ML20108D074

Requests for Rev to Reactor Vessel Matl Surveillance Program Schedule,Per 10CFR50,App H,Section III.B.3.Rev 1 to GE-NE-B1301807-01 Rept Encl

ML20108D074
Person / Time
Site:	Grand Gulf
Issue date:	05/02/1996
From:	Meisner M ENTERGY OPERATIONS, INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20108D076	List: ML20108D074 ML20108D086
References
GNRO-96-00035, GNRO-96-35, NUDOCS 9605070264
Download: ML20108D074 (5)

Text

-. -...

Entsrgy Cperatirna, Inc.

_ ENTERGY

~-

eo 8ox7se Port Gtson. MS 39150 4

Tel 601437 6470 i

M. J. Meisner Drects I

mtar L/y t. Fwgulatory Nixs May 2. 1996 4

4 4

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 Request for a Revision to the Reactor Vessel Material Surveillance Program Schedule GNRO-96/00035 Gentlemen:

Entergy Operations, Inc. is requesting a revision to the Grand Gulf Nuclear Station (GGNS) reactor vessel material surveillance program ,

schedule as required by 10CFR50, Appendix H, Section III.B.3.

Backaround l l

10CFR50, Appendix H, requires that a proposed withdrawal schedule for the  !

reactor vessel material specimens exposed in surveillance capsules be approved by the NRC prior to implementation.

The withdrawal schedule was originally located in the Technical Specifications (TS). It has since been relocated to the.Ur. dated Final Safety Analysis Report (UFSAR) in accordance with Generic Letter 91-01 that allowed relocation since the TS requirement duplicated the Appendix H requirement. The TS change was approved by Amendment 81 on 8/12/91.

Except for its location, GGNS's current schedule remains the same as the original schedule.

The currect withdrawal schedule was developed in accordance with the requirements of 10CFR50, Appendix H. ASTM E185-73 endorsed in Appendix H recommends that, for a Case A plant, the first and second capsules be removed when the capsule fluence reaches approximately 100% of the wall fluence. "GGNS is a Case-A plant, but since the surveillance capsules will not reach'this fluence during the lifetime of the plant, a 25% and 75% of design life criteria of a Case B plant were used to develop the withdrawal schedule for tb3 first two capsules.

I i

070035 aQpf 9605070264 960502 Of'-M/4. 8 PDR OOCK 05000416 1 P PDR

May 2, 1996 GNRO-96/00035 Page 2 of 5 I

1 The current withdrawal schedule requires the removal of the first and l second surveillance capsule at 8 and 24 effective full power years (EFPY), respectively. A third capsule is a spare without a specific l withdrawal schedule.

In accordance with the withdrawal schedule, GGNS withdrew the first reactor vessel material surveillance capsule on 5/7/95 during Refueling cutage 7. ,

After the withdrawal of the first capsule, GGNS became aware that testing 1 of the first capsule at such an early EFPY may not be useful because the l low fluence and good material chemistry will result in a minimal shift. i 1

Because no useful data from testing of the withdrawn material specimens are expected, GGNS decided to request a change to the withdrawal schedule that would allow the first capsule to be placed back into the vessel and would extend the time that the first capsule was due for withdrawal.

Therefore, the specimens have not been shipped for testing.

Discussion The original schedule did not account for GGNS specific conditions:

• Excellent alloy chemistry (low copper of 0.02-0.06%)

• Low reactor pressure vessel beltline fluence (<5 x 10 18 2 n/cm 32 EFPY fluence)

• Resulting low shift in the reference nil-ductility temperature (RTNDT)

Attachment 1 is a technical report from General Electric that gives full details for the conditions that exist at GGNS and provides the basis for a revised withdrawal schedule to allow the first capsule to be removed at 24 EFPY.

GGNS is a member of the Boiling Water Reactors Owner's Group (BWROG) supplemental surveillance program (SSP) . This program is designed to significantly increase the amount of BWR surveillance data in a systematic manner. As part of this program, the BWROG prepared supplemental capsules which were installed in Cooper and Oyster Creek.

These capsules contain the limiting GGNS weld and plate materials. The capsules are due to be withdrawn in 1996, 2000, and 2002. The capsules to be removed in 1996 will have a fluence higher than 25% of the design 1

Greater detail on this program is given in Attachment 1.

