L-13-197, Response to Request for Additional Information on 10 CFR 50.55a Request RR-A37

Response to Request for Additional Information on 10 CFR 50.55a Request RR-A37

ML13206A308
Person / Time
Site:	Davis Besse
Issue date:	07/24/2013
From:	Lieb R FirstEnergy Nuclear Operating Co
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
L-13-197, TAC MF0752
Download: ML13206A308 (14)

Text

FENOC' 5501 North State Route 2 Oak Harbor, Ohio 43449 FirstEnergy Nuclear Operating Company Raymond A Lieb 419-321-7676 Vice President, Nuclear Fax: 419-321-7582 July 24, 2013 L-13-197 10 CFR 50.55a ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

SUBJECT:

Davis-Besse Nuclear Power Station Docket No. 50-346, License No. NPF-3 Response to Request for Additional Information on 10 CFR 50.55a Request RR-A37 (TAC No. MF0752)

By correspondence dated February 27, 2013 (Accession No. ML13059A315),

FirstEnergy Nuclear Operating Company (FENOC) submitted 10 CFR 50.55a Request RR-A37 for the Davis-Besse Nuclear Power Station.

By electronic mail dated June 27, 2013 (Accession No. ML13179A095), the Nuclear Regulatory Commission (NRC) requ~sted additional information to complete its review of Request RR-A37. FENOC's response to this request is attached. Additionally, the performance demonstration qualification summary, as requested in item 6 of the request for additional information, is provided as an enclosure.

There are no regulatory commitments contained in this submittal. If there are any questions or additional information is required, please contact Mr. Thomas A. Lentz, Manager - Fleet Licensing, at (330) 315-6810.

Attachment:

Response to June 27, 2013 Request for Additional Information

Enclosure:

Performance Demonstration Qualification Summary (PDQS) No. 651 cc: NRC Region Ill Administrator NRC Resident Inspector NRC Project Manager Utility Radiological Safety Board

Attachment L-13-197 Response to June 27, 2013 Request for Additional Information Page 1 of 9 By correspondence dated February 27, 2013, FirstEnergy Nuclear Operating Company (FENOC) submitted a 10 CFR 50.55a Request for Nuclear Regulatory Commission (NRC) review and approval. By electronic mail dated June 27, 2013, NRC staff requested additional information to complete its review. The requested information is presented in bold type, followed by the FENOC response.

1. The licensee states in Proposed Alternative and Basis for Use: Based on radiological survey results from the spring 2012 refueling outage, this work would occur within radiation fields with dose rates up to 500 milli-Rem per hour, resulting in a significant increase in occupational radiation exposure

[dose] to personnel. The Examination Data Sheet for the examination performed on May 15, 2012, indicated that the examination required nearly one hour, but the UT Examination Summary documented a total dose of 32 milli-Rem for the examination.

a. Explain the apparent discrepancy in the dose rate and the total radiological dose.

Response

The total radiological dose of 32 milli-Rem (mR), as cited on the May 15, 2012 weld examination summary document, was the result of performing the ultrasonic (UT) examination with shielded piping adjacent to the weld. The 32 mR is for the weld examination itself; it does not include any ancillary activities, such as installing and subsequently removing access scaffolding or radiological shielding.

A spring 2012 refueling outage radiological survey used during development of Request RR-A37 revealed a maximum dose rate of 500 mR/hour on contact with the cold leg drain pipe. Therefore, should the piping require a modification, this work would occur within radiation fields with dose rates up to 500 mR/hour.

b. Justify why the dose incurred would present a hardship.

Response

Radiological dose does not present a hardship; however, unnecessary dose to personnel should be avoided. As discussed during a FENOC-NRC teleconference on June 26, 2013, implementing a modification to reroute the American Society of Mechanical Engineers (ASME) Class 1 piping would require offloading the reactor core, flushing and draining the system, installing (and subsequently removing) scaffolding and rigging, cutting out the existing piping, removing associated pipe supports, installing new pipe supports, installing a new section of piping, and performing any requisite examinations.

