NL-08-1798, Fourth 10-Year Interval Lnservice Inspection Program Submittal of Relief Request RR-01

Fourth 10-Year Interval Lnservice Inspection Program Submittal of Relief Request RR-01

ML083570437
Person / Time
Site:	Hatch
Issue date:	12/19/2008
From:	Ajluni M Southern Nuclear Operating Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NL-08-1798
Download: ML083570437 (15)

Text

Southern Nuclear Operating Company, Inc.

40 Inverness Center Parkway Post Office Box 1295 Birmingham, Alabama 3521]1-1295 Tel 205.992.5000 SOUIHERNA COMPANY December 19, 2008 Energy to Serve )'our World'"

Docket No.: 50-321 NL-08-1798 U. S. Nuclear Regulatory Commission ATrN: Document Control Desk Washington, D. C. 20555-0001 Edwin I. Hatch Nuclear Plant - Unit 1 Fourth 10-Year Intervallnservice Inspection Program Submittal of Relief Request RR-01 Ladies and Gentlemen:

Pursuant to 10 CFR 50.55a(g}(5}(iii}, Southern Nuclear Operating Company hereby submits the enclosed relief request for the Hatch Nuclear Plant - Unit 1, Fourth 10-Year Intervallnservice Inspection Program. This relief request is needed due to impracticality where there is reasonable assurance of structural integrity. The relief is requested to be approved by December 31, 2009.

This letter contains no NRC commitments. If you have any questions, please advise.

