ML13317B224

Provides Followup Info Re Thermal Shield Sample Bolts Shipped to NRC for Corrosion Testing.Info Includes Bolt Dimensions,Matl Type & Torque Applied to Each Bolt

ML13317B224
Person / Time
Site:	San Onofre
Issue date:	11/29/1990
From:	Nandy F SOUTHERN CALIFORNIA EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9012030040
Download: ML13317B224 (14)

Text

Southern. California Edison Company 23 PARKER STREET IRVINE, CALIFORNIA 92718 F. R. NANDY November 29, 1990 TELEPHONE MANAGER. NUCLEAR LICENSING (714) 454-4504 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 Gentlemen:

Subject:

Docket No. 50-206 Corrosion Testing Of Sample Bolts Thermal Shield Replacement Support System San Onofre Nuclear Generating Station Unit 1 The purpose of this letter is to provide follow up information regarding the thermal shield sample bolts shipped to the NRC for corrosion testing.

As discussed in our August 28, 1990 letter, we believe that the existing data and plant experience demonstrates that stress corrosion cracking of the thermal shield replacement fastener locking cups is not a significant issue. The locking cup design has been used by KWU on approximately 5000 bolts currently in service (some for over four years) and subject to regular inspections, with no indication of cracks.

However, consistent with your request, on November 16, 1990, three sample bolts were shipped to the NRC for corrosion testing. These bolts are similar to those installed in the thermal shield replacement support blocks. Prior to shipment, the sample bolts were installed in blocks, torqued to specification, and locked in place using the crimping device. The enclosed information includes bolt dimensions, bolt material type, and torque applied to each bolt.

If you have any questions or comments, or if you would like additional information, please let me know.

Sincerely, Enclosure cc: J. B. Martin, Regional Administrator, NRC Region V C. W. Caldwell, NRC Senior Resident Inspector, SONGS 1, 2 and 3 C. D. Townsend, NRC Resident Inspector, San Onofre Unit 1

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ENCLOSURE INFORMATION ON THE SAMPLE BOLTS

SCE DATA SHEET:.IGSCC Test Specimen date: November 5,1990 QA Engineering Preparer: Eusebio Ramos Specimen #: HT#22835 (no. 1)

Nominal Bolt Size:

1/2 in.

Material Type:

304 Stainless Steel Recommended Torque Value: 31 Ft-Lbf Torque Value Range: 2 Ft-Lbf Overall Bolt Length: 5.280 in.

Overall Threaded Length: 1-1/4 in.

Tapped Hole for Thread: 27/64 Tap Size: 1/2-13 referenced dwgs: 1810-AA086-D1564-1 (Westinghouse #1972E97) 1810-AA086-D1571 (Westinghouse #3D21493)

Note: See Attachment 1 for Block Details

SCE DATA SHEET:. IGSCC Test Specimen date: November 5,1990 QA Engineering Preparer: Eusebio Ramos Specimen #: HT#22835 (no. 2)

Nominal Bolt Size:

1/2 in.

Material Type:

304 Stainless Steel Recommended Torque Value: 31 Ft-Lbf Torque Value Range: 2 Ft-Lb Overall Bolt Length: 5.280 in.

Overall Threaded Length: 1-1/4 in.

Tapped Hole for Thread: 27/64 Tap Size: 1/2-13 referenced dwgs: 1810-AA086-D1564-1 (Westinghouse #1972E97) 1810-AA086-D1571 (Westinghouse #3D21493)

Note: See Attachment 1 for Block Details

SCE DATA SHEET;.IGSCC Test Specimen date: November 5,1990 QA Engineering Preparer: Eusebio Ramos Specimen #: HT#13482 Nominal Bolt Size:

7/8 in.

Material Type:

304 Stainless Steel Recommended Torque Value:

192 Ft-Lbf Torque Value Range: 9 Ft-Lb, Overall Bolt Length: 3.790 in.

Overall Threaded Length: 1-1/4 in.

Tapped Hole for Thread: 49/64 Tap Size: 7/8-9 referenced dwgs: 1810-AA086-D1571 (Westinghouse #3D21493) 1810-AA086-D1572 (Westinghouse #1880E17)

Note: See Attachment 2 for Block Details

0.106 0.580 R*0.015 +.005 2.850 -:0

.680 1/2-13

-TAP 5.280 fAnterial : 304 SS 27/64 hole Block : 1-3/4 squereN NOTE: ALL DI/\\ENSICES IN INCHES ALL1chment 1: 12' bolL IGSCC Test Specimen

1.i580 0.108 1 041 R-0.015 +.005

.930

E.

