ML20153A935

Requests Relief from Certain Requirements of ASME Section XI Code Associated with Examinations Where Only Partial Coverage Could Be Obtained.Relief Requests NDE-040,NDE-041 & NDE-042,encl

ML20153A935
Person / Time
Site:	North Anna
Issue date:	09/18/1998
From:	Hartz L VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
98-503, NUDOCS 9809220237
Download: ML20153A935 (22)

Text

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l hoisir ELEcriue ANI) POWER CONil%NY Racissiosin, VIRGINI A 232(el September 18, 1998 United States Nuclear Regulatory Commission Serial No.98-513 Attention: Document Control Desk NL&P/ETS Washington, D.C. 20555 Docket No.

50-339 License Nos. NPF-7 Gentlemen:

VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNIT 2 ASME SECTION XIINSERVICE INSPECTION PROGRAM RELIEF REQUESTS During the recent refueling outage, North Anna Power Station Unit 2 completed examinations in the third period of the second ten-year interval. Examinations were conducted to the requirements of the 1986 Edition of ASME Section XI. In several instances interferencec or weld geometry prohibited the complete examination of the welds.

Pursuant to 10 CFR 50.55a (g) 5, relief is requested from certain requirements of ASME Section XI Code associated with examinations where only partial coverage could be obtained.

Relief requests NDE-040, NDE-041, and NDE-042, are attached and provide the basis of this request.

These relief requests have been approved by the Station Nuclear Safety and Operating Committee. If you have any additional questions concerning these requests, please contact us.

Very truly yours,

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L. N. Hartz Vice President - Nuclear Engineering and Services Attachment

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l Commitments made in this letter:

l None 9809220237 980918 ~

PDR ADOCK 05000339<

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U. S. Nuclear Regulatory Commission l

Region il Atlanta Federal Center 61 Forsyth St., SW, Suite 23T85 l

Atlanta, Georgia 30303 Mr. M. J. Morgan NRC Senior Resident inspector North Anna Power Station i

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Attachment l

Relief Requests NDE-40,41, and 42 1

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i 1-Virginia Power Electric and Power North Anna Power Station Unit 2 l

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Virginia Electric & Power Company L

North Anna Power Station Unit 2 Second Ten Year Interval l

Request for Relief No. NDE-040 1

1.

Identification of Component:

l Weld No..

Drawing No.

Line No.

Class I

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• 32 12050-WMKS-0109G-1 31"-RC-308-2501 R-Q1 1A

• 33 12050-WMKS-0109G-1 271/2"-RC-409-2501 R-Q1 1A i

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Code requirements:

The 1986 Edition of ASME Section XI Table IWB-2500-1, examination category L

B-J, item number B9.11 requires a surface and volumetric examination of the weld and adjacent base metal as defined by Figure IWB-2500-8. The Code does not allow any reductions to the required surface and volumetric examinations. Code Case N-460, /riternative Examination Coverage for Class 1 and Class 2 Welds, allows a reduction in coverage, if it is less than 10 percent.

Ill.

Code Requirement from Which Relief is Requested:

Relief is requested from fully performing the Code-required (1986 Edition of ASME Section XI Table IWB-2500-1, examination category B-J, item number B9.11) volumetric examination on the pipe to pump welds identified above.

IV.

Basis for Relief:

The components listed above have been examined to ;he extent practical as required by the Code. However, due to the configuration of the weld (pipe to reactor coolant pump) along with the material type, the required volumetric coverage could not be obtained. The extent of volumetric and surface coverage is detailed in Table NDE-40-1. Figures NDE-40-1 and NDE-40-2 are provided as graphic detail of the limitations. experienced. These welds are terminal end welds and, as such, all welds of this type are _ scheduled for examination.

L Therefore, substitution with another weld is not feasible.

V.

Proposed Alternate Examination:

It is proposed that the volumetric examination completed at the reduced l

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coverage be accepted as meeting the Code requirements. In addition:

1. A visual (VT-2) examination will be performed in accordance with Code l

requirements during the normally scheduled system leakage test each refueling outage.

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2. Technical Specifications require that the reactor coolant system (RCS) leak rate be limited to one gallon per minute unidentified leakage. The RCS leakage is calculated at least once per 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> in accordance with Technical l

Specifications.