Though detailed planning and man-hour estimates for the modification do not exist, it is roughly estimated that several hundred man-hours of work would occur within radiation fields with dose rates up to 500 mR/hour, resulting in a significant increase in occupational radiation exposure [dose] to personnel involved with implementing the modification.

Attachment L-13-197 Page 2 of 9

2. The NRC staff is unable to determine the exact volumes that were examined and the part of the required volume that was not examined from the drawings provided in the proposed alternative.

Provide clear scale drawings (with scale indicated) of the subject DMBW

[dissimilar metal butt weld], including weld butter and FSWOL [full structural weld overlay] indicated. Clearly show the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (Code) Case N-770-1 required examination volume and the volume of material interrogated by the examination in the axial and circumferential scan directions.

Response

The requested information is provided in Figures 1 and 2.

3. Provide a table detailing the scan coverage achieved for each of the following:

a. carbon steel nozzle;

b. stainless steel elbow;

c. susceptible weld metal; and

d. full structural weld overlay.

Provide values for scans in the circumferential and axial directions.

Response

The requested information is provided in Figures 3 and 4 with coverage values expressed as percentages.

4. The licensee states that limitations imposed by the weld geometry resulted in incomplete scan coverage. Describe these limitations and their effects on scan coverage.

Response

The whole footprint of the search unit must be on the examination surface during scanning. At the point where the search unit loses contact with the surface or hits an obstruction is where the exit point of the sound beam is measured. Examples of this limitation, which results in reduced or incomplete scan coverage values, would be the FSWOL tapers or elbow intrados. Figure 5 provides an example.

Attachment L-13-197 Page 3 of 9

5. The technical report detailing the preservice examination of Cold Leg Drain Nozzle 1-2 (ISI Component ID RC-40-CCA-18-3-FW9) FSWOL in 2010, Summary of Weld Overlay Ultrasonic Examinations for Reactor Coolant Pump Suction and Discharge Welds, Core Flood Nozzle Welds, and Cold Leg Drain Line Welds at Davis-Besse Nuclear Power Station, Unit 1 (ADAMS Accession No. ML101230641), states 100 percent axial scan coverage and 80.1 percent circumferential scan coverage of the ASME Code Case N-740 [8]

required volume, as documented in the Relief Request [5], was achieved during the examinations.

a. Why does the current examination not achieve 100 percent coverage for scans in the axial direction and at least 80 percent coverage for scans in the circumferential direction?

Response

The winter 2010 refueling outage (1R16) preservice inspection examination limited examination calculations were not correct. The spring 2012 refueling outage (1R17) inservice inspection examination limitation calculation is correct. The noted discrepancies have been entered and addressed within FENOCs corrective action program. The 1R17 calculated coverage values have subsequently been verified with field measurements and detailed coverage drawings. The 1R17 coverage calculations are more conservative than those documented in the 1R16 examination and will be used for all future examinations. The 1R17 calculated coverage values were used in Request RR-A37. For alignment and consistency, the 1R16 datasheet has been updated to reflect the 1R17 calculated coverage values.

b. Provide a detailed explanation for the differences in examination coverage between the preservice and the current inservice examination.

Response

Response to RAI 5a contains the requested information.

6. Provide a copy of the Performance Demonstration Qualification Summary (PDQS) for the UT examination procedure used. Describe any limitations of the ASME Code,Section XI, Appendix VIII qualified examination procedure.

Response

A copy of the PDQS is provided as an enclosure to this letter. Limitations on its use are specifically described in the PDQS.

7. Was the subject inservice examination performed by team scanning?

Response

Attachment L-13-197 Page 4 of 9 No. The inservice examination was performed by one individual.

Note: Acronyms or symbols used on the following figures:

Dissimilar Metal Weld: DMW Square Inch: sq. in.

