RNP-RA/14-0003, Response to NRC Request for Additional Information Regarding Fourth 10-Year Interval Inservice Inspection Program Plan Requests for Relief (RR)-20
| ML14028A260 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 01/21/2014 |
| From: | William Gideon Duke Energy Progress |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| RNP-RA/14-0003 | |
| Download: ML14028A260 (7) | |
Text
W. R. Gideon H. B. Robinson Steam Electric Plant Unit 2 DUKE Site Vice President Duke Energy Progress ENE RGY 3581 West Entrance Road Hartsviyle, SC 29550 0:843857 1701 F: 843 857 1319 Ranidv.Gideon@duke-energy.com 10 CFR 50.4 Serial: RNP-RA/14-0003 JAN 21 2014 ATTN: Document Control Desk United States Nuclear Regulatory Commission Washington, DC 20555-0001 H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT NO. 2 DOCKET NO. 50-261/RENEWED LICENSE NO. DPR-23 RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION REGARDING FOURTH 10-YEAR INTERVAL INSERVICE INSPECTION PROGRAM PLAN REQUESTS FOR RELIEF (RR)-20 Ladies and Gentlemen:
By e-mail dated December 31, 2013, the NRC requested that Duke Energy Progress, Inc.
respond by January 31, 2014 to a request for additional information (RAI) regarding the Relief Request (RR)-20 for Limited Examinations performed in the Fourth Ten-Year Inservice Inspection Program Plan submitted on June 3, 2013. The attachment to this letter provides the RAI response for the H. B. Robinson Steam Electric Plant, Unit No. 2.
There are no regulatory commitments made in this submittal. If you have any questions regarding this submittal, please contact Mr. R. Hightower at (843) 857-1329.
I declare under penalty of perjury that the foregoing is true and correct.
Executed On:
( ( i' Sincerely, W. R. Gideon Site Vice President WRG/cac
United States Nuclear Regulatory Commission Serial: RNP-RA/14-0003 Page 2 of 2 Attachments:
I.
Response to NRC Request for Additional Information Regarding Fourth 10-Year Interval Inservice Inspection Program Plan Requests for Relief (Relief Request-20)
I1.
HBR2-7064 Sh 1, Tank - 900 Gal. Boron Injection I1l.
Boron Injection Tank Photograph cc:
Mr. V. M. McCree, NRC, Region II Mr. Siva P. Lingam, NRC Project Manager, NRR NRC Resident Inspector, HBRSEP, Unit No. 2
U. S. Nuclear Regulatory Commission Attachment I to Serial: RNP-RA/14-0003 3 Pages (including cover sheet)
RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION REGARDING FOURTH 10-YEAR INTERVAL INSERVICE INSPECTION PROGRAM PLAN REQUESTS FOR RELIEF (RELIEF REQUEST-20)
U. S. Nuclear Regulatory Commission Attachment I to Serial: RNP-RA/14-0003 2.1 Request for Relief RR-20. Examination Category F-A, Item F1.40, Supports 2.1.1 The Reactor Vessel Cold Leg Loop "A", "B", and "C" Supports 101/A, 101/B, and 101/C, achieved 50 percent of the ASME Code required visual examination coverage according to Sections 2.3, 3.3, and 4.3 "Impracticality of Compliance," respectively. In the supplemental report provided on page 9 of 221, the licensee states that "only 20 percent of the support can be seen from this available remote vantage point due to the HVAC [heating, ventilation and air-conditioning] duct configuration and the approach being blocked by debris" for Reactor Vessel Cold Leg Loop "A" Support 101/A. In the supplemental reports provided on pages 20 and 25 of 221, the licensee states that only "1/3 of the support can be seen from this available remote vantage point due to the HVAC duct configuration" for Reactor Vessel Cold Leg Loop "B" and "C" Supports 101/B and 101/C.
From these conflicting statements, it is unclear as to the level of visual examination coverage achieved. Please clarify and state the actual visual coverage achieved for each of the Reactor Vessel cold leg supports mentioned above.
Response to Examination Category F-A, Item F1.40. Supports The percentage coverage are as stated on the NDE examiners visual report. "101/A" support is 20% (page 9), "101/B" support is 1/3 (page 20) and "101/C" support is 1/3 (page 25).
