CP-201500777, Relief Request B-10, Second Ten Year Inservice Inspection Interval from 10CFR50.55a Inspection Requirements Due to Physical Interferences (1998 Edition of ASME Code, Section XI, 2000 Addenda Second Interval Start Date: August..

Relief Request B-10, Second Ten Year Inservice Inspection Interval from 10CFR50.55a Inspection Requirements Due to Physical Interferences (1998 Edition of ASME Code,Section XI, 2000 Addenda Second Interval Start Date: August..

ML15224B363
Person / Time
Site:	Comanche Peak
Issue date:	08/03/2015
From:	Flores R, Madden F Luminant Generation Co, Luminant Power
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CP-201500777, TXX-15117
Download: ML15224B363 (8)

Text

Senior Vice President P 0 Box 1002 SRafael Flores Officer Luminant Power

____& Chief Nuclear 6322 North FM 566 Luminant Refael.Flores@Luminant.com Glen Rose, TX 76043 25487559 CP-201500777 Ref. # 10CFR50.55a(g)(5)iii TXX-15117 August 3, 2015 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555

SUBJECT:

COMANCHE PEAK NUCLEAR POWER PLANT DOCKET NO. 50-446 RELIEF REQUEST B-10 FOR UNIT 2 SECOND TEN YEAR INSERVICE INSPECTION INTERVAL FROM 10CFR50.55a INSPECTION REQUIREMENTS DUE TO PHYSICAL INTERFERENCES (1998 EDITION OF ASME CODE, SECTION XI, 2000 ADDENDA SECOND INTERVAL START DATE: AUGUST 3, 2004 SECOND INTERVAL END DATE: AUGUST 2, 2014)

Dear Sir or Madam:

Pursuant to 10 CFR 50.55a(g)(5)(iii)), Luminant Generation Company, LLC (Luminant Power) is submitting Relief Request B-10 (see attachments) for Comanche Peak Unit 2 for the second ten year inservice inspection interval. Luminant Power has determined that certain inspection requirements of ASME Section XI. are impractical due to physical interferences.

The geometry of the Safety Injection piping makes the Code required examination coverage requirements impractical. Ultrasonic Testing (UT) of the subject welds was performed during the second interval to the maximum extent practical based on design configuration restrictions. Pressure test VT-2 visual examinations were also performed with no evidence of leakage identified for the subject component. No undue risk to the public health and safety is presented by this request.

This communication contains no new licensing basis commitments regarding Comanche Peak Unit 2.

U. S. Nuclear Regulatory Commission TXX-1 5117 Page 2 of 2 08/03/2015 Should you have any questions, please contact Mr. Jack Hicks at (254) 897-6725.

Sincerely, Luminant Generation Company LLC Rafael Flores Fi'redt W. Madden Director, External Affairs - Relief Request B-10 for Unit 2 Second Ten Year ISI Interval from 10CFR5O.55a Inspection Requirements due to Physical Interferences - Examination Data Sheets and Sketch c - Marc L. Dapas, Region IV Baiwant K. Singal, NIRR Resident Inspectors, Comanche Peak Rob D. Troutt, TDLR Jack Ballard, ANII, Comanche Peak Ito TXX-15117 Page 1 of 3 COMANCHE PEAK NUCLEAR POWER PLANT UNIT 2 Relief Request Number B-10 for Unit 2 Second 10 Year 1SI Interval From 10CFR50.55a Inspection Requirements due to Physical Interferences (Second 10-Year ISI Interval Start Date: August 3, 2004; End Date: August 2, 2014)

1. ASME Code Component Affected:

Class 1 Risk-Informed Inservice Inspection (RI-ISI) piping welds as shown:

RI-ISI Piping Welds (formerly Code Category B-I)

Code Cat/Item No. Description Weld No.

R-A/R1.16 10" elbow to pipe weld TCX-1-4301-10

2. Applicable Code Edition and Addenda:

The applicable ASME Boiler and Pressure Vessel Code (hereafter referred to as the 'Code")

edition and addenda is ASME Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components," 1998 Edition through 2000 Addenda. In addition, as required by 10 CFR 50.55(a), ASME Section XI, 1995 Edition, 1996 Addenda is used for Appendix VIII, Performance Demonstration for Ultrasonic Examination System.

3. Applicable Code Requirement:

ASME Section XI, Figure IWC-2500-8(c) 1998 Edition through 2000 Addenda, requires a volumetric examination of a minimum weld volume of the inner l/3t (one third of the thickness) extending into the piping base metal for a distance of 1/4" past the edge of the weld crown for NPS 4" and larger. The subject pipe size is 10" and Table IWB-2500-1 calls for a surface examination of the weld.

In a letter (NRR 10580) dated October 5, 2006, from the NRC to Comanche Peak Steam Electric Station, Unit No. 1, the NRC approved in a relief request alternative Risk Informed (RI) - ISI examinations for selected ASME Code Class 1 and 2 piping welds for the second interval. The methodology in EPRI TR-112657 Revision B-A is used as the examination method as well as for the selection of welds to be examined.