Ultrasonic: UT Percent: %

Carbon Steel: CS Stainless Steel: SS Full Structural Weld Overlay: FSWOL

Attachment L-13-197 Figure 1 Page 5 of 9 1-2 RCS COLD LEG DRAIN NOZZLE RC-40-CCA-18-3-FW9 OVERLAY CIRC. COVERAGE CIRCUMFERENTIAL COVERAGE 1.55 sq. in. = TOTAL [area of interest]

1.55 1.18- TOTAL sq. in. = scan achieved [2 directions]

Nozzle (typical) 1.18 - 100%

1.18 / 1.55 1.18 / 1.55 = .761

= 0.76 76% coverage 76%

Outline of UT Equipment (typical)

EXTRADOSE EXTRADOS Required examination volume (typical)

P A B C EXTRADOSE = 76% FSWOL EXTRADOSE = 76%

INTRADOSE = 70% INTRADOSE = 70%

90 Degrees = 68% 90 deg. = 68%

Butter 270 Degrees = 73% 270 deg. = 73%

Elbow (typical)

Circumferential Composite = 71%

Circ. Composite = 71%coverage DMW SS Cladding 1.61 - TOTAL 1.61 sq. in. = TOTAL [area of interest]

1.14 - 100%

1.14 sq. in.

1.14 / 1.61 = 70%

= scan achieved [2 directions]

1.14 70% / 1.61 = 0.70 INTRADOS 70% coverage INTRADOSE 1.0" 1.0" 1.54 - TOTAL SCALE 1.54 sq. in. = TOTAL [area of interest]

1.06 - 100%

1.06 sq. in. = scan achieved [2 directions]

1.06 / 1.54 = .68 1.06 68%

/ 1.54 = 0.68 68% coverage 90 deg.

90 Degrees 1.57 TOTAL 1.57 sq. in. = TOTAL [area of interest]

1.15 - 100%

1.15 sq. in. = scan achieved [2 directions]

1.15 / 1.57 = .73 1.15 73% / 1.57 = 0.73 73% coverage 270 Degrees 270 deg.

Attachment Figure 2 L-13-197 1-2 RCS COLD LEG DRAIN NOZZLE Page 6 of 9 RC-40-CCA-18-3-FW9 OVERLAY AXIAL COVERAGE Outline of UT Equipment (typical) 1.55 1.55 - TOTAL sq. in. = TOTAL [area of interest]

Nozzle (typical) 0.83 0.83- 100%

sq. in. = scan achieved [2 directions]

0.64 - 50%

0.64 sq. in. = scan achieved [1 direction]

(.64 x .5) + .83 = 1.15 / 1.55 = .74 (0.64 74% x 0.5) + 0.83 = 1.15 1.15 / 1.55 = 0.74 74% coverage EXTRADOS EXTRADOSE Required examination volume (typical)

P A B C FSWOL EXTRADOS =EXTRADOSE 74% = 74%

INTRADOS = INTRADOSE 60% = 60% Elbow (typical)

Butter 90 Degrees = 69%90 deg. = 69%

270 Degrees = 73%270 deg. = 73% DMW Axial Composite = 69%=coverage Axial Composite 69%

SS Cladding 1.61 - TOTAL 1.61 sq. in. = TOTAL [area of interest]

0.60 - 50%

0.68 sq. in. = scan achieved [2 directions]

0.68 - 100%

0.60 sq.+ .68

(.60 x .5) in.==.98scan achieved

/ 1.61 = .60 [1 direction]

INTRADOS (0.60 60% x 0.5) + 0.68 = 0.98 INTRADOSE 0.98 / 1.61 = 0.60 60% coverage 1.0" 1.0" 1.54 - TOTAL SCALE 1.54 sq. in. = TOTAL [area of interest]

0.72 - 100%

0.72 sq. in. = scan achieved [2 directions]

0.70 - 50%

0.70 sq. in. = scan achieved [1 direction]

(.70 X .5) + .72 = 1.07 / 1.54 = .694 (0.70 x 0.5) + 0.72 = 1.07 69%

1.07 / 1.54 = 0.69 69% coverage 90 Degrees 90 deg.

