NL-09-0586, Unit 2, VEGP-ISI-RR-01, Version 1.0, Relief Request in Accordance with 10 CFR 50.55a(g)(5)(iii)
| ML091140341 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 04/23/2009 |
| From: | Ajluni M Southern Nuclear Operating Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NL-09-0586, VEGP-ISI-RR-01, Version 1.0 | |
| Download: ML091140341 (5) | |
Text
Southern Nuclear Operating Company, Inc.
SOUTHERN'\\.
COMPANY April 23, 2009 Ellergy to.Serve Your World Docket No.:
50-425 NL-09-0586 U. S. Nuclear Regulatory Commission ATIN: Document Control Desk Washington, D. C. 20555-0001 Vogtle Electric Generating Plant - Unit 2 VEGP-ISI-RR-01, Version 1.0, Relief Request in Accordance With 10 CFR 50.55a(g)(5)(iii)
Ladies and Gentlemen:
Pursuant to 10 CFR 50.55a, Southern Nuclear Operating Company (SNC) hereby requests NRC approval of relief request VEGP-ISI-RR-01, which request relief from performing strand testing on Unit 2 containment tendons. The proposed relief request is applicable for the 3rd Inservice Inspection Interval.
The details of the 10 CFR 50.55a request are contained in the enclosure. Approval is requested by May 1, 2010, to support 3rd interval examinations to be performed during the Summer 2010. This relief request is equivalent to relief request RR-L-3 submitted for the previous inspection interval. The NRC approved this relief request per a safety evaluation dated June 16, 2000.
This letter contains no NRC commitments. If you have any questions, please advise.
Sincerely, M. J. Ajluni Manager, Nuclear Licensing MJAITAH/daj
Enclosure:
VEGP-ISI-RR-01, Version 1.0, Relief Request in Accordance With 10 CFR 50.55a(g)(5)(iii)
U. S. Nuclear Regulatory Commission NL-09-0586 Page 2 cc:
Southern Nuclear Operating Company Mr. J. T. Gasser, Executive Vice President Mr. T. E. Tynan, Vice President - Vogtle Ms. P. M. Marino, Vice President - Engineering RType: CVC7000 U. S. Nuclear Regulatory Commission Mr. L. A. Reyes, Regional Administrator Mr. R. E. Martin, NRR Project Manager - Vogtle Mr. M. Cain, Senior Resident Inspector - Vogtle
Vogtle Electric Generating Plant - Unit 2 Enclosure VEGP-ISI-RR-01, Version 1.0, Relief Request in Accordance With 10 CFR 50.55a(g)(5)(iii)
Enclosure Southern Nuclear Operating Company Relief Request in Accordance with 10 CFR 50.55a(g)(5)(iii)
VEGP-ISI-RR-01, Version 1.0 E1-1 Plant Site - Unit:
Vogtle Electric Generating Plant (VEGP) - Unit 2.
Interval-Interval Dates:
3rd ISI Interval, May 31, 2007 through May 30, 2017.
Requested Date for Approval:
Approval is requested by May 1, 2010, to support examinations scheduled during the summer of 2010.
ASME Code Components Affected:
VEGP-2 tendon strands.
Applicable Code Edition and Addenda:
ASME Section XI, 2001 Edition through the 2003 Addenda.
Applicable Code Requirement:
IWL-2523 requires that a strand sample be examined and tested.
IWL-2523.1 requires that one sample tendon, from each type, be detensioned completely and a single strand removed from each detensioned tendon.
IWL-2523.2 requires that the strands selected in IWL-2523.1 are tension tested and examined for corrosion and mechanical damage.
Impracticality of Compliance:
The VEGP Unit 2 post-tensioning system was designed so that no tendons can be detensioned without creating voids in the sheathing filler material. Without the capability to completely detension a tendon, strand samples cannot be removed and tested. VEGP was originally licensed so that tendon lift-off and strand testing would be performed on Unit 1 only.
Only the Unit 1 containment structure is equipped with the provision for tendon removal with detensionable anchorage assemblies as stated in VEGP UFSAR section 3.8.1.7.2.
Therefore, relief from the Code requirements should be granted under 10 CFR 50.55a(g)(6)(i) based on impracticality. The Unit 2 containment post tensioning system can not be modified to allow for compliance with the code requirements. The proposed alternative, which is based on testing that was approved by the NRC, ensures that the structural integrity of the containment is being maintained.
Enclosure Southern Nuclear Operating Company Relief Request in Accordance with 10 CFR 50.55a(g)(5)(iii)
VEGP-ISI-RR-01, Version 1.0 E1-2 Burden Caused by Compliance:
The current Unit 2 containment configuration does not provide for compliance with the code requirements and the post tensioning configuration can not be modified to allow for compliance.
Proposed Alternative and Basis for Use:
- 1. VEGP will perform lift-off testing on the Unit 2 tendons in accordance with IWL-2520.
- 2. The strands selected during lift-off testing of Unit 1 will be credited for Unit 2.
Post tensioning VEGP Unit 1 was completed in April, 1986 (4/26/86) and Unit 2 in December, 1986 (12/3/86). Therefore, the VEGP containments meet the criteria of IWL-2421(a) for sites with multiple plants. Therefore, performance of IWL-2520 exams on Unit 2 while crediting Unit 1 strand testing for Unit 2 provides reasonable assurance of structural integrity of the Unit 2 unbonded post tensioning system.
Duration of Proposed Alternative:
3rd ISI Interval, May 31, 2007 through May 30, 2017.
Precedents:
An equivalent Relief Request (RR-L-3) was previously approved.
References:
NRC Safety Evaluation dated June 16, 2000 - TAC NOS. MA5314 AND MA5315.
Status:
Awaiting NRC approval.