-CH-328 Approximate length - 100 feet Drawing: 11715-CBM-095C-4, Sheet 1 of 2
- 2. APPLICABLE CODE EDITION AND ADDENDA ASME Section Xl, 2004 Edition
- 3. APPLICABLE CODE REQUIREMENTS IWB-5222(b) states, "The pressure retaining boundary during the system leakage test conducted at or near the end of each inspection interval shall extend to all Class 1 pressure retaining components within the system boundary." IWB-5221(a) states, "The system leakage test shall be conducted at a pressure not less than the pressure corresponding to 100% rated reactor power."
The paragraphs require pressurization at reactor coolant system nominal operating pressure for this portion of the extended Class 1 boundary at or near the end of the interval.
Serial No.15-245 Docket No. 50-338 Request for Alternative Ni SPT-006
- 4. REASON FOR REQUEST Pressurizer pressure is maintained via normal pressurizer spray, which uses the Reactor Coolant Pumps (RCP).
Normal pressurizer spray is controlled by the pressurizer Pressure Control System which automatically controls the pressurizer environment. The primary purpose of the auxiliary spray line is for pressure control when the RCPs are not running (i.e., during a post accident condition when it is desired to decrease Reactor Coolant System (RCS) pressure). Operation of the auxiliary spray line at hot standby or power would lead to an unnecessary plant transient. To meet Code requirements, the normally closed upstream isolation valve 1-CH-HCV-1311 must be opened to pressurize the subject pipe segment. Water in this line is supplied from the Charging System which operates at a pressure slightly greater than the RCS normal operating pressure. Therefore, opening of valve 1-CH-HCV-1 311 at hot standby or power would increase pressurizer spray flow which will cause an adverse reduction in RCS pressure. In addition, this piping segment is at containment ambient temperature and with the RCS at normal operating temperature, this test would create a thermal shock transient in the spray piping and spray nozzle.
- 5. PROPOSED ALTERNATIVES AND BASIS FOR USE The RCPB pipe segment described in this request is a portion of the auxiliary pressurizer spray line, which is not normally pressurized. This request proposes to perform an ASME Code Section Xl, Table IWB-2500-1 and IWB-5221 system leakage test with the isolation valve 1-CH-HCV-1311 in the normally closed position as an alternative to the system leakage test requirements of IWB-5222(b) for this piping segment. This examination will be performed at nominal operating pressure associated with 100% reactor power after satisfying the ASME Code required hold time.
Testing of this piping segment at full RCS operating pressure does not provide a compensating increase in the level of quality or safety for the following reasons:
- 1. The design pressure rating of this piping segment is the same as the RCPB; however, the operating pressure of the piping segment is well below the normal RCS operating pressure.
- 2. This segment is isolated from the RCS pressure under normal operating conditions.
This examination is performed with the segment isolated from the RCS and the RCS at its normal operating pressure and temperature.
This examination is performed each refueling outage and is sufficient to identify any structural defects that could potentially challenge the integrity of the segment during normal operation.
Serial No.15-245 Docket No. 50-338 Request for Alternative N 1-14-SPT-006 Dominion has determined that compliance with the system leakage test requirements of IWB-5222(b) for this piping segment for North Anna Power Station Unit 1 results in an unnecessary hardship and adverse impact to plant equipment without a sufficient compensating increase in the level of quality and safety.
Therefore, Dominion requests approval of this alternative pursuant to the provisions of 10 CFR 50.55a(a)(3)(ii).
- 6. DURATION OF PROPOSED ALTERNATIVE The proposed alternative to the ASME Code is applicable for the fourth 10-year Interval at NAPS Unit 1.
- 7. PRECEDENTS Similar alternatives to the test requirements of Section XI have been approved for Kewaunee Power Station, Indian Point Units 2 and 3, Millstone Power Station Units 2 and 3, and North Anna Power Station Unit 2. Information for the precedents cited are provided below.
- 1. Kewaunee Power Station, dated February 18, 2005 (ADAMS Accession No. ML050350225).
- 2. Indian Point Generating Units 2 and 3, dated December 7, 2005 (ADAMS Accession No. ML053110525).
- 3. Millstone Power Station Unit 3, dated September 27, 2007 (ADAMS Accession No. ML072620318).
- 4. North Anna Power Station Unit 2, dated November 2, 2010 (ADAMS Accession No. ML102510218).
- 5. Millstone Power Station Unit 2, dated July 27, 2011 (ADAMS Accession No. ML111881029).