2. 040 7/8-9 TAP1.75 4.50' 1steriel 304 SS 49/64 hole Black :. 1-3/4 square NOTE: ALL DIAENSION IN INCHES AL:chmenL 2 : 7/8 bolL IGSCC TesL Specimen

Southern California Edison Company 23 PARKER STREET IRVINE, CALIFORNIA 92718 F. R. NANDY November 29, 1990 TELEPHONE MANAGER, NUCLEAR LICENSING (714) 454-4504 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 Gentlemen:

Subject:

Docket No. 50-206 Corrosion Testing Of Sample Bolts Thermal Shield Replacement Support System San Onofre Nuclear Generating Station Unit 1 The purpose of this letter is to provide follow up information regarding the thermal shield sample bolts shipped to the NRC for corrosion testing.

As discussed in our August 28, 1990 letter, we believe that the existing data and plant experience demonstrates that stress corrosion cracking of the thermal shield replacement fastener locking cups is not a significant issue. The locking cup design has been used by KWU on approximately 5000 bolts currently in service (some for over four years) and subject to regular inspections, with no indication of cracks.

However, consistent with your request, on November 16, 1990, three sample bolts were shipped to the NRC for corrosion testing. These bolts are similar to those installed in the thermal shield replacement support blocks.

Prior to shipment, the sample bolts were installed in blocks, torqued to specification, and locked in place using the crimping device. The enclosed information includes bolt dimensions, bolt material type, and torque applied to each bolt..

If you have any questions or comments, or if you would like additional information, please let me know.

Sincerely, Enclosure cc: J. B. Martin, Regional Administrator, NRC Region V C. W. Caldwell, NRC Senior Resident Inspector, SONGS 1, 2 and 3 C. D. Townsend, NRC Resident Inspector, San Onofre Unit 1 FUDR 2~~

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ENCLOSURE INFORMATION ON THE SAMPLE BOLTS

SCE DATA SHEET:.IGSCC Test Specimen date: November 5,1990 QA Engineering Preparer: Eusebio Ramos Specimen #:, HT#22835 (no. 1)

Nominal Bolt Size:

1/2 in.

Material Type:

304 Stainless Steel Recommended Torque Value: 31 Ft-Lbf Torque Value Range: 2 Ft-Lbf Overall Bolt Length: 5.280 in.

Overall Threaded Length: 1-1/4 in.

Tapped Hole for Thread: 27/64 Tap Size: 1/2-13 referenced dwgs: 1810-AA086-D1564-1 (Westinghouse #1972E97) 1810-AA086-D1571 (Westinghouse #3D21493)

Note: See Attachment 1 for Block Details

SCE DATA SHEET:.IGSCC Test Specimen date: November 5,1990 QA Engineering Preparer: Eusebio Ramos Specimen #:

HT#22835 (no. 2)

Nominal Bolt Size:

1/2 in.

Material Type:

304 Stainless Steel Recommended Torque Value: 31 Ft-Lbf Torque Value Range: 2 Ft-Lbf Overall Bolt Length: 5.280 in.

Overall Threaded Length: 1-1/4 in.

Tapped Hole for Thread: 27/64 Tap Size: 1/2-13 referenced dwgs: 1810-AA086-D1564-1 (Westinghouse #1972E97) 1810-AA086-D1571 (Westinghouse #3D21493)

Note: See Attachment 1 for Block Details

SCe DATA SHEET;.IGSCC Test Specimen date: November 5,1990 QA Engineering Preparer: Eusebio Ramos Specimen #:

HT#13482 Nominal Bolt Size:

7/8 in.

Material Type:

304 Stainless Steel Recommended Torque Value:

192 Ft-Lbf Torque Value Range: 9 Ft-Lb Overall Bolt Length: 3.790 in.

Overall Threaded Length: 1-1/4 in.

Tapped Hole for Thread: 49/64 Tap Size: 7/8-9 referenced dwgs: 1810-AA086-D1571 (Westinghouse #3D21493) 1810-AA086-D1572 (Westinghouse #1880E17)

Note: See Attachment 2 for Block Details

-1

. 160 ::flg 0.108 0580 R0.015 +.005 2.650 -.

7 L

.560 w

.680 1/2-13 TAP1.75 5.280 Material 304 SS 27/64 hole Block : 1-3/4 square NOTE: ALL DIAENSIONS IN INCHES ALLEchment 1:172" bolL IGSCC Test Specimen

f- -I.580 1::

0.

108 1.04

--- R-0.015 +.005 2.040 I-~.3

.710 TAP 1?

[4.50' Ant.erial 304 SS 49/64 hole Bok:1-3/4 squae.

NOTE: ALL DIAENSION IN INCHES ALLenchmenL 2 : 7/9" bolL 10500 TesL Specimen