ML20077Q752

Forwards Supplemental Response to GL 94-03, IGSCC of Core Shrouds in Bwrs, Providing Core Shroud Insp Plan as Stipulated in GL 94-03,Requested Action 3 & Reporting Requirement 2

ML20077Q752
Person / Time
Site:	Grand Gulf
Issue date:	01/10/1995
From:	Hutchinson C ENTERGY OPERATIONS, INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-94-03, GL-94-3, GNRO-95-00004, GNRO-95-4, NUDOCS 9501190332
Download: ML20077Q752 (7)

Text

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86 Ent:rgy Cperatirnt, in3.

ENTERGY eo. eox 7se Port Gbson,MS 39150 g

Tel 601437 2800 1

C. R. Hutchinson vce Prestkwit Opeatens Grard gun Nuck:ar Staton Januatr 10, 1995 U.S. Nuclear Regulatory Commission Mail Station P1-37 Washington, D.C.

20555 Attention:

Document Control Desk

Subject:

Grand Gulf Nuclear Station Docket No. 50-416 License No. NPF-29 Supplemental Response to Generic Letter 94-03 GNRO-95/00004 Gentlemen:

This submittal provides the Grand Gulf Nuclear Station (GGNS) supplemental response to Generic Letter (GL) 94-03 "Intergranular Stress corrosion Cracking of Core Shrouds in Boiling Water Reactors".

On August 19, 1994, Entergy Operations submitted the initial required response to GL 94-03 Requested Licensee Actions 1 through 5 in accordance with the 30 day requirements established in Reporting Requirements 1 in GNRO-94/00108. to this submittal provides the core shroud inspection plan for GGNS as stipulated in GL 94-03 Requested Action 3 and Reporting Requirements 2.

This supplemental response reflects Entergy's continuing participation in the BWR Vessel and Internals Project's efforts to resolve this issue in a generic manner.

1C0007 G9501061 9501190332 950110 PDR ADOCK 05000416 l

P PDR

January 10, 1995 GNRO-95/00004 Page 2 of 3 i

1 Should you have any questions or require additional information regarding this matter, please contact George Lee at 601-437-6214.

l A

Yours t y,

~

i CRH/G attachments:

1.

Affirmation per 10CFR50.30 l

2.,

Supplemental Response to Generic Letter GL 94-03 cc:

Mr. J. Tedrow (w/a)

Mr. H. W. Keiser (w/a)

Mr. R. B. McGehee (w/a)

Mr. N.

S. Reynolds (w/a)

Mr. H. L. Thomas (w/o)

Mr. Stewart D. Ebneter (w/a)

Regional Administrator U.S. Nuclear Regulatory Commission Region II 101 Marietta St.,

N.W.,

Suite 2900 Atlanta, Georgia 30323 Mr.

P. W. O'Connor, Project Manager (w/2)

Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop 13H3 Washington, D.C.

20555 G9501061

1 3

BEFORE THE a

UNITED STATES NUCLEAR REGULATORY COMMISSION l

LICENSE NO. NPF-29 I

i j

DOCKET NO. 50-416 l

i IN THE MATTER OF i

HISSISSIPPI POWER & LIGHT COMPANY and-SYSTEM ENERGY RESOURCES, INC.

)

and l

SOUTH MISSISSIPPI ELECTRIC POWER ASSOCIATION i

and ENTERGY OPERATIONS, INC.

AFFIRMATION j

I, C. R. Hutchinson, being duly sworn, state that I am Vice President, 1

Operations GGNS of Entergy Operations, Inc.; that on behalf of Entergy j

Operations, Inc., System Energy Resources, Inc., and South Mississippi l

Electric Power Association I am authorized by Entergy Operations, Inc. to j

sign and file with the Nuclear Regulatory Commission, this application for amendment of the Operating License of the Grand Gulf Nuclear Station; that i

I signed this application as Vice President, Operations GGNS of Entergy j

Operations, Inc.; and that the statements made and the matters set forth therein are true and correct to the best my owl g3, information and belief.

e-J C. R.'Hutchinson STATE OF MISSISSIPPI COUNTY OF CLAIBORNE SUBSCRIBED AND SWORN TO before me, a Notary Public, in and for the County and State above named, this

//

day of Tqw%tt.?l 1995.

