BVY 06-072, Response to Request for Additional Information Regarding Relief Request ISI-013, Fourth 10-Year ISI Interval

Response to Request for Additional Information Regarding Relief Request ISI-013, Fourth 10-Year ISI Interval

ML062410404
Person / Time
Site:	Vermont Yankee
Issue date:	08/25/2006
From:	Ted Sullivan Entergy Nuclear Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
BVY 06-072
Download: ML062410404 (34)

Text

Entergy Nuclear Operations, Inc.

Vermont Yankee P.O. Box 0500 185 Old Ferry Road

~Entergy Bratlieboro, VT 05302-0500 Tel 802 257 5271 August 25, 2006 BVY 06-072 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Vermont Yankee Nuclear Power Station License No. DPR-28 (Docket No. 50-271)

Response to Request for Additional Information Regardingl Relief Request ISI-013, Fourth 10-Year ISI Interval

References:

(1) Letter, USNRC to Entergy Nuclear Operations, Inc., "Vermont Yankee Nuclear Power Station - Request for Additional Information Regarding Relief Request Inservice Inspection (ISI)-013, Fourth 10-Year ISI Interval (TAC No. MD0287)," NVY 06-098, dated July 27, 2006.

(2) Letter, Entergy Nuclear Operations, Inc. to USNRC, "Relief Request ISI-012, Fourth ISI Interval," BVY 06-011, dated February 16, 2006.

(3) Letter, Entergy Nuclear Operations, Inc. to USNRC, "Relief Request ISI-013, Fourth ISI Interval," BVY 06-029, dated March 27, 2006.

In Reference (1), the Nuclear Regulatory Commission has requested additional information regarding Vermont Yankee's request, submitted in Reference (2) and supplemented in Reference (3), for relief from requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code,Section XI, pertaining to examination of Category B-F, Item 5.10, nozzle-to-safe-end welds.

Vermont Yankee's response to this request is provided in Attachments 1 and 2. Enclosure 1 provides copies of the requested component drawings.

No new regulatory commitments are being made in this submittal.

If you have any questions or require additional information regarding this response, please contact Mr. Jim DeVincentis at (802) 258-4236.

Sincerely, Ted A. Iliva Site Vic& esident Vermont Yankee Nuclear Power Station Attachments (2)

Enclosure cc listing (next page)

BVY 06-072 Page 2 of 2 cc: Mr. Samuel J. Collins (w/o enclosure)

Regional Administrator, Region 1 U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406-1415 Mr. James J. Shea, Project Manager Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop O-8C2A Washington, DC 20555 USNRC Resident Inspector (w/o enclosure)

Entergy Nuclear Vermont Yankee, LLC P.O. Box 157)

Vernon, Vermont 05354 Mr. David O'Brien, Commissioner (w/o enclosure)

VT Department of Public Service 112 State Street - Drawer 20 Montpelier, Vermont 05620-2601

BVY 06-072 Attachment 1 Vermont Yankee Nuclear Power Station License No. DPR-28 (Docket No. 50-271)

Response to Request for Additional Information Regarding Request for Relief No. ISI-013 Fourth 10-Year Inservice Inspection Interval Responses to RAI Questions

BVY 06-072 Attachment 1 Page 1 of 3 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING REQUEST FOR RELIEF NO. ISI-013 FOURTH 10-YEAR INSERVICE INSPECTION INTERVAL The staff reviewed the information submitted by Vermont Yankee and, based on this review, determined that additional information is required to complete the evaluation.

Following are responses to each of the RAI questions.

Question 1:

Please provide drawings or sketches of the American Society of Mechanical Engineers (ASME) Code,Section XI, Category B-F components listed in the List of Affected B-F Welds attached to the licensee's letter dated February 16, 2006.

Drawings or sketches of every component are not required. An example of one of each type of similar component will satisfy this request.

Response

Enclosed are twenty-five (25) component sketches/drawings for the American Society of Mechanical Engineers (ASME) Code,Section XI, Category B-F components listed in the List of Affected B-F Welds attached to the licensee's letter dated February 16, 2006 (Reference Attachment 2 for affiliated drawings).

Question 2:

In the List of Affected B-F Welds, under materials please clarify the materials for the components listed in the table and provide weld rod material.

Response

Per your request, Attachment 2 provides clarification for the materials and components listed in the table of affected B-F Welds and provides weld rod material used.

The information requested is also contained in the following:

a. Letter FVY 88-62, dated July 27, 1988, "Vermont Yankee Response to NRC Position on IGSCC in BWR Austenitic Stainless Steel Piping (Generic Letter 88-01)."

b. Letter BVY 89-70, dated July 25, 1989, "Vermont Yankee's Response to NRC's Request for Additional Information: USNRC Generic Letter 88-01 ."

c. "Safety Evaluation by the Office of Nuclear Reactor Regulation, Evaluation of NRC Generic Letter 88-01 Response, Vermont Yankee Nuclear Power Corporation," and enclosed 'Technical Evaluation Report on Response from the Vermont Yankee Nuclear Power Corporation to Generic Letter 88-01 Pertaining to the Vermont Yankee Nuclear Power Station," published September, 1989.

BVY 06-072 Attachment 1 Page 2 of 3 Question 3:

In accordance with BWRVIP-75-A, "BWR Vessel and Internals Project Technical Basis for Revisions to Generic Letter 88-01 Inspection Schedules," Chapter 3, page 3-1 second paragraph, please provide a discussion as to how the conditions contained in BWRVIP-75-A are applicable to Vermont Yankee. Include a discussion as to why your material is resistant to inter-granular stress corrosion cracking (IGSCC) (For example, hydrogen water chemistry treatment program, material of subject components and/or other measures such as control of conductivity to prevent IGSCC).