2.2 Request for Relief RR-20, Examination Category C-A, Item C1.20, Pressure Retaining Welds in Class 2 Pressure Vessels 2.2.1 The licensee's submittal states that the subject weld areas were interrogated with a combination of 45-and 60-degree shear waves to detect axial and circumferentially-oriented flaws.
Confirm the insonification angles and wave modalities used to examine each of the subject welds. If only shear wave techniques were used to examine the subject stainless steel welds, please explain why refracted longitudinal wave (L-wave) techniques were not used. The L-wave method has been shown capable of detecting planar inside diameter surface-breaking flaws on the far-side of wrought stainless steel welds. Recent studies (References 1, 2 and 3) recommend the use of both shear and L-waves to obtain the best detection results, with minimum false calls, in austenitic welds.
Response to Examination Category C-A, Item C1.20. Pressure Retaining Welds in Class 2 Pressure Vessels The insonification angles and wave modalities utilized were performed to the 1995 Edition through 1996 Addenda of ASME Section Xl. The welds were examined in accordance with ASME Section XI and meet the requirements thereof. Utilization of the refracted longitudinal wave (L-wave) will not increase the coverage percentage and is currently not required under ASME Section Xl for the components examined. RNP will incorporate the "L" wave into the vessel examination procedure and use the L-wave as a supplemental examination to be applied in limited areas that are one-sided scans on stainless steel welds. RNP will apply this supplemental technique to future examinations.
U. S. Nuclear Regulatory Commission Attachment I to Serial: RNP-RA/14-0003 2.3 Request for Relief RR-20. Examination Category C-B, Item C2.21, Pressure Retaining Nozzle Welds in Class 2 Vessels 2.3.1 Please state the materials of construction for the boron injection tank lower and upper head-to-nozzle welds.
Response to Examination Category C-B, Item C2.21, Pressure Retaining Nozzle Welds in Class 2 Vessels The Boron Injection Tank head to nozzle materials of construction are; nozzle forgings (SA-182 F304); head (SA-240 Type 304) for both the upper and lower head to nozzle configuration. See Attachment II for clarification.
2.4 Request for Relief RR-20. Examination Category C-C, Item C3.10. Integral Attachments for Class 2 Vessels, Piping, Pumps, and Valves The licensee has provided a sketch on page 151 of 221 of their RR-20, regarding the impracticality of obtaining ASME Code-required surface examination for the boron injection tank support leg attachment. However, the sketch is unclear due to the lack of labeling of what the shaded area represents on the support leg plate, and the dimensions on the top (13 inches) and bottom (16 inches) do not appear to add up correctly.
2.4.1 Please submit a detailed and clear sketch or photograph to augment the description of the limitation of the surface examination for the boron injection tank support leg attachment.
Response to Examination Category C-C. Item C3.10, Integral Attachments for Class 2 Vessels, Piping, Pumps, and Valves The sketch supplied identifies 13" at the top and the bottom number is actually 10", not 16".
The shaded areas are from a historical copy which is somewhat illegible. See Attachment II and Attachment III for configuration clarification.
REFERENCES
- 1. F. V, Ammirato, X. Edelmann, and S.M. Walker, Examination of Dissimilar Metal Welds in BWR Nozzle-to-Safe End Joints, 8 th International Conference on NDE in the Nuclear Industry, ASM International, 1987.
- 2. P. Lemaitre, P., T.D. Koble, and S.R. Doctor, PISC Ill Capability Study on Wrought-to-Wrought Austenitic Steel Welds: Evaluation at the Level of Procedures and Techniques, Effectiveness of Nondestructive Examination Systems and Performance Demonstration, PVP-Volume 317, NDE-Volume 14, ASME, 1995.
- 3. M. T. Anderson, M.T., A.A. Diaz, A.D. Cinson, S.L. Crawford, S.E. Cumblidge, S.R Doctor, K.M.
Denslow, and S. Ahmed, 2011. An Assessment of Ultrasonic Techniques for Far-Side Examinations of Austenitic Stainless Steel Piping Welds, NUREG/CR-7113, PNNL-19353, U. S. Nuclear Regulatory Commission, Washington, DC.
U. S. Nuclear Regulatory Commission Attachment III to Serial: RNP-RA/14-0003 2 Pages (including cover sheet)
BORON INJECTION TANK PHOTOGRAPH
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