ML20155B983

Requests Temporary Exemption from Requirements of 10CFR50.44,10CFR50.46 & 10CFR50,App K to Allow Up to 2 LTAs Fabricated with Low Tin Version of Zirlo.Proprietary & non- Proprietary Supporting Info Encl.Proprietary Info Withheld

ML20155B983
Person / Time
Site:	Byron
Issue date:	10/22/1998
From:	Graesser K COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20138L482	List: ML20155B983 ML20155B988
References
BYRON-98-0290, BYRON-98-290, NUDOCS 9811020028
Download: ML20155B983 (3)

Text

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. Commonwealth lilison Compan) e ll)rwn Generating Station I -*

• l . 4150 North German Churc h Itoad

! II) ron, !!,61010979 i Tel 815 23 05 6 6 i October 22,1998 LTR: BYRON-98-0290 File: 2.01.0700 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Subject. Exemption Request for Two Lead Test Assemblies (LTAs)

Reference:

Byron Station, Units 1 and 2 Facility Operating License Nos. Ih F-37 and NPF-66 NRC Docket Nos. STN 50-454 and STN 50-455 Pursuant to Title 10, Code of Federal Regulations, Part 50, Section 12 (10 CFR 50.12),

Commonwealth Edison (Comed) Company requests a temporary exemption from the requirements of 10 CFR 50 44,10 CFR 50.46, and 10 CFR 50, Appendix K for Byron Station Units 1 and 2. This exemption will allow up to two Lead Test Assemblies (LTAs) containing fue! '

rods, guide thimble tubes, and instrumentation tubes fabricated with a low tin version of ZIRLO . The exemption request is required since the tin content in the ZIRLO material will be below the current licensing basis of ZIRLO as specified in WCAP-12610-P-A. " VANTAGE

+ Fuel Assembly Reference Core Report." The LTAs are planned to be inserted into the Byron Station Unit 1 Cycle 10 core in non-limiting core locations during its next refueling outage. This refueling outage is scheduled to begin March 27,1999. The exemption is needed to allow testing of these assemblics for Byron Station Unit 1 Cycle 10 and two cycles thereafter in either the Byron Station Unit 1 or Unit 2 core. This degree of flexibility, of using the LTAs in either unit, is desirable ifinitial installation or future re-insertion is delayed.

An optimization ofZIRLO corrosion resistance is being pursued to support the improved fuel performance and reliability at increasing burnup levels. Available industry data indicates that levels of tin composition near the lower end on the current range of ZIRLO should enhance the in-reactor corrosion resistance. The patent for ZIRLO specifies a tin composition that bounds the licensing basis of tin content.~ The licensing basis for ZIRLOm, as defined in WCAP-12610-P-A, specifies the tin composition as being between 0.80% and 1.20%. The proposed level of tin composition in the LTAs will be nominally between the lower bound patent limit and 0.80%

Further details justifying the acceptability of the low tin ZlRLOm LTAs is provided in .

Attachment 1.

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The requirements of 10 CFR 50.44,10 CFR 50.46, and 10 CFR 50, Appendix K, only include standards and acceptance criteria for fuel rods clad with Zircaloy or ZlRLOm Due to the tin i:omposition of the LTAs falling below the licensing basis for ZlRLO , but still within the patent's limits, this exemption is requested to allow use of these LTAs. Comed believes that the standards of 10 CFR 50.12(a) are satisfied in this case. Special circumstances are present, pursuant to 10 CFR 50.12(a)(2)(ii), to warrant granting the exemption request.

Comed requests that this exemption request be reviewed and approved by January 15,1999, in order to support fuel procurement and delivery for Byron Station Unit 1 Cycle 10.

Enclosed is:

1

1. One copy of Attachment 1, " Request for Exemption From the Provisions of 10 CFR l

50.44,10 CFR 50.46, and 10 CFR 50 Appendix K For Two Lead Test Assemblies (LTAs) l and Supporting Justification," (Proprietary), October 1998.

2. One copy of Attachment 1, " Request for Exemption From the Provisions of 10 CFR 50.44,10 CFR 50.46, and 10 CFR 50 Appendix K For Two Lead Test Assemblies (LTAs) and Supporting Justification," (Non-Proprietary), October 1998.

Also enclosed are a Westinghouse authorization letter, CAW-98-1291 and accompanying Amdavit, Proprietary Information Notice, and Copyright Notice.

As Item I contains information proprietary to Westinghouse Electric Company, a division of CBS Corporation (" Westinghouse"), it is supported by an aflidavit signed by Westinghouse, the owner of the information. The Aflidavit sets forth the basis on which the information may be withheld from public disclosure by the Commission and addresses with specificity the considerations listed in paragraph (b)(4) of Section 2.790 of the Commission's regulations.

Accordingly, it is respectfully requested that the information which is proprietary to Westinghouse be withheld from public disclosure in accordance with 10 CFR Section 2.790 of the Commission's regulations.

Correspondence with respect to the copyright or proprietary aspects of the items listed above or the supporting Westinghouse Affidavit should reference CAW-98-1291 and should be addressed to Henry A. Sepp, Manager of Regulatory and Licensing Engineering, Westinghouse Electric Company, P. O. Box 355, Pittsburgh, Pennsylvania 15230-0355.

Actions described in the submittal represent intended or planned actions by Comed. They are described for the NRC's information and are not regulatory commitments.

I Ps98byttr 1980290. doc

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Should you have any questions, please contact Mr. B. J. Adams at (815) 234-5441, extension 2280.

Respectfully, K. L Graesser l Site Vice President Byron Station Attachments cc: Regional Administrator - USNRC, Region 111 NRC Senior Resident Inspector - Byron Station P598bpttf980290. doc

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