Response

Vermont Yankee (VY) complies with the latest version (BWRVIP-130) of the EPRI BWR Water Chemistry Guidelines control parameters. This document and applicable Entergy and VY procedures have the controls, limits and action levels for the parameters that contribute to IGSCC, such as sulfate, chloride and conductivity.

This justifies using the normal water chemistry schedule for the respective weld categories in BWRVIP-75-A for all the IGSCC welds.

VY applied Noble Metal Chemical Addition (NMCA) in April 2001, followed with feedwater hydrogen injection (Hydrogen Water Chemistry) in November 2003.

When the open issues on the definition of effective HWC/NMCA between the BWRVIP and NRC have been dispositioned (such as ECP, molar ratio, HWC availability, etc.), VY will evaluate use of the HWC/NMCA inspection frequency only on the welds where NMCA would be effective (i.e. on Recirculation System and RWCU System, but not on Core Spray System).

VY has a total of 156 welds that are classified as BWRVIP Category A. These welds are located in the Recirculation, Residual Heat Removal, Core Spray, Nuclear Instrumentation (including Jet Pump), Control Rod Drive and Reactor Water Clean-Up Systems.

The piping in the Recirculation and Residual Heat Removal Systems is so categorized as a result of being replaced with IGSCC-resistant 316 austenitic stainless steel during the 1986 refueling outage.

The Core Spray System is normally a non-flowing system. The portion from the reactor pressure vessel to the first isolation valve is low carbon type 316 stainless steel. The welds are low carbon type 308 stainless steel. This portion of the Core Spray System is Category A.

Since the system is non-flowing, the temperature will be below 200 OF before the first valve; therefore, the remaining portion of the system does not fall under the requirements of Generic Letter 88-01.

The Reactor Water Clean-Up (RWCU) System piping is low carbon type 304 or low carbon type 316 stainless steel. The welds are low carbon type 308 stainless steel.

The piping susceptible to IGSCC was replaced during the 1980 timeframe. Thus, all Reactor Water Clean-Up piping 4 inches or greater in diameter and operating at greater than 200 OF is classified as Category A.

BVY 06-072 Attachment 1 Page 3 of 3 With the exception of the Core Spray safe ends and associated welds, all other system piping is of low carbon type 304 or low carbon type 316, stainless steel. The welds are low carbon type 308 stainless steel.

Question 4:

Please clarify that the personnel and procedures used for the examinations of Category A piping at Vermont Yankee are in accordance with the Electric Power Research Institute demonstration initiative program, under ASME Code,Section XI, Appendix VII and Appendix VIII.

Response

Personnel and procedures used for the examinations of Category A piping at Vermont Yankee comply with the Electric Power Research Institute Performance Demonstration Initiative (PDI) Program, under the ASME Code, Section Xl, Appendix VII and Appendix VIII. Examination personnel and procedures are selected based on their specific qualifications relative to Appendix VIII Supplement requirements.

Information regarding these qualifications is retained in plant In-Service Inspection records.

BVY 06-072 Attachment 2 Vermont Yankee Nuclear Power Station License No. DPR-28 (Docket No. 50-271)

Response to Request for Additional Information Regarding Request for Relief No. ISI-013 Fourth 10-Year Inservice Inspection Interval Description of Materials

ATTACHMENT 2 TO BVY 06-072 REQUEST FOR ADDITIONAL INFORMATION REQUEST FOR RELIEF NO. ISI-013 4th 10-YEAR IN-SERVICE INSPECTION INTERVAL Nozzle ID Nozzle Material Safe End Material Weld Material Butter Material Drawings A508 CLII w/ ASTM ER 308L - Root Safe End: 5920-6623 NIA & N1B A371 Type ER SA 182 F316 E 308-15 Weld E 308L Nozzle : 5920-238 308L SS Clad A508 CLII w/ ASTM ER 308L - Root Safe End: 5920-6624 N2A thru N2K A371 Type ER SA 182 F316 E 308-15 Weld E 308L Nozzle : 5920-656 308L SS Clad A508 CLII wI/ASTM A58CIIw SMER 308L - Root Flange: 5920-5331, 5263 N6A & N6B A371 Type ER SA 336 CL F8 E 308- Root E 308L Flange: 5920-53 308L SS Clad E 308-15 Weld Nozzle. 5920-243 A508 CLII w/ ASTM

- ER 308L - Root Flange: 5920-5331, 5263 N7 A371 Type ER SA 336 CL F8 E 308-15 Weld E 308L Nozzle: 5920-244, 71 308L SS Clad Header: 5920-5331, 5263 SA 336 CL F8 iNozzle: 5920-245.

A508 CLII w/ ASTM CLaF8 NoAe336e Penetration seal ER 308L - Root Note: The header N8A & N8B A371 Type ER (header low carbon 304 E 308-15 Weld E 308L (penetration seal) is 308L SS Clad Stainless Steel) welded directly to the nozzle. This safe-end was eliminated A508 CLII w/ ASTM Safe End: 5920-246 Sh.2 N9 A371 Type ER SA 336 CL F8 ER 316L E 308L Nozzle: 5920-246 308L SS Clad I I I _II

BVY 06-072 Enclosure 1 Vermont Yankee Nuclear Power Station License No. DPR-28 (Docket No. 50-271)

Response to Request for Additional Information Regarding Request for Relief No. ISI-013 Fourth 10-Year Inservice Inspection Interval Component Drawings