70 - 50%

1.57 TOTAL 1.57 sq. in. = TOTAL [area of interest]

0.76 - 100%

0.76 sq. in. = scan achieved [2 directions]

0.79 - 50%

0.79

(.79 X sq. in. ==1.155

.5) + .76 scan achieved

/ 1.57 = .735 [1 direction]

(0.79 73% x 0.5) + 0.76 = 1.15 1.15 / 1.57 = 0.73 73% coverage 270270 deg.

Degrees

Attachment L-13-197 Figure 3 Page 7 of 9 1-2 RCS COLD LEG DRAIN NOZZLE Outline of UT Equipment RC-40-CCA-18-3-FW9 OVERLAY (typical)

CIRC. COVERAGE CIRCUMFERENTIAL COVERAGE FSWOL Nozzle (typical) EXTRADOSE Coverage Scan Section Total Area (sq. in.) Coverage (sq. in.)

50% 100% (ACTUAL / TOTAL )

CS Nozzle Base Material 0.08 N/A 0.08 100%

EXTRADOS EXTRADOSE Susceptible Weld Metal 0.13 N/A 0.12 92%

SS Elbow Base Material 0.04 N/A 0.0 0%

FSWOL Material 1.31 N/A 0.98 74%

Required examination volume (typical) Butter Elbow (typical)

DMW SS Cladding INTRADOSE Coverage Scan Section Total Area (sq. in.) Coverage (sq. in.)

INTRADOS INTRADOSE 50% 100% (ACTUAL / TOTAL )

CS Nozzle Base Material 0.09 N/A 0.09 100%

Susceptible Weld Metal 0.14 N/A 0.11 78%

SS Elbow Base Material 0.11 N/A N/A 0%

FSWOL Material 1.27 N/A 0.92 72%

90 Degrees 90° Coverage Scan Section Total Area (sq. in.) Coverage (sq. in.)

50% 100% (ACTUAL / TOTAL )

CS Nozzle Base Material 0.07 N/A 0.07 100%

Susceptible Weld Metal 0.12 N/A 0.11 83%

91%

90 Degrees 90 deg. SS Elbow Base Material 0.06 N/A 0%

0.00 FSWOL Material 1.27 N/A 0.89 70%

270 Degrees 270° Coverage Scan Section Total Area (sq. in.) Coverage (sq. in.)

50% 100% (ACTUAL / TOTAL )

CS Nozzle Base Material 0.06 N/A 0.06 100%

Susceptible Weld Metal 0.13 N/A 0.13 100%

SS Elbow Base Material 0.06 N/A 0.00 0%

270 Degrees 270 deg.

FSWOL Material 1.32 N/A 0.97 73%

Attachment L-13-197 Figure 4 Page 8 of 9 1-2 RCS COLD LEG DRAIN NOZZLE Outline of UT Equipment RC-40-CCA-18-3-FW9 OVERLAY (typical)

AXIAL COVERAGE FSWOL EXTRADOSE Coverage Scan Nozzle (typical) Section Total Area (sq. in.) Coverage (sq. in.)

50% 100% (ACTUAL / TOTAL )

CS Nozzle Base Material 0.08 N/A 0.08 100%

Susceptible Weld Metal 0.13 0.09 0.04 65%

EXTRADOSE SS Elbow Base Material 0.04 0.04 N/A 50%

EXTRADOS FSWOL Material 1.31 0.53 0.7 73%

Required examination volume (typical) Butter Elbow (typical)

DMW SS Cladding INTRADOSE Coverage Scan INTRADOS Section Total Area (sq. in.) Coverage INTRADOSE (sq. in.)

