RBG-47285, Request for Relief RBS-ISI-018, Request for Relief from ASME Code Section XI Inservice Inspection Requirements for Reactor Pressure Vessel Support Skirt

Request for Relief RBS-ISI-018, Request for Relief from ASME Code Section XI Inservice Inspection Requirements for Reactor Pressure Vessel Support Skirt

ML12277A387
Person / Time
Site:	River Bend
Issue date:	09/25/2012
From:	Clark J Entergy Corp
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
RBG-47285, RBS-ISI-018
Download: ML12277A387 (5)

Text

~River Bend Station En e g 6 1 5485 U.S. Highway 61 N St. Francisville, LA 70775 Tel 225-381-4177 Joseph A Clark Manager, Licensing RBG- 47285 September 25, 2012 U. S. Nuclear Regulatory Commission Attn.: Document Control Desk Washington, DC 20555-0001

SUBJECT:

River Bend Station, Unit 1 - Request for Relief RBS-ISI-018 Request for Relief from ASME Code Section Xl Inservice Inspection Requirements for Reactor Pressure Vessel Support Skirt Docket No. 50-458 License No. NPF-47

REFERENCE:

NRC SER dated October 20, 1987

Dear Sir or Madam:

Pursuant to 10 CFR 50.55a, "Codes and Standards," paragraph (g)(5)(iii), Entergy requests relief from certain American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (BPV), 1992 Edition with 1993 Addenda, Section Xl, Sub Article IWF-2500 Inservice Inspection (ISI) requirements for Examination Category F-A, Supports. This relief is requested for the second 10-year interval of the Inservice Inspection Program for the River Bend Station (RBS).

This request for relief is being submitted beyond the 12 month timeframe following the second 120 month interval as specified under 10 CFR 50.55a(g)(5)(iv). This condition has been addressed in Entergy's Corrective Action Process.

In accordance with 10 CFR 50.55a(g)(6)(i), the proposed relief to the referenced requirements may be approved by the NRC giving due consideration to the burden upon the licensee that could result if the requirements were imposed on the facility. Entergy believes full compliance with the ASME Code,Section XI requirements is not practical.

The specific details of the requested relief are enclosed in Attachment 1.

The NRC previously granted relief for this examination in the Safety Evaluation identified in the Reference.

There are no new commitments in this letter.

RBG- 47285 Page 2 of 2 If you have any questions concerning this letter, please contact me at (225) 381-4177.

Respectf 1y JAC/bmb - RIVER BEND STATION - UNIT 1, SECOND 10 YEAR INTERVAL INSERVICE INSPECTION PROGRAM, REQUEST FOR RELIEF, RBS-ISI-018 RBF1-12-0137 cc: Regional Administrator U. S. Nuclear Regulatory Commission, Region IV 1600 East Lamar Blvd.

Arlington, TX 76011-4511 NRC Senior Resident Inspector P. 0. Box 1050 St. Francisville, LA 70775 U. S. Nuclear Regulatory Commission Attn: Mr. Alan Wang MS O-8B1 One White Flint North 11555 Rockville Pike Rockville, MD 20852 Department of Environmental Quality Office of Environmental Compliance Radiological Emergency Planning and Response Section JiYoung Wiley P.O. Box 4312 Baton Rouge, LA 70821-4312 Public Utility Commission of Texas Attn: PUC Filing Clerk 1701 N. Congress Avenue P. 0. Box 13326 Austin, TX 78711-3326

ATTACHMENT I TO RBG- 47285 RIVER BEND STATION - UNIT I SECOND 10 YEAR INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF RBS-ISI-01 8 to RBG- 47285 Page 1 of 2 RIVER BEND STATION - UNIT 1 Relief Requested in Accordance with 10 CFR 50.55a(g)(5)(iii)

RBS-ISI-018 I. ASME Code Component(s) Affected / Applicable Code Edition and Addenda Component(s) Affected: B13-D001-SUP (Reactor Vessel Support Skirt)

Code Class: ASME Code Class 1

References:

ASME Section Xl 1992 Edition, 1993 Addenda, Table IWF-2500-1 Inspection Program B Examination Category: F-A, Supports Item Number(s): F1.40, Supports Other Than Piping Supports (Class 1, 2, 3 and MC)

Unit / Inspection Interval Applicability: River Bend Station (RBS) Unit 1, Second (2nd) 10-year interval - December 1, 1997 through May 31, 2008 I1. Applicable Code Requirement(s)

Table IWF-2500-1, Examination Category F-A, Supports, Item F1.40, Supports Other Than Piping Supports (Class 1, 2, 3 and MC) requires essentially 100% visual examination of the reactor vessel support skirt.

II1. Impracticality of Compliance Performing the VT-3 examination of essentially 100% of the reactor vessel support skirt as required by the ASME Code requires access to the inside of the skirt under the vessel. Access is accomplished through four openings in the skirt wall. An insulation package is located inside the skirt which covers the lower skirt, the interior ring of bolting and the base plate.

The area inside the skirt experiences high radiological dose rates. The reactor vessel internal component configuration prevents flushing of the bottom head region to potentially reduce the dose rates. The configuration of the Control Rod Drive stub tubes under the bottom head make the use of lead shielding impractical.

Performing the full Code examination requires removal of the insulation package which is labor intensive due to the configuration and the confined aspect of the area. The actual time required to remove the insulation package is indeterminate as it has not been previously removed in its entirety. Therefore, an accurate dose estimate for the task can not be developed at this time.

Based on the dose rates and the difficulty entailed in removing the insulation, Entergy has determined that performing the examination as required by the ASME Code is impractical.

IV. Proposed Alternatives and Basis of Use Relief is requested from performing the full Code examination on essentially 100% of the reactor vessel support skirt. The skirt will continue to receive VT-3 examination of the entire exterior portion, and as much of the interior as can be accessed through the access openings without removal of the insulation package.

V. Duration of Requested Relief Relief is requested for the second ISI Interval from December 1, 1997 through May 31, 2008.

to RBG- 47285 Page 2 of 2 VI. Precedents Relief from the subject examination was previously approved by the NRC Staff for the first ISI Interval under RRO012G revision 1 as documented in NRC SER dated October 20, 1987.