2CAN051202, Additional Information Related to Request for Alternative ANO2-ISI-007 Code Case N-770-1 Baseline Examination

Additional Information Related to Request for Alternative ANO2-ISI-007 Code Case N-770-1 Baseline Examination

ML12142A319
Person / Time
Site:	Arkansas Nuclear
Issue date:	05/21/2012
From:	Pyle S Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
2CAN051202, TAC ME7646
Download: ML12142A319 (13)

Text

Entergy Operations, Inc.

1448 S.R. 333 Russellville, AR 72802 Tel 479-858-4704 Stephenie L. Pyle Manager, Licensing Arkansas Nuclear One 2CAN051202 May 21, 2012 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555

SUBJECT:

Additional Information Related to Request for Alternative ANO2-ISI-007 Code Case N-770-1 Baseline Examination Arkansas Nuclear One, Unit 2 Docket No. 50-368 License No. NPF-6

REFERENCES:

1. Entergy letter dated November 30, 2011, Use of Alternate ASME Code Case N-770-1 Baseline Examination Request for Alternative ANO2-ISI-007 (2CAN111101) (ML113340158)

2. NRC email dated February 23, 2012, RAI for the Request to use Alternate ASME Code Case N-770-1 Baseline Examination, Request for Alternative ANO2-ISI-007 (TAC No. ME7646) (ML120541089)

3. Entergy letter dated April 13, 2012, Response to the Request for Additional Information Regarding Request for Alternative ANO2-ISI-007 Code Case N-770-1 Baseline Examination (2CAN041202)

(ML12104A066)

Dear Sir or Madam:

Entergy Operations, Inc. requested NRC approval of a Request for Alternative for Arkansas Nuclear One, Unit 2 via Reference 1. The request is associated with the use of an alternative to the requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Code Case N-770-1, as conditioned in the Final Rule 10 CFR 50.55a(g)(6)(ii)(F)(3), dated June 21, 2011.

In Reference 2, the NRC determined that additional information was needed to complete the review of Reference 1. Reference 3 provided the requested information. Subsequently, a conference call was held with the NRC on April 26, 2012, to discuss the responses provided in Reference 3 and to clarify a portion of the request in Reference 2. Based on this conference call, it was determined that additional information was required. The purpose of this submittal is to provide that information.

This submittal contains no regulatory commitments.

2CAN051202 Page 2 of 2 Should you have any questions, please contact me.

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

Attachment:

Additional Information Related to Request for Additional Information -

Use of ASME Code Case N-770-1 Baseline Examination cc: Mr. Elmo E. Collins 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-8 B1 One White Flint North 11555 Rockville Pike Rockville, MD 20852

Attachment to 2CAN051202 Additional Information Related to Request for Alternative ANO2-ISI-007 Code Case N-770-1 Baseline Examination

Attachment to 2CAN051202 Page 1 of 10 ADDITIONAL INFORMATION RELATED TO REQUEST FOR ALTERNATIVE ANO2-ISI-007 CODE CASE N-770-1 BASELINE EXAMINATION The NRC request is provided below in bold, followed by the response to the request.

1. The response to Question 5 of the Request for Additional Information (RAI) response states that the coverage limitations are the result of irregular surfaces or tapered surfaces. The staff is concerned by the different coverage which would result from these geometries; intermittent lack of coverage due to irregular weld surfaces is significantly different than a continuous lack of coverage at the root which could result from a tapered weld surface. Please describe the reason for the lack of examination coverage for the susceptible material in each weld and, if due to weld taper, whether the root of the weld is being examined.

The examination coverage estimates reported at the time of the ultrasonic examinations indicated a combination of weld surface, joint taper, and cast stainless steel being limitations to coverage. The cast stainless steel portion of the limitation is somewhat quantified by the cross sectional profiles of the weld joint geometry and related thicknesses.

It should be noted that the scan coverage estimations do not factor in the probe skew of +/- 10 degrees. The probe skew decreases the extent of the actual limitation.

The limitation due to irregular weld surfaces or weld joint taper was not specifically quantified in the ultrasonic data. The estimated coverage provided considered the net effect of all limitations. However; the coverage estimates and scan plots were reviewed to estimate the volume of susceptible material and circumferential scan coverage of that volume. Table 1 provides the results of the review. The scan plot for each weld is provided after the table.

2. In Table 1 of the RAI response, the coverage in the circumferential direction is identical for the ferritic material and the susceptible material. Please describe how this is occurs.

