ML17325A297

Informs of Intent to Change Design of Lower Tie Plate in Fuel Assemblies.Advanced Nuclear Fuels Corp Fuel Assemblies Will Be Installed During Cycle 7 Reload.Assemblies Incorporate debris-resistant Tie Plate.Fee Paid

ML17325A297
Person / Time
Site:	Cook
Issue date:	09/14/1987
From:	Alexich M INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:	Murley T NRC, NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
AEP:NRC:1035, NUDOCS 8709210518
Download: ML17325A297 (8)

Text

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ACCESSION NOR: 870'7210518 'OC. DATE: 87/09/14 NOTAR I ZED: NO DOCKET 0 FAClL:,50-316 Donald C. Cook Nuclear Power Plant Unit 2i Indiana Zc 05000316 AUTH. NAME AUTHOR AFFILIATION ALEXICH> M. P. Indiana 5 Michigan Electric Co.

RECIP. NAME RECIPIENT AFFILIATION MURLEY> T. E. NRC No Detailed Affiliation Given

SUBJECT:

Informs of util intent to change design of lower tie plate in fuel assemblies. Advanced Nuclear Fuels Corp fuel assemblies will be installed during Cycle 2 reload.

Assemblies incorporate debris-resistant tie plate.

DISTRIBUTION CODE: A001D COPIEB RECEIVED: LTR ENCL SIZE:

TITLE: OR Submittal: General Distribution NOTES:

REC IP IENT COPIES HAEC IP IENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD3-3 L* 1 0 PD3-3 PD 5 5 MIGGINGTONz D 1 1 INTERNAL: ARM/DAF/LFMB 1 0 NRR/DEST/ADB 1 1 NRR/DEBT/CEB 1 1 NRR/DEBT/MTB NRR/DEBT/RBB 1 1 NRR/DOEA/TSB 1 B/ILRB 1 1 OQC/HDS1 1 0 REQ FILE 01 1 1 REB/DE/EIH 1 1 EXTERNAL'QM HRUSKEi S LPDR NRC PDR 1 1 NBIC vlggg 4I5$

TOTAL NUMBER OF COPIES REQUIRED: LTTR 21 ENCL 18

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INDIANA & MICHIGAN ELECTRIC COMPANY P.O. BOX 16631 COLUMBUS, OHIO 43216 September 14, 1987 AEP'NRC:1035 Donald C. Cook Nuclear Plant Unit 2 Docket No. 50-316 License No. DPR-74 UNIT 2 CYCLE 7 RELOAD: CHANGES TO LOWER TIE PLATE DESIGN U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555 Attn: T. E. Murley

Dear Dr. Murley:

The purpose of this letter is to inform you of our intent to make a change to the design of the lower tie plate in the fuel assemblies which will be fabricated by Advanced Nuclear Fuels Corporation (ANF) for the upcoming D. C. Cook Unit 2 Cycle 7 reload. D. C. Cook Unit 2 Cycle 7 is scheduled to begin operation in June 1989. The reload will consist of 80 assemblies supplied by ANF. The assemblies will incorporate a debris-resistant lower tie plate in the fuel assembly design to provide protection for the assemblies in the unlikely event that debris is present in the primary coolant system. The new lower tie plate is specifically designed to entrap debris of the size which would be expected to become entrapped in the fuel assembly spacers. Unit 2 Cycle 7 will be preceded by an extended outage to replace all four steam generators. Although extreme caution will be exercised during this outage to prevent debris from entering the primary coolant system, the revised lower tie plate design is considered additional protection against fuel damage.

A safety review of the revised lower tie plate design has been performed by ANF and is included as an attachment to this letter. This review concluded that the revised design does not constitute an unreviewed safety question as defined in 10 CFR 50.59. This conclusion was based on pressure drop data obtained experimentally by ANF. These experiments demonstrated that the pressure drop for the revised lower tie plate design was less than 0.5% higher than the present design.

This difference was considered exceedingly small and is bounded by the assumptions of the current D. C. Cook Unit 2 Cycle 6 safety analyses performed by ANF.

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Dr. T. E. Murley AEP:NRC:1035 Since the D. C. Cook Unit: 2 Cycle 7 reload will be very similar to the present Cycle 6 reload, the current plans for Cycle 7 are to review the reload in house under the provisions of 10 CFR 50.59, rather than seek formal NRC review. Since the safety review of the revised lower tie plate design concluded that there are no unreviewed safety questions associated with the design change, the plans to review the reload under the provisions of 10 CFR 50.59 are unaltered. However, because the Cycle 7 fuel will differ in design from that previously reviewed by the NRC, we have decided as a courtesy to inform you of the change and to solicit your comments. As stated above, the 10 CFR 50.59 safety evaluation performed by ANF is attached to this letter; in addition, ANF has transmitted to you, via their letter DAA:014:87, dated August 25, 1987, a copy of their report ANF-87-91, "D. C. Cook 2 Debris-Resistant Lower Tie Plate Pressure Drop Test Report."

