W3P87-1675, Submits Shoulder Gap Evaluation During Cycle 3 for Review. Evaluation Concludes That Gaps Adequate for Cycle 3 & Satisfy License Condition 2.C.7.Response Requested by 871215

Submits Shoulder Gap Evaluation During Cycle 3 for Review. Evaluation Concludes That Gaps Adequate for Cycle 3 & Satisfy License Condition 2.C.7.Response Requested by 871215

ML20236C615
Person / Time
Site:	Waterford
Issue date:	07/24/1987
From:	Cook K LOUISIANA POWER & LIGHT CO., NEW ORLEANS PUBLIC SERVICE CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
W3P87-1675, NUDOCS 8707300131
Download: ML20236C615 (3)

Text

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f LOUISlANA PT.,WER O L12HT COMPANY e Post Office Bcx 6008 = New Orleans. Louisiana 70174 WMMO NEW ORLEANS PUBLIC SERVICE INC.

• Post Office Bax 60340 New Orleans. Louisiana 70160 I

July 24, 1987 -

1 l

W3P87-1675 l A4.05 j QA I

U.S. Nuclear Regulatory Commission )

ATTN: Document Control Desk j Washington, D.C. 20555

SUBJECT:

Waterford SES Unit 3 Docket No. 50-382 License Condition 2.C.7 Cycle 3 Shoulder Gap Evaluation

(

REFERENCES:

.(1) CEN-335(C)-P, Waterford Unit 3 I Cycle 2, Shoulder Gap Evaluation (July, 1986)

(2) NRC letter dated December 8, 1986 from Wilson (NRC) to Dewease (LP&L)

Centlemen:

As regards axial fuel growth, the Waterford 3 License contains the following condition (2.C.7):

' Prior to' entering Startup (Mode 2) after each refueling, the licensee shall either provide a report that demonstrates that the existing fuel element assemblies (FEA) have sufficient available shoulder gap clearance for at least the next cycle of operation, or identify to the NRC and implement a modified FEA design that has adequate shoulder gap clearance for at least the next cycle of operation. This requirement will apply until the NRC concurs that the shoulder gap cl.earance is adequate for the design life of the fuel.

Reference (1) was submitted to the NRC (on September 2, 1986) describing the methodology utilized in evaluating the adequacy of Cyle 2 shoulder gaps and demonstrating that, under conservative assumptions, the Cycle 2 shoulder gaps were acceptable. By Reference (2) the NRC evaluated the Reference ,

(1) methodology and results, finding that the shoulder gaps in all Waterford 3 j fuel were acceptable through Cycle 2.

B707300133 9707g4 DR ADOCK 05000382-PDR yQk "AN EQUAL OPPORTUNITY EMPLOYER" 'D

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, W3P87-1675

. July 24, 1987 1

For Cycle 3, fuel with the following initial shoulder gaps will be loaded 3 in the core:

Fuel Design Shoulder Gap (in.)

Batch C 2.032 Batch D 2.382 j Batch E 2.382 During Cycle'3 the Batch C fuel, which had 2.032 inches initial shoulder gap, will be limiting with regard to shoulder gap. Using the existing j measured database _ technique of Reference (1), as approved by the NRC in '

Reference (2), and the same bounding assumptions, we have determined that "

the Batch C fuel design is acceptable for a fuel rod fluence of 10.2 x 1021 nvt.

The peak Batch C fuel rod fluence at the end of Cycle 3 will be no larger than 9.5 x 1021 nyt. This fluence is a bounding value, which includes physics uncertainties, and is based on Cycle 2 operation to the upper end of the shutdown window (i.e. to 14,400 MWD /T or 380 EFPD) followed by Cycle 3 operation to a bounding endpoint (17,000 MWD /T or 450 EFPD). The Cycle 3 endpoint assumption corresponds to between 10 and 20 EFPD of Cycle 3 4 operation beyond 0 ppm boron concentration. l Based on the above evaluation, fuel shoulder gaps are adequate for Cycle 3 and satisfy License Condition 2.C.7.

In order to conclude that no unreviewed safety question exists, the review of fuel mechanical design is an essential element of each reload for Waterford 3. Considering the results of the first 3 cycles, LP&L feels that there is now sufficient information and expe.rience to close License Condition 2.C.7 for Cycle 4 and subsequent cycles while relying on the standard reload process to ensure an adequate fuel shoulder gap.

Using the Reference (1) technique and bounding assumporans, we have deter- ,

mined that the Batch D and E fuel design is acceptable for a iluence of l

'11.9 x 1021 nyt. For_ future cycles in which Batch D or E is limiting with j regard to shoulder gap, our standard approach would dictate verification 3 that fuel rod fluence in the batch would not exceed 11.9 x 10 21 nyt, includ-ing physics uncertainties. This same approach would apply for batches subsequent to Batch E. (It is expected that the subsequent batches will continue to be designed with an initial shoulder gap of 2.382 inches, identi-cal to Batches D and E.) A future design change to the initial shoulder l gap, however, would necessitate (as part of the reload process) recalcu-lation of the fluence limit and verification that fuel rod fluence did not exceed the revised fluence limit (including physics uncertainties).

Additionally,_it is worthwhile to emphasize that a large degree of conserva-tism is built into the shoulder gap evaluation methodology of Reference (1). j l

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W3P87-1675; i July'24L1987 For: instance,;the methodology conservatively ignores ~ guide' tube growth beyond a . fluence of 4.8 x'1021 nyt-(whichicorresponds to peak fluence for.:

measured' data).

By,this submittal LP&L requests your review and an SER:to confirm the fuel shoulder. gap adequacy for CycleL3 as.well as an overall review of our approach.for. subsequent cycles to.close the shoulder gap license condition.

'In orderi o.

t resolve any open; issues in a' timely fashion.to. support Cycle 3

. fuel receipt (tentatively scheduled for mid-February, 1988)'it would be

, helpful: to receive the results of your review by December 15, 1987.

^Should youirequire additional.information to assist-in your review,'p, lease contact.-Mike Meisner 'at (504.) 595-2832.

s

.Yours very truly, K.W. Cook Nuclear Safety &

Regulatory Affairs Manager KWC/MJM/pim becs. E.L. Blake, W.M. Stevenson, J.A. Calvo, J.H. Wilson, R.D. Marcin,

.NRC' Resident. Inspector's Office (W3) i' m

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