The RI-ISI program requires volumetric examination of the subject weld and extends the Code required volume of the inner 1/3t to 1/2" past the edge of the weld crown if no counterbore is present or a distance of 1/4" on either side of the weld counterbore, whichever is greater.

The Comanche Peak Nuclear Power Plant (CPNPP) second ten-year interval Inspection Program Plan also implements Code Case N-460, which is endorsed by the NRC in revision 15 of Regulatory Guide 1.147, "Inservice Inspection Code Case Acceptability ASME Section XI, Division L" Code Case N-460 states, in part, when the entire examination volume or area cannot be examined due to interference by another component or part geometry, a reduction in examination coverage on any Class 1 or Class 2 weld may be accepted, provided the reduction coverage for that weld is less than 10 percent.

NRC Information Notice (IN) 98-42, "Implementation of 10 CFR 50.55a (g) Inservice Inspection Requirements," termed a reduction in coverage of less than 10 percent to be "essentially 100 percent." IN 98-42 states, in part, "The NRC has adopted and further refined the to TXX-15117 Page 2 of 3 COMANCHE PEAK NUCLEAR POWER PLANT UNIT 2 Relief Request Number B-10 for Unit 2 Second 10 Year 1SI Interval From 10CFR50.55a Inspection Requirements due to Physical Interferences (Second 10-Year ISI Interval Start Date: August 3, 2004; End Date: August 2, 2014) definition of "essentially 100 percent" to mean "greater than 90 percent" ... has been applied to all examinations of welds or other areas required by ASME Section XI."

4. Impracticality of Compliance:

The examinations of the subject piping welds were limited by the closeness of the piping welds to safety injection piping structural restraints, attached to the steam generator lower beam. This configuration limited portions of the weld volume from being examined.

Volumetric examinations were performed with shear search units having a nominal angle of 450 in the two axial and circumferential directions. Minimum coverage obtained was 76.5 % for TCX-1-4301-10 (Refer to Attachment 2). The examinations were conducted in accordance with procedure TX-ISI-302, "Ultrasonic Examination of Austenitic Piping Welds."

Consideration was given to selecting other welds that possibly could have provided full coverage, but it was not feasible. There are only twelve welds in four SI segments, classified as risk category 5a, with a medium consequence and a degradation mechanism of IGSCC. The SI piping, subject piping welds, and support configurations are identical in each of the Loop Rooms. Four of the welds, one per Loop, are at valves, with the examination single sided. The other eight welds, two per Loop, are identical to the ones selected, with structural steel supports limiting the examinations. After looking at all of the associated piping in the four Loop Rooms, it was determined that the welds in Loop 3, TCX-1-4301-9 and TCX-1-4301-lO, would provide the most coverage. A 100 % coverage was feasible at weld TCX-1-4301-9; however, 76.5% coverage was obtained for TCX-1-4301-10 (see Attachment 2).

5. Burden caused by Compliance:

The design configuration restrictions of the subject components make the Code required examination coverage requirements for the weld volume impractical. Plant modifications or replacement of components designed to allow for complete coverage would be needed to meet the Code requirements. This would cause considerable burden to CPNPP.

6. Proposed Alternative and Basis for Use:

Proposed Alternative:

The following alternatives are proposed in lieu of the required examination coverage of essentially 100 percent:

1. Ultrasonic testing (UT) of the subject component weld was performed to the maximum extent practical during the second ten-year interval.

2. Pressure test VT-2 visual examinations were performed, as required by Code Category B-P, during the second ten-year interval. No evidence of leakage was identified for this component.

to TXX-15117 Page 3 of 3 COMANCHE PEAK NUCLEAR POWER PLANT UNIT 2 Relief Request Number B-10 for Unit 2 Second 10 Year ISI Interval From 10CFR50.55a Inspection Requirements due to Physical Interferences (Second 10-Year ISI Interval Start Date: August 3, 2004; End Date: August 2, 2014)

Basis for use:

The basis for use of this alternative is that it provides the best examination coverage practical within the limitations of the current configuration. Based on the percentage of the examination volume completed and the lack of any indications identified, there is a high level of confidence in the continued structural integrity of the weld. CPNPP believes that there is no undue risk to the public health and safety presented by this request.

7. Duration of Proposed Alternative:

The second ten-year ISI interval for Unit 2 began on August 3, 2004 and ended on August 2, 2014.

8. Precedents:

Relief Request B-10 was submitted in letter TXX-10157 from CPNPP to USNRC in December 15, 2010 for the second ten-year interval for Unit 1.