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3. The containment atmosphere particulate radioactivity is checked every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> in accordance with Technical Specifications.

The proposed alternatives continue to ensure that the overall level of plant quality and safety will be maintained.

• Relief was approved for an identical welds on loops A and B by the NRC in a letter dated July 29,1997.

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Table NDE-40-1 North Anna Unit 2 Examination Coerage Estimates Category B4, item B9.11 UT Coverage %

Surface Examination Weld No.

2

_5 7

8 Coverage %

Reason for Partial Examination 33 100 0

55 55 100 The weld was not accessible from the 5 side due to the configuration of the reactor coolant pump. The beam path could not be extended to l

examine the weld in two directions from the 2 side because the piping material is type ASTM A-351 austenitic steel casting, which requires the use of focused L-waves. Focused L-waves cannot be extended beyond the first sound leg. The weld was exam!ned to the maximum i

extent practical using 45 L and 60 L RTD search units from the loop

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pipe side. Approximately 100% of the lower 1/3 of the weld was covered in the 2 direction.

i 32 0

100 100 100 100 The weld was not accessible from the 2 side due to the configuration of the reactor coolant pump. The beam path could not be extended to j

examine the weld in two directions from the 5 side because the piping material is type ASTM A-351 austenitic steel casting, which requires i

the use of focused L-waves. Focused L-waves cannot be extended l'

beyond the first sound leg. The weld was examined to the maximum extent practical using 45*L SWS dual transducer search unit from the loop pipe side. Approximately 100% of the lower 113 of the weld was j

covered in the 5 direction.

UT Scan Direction Definitions 2 - Axial scan,180 degrees from isometric flow direction.

l 5 - Axial scan, the same direction as the isometric flow.

7 - Circumferential scan, clockwise rotation when viewing in the direction of isometric flow.

t 8 - Circumferential scan, counterclockwise rotation when viewing in the direction of isometric flow.

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Fignm NDE-40-1 Weld 32 on Line 31"-RC-408-2501R-Ql

+ 2e-sc Drawing: 12050-WMKS-0109G-1 31*WA38-2$01R41 Search Unit Search Unit p

N 45 Degree Angle Beam 45 Degree Angle Beam g

Reactor Coolant Punp 31"-RC408-2501R-Q1 1C y

Pipe Side of Weld A

10 1/3t ExarnnetionVolume v

2 Side 5 Side Page 4 of 5

Figure NDE-40-2 Weld 33 on Line 27 il2-RC-409-2501R-Q1 Drawing 12050-WMKS-0109G-1 wee 33 s. H#

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45' Angle Beam Path Reactor Coolant Ptsm 271/2"-RC409-2501R-Q1 2Wu-P-1C Pipe Side of Weld Sideof Wald 45* Angle Beam Path 60* Angle Beam Path N

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Lower 1/3 Examination Vokm) i 2 Side 5 Side 1

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Virginia Electric & Power Company J

North Anna Power Station Unit 2 l

Second Ten Year liiterval 4

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Request for Relief No. NDE-041 I

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Identification of Component:

Weld No.

Drawing No.

Line No.

Class i

SW-35 12050-WMKS-0109G-2 29"-RC-407-2501 R-Q1 1A SW-36 12050-WMKS-0109G-2 29"-RC-407-2501 R-Q1 1A

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SW-47 12050-WMKS-0109G-2 27%"-RC-409-2501 R-Q1.1 A l-SW-48 12050-WMKS-0109G-2 27%"-RC-409-2501 R-Q1 1A SW-49 12050-WMKS-0109G-2 27%"-RC-409-2501 R-Q1 1A j

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Code requirements:

i The 1986 Edition of ASME Section XI Table IWB-2500-1, examination category B-J, item number B9.31 requires a surface and volumetric examination of the

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weld ar.d adjacent base metal as' defined by Figure IWB-2500-9. The Code i

does not allow any reductions in the required surface and volumetric examinations. Code Case N-460, Alternative Examination Coverage for Class 1 and Class 2 Welds, allows a reduction in coverage, if it is less than 10 percent.

Ill.