ANF is scheduled to begin fabrication of the Cycle 7 reload fuel by October 13, 1987. Therefore, we request that you inform us of any comments you have on the new lower tie plate design by September 30, 1987, so that we do not risk disruption of the fabrication schedule.

Pursuant to the requirements of 10 CFR 170.12(c), we have enclosed an application fee of $ 150.00.

This document has been prepared following Corporate procedures which incorporate a reasonable set of controls to insure its accuracy and completeness prior to signature by the undersigned.

Very truly yours, M. P. Al ich Vice President cm Attachment cc: John E. Dolan V. G. Smith, Jr. - Bridgman G. Bruchmann R. C. Callen G. Charnoff NRC Resident Inspector - Bridgman A. B. Davis - Region III

Attachment to AEP:NRC:1035 Advanced Nuclear Fuels Safety Evaluation of Revised Lower Tie Plate Design

.ADyANCEDNUCLEAR FUELS CQRPORATION

0! HORN RAPIDS ROAD. PO BOX 130, RICHL4PID, WA 993524130 FUEL ENGINEERING 4 is09i 3rs ei00 TELEx

Ie 2ere TECHNICAL SERVICES July 30, 1987 ANF-AEP/0597 Indiana 5 Michigan Electric Company c/o Mr. Thomas Georgantis Engineer, Nuclear Materials 3 Fuel Management American Electric Power Service Corp.

One Riverside Plaza, 20th Floor Columbus, OH 43216-6631

Reference:

ANF-87-91(P), "Debris-Resistant Lower Tie Plate Pressure Drop Test Report," Advanced Nuclear Fuels Corp., July 1987

Dear Hr. Georgantis:

At AEP's request, Advanced Nuclear Fuels (ANF) has incorporated a debris-resistant lower tie plate (LTP) in the fuel assembly design as a precaution against the unlikely event of debris being present in the primary coolant system. The debris-resistant LTP has been designed to reduce the possibility of debris entering the fueled region of the fuel assembly from the primary coolant system. Specifically, it is designed to entrap debris of *the size which would be expected to become entrapped in the fuel assembly spacers.

This is an improvement over the current LTP design in that it will aid in the prevention of fuel rod failures associated with debris becoming entrapped in the fuel assembly spacers and producing failures due to fretting. Further, entrapping debris in the LTP instead of in a spacer will provide more time for the flow to recover due to cross flow affects before reaching the HONBR region, A review of the pressure drop information provided in Reference (1) indicates that the unchamfered debris-resistant LTP proposed for D. C. Cook Unit 2 has essentially the same pressure drop as the current LTP. That is, less than a 0.5% difference was observed in the test data obtained between the current LTP and the prcposed unchamfered debris-resistant LTP. Since this difference is exceedingly small, it will produce only a very minor inlet flow perturbation.

This minor inlet flow perturbation would be expected to disappear due to cross flow effects prior to reaching the axial location at which HONBR would occur.

Further, the current HONBR analysis performed for 0, C. Cook Unit 2 assumed a 5% inlet flow maldistribution for the hot channel which is significantly larger than the inlet flow maldistribution which would be expected from the LTP change. Based on this, it is concluded that the Cycle 6 safety analysis will cover the plant conditions expected to occur as a result of the LTP change.

Thus, Advanced Nuclear Fuels (ANF) has concluded that the results presented in the Cycle 6 Disposition of Events and safety analysis reports are not affected by the change in LTP and that these reports will remain applicable to future

T. Georgantis (AEP) July 30, 1987 ANF-AEP/0597 cycles with the unchamfered debris-resistant LTP. Consequently, ANF concludes that the substitution of the unchamfered debris-resistant LTP for the current D. C, Cook Unit 2 LTP:

(I) Does not involve a significant increase in the probability of occurrence or the consequences of an accident previously evaluated in the safety analysis reports (2) Does not create the possibility for an accident or malfunction of a different type than any evaluated previously in the safety analysis report.

(3) Does not involve a significant reduction in the margin of safety as defined in the bases for the technical specifications.

Therefore, ANF concludes that the substitution of the unchamfered debris-resistant LTP for the current LTP does not involve an unreviewed safety issue as defined in 10 CFR 50.59. No additional analyses are required in support of this finding.

If you have any questions or comments regarding the above, please feel free to contact us.

Sincerely,

.r.-..

'-w g N. Ward, Manager

ary Reload Licensing cc  : J. M. Cleveland D H. Malin

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