I

May 2, 1996 GNRO-96/00035 Page 3 of 5 life fluence used in establishing-the original schedule. .Therefore, with the use of the SSP test results, GGNS will meet the intent of the original test schedule. In the future, if the specimen results indicate that a change-to the GGNS withdrawal schedule is warranted, GGNS will propose changes to the schedule to reflect the testing results.

Provosed l'h=nne to the Withetraual St~h=dule In accordance with 10CFR50, Appendix H, Section III.B.3, GGNS requests a change.to the withdrawal schedule for the reactor vessel surveillance-capsules.

The current schedule for withdrawal of the surveillance capsules is withdrawal of the first capsule at 8 EFPY, the second capsule at 24 EFPY and the third at 32 EFPY (standby) .

The revised schedule for withdrawal of the surveillance capsules is the first-capsule-at 24 EFPY. The withdrawal schedule for the second capsule is to be determined at a later date. The third capsule (currently ..

withdrawn and requested to be returned to the vessel) will be returned to the. vessel and retained as a standby capsule.

The capsules currently in the vessel (denoted as No. 2 and No. 3 in the current schedule) are considered equivalent concerning the materials in l each capsule and the fluence on each capsule. The three capsules.  !

originally installed contained the same number and type of specimens

-(Charpy and flux wires) . The capsules were. installed in locations that have a similar fluence and temperature environment. The physical location of each of the capsules in the vessel (No. 1 at 3', No. 2 at

.177*, and No. 3 at 183') doesn't affect the. testing results of the specimens in the capsules. Each has remained in the vessel for the er.me length of time. Since the important characteristics of the two remaining capsules are the'same, either of these two capsules may be the capsule proposed to be withdrawn at 24 EFPY. The schedule for removing the remaining ~ capsule (either No. 2. or No. 3) would be determined at a later date. Therefore,.either of these capsules would be acceptable as the

'first capsule to be withdrawn.

Additionally, since testing the capsule specimens destroys the specimens themselves and the testing at 8 EFPY is not justified according to Attachment 1, GGNS is not planning to test the specimenc that have been withdrawn. GGNS proposes to return the withdrawn capsule to the vessel during RFOS scheduled to begin 10/96. Since the withdrawn capsule has been stored outside.the vessel for almost a year, GGNS wishes to return the capsule to the vessel as soon as possible so as not to waste any more exposure.to the capsule.

P i

May 2, 1996 GNRO-96/00035 Page.4 of 5 l'

l

[

Therefore, GGNS' requests that NRC review be completed by 9/15/96. This will allow the withdrawn. capsule to be ieturned to the vessel during the outage scheduled for 10/96.

t l' It should be noted however that there is little industry experience in i returning the spring loaded capsules to holders like those located in GGNS's reactor vessel. At this time, GGNS expects no problems returning j the capsule to the holder and intends to make every reasonable effort to do so if this request is approved. However, if problems were to arise during RFO8, GGNS would provide an alternate proposal to the NRC.

l GGNS is now. aware of an Atomic Safety and Licensing Board decision issued  !

on October 4, 1995 concerning an amendment request from Perry Nuclear Power Plant. The decision requires that changes to the specimen withdrawal schedule be submitted as licensing amendments and include the information required by 10CFR50.91 and 50.92. In accordance with this decision, GGNS will provide a no significant hazards consideration f evaluation.for the requested changes. This evaluation will be submitted

soon under separate cover.

j If you have any questions, please contact Sheri Mahoney at 601-437-6552.

l -Yours truly, -l MJM/SBM/mtc attachment: Surveillance Specimen Program Evaluation for Grand Gulf Nuclear Station cc: Mr. J. E. Tedrow (w/a)

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

Mr. N. S. Reynolds (w/a)

Mr. H. L. Thomas (w/o) l~ Mr. J. W. Yelverton (w/a)

Mr. L. J. Callan (w/a)

Regional Administrator U.S. Nuclear Regulatory Commission l Region IV

! 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011 Mr. J. N. Donohaw, Project Manager (w/2)

Office of Nuclear Reactor Regulation l U.S. Nuclear Regulatory Commission

! Mail Stop 13H3 Washington, D.C. 20555 l

l

AttEchm2nt to GNRO-96/00035 Attachment 1 Surveillance Specimen Program Evaluation for Grand Gulf Nuclear Station 1 I

I i

i I