Code Requirement from Which Relief is Requested:

Relief is requested from fully performing the Code-required (1986 Edition of ASME'Section XI Table IWB-2500-1, examination category B-J, item number B9.31) volumetric examination on the pipe branch connection welds identified above.

IV.

Basis for Relief:-

The components listed above have been examined to the extent practical as required by the Code.

However, due to the configuration of the weld joint (branch connection) along with the material type, the required volumetric coverage was not obtained.- The extent of volumetric and surface coverage is detailed in Table NDE-41-1. Figures NDE-41-1, through NDE-41-5 are provided as graphic detail of the limitations experienced.

These welds are branch connection welds and, as such, all welds of this type are scheduled for examination. Therefore, substitution with another weld is not feasible.

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i V.

Proposed Alternate Examination:

l It is proposed that the volumetric examination completed at the reduced coverage be accepted as meeting the Code requirements. In addition:

1.

A visual (VT-2) examination will be performed in accordance with Code requirements during the normally scheduled system leakage test each refueling outage.

2.

Technical Specification requires that the reactor coolant system (RCS) leak rate be limited to one gallon per minute unidentified leakage. The RCS leakage is calculated at least once per 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> in accordance with Technical Specifications.

3.

The containment atmosphere particulate radioactivity is checked every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> in accordance with Technical Specifications.

The proposed alternative continues to ensure that the overall level of plant quality and safety will be maintained.

Relief was approved for similar welds on loop A by the NRC in a letter dated August 8,1995.

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Table NDE-41-1 North Anna Unit 2 Examination Cove rage Eshmates Category B.J, item B9.31 uT Coverage %

Surface Examhation Wold No.

_2

_5 7

8 Coverage %

Reason for Partial Examination SW-35 77 0

30 30 100 Due to the weld geometry it is not feasible to scan from the smaller pipe side, i.e., the required lower 1/3 area of the weld is not reachable with the sound beam path from this direction. The beam path could not be extended to examine the wold in two directions from the 2 side because the piping material is type ASTM A-351 austenitic steel casting, which requires the use of focused L-waves Focused L-waves cannot be extended beyond the first sound leg. The weld was examined to the maximum extent practical using 45*L RTD search unit from the large pipe side. Approximately 77% of the lower 113 of the weld was covered with the 2 scan.

SW-36 0

87 30 30 100 Due to the weld geometry it is not feasible to scan from the smaller pipe side, i.e., the required lower it3 area of the weld is rat reachable with the sound beam path from this direction. The beam path could not be extended to examine the weld in two directions from the 5 side because the piping material is type ASTM A-351 austenitic steel casting, which requires the use of focused L-waves Focused L-waves cannot be extended beyond the first sound ;eg. The weld was examined to the maximum extent practical using 45*L RTD search unit from the large pipe side. Approximately 87% of the lower 1/3 of the weld was covered with the 5 scan.

SW.47 47 0

33 33 100 Due to the weld geometry it is not feasible to scan froen the smaller pipe side, i.e., the required lower 1/3 area of the weld is not reachable with the sound beam path from this t

directiort The beam path could not be extended to examine the weld in two directions from the 2 side because the piping material is type ASTM A-351 austenitic steel casting, which requires the use of focused L-waves. Focused L-waves cannot be extended I

beyond the first sound leg. The weld was examined to the maximum outent practical using 47*L RTD search unit from the large pipe side. Approximately 47% of the lower 1/3 of the weld was covered with the 2 scan.

l UT Scan Direction Definitions 2 - Axial scan,180 degrees from isometric flow direi. tion.

j 5 - Axial scan, the same direction as the isometric flow, j

7 - Circumferential scan, clockwise rotation when viewing in the direction of isometric flow.

8 - Circurr=ferential scan, counterclockwise rotation when viewing in the direction of isometric flow.

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4 Tabis NDE.41-1 (continued)

North Anna Unit 2 Examination Coverage Estunates Category B4, lawn 89.31 UT Coverage %

Surfaca Examinabon Wold No.

_2 5

. 7 8

Coverage %

Reason for Partial Examination SW-48 53 35 50 50 100 Due to the wood geometry it is not feasible to achieve the required ccverage. The beam poth was extended to examine the wold in two directions. The weld was examined to the maximum extent practical using 0.25" 45* and 60* search units. Approximately 53%

of the lower 1/3 of the weld was covered in the 2 direction, and Approximately 35% of the lower 1/3 of the weld was covered in the 5 direction.

