ML071080222

Repair of the Core Shroud Stabilizer Assemblies - Torsion Arm Clamp Stress Evaluation Report

ML071080222
Person / Time
Site:	Pilgrim
Issue date:	04/10/2007
From:	Bethay S Entergy Nuclear Operations
To:	Document Control Desk, NRC/NRR/ADRO
References
2.07.035, eDRF 0000-0064-9390, eDRF 0000-0066-7000-R0, TAC MD4918 GE-NE-0000-0066-0380-R1-NP
Download: ML071080222 (3)

Text

Entergy Nuclear Operations, Inc.

Pilgrim Nuclear Power Station 600 Rocky Hill Road Plymouth, MA 02360 Stephen J. Bethay April 10, 2007 Director, Nuclear Assessment U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555-0001

SUBJECT:

Entergy Nuclear Operations, Inc.

Pilgrim Nuclear Power Station Docket No. 50-293 License No. DPR-35 Pilgrim Repair of the Core Shroud Stabilizer Assemblies- Torsion Arm Clamp Stress Evaluation Report (TAC NO. MD4918)

REFERENCES:

1. Entergy Letter No. 2.07.016, Request for Authorization Under the Provision of 10 CFR 50.55a(a)(3((1) for Modification of the Core Shroud Stabilizer Assemblies, dated March 22, 2007 LETTER NUMBER: 2.07.035

Dear Sir or Madam:

By Reference 1, Entergy proposed a preemptive repair to the Pilgrim core shroud stabilizer assemblies (i.e., tie rods) upper support components. The proposal included installation of a clamp on each of the upper support spring torsion arm bolts. Pilgrim has completed the final clamp design and associated stress calculations. Attachment 1 provides the spring torsion arm clamp stress evaluation report. is a GE proprietary 'Torsion Arm Clamp Stress Evaluation Report "dated April 2007, with an embedded GE Affidavit. The GE Affidavit details the reasons for requesting to withhold from public disclosure the stress analysis report. Therefore, on behalf of GE, Entergy hereby makes application to withhold Attachment 1 from public disclosure in accordance with 10 CFR 2.390(b)(1). A non-proprietary version of this report is included with this letter as .

The tie rod assemblies are not included under the ASME Code Section Xl definition for repair or replacement. As such, the design details of the proposed tie rod modification are being submitted to the NRC for review and approval as an alternative repair pursuant to 10 CFR 50.55a(a)(3)(i). This submittal, along with the Reference 1 submittal, contains the basis for concluding that the modification provides an acceptable level of quality and safety.

AnI

Entergy Nuclear Operations, Inc. Letter Number: 2.07.035 Pilgrim Nuclear Power Station Page 2 There are no regulatory commitments in this submittal.

NRC authorization to use this proposed alternative is requested by April 25, 2007, to support the scheduled startup of Pilgrim following RFO-16.

If you have any questions or require additional information, please contact Mr. Bryan Ford, Licensing Manager, at (508) 830-8403.

Sincerely,

• Stepe ./ta~

SJB/dl Attachments

1. GE Proprietary Report with Embedded GE Affidavit, GE-NE-0000-0066-0380-R1-P, Pilgrim Nuclear Power Station Torsion Arm Clamp Stress Evaluation Report, dated April 2007 (18 pages)

2. GE Non-Proprietary Report, GE-NE-0000-0066-0380-R1-NP, Pilgrim Nuclear Power Station Torsion Arm Clamp Stress Evaluation Report, dated April 2007 (15 pages) cc: Mr. James S. Kim, Project Manager

'Plant Licensing Branch I-1 Division of Operator Reactor Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission One White Flint North 4D9A 11555 Rockville Pike Rockville, MD 20852 Regional Administrator, Region 1 U.S. Nuclear Regulator Commission 475 Allendale Road King of Prussia, PA 19406 Senior Resident Inspector Pilgrim Nuclear Power Station

ATTACHMENT 2 Pilgrim Nuclear Power Station Torsion Arm Clamp Stress Evaluation Report GE Non-Proprietary Report No. GE-NE-0000-0066-0380-R1-NP, dated April 2007 (15 pages)