ML20209E739

Forwards Proposed Revised Znps Defueled Station Emergency Plan & Supporting Calculations.Revs to Proposed Defueled Station Emergency Plan Have Been Reviewed & Approved IAW Comed QA Program

ML20209E739
Person / Time
Site:	Zion  File:ZionSolutions icon.png
Issue date:	07/08/1999
From:	Krich R COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20209E743	List: ML20209E739 ML20209E770 ML20209E777 ML20209E789 ML20209E807
References
NUDOCS 9907150141
Download: ML20209E739 (3)

Text

p 1 Commonwealth Edison Com,nany 1400 Opus Place Downers Grove, l' V)515-5701 I

i July 8,1999 l

U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 l l

Zion Nuclear Power Station, Units 1 and 2 Facility Operating License Nos. DPR-39 and DPR-48 '

NRC Docket Nos. 50-295 and 50-304

Subject:

Revision to Request for A'pproval of Defueled Station Emergency Plan and Exemption from 10 CFR 50.47(b) and 10 CFR 50.47(c)(2)

Reference:

Comed letter, " Request for Approval of Defueled Station Emergency Plan and Exemption from 10 CFR 50.47(b) and 10 CFR 50.47(c)(2)," dated April 13,1999 in the referenced letter, we requested NRC approval of the proposed Zion Nuclear Power Station (ZNPS) Defueled Station Emergency Plan and exemptions from 10 CFR 50.47(b) and 10 CFR 50.47(c)(2). Based on telephone conference calls between representatives of Commonwealth Edison (Comed)

Company and the NRC, we have made revisions to our proposed Defueled Station Emergency Plan and supporting information.

Attachment 1 contains the revised ZNPS Defueled Station Emergency Plan. In l general, additional information was added to provide more detail or clarifications /

to various sections of the plan. All changes are annotated with a vertical bar in i

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4 the margin of the affected pages.  !

/

l 150028 }'c 9907150141 990700 PDR ADOCK 05000295 F PDR ,

A Unicom Company g

July 8,1999 U. S. Nuclear Regulatory Commission Page 2 Attachment 2 contains revisions to "Defueled Station Emergency Plan Compliance with Section IV of Appendix E to Part 50," which was included in the referenced letter and identifies the requirements of Section IV of Appendix E to 10 CFR 50 that would continue to be met. The revisions involve notification procedures, communications, and conduct of periodic emergency plan exercises.

All changes are annotated with a vertical bar in the margin of the affected pages.

Attachment 3," Determination of the Heat Load for Assemblies F50D and Z33A,"

is a new calculation that determines the thermal output from the hottest fuel 1 assembly in the ZNPS spent fuel pool. This heat load is used as input to the I revised calculation of maximum cladding temperature of an uncovered spent fuel assembly, contained in Attachment 5.

Attachment 4, " Calculation of Decay Heat Load for Zion Spent Fuel Pool,"is a new calculation that determines the total spent fuel pool decay heat generation i rate as of May 1999. This heat load is also used as input to the revised l calculation of maximum cladding temperature of an uncovered spent fuel assembly, contained in Attachment 5.

Attachment 5 contains a revision to the calculation, " Maximum Cladding Temperature for Uncovered Spent Fuel Rod," that was previously submitted in the referenced letter. This calculation was submitted for demonstration purposes only to address the effects of a complete drain down of the water inventory in the spent fuel pool. This event is beyond the design basis for ZNPS and some of the assumptions related to it are not based on mechanistic determinations. The revision to the calculation shows that, as of June 30,1999, decay heat could not heat the spent fuel cladding above 482*C in the event that all water was drained from the spent fuel pool. Since this is well below the critical cladding temperature of 565'C, the revised calculation continues to support the conclusion stated in the referenced letter that it is no longer possible for a complete loss of water inventory from the ZNPS spent fuel pool to result in a release offsite that exceeds the early phase Environmental Protection Agency (EPA) Protective Action Guides.

Attachment 6 contains three pages that were inadvertently omitted from the calculation, " Gamma Shine Dose at the Exclusion Area Boundary Resulting from Spent Fuel Pool Dewatering Event," submitted in the referenced letter.

Attachment 7 contains the meteorological contract information as it applies to the ZNPS onsite meteorological tower.

We have discussed the proposed Defueled Station Emergency Plan with representatives of the local agencies in Illinois and Wisconsin who are involved I

p ,

J July 8,1999 U. S. Nuclear Regulatory Commission Page 3 with implementation of the current emergency plan for ZNPS. They did not ,

object to the proposed plan. 1 The revisions to the proposed Defueled Station Emergency Plan have been reviewed and approved in accordance with the Comed Quality Assurance Program. i If you have any questions about this letter, please contact K. A. Ainger at (630) 663-7350.

Respectfully, l

I R. M. Knch j Vice President - Regulatory Services '

i l

Attachments cc: Regional Administrator- NRC Region Ill (two copies) l l