50% 100% (ACTUAL / TOTAL )

CS Nozzle Base Material 0.09 0.07 0.03 72%

Susceptible Weld Metal 0.14 0.11 0.05 75%

SS Elbow Base Material 0.11 0.09 N/A 40%

1.0" FSWOL Material 1.27 .54 0.64 71%

1.0" SCALE 90 Degrees 90° Coverage Scan Section Total Area (sq. in.) Coverage (sq. in.)

50% 100% (ACTUAL / TOTAL )

CS Nozzle Base Material 0.07 N/A 0.07 100%

Susceptible Weld Metal 0.12 0.09 0.03 62%

90 Degrees 90 deg.

SS Elbow Base Material 0.06 0.06 N/A 50%

FSWOL Material 1.27 0.52 0.65 71%

270 Degrees 270° Coverage Scan Section Total Area (sq. in.) Coverage (sq. in.)

50% 100% (ACTUAL / TOTAL )

CS Nozzle Base Material 0.06 0.04 0.02 66%

Susceptible Weld Metal 0.13 0.09 0.04 65%

SS Elbow Base Material 0.06 0.06 N/A 50%

270 Degrees 270 deg.

FSWOL Material 1.32 0.58 0.70 75%

Attachment L-13-197 Page 9 of 9 Figure 5 - Example of Methodology for Limited Scanning Measurements Outline of UT Equipment Scan up to any physical (typical)

Scan up to limitation to sound any physical unit (SU) limitations to SUis,movement.

movement (that elbow Sound exit point is measured at the point where intradose).

(i.e. elbow intradose). Sound any partexit point of the is measured sound unit (SU)atscan the point surfacewhere any part loses of the(that contact SU is, scan surface edge of weldlooses contact overlay).

with the component surface. (i.e. taper)

FSWOL Nozzle Elbow Scanning Scanningcontinues continuesuntiluntilthe sound sound beam Required examination beam signal is lost; however, this signal is lost, however this scanning Butter volume scanning area is not required for or area is not factored into the limited factored into the limited scan DMW scan calculations.

calculations.

SS Cladding

Enclosure L-13-197 Performance Demonstration Initiative Program Performance Demonstration Qualification Summary (PDQS) No. 651 (3 pages total)

PerformaDce Demonstration Initiative Program Printed: J'I-Jan-lJ PERFORMANCE DEMONSTRATION PROGRAM In Accordance with tbe PDllmplementation or Section ~ Appendix Vlll PDQSNo: 651 Specific Detam of Qualifications Owner: EPRI NDE CENTER Procedure: EPRI-WOL-PA-l; Revision: 2; Addenda: 0 Procedure for Manual Phased Array Ultrasonic Examination of Weld Overlaid Similar and Dissimilar Metal Welds PDQSRrv: 3 Hardwan: N/A Date of Issue: 3()'Jan-lJ AquisitioD SW TyptJlb,*: N/A Category: Ovi:rlay Aualysis SW TypeJRu: NlA Mao Applic:atioa: Mmusl Ranges Demonstrated:

Date: OS-Feb-IO

\tinDiam: 2.00 MinTbick; 0.1 S

\t8l[Diam: 28.00 '\luTbick: \.10 Material: Austenitic Examination: Overlay Acrrss: Dual Weld Crown Condition:

Shan Range: Roughness:>=250 ,RMS Lon!! Ranl!e Roughness;e=lJ32 Gap Under Sc:m:h Cnit For Entire Length of Scan Paad or J

. .~- ~ .... :. '"