Sincerely,

~~~

M. J. Ajluni Manager, Nuclear Licensing MJA/MNW/daj

Enclosure:

RR-01, Hatch - Unit 1, Reactor Pressure Vessel Longitudinal Welds cc: Southern Nuclear Operating Company Mr. J. T. Gasser, Executive Vice President Mr. D. R. Madison, Vice President - Hatch Mr. D. H. Jones, Vice President - Engineering RTYPE: CHA02.004 U. S. Nuclear Regulatorv Commission Mr. L. A. Reyes, Regional Administrator Mr. R. E. Martin, NRR Project Manager - Hatch Mr. J. A. Hickey, Senior Resident Inspector - Hatch

Edwin I. Hatch Nuclear Plant - Unit 1 Enclosure Relief Request RR-01, Reactor Pressure Vessel Longitudinal Welds

SOUTHERN NUCLEAR OPERATING COMPANY PROPOSED RELIEF REQUEST IN ACCORDANCE WITH 10 CFR 50.55a(g)(5)(iii)

Fourth Interval RR-Ol, Version 1.0 Plant Site Plant - Hatch Unit 1.

Unit:

Interval 4th lSI Interval - December 31,2005 through December 31,2015.

Interval Dates:

Requested Approval is requested by December 31, 2009 Date for Approval and Basis:

ASMECode Class 1, ASME Section XI Category B-A, Item Number B1.12 reactor pressure Components vessel (RPV) longitudinal welds as shown in Table 1.

Affected:

Applicable ASME Section XI, 2001 Edition with 2003 addenda.

Code Edition and Addenda:

Applicable Examination Category B-A, Table IWB-2500-1 of the 2001 Edition with 2003 Code addenda of the ASME Section XI Code requires a volumetric examination. The Requirements: examinations were performed from the inside of the reactor vessel using automated tooling. The examination volumes are shown in ASME Section XI Figures IWB-2500-2 and include essentially 100% of the weld length.

Impracticality Physical obstruction of some examination surfaces due to permanently of attached equipment adjacent to the examination areas caused restricted Compliance: coverage of the examination volume as required by Figure IWB-2500-2. Nine of the eleven weld examinations were affected. The nine welds with limitations are described in Table RR-01-1 and the obstructions are depicted in Figures RR 01-01 through RR-01-09.

Burden Compliance would require removal of the permanently attached adjacent Caused by structures located inside the reactor vessel to achieve a complete examination.

Compliance:

Page 1 of 13

SOUTHERN NUCLEAR OPERATING COMPANY PROPOSED REUEF REQUEST IN ACCORDANCE WITH 10 CFR SO.SSa(g)(S)(iii)

Fourth Interval RR*01, Version 1.0 Proposed Volumetric examinations for the 4th Inspection Interval were performed on the Alternative Hatch-1 RPV longitudinal welds using a newly developed scanning tool. The and Basis for tool scans from the inside surface of the reactor vessel and provided greatly Use: improved coverage of the welds located in the high fluence areas of the beltline region and similar composite coverage of welds not in the beltline region when compared to the previous examination. The previous interval examination coincided with RPV insulation replacement and some of the scanning was performed from the vessel exterior. All examinations performed during the 4th interval were done from the vessel interior.

Coverage for the higher fluence welds (C-3-A, C-3-B, C-3-C, C-4-A, C-4-B, and C-4-C) was an average of approximately 80%. This coverage, in addition to the coverage obtained for lower fluence welds C-2-A, C-2-B, and C-2-C, provides reasonable assurance of structural integrity of these welds. Therefore, relief should be granted per 10 CFR 50.55a(g)(6)(i).

Duration of The proposed relief request is applicable for the Hatch Unit 14th Inspection Proposed Interval.

Relief Request:

Precedents: The physical limitations described in this relief request are similar to Hatch-1 for the 3rd lSI interval which was approved by the NRC on March 11, 1999. The ultrasonic examinations performed for the 4th interval under this relief request contained an overall higher composite coverage and significantly greater coverage in the beltline region of the RPV, including the previously inaccessible weld C-4-B.

References:

The NRC SER TAC No. for the 3rd interval "Edwin I. Hatch Nuclear Plant Unit 1- relief request for authorization to alternative reactor pressure vessel examination for circumferential welds" is (MB3843).

Status: Awaiting NRC approval.

Page 2 of 13

SOUTHERN NUCLEAR OPERATING COMPANY PROPOSED RELIEF REQUEST IN ACCORDANCE WITH 10 CFR 50.55a(g)(5)(iii)

Fourth Interval RR-01, Version 1.0 Class 1 Vessel Welds Table RR-Ol-1 Weld Identification No. Examination Description Limitation Coverage Results Weld C-2-A Reactor Vessel Limited UT examination coverage due to adjacent No Longitudinal Weld permanently mounted equipment in the reactor vessel. 12.3% Recordable o degree Az. Obstructions are caused by the Upper guide rod located at 0 Indications Site Elevation Non- beltline region degrees, feed water spargers and core spray piping. See 189' 7" to 189' 7" Figure RR-01-01 for depiction of obstructions.

Weld C-2-B Reactor Vessel Limited UT examination coverage due to adjacent No Longitudinal Weld permanently mounted equipment in the reactor vessel. 77.3% Recordable 120 degree Az Obstructions are caused by feed water spargers and core Indications Site Elevation Non- beltllne region spray piping. See Figure RR-01-02 for depiction of 177' 1" to 189' 7" obstructions.