The ultrasonic examination data sheets did not quantify the exact area or extent of the circumferential scan limitation. The estimated coverage number was applied to both the susceptible material and/or the ferritic material.

Each of the weld scan plots was reviewed and the susceptible volume estimated. The approximate scan lines were extrapolated and coverage estimates re-calculated for that area only, which is what appears in Table 1 of this submittal.

Attachment to 2CAN051202 Page 2 of 10 Table 1 Coverage Estimation and Limitations Component Lower 1/3 Upper 2/3 T Sketch Location of Circumferential Coverage Number Thickness (T) Circumferential Limitation of the Susceptible Material Volume Circumferential Scan Coverage %

Scan Coverage %

08-014 100 92 Limitation in upper 2/3 T inconel weld at cast austenitic stainless steel (CASS) bevel preparation area and at cap transition to elbow.09-008 55 64 Limitation to coverage appears to be concave area near center of weld cap indicating missed scan coverage is in the inconel weld, cap to root.10-014 14 73 Limitation appears to be from weld taper and indicates the majority of the limitation is in the inconel weld and adjacent butter region with no coverage of weld root area.11-008 62 73 Limitation to coverage appears to be convex area near center of weld cap indicating missed scan coverage is in the inconel weld, cap to root.12-014 50 86 Limitation appears to be from weld taper and indicates the majority of the limitation is in the inconel weld with little coverage of weld root area.13-008 87 85 Limitation to coverage appears to be convex area near the ferritic side of the weld cap indicating missed scan coverage is in the inconel weld with most of the lower 1/3 T examined to the root.14-014 87 96 Limitation is near the CASS bevel prep area, indicating missed scan coverage cap to root on the safe end side of the weld. Most of lower 1/3 T scanned.15-008 85 89 Limitation to coverage primarily appears to be convex area near center of weld cap indicating missed scan coverage is in the inconel weld, cap to root.

Attachment to 2CAN051202 Page 3 of 10 Arkansas Nuclear One Unit 2 Reactor Coolant Pump Suction Nozzle DMV DM Weld # 08-014 Legend Green = 2/3 T Coverage Yellow = 1/3 T Coverage Pink = No Coverage Safe End Side (Cast Stainless) Elbow Side

Attachment to 2CAN051202 Page 4 of 10 Arkansas Nuclear One Unit 2 Reactor Coolant Pump Suction Nozzle DMV DM Weld # 09-008 Legend Green = 2/3 T Coverage Yellow = 1/3 T Coverage Pink = No Coverage CAST STAINLESS STEEL PIPE

Attachment to 2CAN051202 Page 5 of 10 Arkansas Nuclear One Unit 2 Reactor Coolant Pump Suction Nozzle DMV DM Weld # 10-014 Legend Green = 2/3 T Coverage Yellow = 1/3 T Coverage Pink = No Coverage Safe End Side Elbow Side (Cast Stainless)

Attachment to 2CAN051202 Page 6 of 10 Arkansas Nuclear One Unit 2 Reactor Coolant Pump Suction Nozzle DMV DM Weld # 11-008 Legend Green = 2/3 T Coverage Yellow = 1/3 T Coverage Pink = No Coverage CAST STAINLESS STEEL PIPE

Attachment to 2CAN051202 Page 7 of 10 Arkansas Nuclear One Unit 2 Reactor Coolant Pump Suction Nozzle DMV DM Weld # 12-014 Legend Green = 2/3 T Coverage Yellow = 1/3 T Coverage Pink = No Coverage CAST STAINLESS Elbow Side STEEL

Attachment to 2CAN051202 Page 8 of 10 Arkansas Nuclear One Unit 2 Reactor Coolant Pump Discharge A Nozzle 13-008 / 2P-32C Circumferential Examination Volume Legend Green = 2/3 T Coverage Yellow = 1/3 T Coverage Pink = No Coverage PIPE CAST STAINLESS STEEL

Attachment to 2CAN051202 Page 9 of 10 Arkansas Nuclear One Unit 2 Reactor Coolant Pump Suction Nozzle DMV DM Weld # 14-014 Legend Green = 2/3 T Coverage Yellow = 1/3 T Coverage Pink = No Coverage Safe End Side Elbow Side (Cast Stainless)

Attachment to 2CAN051202 Page 10 of 10 Arkansas Nuclear One Unit 2 Reactor Coolant Pump Suction Nozzle DMV DM Weld # 15-008 Legend Green = 2/3 T Coverage Yellow = 1/3 T Coverage Pink = No Coverage CAST STAINLESS STEEL PIPE