SW-49 75 0

45 45 100 Due to the weld geometry it is not feasible to Man from the smaller pipe side, I.a., the required lower 1/3 area of the weld is not reachable with the sound beam path from this j

direction. The beam path could not be extended to examine the weld in two directions from the 2 side because the piping malertal is type ASTM A-351 austensbc steel casting, which requires the use of focused L-waves. Focused L. waves cannot be extended beyond the first sound leg. The weld was examined to the maximum extent pracbcal using 47*L RTD search unit from the large pipe side. Approximately 75% of the lower 1/3 of the weld was covered with the 2 scart UT Scan Direction Definitions 2 - Axial scan,180 degrees from isometric flow direction.

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5 - Axial scan, the same directea as the isometric flow.

7 - Circumferential scan, clockwise rotabon when viewing in the direction of isometric flow.

8 - Circumferential scan, counterclockwise rotation when viewing in the direction of isometnc flow.

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5 Side 5Sde 4*-RC-415-150241, Weld SW-48 45 Degree Angle 60 Degree Angle.

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I tt shoulo be noted, due to joint con 5guration, that coverage was rd consistent for 360 degrees around the crcumference. That is, coverage in some areas were greater than that shown, whde in other areas the coverage was less than that shown. See Table NDE-41-1 for cowrage Percentages.

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Virginia Electric & Power Company North Anna Power Station Unit 2 Second Ten Year Interval Request for Relief No. NDE-042 1.

Identification of Component:

Weld No.

Drawing No.

Class WS-01 12050-WMKS-CH-P-1C 2

WS-04 12050-WMKS-CH-P-1C 2

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11.

Code requirements:

The 1986 Edition of ASME Section XI Table IWC-2500-1, examination category C-C, item number C3.30 requires a surface examination of the weld and adjacent base metal as defined by Figure IWC-2500-5. The Code does not allow any reductions in the required surface examination.

Code Case N-460, Alternative Examination Coverage for Class 1 and Class 2 Welds, allows a reduction in coverage, if it is less than 10 percent.

lil.

Code Requirement from Which Relief is Requested:

Relief is requested from fully performing the Code-required (1986 Edition of ASME Section XI Table IWC-2500-1, examination category C-C, item number C3.30) rurface examination on the integrally welded attachments identified above.

IV.

Basis for Relief:

The components listed above have been examined to the extent practical as required by the Code. However, due to the configuration of the support the required surface coverage could not be obtained.

The extent of surface coverage is detailed in Table NDE-42-1. Figures NDE-42-1 and NDE-42-2 are provided as graphic detail of the limitations experienced.

Substitution with another integrally welded attachment on this or another charging pump would not necessarily improve the examination coverage since similar geometric conditions are expected.

V.

Proposed Alternate Examination:

It is proposed that the surface examination completed at the reduced coverage be accepted as meeting the Code requirements.

Page 1 of 5

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l The proposed examination coverage will ensure that the overall level of plant 1

quality and safety will be maintained.'

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Relief was approved for identical welds on 2-CH-P-1B by the NRC in a letter dated August 8,1995.

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i Table NDE42-1 North Anna Unit 2 Examination Coverage Estimates (integrally Welded Attachments)

Category C-C, item C3.30 Weld No.

Surface Examination Coverage %

Reason for Partial WS-01 82 The bottom of me welded support is not accessible for examination.

WS-04 70 The bottom of the welded support is not a cessible for examination, and base metal is limited by a flange connection.

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Figure NDE-42-1 Integrally Welded Attachment WS-01 Drawing 12050-WMKS-CH-P-1C WS-01

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2-CH-P-1C

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• D Inaccessible Area is boxed in.

Inaccessible area extends from the left at the base metal fillet weld interface and includes onehalf inch of base metal on the right l

side of the support Page 4 of 5

Figure NDE-42-2 Integrally Welded Attachment WS-04 Drawing 12050-WMKS-CH-P-1C

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A inrxessibe Area inaccessibe Area is the area inside the box.

It extends up the right side d the welded attachment and includes 0.3" d base metal.

The access to the right side is restricted due to a flange.

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