Weld C-2-C Reactor Vessel Limited UT examination coverage due to adjacent 78.4% No Longitudinal Weld permanently mounted equipment in the reactor vessel. Recordable 240 degree Az Obstructions are caused by feed water spargers and core Indications Site Elevation Non- beltline region spray piping. See Figure RR-01-03 for depiction of 177' 1" to 189'. 7" obstructions.

Weld C-3-A Reactor Vessel Limited UT examination coverage due to adjacent No Longitudinal Weld I permanently mounted equipment in the reactor vessel. 69.3% Recordable 30 degree Az Obstructions are caused by specimen brackets and jet pump Indications Site Elevation Located in beltline riser braces. See Figure RR-01-04 for depiction of 164' 6" to 177' 1" region obstructions.

Weld C-3-B Reactor Vessel Limited UT examination coverage due to adjacent No Longitudinal Weld permanently mounted equipment in the reactor vessel. 90.0% Recordable 150 degree Az Obstructions are caused by jet pump riser braces. See Figure Indications.

Site Elevation Located In beilline RR-01-05 for depiction of obstructions.

164' 6" to 177' 1") region Page 3 of 13

SOUTHERN NUCLEAR OPERATING COMPANY PROPOSED RELIEF REQUEST IN ACCORDANCE WITH 10 CFR 50.55a(g)(5)(iii)

Fourth Interval RR-01. Version 1.0 Class 1 Vessel Welds Table RR*01*1 (continued)

Identification No.1 Examination Exam. History Description limitation Coverage Results Weld C-3-C Reactor Vessel Limited UT examination coverage due to adjacent No Longitudinal Weld permanently mounted equipment in the reactor vessel. 83.0% Recordable 270 degree Az Obstructions are caused by jet pump riser braces. See Figure Indications.

Site Elevation Located in beltline RR-01-06 for depiction of obstructions.

164' 6" to 177' 1") region Weld C-4-A Reactor Vessel Limited UT examination coverage due to adjacent No Longitudinal Weld permanently mounted equipment in the reactor vessel. 82.3% Recordable 18 degree Az Obstructions are caused by gusset plates. See Figure RR-Ol Indications Site Elevation Located in belthne 07 for depiction of obstructions.

152' 1" to 164' 6") region Weld C-4-B Reactor Vessel Limited UT examination coverage due to adjacent No Longitudinal Weld permanently mounted equipment in the reactor vessel. 71.5% Recordable 138 degree Az Obstructions are caused by gusset plates and shroud repair Indications.

Site Elevation Located in beltline hardware. See Figure RR-Ol-09 for depiction of obstructions 152' 1" to 164' 6n ) region Weld CA-C Reactor Vessel Limited UT examination coverage due to adjacent No Longitudinal Weld permanently mounted equipment in the reactor vessel. 82.3% Recordable 258 degree Az Obstructions are caused by gusset plates. See Figure RR-Ol Indications.

Site Elevation Located in beltline 10 for depiction of obstructions.

152' 1" to 164' 6") region Page 4 of 13

SOUTHERN NUCLEAR OPERATING COMPANY PROPOSED RELIEF REQUEST IN ACCORDANCE WITH 10 CFR 50.55a(g)(5)(iii)

Fourth Interval RR-01, Version 1.0 C-2 n

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.0" Sketch of obstructions for Hatch 1 RPV longitudinal weld C-2-A (as viewed from vessel inside diameter)

Figure RR-01-01 Page 5 of 13

SOUTHERN NUCLEAR OPERATING COMPANY PROPOSED RELIEF REQUEST IN ACCORDANCE WITH 10 CFR 50.55a(g)(5)(iii)

Fourth Interval RR-01, Version 1.0 o

Sketch of obstructions for Hatch 1 RPV longitudinal weld C-2-B (as viewed from vessel inside diameter)

Figure RR-01-02 Page 6 of 13

SOUTHERN NUCLEAR OPERATING COMPANY PROPOSED RELIEF REQUEST IN ACCORDANCE WITH 10 CFR SO.SSa(g)(S){iii)

Fourth Interval RR-01, Version 1.0 Sketch of obstructions for Hatch 1 RPV longitudinal weld C-2-C (as viewed from vessel inside diameter)

Figure RR-01-03 Page 7 of 13

SOUTHERN NUCLEAR OPERATING COMPANY PROPOSED RELIEF REQUEST IN ACCORDANCE WITH 10 CFR 50.55a(g)(5)(iii)

Fourth Interval RR-01, Version 1.0 n

30' oON 4

Sketch of obstructions for Hatch 1 RPV longitudinal weld C-3-A (as viewed from vessel inside diameter)

Figure RR-01-04 Page 8 of 13

SOUTHERN NUCLEAR OP RATING COMPANY PROPOSED RELIEF REQUEST IN ACCORDANCE WITH 10 CFR SO.SSa(g)(S)(iii)

Fourth Interval RR*01, Version 1.0

-3 .0 W

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,8' Sketch of obstructions for Hatch 1 RPV longitudinal weld C-3-B (as viewed from vessel inside diameter)

Figure RR-01-05 Page 9 of 13

SOUTHERN NUCLEAR OPERATING COMPANY PROPOSED RELIEF REQUEST IN ACCORDANCE WITH 10 CFR 50.55a(g)(5)(iii)

Fourth Interval RR-01, Version 1.0 C-3 3 O' 578 N j

n Sketch of obstructions for Hatch 1 RPV longitudinal weld C-3-C (as viewed from vessel inside diameter)

Figure RR-01-06 Page to of 13

SOUTHERN NUCLEAR OPERATING COMPANY PROPOSED RELIEF REQUEST IN ACCORDANCE WITH 10 CFR SO.SSa(g)(S)(iii)

Fourth Interval RR-01, Version 1.0 Sketch of obstructions for Hatch 1 RPV longitudinal weld C-4-A (as viewed from vessel inside diameter)

Figure RR-01-07 Page J 1 of 13

SOUTHERN NUCLEAR OPERATING COMPANY PROPOSED RELIEF REQUEST IN ACCORDANCE WITH 10 CFR 50.55a(g)(5}(iii}

Fourth Interval RR-01, Version 1.0 Sketch of obstructions for Hatch 1 RPV longitudinal weld C-4-B (as viewed from vessel inside diameter)

Figure RR-01-08 Page 12 of 13

SOUTHER NUCLEAR OPERATING COMPANY PROPOSED RELIEF REQUEST IN ACCORDANCE WI H 10 CFR SO.SSa(g)(S)(iii)

Fourth Interval RR-01, Version 1.0

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Sketch of obstructions for Hatch 1 RPV longitudinal weld C-4-C (as viewed from vessel inside diameter)

Figure RR-01-09 Page 13 of 13