Performance Demonstration Initiative Program Printed: 31-JaD-IJ PfRFOR~A~l"E DEMO~STRATlO~ PROGRAM In Accordance with the PDllmplementatiou or Section XI, Appendix VIII PDQS~o: 651 Specific Details of Qualifications Owner: EPRI NDE CENTER Procedure: EPRI-WOL-PA-l; Revision: 2; Addenda: 0 Procedure for Manual Phased. Array Ultrasonic Examination of Weld Overlaid Similar aod Dissimilar Metal Welds PDQSRev: 3 Hardware: r\IA Dare of Issue: lo-Jan*13 Aqnisltion SW TypelRev: N/A Category: Overlay Aualysls SW TypellUv: N/A Scan AppIiratioo: Manual Tolerances for field applications as follows:

Diamct.:r; PIpe ommclt.:rs within a range of 0.9 tQ 1.5 times the nominal diameter demonstrated shall be considered equivalent.

l>iamerCIS gn:ater lhlDl 24 n need not be demonstrated.

ThIckness I.<mer. 0.100* can be subtracted from the minimum ovcrlay thickness demonstraled.

lipper 0.:250* can be :ulded 10 the maximum overlay lhickness demonstrated_

Comments: Candidates qualified to earlier revisions oflhis procedure are qualified to usc this revision.

2 See procedun: Table I llI1d Table 1 for qun1ified search unit I insmnnenl combinations and CSSCIltw variable scttinp.

3 For PSI axial examinations of the overlay material. 100% coverage can bec:laimcd ifthc cntiR ewnination volwm: is coyc:n:d from aI least one direction.

4 For PSI circumferential ClWIIinations or the overlay materi3l. 100% COVCI1lgl: can be c:laimcd if the* entire examination volume is covered from two directions.

5 For lSI examinations. 100% percent coverage may be claimed When the reqllin:d volume is examined from 2 directions in both the eire. and axial scan directions.

6 For lSI examinations of component diameters:! 4" (pre-ovcrtay). examination coYenJge may be claimed when the required volume is examined Ylith angles:i! 25°.

7 For lSI ell:aminations of component diameters < 4" (pre-overtay). examinalion coverage rna)' be claimed when Ihe required \"Olume is examined with angles O! 45°.

8 The Appendix VID demonstration requimnents applicable to this procedure dt) nOI conlain provisions to demonstrate sizing ofaxial fJnws. \\'ben required, the tcchniquC$ described for circumfer~'I1l1al flaw Sizing shall be used for axial Raw sizing.

I.imitations: 1 This proc.:dure/candidale is nol qualified for establishing the through waD dimension of flows contained within the weld overlay material. lIowen:r. estnbli~hing the ~'I113ining ligament abov!: a l1a\\ tip b qualified.

2 This procedurclcandidate is nol qualitied for detc:clion. length or depth sizing oftlaws contained Ylithin the: base material of ca.~1 stainless steel Cornpolletll~.

Performance Demonstration Initiative Program Priot~d: JI-Jao-lJ I'£RFORMA.'E DEMONSTRATION PROGRAM In Aeeonlance with the PDllmplementation of Section Xl, Appendix Vlll PDQSNo: 651 Specific Details of Qualifications Owner: EPRI NDE CENTER Procedure: EPRI-WOL-PA-l; Revision: 2; Addenda: 0 Proeedure ror Manual Phased Array Ultrasonic Examination or Weld Overlaid Similar and Dissimilar Melal Welds PDQSRtv: .} Hardware: N/A Date or Issor: JO-JIIII-1J AqoisilioD SW TyptIR~-: l\!:A Catqtory: Overlay Allalysis SW TyprlR~v: NiA Scaa Applieatiou: Manual The above procedure bas met the requirements of The Performance Demonstration lnitiative1 s Implementation or The Ameriean Society of Mechanical Engineers Boiler and Pressure Vessel Code, SeetioD XI, Appendix Vnl, as stated in this document

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Date: ~ \~ J &\,.:l!3 Perro aace Demonstration Initiative Piping SupervisorlLevellll 41JI<~n

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Performance Demonstration Initiative Piping Projed Manager PllgeJor 3