_b I

Notary Public My coxnission' expires:

My CommisSon Expires Jan. 27,1996 G9501061

. to GNRO-95/00004 Page 1 of 4 CRAND GULF NUCLEAR STATION UNIT 1 SUPPLEMENTAL RESPCNSE TO GENERIC LETTER GL 94-03 INTERGRANULAR STRESS CORROSION CRACKING OF SHROUDS IN BOILING WATER REACTORS Prepared By:

Nuclear Plant Engineering Mr. D. G. Bost, Director I

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Introduction J

l This Shroud Inspection Plan for Grand Gulf Nuclear l

Station supplements Entergy's original response to item 3 of Generic Letter (GL) 94-03, "Intergranular Stress j

Corrosion Cracking of Core Shrouds In Boiling Water Reactors".

consistent with Entergy's previous response, the j

development of the Grand Gulf Shroud Inspection Plan follows the guidance of the Boiling Water Reactor Vessel l

and Internals Project (BWRVIP).

This guidance is contained in "BWR Core Shroud Inspection and Flaw j

Evaluation Guidelines", GENE-523-113-0894, which the NRC has received for review.

Without duplicating the details contained in that report, this inspection plan describes l

the manner in which the BWRVIP guidance is applicable to i

Grand Gulf.

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As the BWRVIP continues its work to establish effective inspection guidance that is acceptable to the NRC, some r

j of the current plans may not represent the best available technology at the time the inspection is actually l

performed.

Grand Gulf intends to implement, without I

further notification, that shroud inspection guidance endorsed by the BWRVIP at the time of inspection.

Notwithstanding future efforts by the BWRVIP, the

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following represents the current Shroud Inspection Plan for Grand Gulf.

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G9501061

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. to GNRO-95/00004 Page 3 of 4 II.

Requested Licensee Actions NRC Requested Action:

3.

Develop an inspection plan which addresses:

(a) all shroud welds (from support attachments to the vessel to the top of the shroud) and/or provides a justification for elimination of particular welds from consideration; and (b) examination methods with appropriate consideration given to use to the best j

available technology and industry inspection j

experience (e.g.,

enhanced VT-1 visual inspections, I

optimized UT techniques).

Standard methods for I

inspection of core support structures as specified by the ASME Code,Section XI have been shown to be inadequate for consistent detection of IGSCC in core shrouds.

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Response

Based upon the susceptibility criteria described in GENE-523-113-0894, Grand Gulf is a Category B (Limited Inspection) plant and plans to perform those inspections required by Table 3-2 of that same document with the following clarifications:

(1)

Grand Gulf plans to inspect welds H3, H4, H6A, and H7, which are equivalent to the H3, H4, H5, and H7 welds listed in Table 3-2.

The difference in nomenclature occurs because Grand Gulf has a second mid-core weld, H5, compared to the example core shroud shown in Figure 1-1 of the subject report.

Grand Gulf does not plan to inspect weld H5 and H6B because the H4 and H6A welds, respectively, are j

representative of the area.

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, to GNRO-95/00004 Page 4 of 4

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(2) of the several inspection options listed in Table 3-2, Grand Gulf plans to perform'all inspections ~with ultrasonic test devices.from the outside of the shroud.

Based upon new but unpublished guidance provided by the BWRVIP, Grand Gulf plans to use a-1 creeping wave examination as a supplement for examining the OD surface.

.This is consistent with the best current industry practices.

(3)

Since the H7 weld at Grand Gulf does include a H

backing ring, Grand Gulf's inspection plans are consistent with the corresponding inspection requirements of Table 3-2.

(4)

Based upon a Grand Gulf Shroud Inspectability Study, welds H6A and H7 have limited access (less than required for Lgin).

For these cases, all of the accessible portions of the welds will be inspected and evaluated.

(5)

In the unlikely event that cracked segments are found, Grand Gulf plans to perform additional inspections as established by the.BWRVIP and accepted by the NRC.

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