1CAN051301, Response to Request for Additional Information on Relief Request ANO1-ISI-022

Response to Request for Additional Information on Relief Request ANO1-ISI-022

ML13136A142
Person / Time
Site:	Arkansas Nuclear
Issue date:	05/16/2013
From:	Pyle S Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
1CAN051301, ANO1-ISI-022, TAC ME9147, TAC ME9148
Download: ML13136A142 (5)

Text

Entergy Operations, Inc.

1448 S.R. 333 Russellville, AR 72802 Tel 479-858-4704 Stephenie L. Pyle Manager, Licensing Arkansas Nuclear One 1CAN051301 May 16, 2013 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555

SUBJECT:

Response to Request for Additional Information Request for Relief ANO1-ISI-022 Arkansas Nuclear One, Unit 1 Docket No. 50-313 License No. DPR-51

REFERENCES:

1. Entergy letter to NRC, Requests for Relief from American Society of Mechanical Engineers (ASME)Section XI Volumetric Examination Requirements - Fourth 10-Year Interval, First Period, dated July 25, 2012 (1CAN071202) (ML12207A594)

2. NRC email to Entergy, RAI on Request for Relief ANO1-ISI-022, (TAC No. ME9148) dated April 10, 2013 (TAC No. ME9147) (ML13100A247)

Dear Sir or Madam:

Entergy Operations, Inc. requested NRCs approval of several Requests for Relief for Arkansas Nuclear One, Unit 1 via Reference 1. These requests are associated with the requirements of the ASME, Boiler and Pressure Vessel Code,Section XI pertaining to volumetric examinations. In several locations, the required coverage cannot be obtained due to interference or geometry.

In Reference 2 the NRC determined that additional information was needed to complete the review of Request for Relief ANO1-ISI-022 provided in Reference 1. Attached are the responses to the request for additional information.

This submittal contains no regulatory commitments.

1CAN051301 Page 2 of 2 If you have any questions or require additional information, please contact me.

Sincerely, Original signed by Stephenie L. Pyle SLP/rwc

Attachment:

Response to Request for Additional Information Relief Request - ANO1-ISI-022 cc: Mr. Arthur T. Howell Regional Administrator U. S. Nuclear Regulatory Commission Region IV 1600 East Lamar Boulevard Arlington, TX 76011-4511 NRC Senior Resident Inspector Arkansas Nuclear One P. O. Box 310 London, AR 72847 U. S. Nuclear Regulatory Commission Attn: Mr. Kaly Kalyanam MS O-8B1 One White Flint North 11555 Rockville Pike Rockville, MD 20852

Attachment to 1CAN051301 Response to Request for Additional Information Relief Request - ANO1-ISI-022

Attachment to 1CAN051301 Page 1 of 2 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION RELIEF REQUEST - ANO1-ISI-022 By letter dated July 25, 2012, (Agency Wide Document Access and Management System (ADAMS) accession number ML12207A594) Entergy Operation Incorporated (the licensee) submitted relief request ANO1-ISI-022. The licensee has requested relief from the weld examination coverage requirements specified in American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code,Section XI, 2001 Edition through the 2003 Addenda, for obtaining essentially 100 percent coverage for two welds.

The U.S. Nuclear Regulatory Commission (NRC) staff requests that Entertgy provide additional information to support the relief from ASME Code Section XI-required volumetric examination of essentially 100 percent of the two full-penetration welds.

1. In order to know the safety significance of the weld the NRC staff need to know which systems would be affected by a leak or failure of the welds. Please describe the locations of the welds and systems in which the welds are located.

Two welds were discussed in Relief Request ANO1-ISI-022. Welds22-060 and 22-064 are both part of the Makeup and Purification (MUP) system. They are located in the High Pressure Injection piping to reactor coolant system piping on the discharge side of A Reactor Coolant Pump.

Weld 22-060 is a pipe to check valve circumferential weld. Weld 22-064 is downstream of weld 22-060 and is a pipe to elbow circumferential weld.

2. The sizes of the welds are important in determining the safety significance of a leak or failure of the welds. Please provide the weld diameters and thicknesses.

Both welds are in 2.5 inch nominal pipe size (NPS), schedule 160 stainless steel piping (nominal 0.375 inch thickness).

3. What are the materials of construction of the piping and what are the weld metals?

• Piping material is American Society for Testing and Materials (ASTM) SA-312, TP-316 stainless steel.

• Check valve is ASTM A-182, F-316 stainless steel.

• Elbow is ASTM A-403, WP-316 stainless steel.

• Weld filler material for weld 22-060 is ER316 and E316.

• Weld filler material for weld 22-064 is ER316L.

Attachment to 1CAN051301 Page 2 of 2

4. The choice of welds for inspection was guided by the plants risk informed ISI program. Were additional welds in the same risk segment inspected to make up for the missed weld volume? Are there other welds within the same system(s), subject to the same degradation mechanisms that will allow for essentially 100 percent coverage that can be substituted for these welds? If so, will this be done in the next inspection interval Additional welds were not selected to make up for missed weld volume. There are other welds in the MUP system which are selected in the Inservice Inspection (ISI) plan for examination, but not as a substitution with the intent of acquiring a 100 percent examination versus a limited examination. It is important to note that 2 inch NPS pipe to valve and pipe to fitting (elbow and tee) configurations usually have geometric configurations that limit examination coverage.

In addition to other factors, the component selection process purposely includes welds that have configurations to fittings such as elbows, tees, valves and nozzles. To remove these components in favor of a non-restricted component, e.g., pipe to pipe, would result in an ISI program selection process that would not be conservative or represent the piping system configurations.