ML20133C769

Forwards Revised NSHC of 850625 Application for Amends to Licenses DPR-39 & DPR-48,deleting Items A.1 & A.2 of 800229 Confirmatory Order Re Calculated Peak Fuel Cladding Temp During LOCA & Load Changes,Respectively

ML20133C769
Person / Time
Site:	Zion  File:ZionSolutions icon.png
Issue date:	08/01/1985
From:	Leblond P COMMONWEALTH EDISON CO.
To:	Harold Denton Office of Nuclear Reactor Regulation
References
0436K, 436K, NUDOCS 8508070135
Download: ML20133C769 (5)

Text

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Commonwealth Edison

? One First N; tion 11 Ptn. Chicigo, Ilknog

' Address Reply to: Post Office Box 767

\ ,- Chicago, Illinois 60690

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August 1, 1985 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555

Subject:

Zion Nuclear Power Station Units 1 and 2 Proposed Amendment to Facility Operating License Nos. DPR-39 and DPR-48 tEC Docket Nos. 50-295 and 50-304 References (a): June 25, 1985 letter from P. C. LeBlond to H. R. Denton.

(b): February 29, 1980 letter from H. R. Denton to D. L. Peoples.

Dear Mr. Denton:

Reference (a) transmitted a proposed amendment to Facility Operating License Nos. DPR-39 and DPR-48. This change proposes to delete Items A.1 and A.2 of reference (b). Item A.1 is concerned with the calculated peak fuel cladding temperature during a LOCA. Item A.2 places restrictions on when load changes are permissible.

Mr. J. A. Norris of your office has requested a revised demonstration of no significant hazards consideration that more directly addresses the three criteria contained in 10 CFR 50.92. This revised analysis is enclosed with this letter. Please replace Attachment 4 of reference (a) with the attached document.

As required by 10 CFR 50.91, the State of Illinois is being notified of this amendment by transmittal of a copy of this letter and the attachment.

Three signed original and thirty-seven (37) copies of this letter and its attachments are hereby provided for your review.

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l H. R. Denton August 1, 1985 If there are any further questions regarding this matter, please contactthigoffice.

Very truly yours, P. C. LeBlond Nuclear Licensing Administrator 1m Attachment cc: NRC Resident Inspector - Zion J. Norris - tRR G. Wright - State of Ill.

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ATTACHENT EVALUATION OF SIGNIFICANT HAZARDS CONSIDERATION PROPOSED CHANGES TO ZION OPERATING LICENSE NOS. OPR-39 and DPR-48 COWIRMATORY ORDER DATED FEBRUARY 29, 1980 ITEMS A.1 and A.2 DESCRIPTION OF AENDENT REQUEST An amendment to Facility Operating License Nos. OPR-39 and DPR-48 is proposed to;

-(l) Delete the requirement to restrict power level to maintain a calculated peak fuel clad temperature of 20500F under the conditions of'the 10 CFR 50, Appendix K analysis submitted on October 22,-1979.

'(2) Delete the restrictions on load following maneuvers.

BACKGROUto 10 CFR 50.92 states that a proposed amendment will involve a no significant. hazards consideration if the proposed amendment does not:

(1) Involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) Create the possibility of a new or different kind of accident from

.any accident previously evaluated; or (3) Involve a significant reduction in a margin of safety.

In addition, the Commission has providad guidance in the practical application of these criteria by publishing eight examples in 48 FR 14870.

The discussion below below addresses each of these three criteria and demonstrates that the proposed amendment involves a no significant hazards consideration.

BASIS FOR NO SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION Does the proposed amendment (1) Involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) Create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) Involve a significant reduction in a margin of safety?

DISCUSSION - ITEM 1 Proposed Change #1 The deletion of the 2050oF restriction on peak clad temperature during a large break LOCA has no relationship to the probability of the initiating pipe break. The consequences of a LOCA are not significantly increased by the deletion of the 2050of limit and the subsequent adherence to the 22000F limit of 10 CFR 50.46.

Proposed Change #2 Attachment 3 demonstrated that there was no observable correlation between load changes above 50% and the frequency of reactor trips.

Thus, the probability of an accident is not affected.

The FSAR already assumes conservative core parameters for the accident analyses. These values (Tavg, Pressure, etc) will still bound actual core conditions during load changes. Thus, the consequences of any postulated accident are unchanged.

Note that while load follow maneuvers may been considered to represent an additional risk in 1980, the experience gained since that time has shown that these load changes are routine in nature.

Thus example (iv) is applicable in this instance. Example (iv) reads as follows:

(iv) A relief granted upon demonstration of acceptable operation from an operating restriction that was imposed because acceptable operation was not yet demonstrated. This assumes that the operating restriction and the criteria to be applied to a request for relief have been established in a prior review and that it is justified in a satisfactory way that the criteria have been met.

DISCUSSION - ITEM #2 Proposed Change #1 The 1500F increase in allowed peak cladding temperature during a LOCA does not create the possibility of a new or additional accident.

Proposed Change #2 The performance of load follow maneuvers is part of Zion's design.

These power changes do not create the possibility of a new or different kind of accident.

DISCUSSION - ITEM #3 Proposed Change #1 The 1500F (2050 to 22000F) increase in allowable peak clad temperature does not involve a significant reduction of safety margins. Attachment 2 demonstrates the calculational superiority of the current analysis over the methodology used for the October 22, 1979 submittal. It also demonstrates that Zion will be in compliance with 10 CFR 50.46 and the Standard Review Plan.

Thus, example (vi) is applicable in this instance. Example (vi) reads as follows:

(vi) A change which either may result in some increase to the probability or consequences of a previously-analyzed accident or may reduce in some way a safety margin, but where the results of the change are clearly within all acceptable criteria with respect to the system or component specified in the Standard Review Plan: for example, a change resulting from the application of a small refinement of a previously used calculational model or design method.

Proposed Change #2 Zion's safety analysis utilizes conservative core parameters as initial accident conditions. These values will still bound actual conditions during load changes. Thus, there has been no reduction in safety margins.

Therefore, since the application for amendment satisfies the criteria specified in 10 CFR 50.92 and is similar to examples for which no significant hazards consideration exists, Commonwealth Edison Company has made a determina-tion that the application involves no significant hazards consideration.

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