PDI Calibration Data Sheet r I 1.5 '= ht* 'r*/H Plant / Unit Company COMANCHE PEAK UNIT 2 Comp /System SAFETY INJECTION WESDYNE Data Sheet #

Page J/

11 UT-23 of_.

80 8[

/7 Procedure No. TX-ISI-302 Cal. Checks Time Rev I Chng. No. 3 / N/A Initial Calib. 0800 Cal. Block No. PDI-03 Initial Calib. Date 10/15109 0 24 B /

Cal. Block Temp. 780 Comp. Temp 84_._0Intermediate 'N/A 20 20 Therm SIN: RF-2212 Intermediate N/A Size 10" Sch. 140/1.0".. .T" Final Calib. 1525 E Ferritic W-Austenitic Final Calib. Date 10/15/09 0 2 4 B B 1 CRT Div. = .3" 1 CRT Div. =

Cal. Direction: X Axial Circ. Both Couplant Scan Area: .L to Weld Searchi iU#

Type: ULTRA GEL II Search Unit #1 111 to Weld Batch: 06225 Manufacturer: KBA Serial No.: 00YF95 Freq.: 2.25MHz Serial No.: Freq.: _

Manufacturer: hae Recordable Size: .375" Shape: ROUND Size: ____ ae _____

4-Access Indications Exam Sens. Exam Angle: 450 Model: COMP-G Exam Angle: __.ode!: 4-Examination Area / Weld ____Yes No Gec ___m____Measured Angle: 450 Measured Angle:__________

TCX-1-.4301 9 2 SIDED __X 36.2 dB Wedge Style: NON-INTEGRAL Wedge Style: .

TCX-1-4301 10 2 SIDED __X 36.2 dB Search Unit Cable Search Unit Cable Type: RG-174 Tvoe:

_______Length: 6' No. of Connectors: 0 4 '4J1 Lnt: No. of Connectors:

Remarks / Reason for Incomplete Scan(s)

EXAMINATION PERFORMED IN ACCORDANCE WITH RISK BASED Make / Model:

Instrument Settings KBA / USN 60 SW Make / Mod.Innth I:trument Settings VOLUME CRITERIA. Serial No.: SAP / 105211 *Serial No.: SAP 3.0"l Dis,.Delay *JS Range:____

Dis. Delay: 0.000 ps Range:

WELD #9: 100% CODE COVERAGE ACHIEVED. Prb.Delay: 5.6916 ps Pwidth: 220 Pr.Dela : ps Pwidth: ____

M'tl CaI/Ve!: 0.1241 p.s Pulser: SQUARE M'tl Calel ps Pulser: _____

WELD #10: SEE ATTACHED LIMITATION SHEET FOR ACHIEVED Damping: 500 C) Reject: 0% Dampi g:C Reject:____

COVERAGE. Rep. Rate: AUTOHIGH Freq.: 2.25 MHz Rep. at:AUTOHIGH Freq.: ____

Filter: FIXED Mode: P/E Filte. __ __ Mode: ____

Voltage: 450 Rectify: FULLWAVE Vel e: _____Rectify: FULLWAVE Examiner: PAUL BLECHA Level Ill Date 10/15/09 Reference Sensitivity (Sens.) R Herence Sensitivity (Sens.)

Axial: 16.2 dB Circ: S16.2 dB Ia: _________ Circ: ________

Examiner: N/A Level N/A Date N/A SDH Sensitivty:n/a DH Sensitivity: ____________

Further Evaluation Required? E] Y

'es ,,*No .g Reviewor I Date Reviewer I Date gs4cr

~~c9 -. c~' 2

PROFILE OF THE *EXAMINATION

!REPORT NO. ___________STATION COMANCHE PEAK UNIT 2 PAGE OF __

SYSTEM SAFETY INJECTION COMPONENT PIPE TO ELBOW DRAWING NO. TCX-1-4301 IDENT NO. 10 PROFILE SECTION DIAMETER 10" WELD LENGTH 34" CROWN WIDTH 1.1" CROWN HEIGHT .05" LONG SEAM LOCATION(S) N/A CENTERLINE WELD PIPE ELBOW 0

!H

.980' .944" .931" .93"I 1.015" 1.105" 1.105' 1.097" 1.086" C

+ 1112" + 1" + I/2" TOE CM.. TOE ÷ 112" 4 1" + 11/2" .4 UPSTREAM FLOW DOWNSTREAM 'MEASUREMENTS START AT CIL OF ThE WELD, THEN TOE OF WELD AND THEN 112" FROM TOE, + 1" AND ÷+1 1/2" ON BOTH SIDE OF WELD AS APPLICABLE PROFILE EXAM COMMENTS PROFILE TAKEN AT TDC COVERAGE ACHIEVED SECTION XI x RISK INFORMED X AUGMENTED N/A PREVIOUS DATA REVIEWED N/A TYPE N/A EXAMINER PAUL BLECHA (c.J5 L~.-DATE, 10115109 EXAMINER N/A DATE N/A REVIEW N/ DATE * "EVIEWER f¢ 7) I<DAN/" "1lzl.

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LIMITATION TO EXAMINATION PLANT COMANCHE PEAK UNIT 2 SKETCH TCX-1-4301 SYST.ICOMP. SAFEThY INJECTION PROCEDURE TX-!SI-302, REV.3 EXAMINER PAUL BLECHA P*kQ S" ,3/L, L DATE 10/1 5/09 RELATED TO: UT X PT MT VT IDENT. NO. to PROVIDE GENERAL INFORMATION TO DESCRiBE APPROX WdATESIZE, LOCATION AND TYPE OF LIM1TATJON.

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