ML20212J172

Safety Evaluation Supporting Amends 100 & 90 to Licenses DPR-39 & DPR-48,respectively

ML20212J172
Person / Time
Site:	Zion  File:ZionSolutions icon.png
Issue date:	02/26/1987
From:	Office of Nuclear Reactor Regulation
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ML20212J146	List: ML20212J141 ML20212J156 ML20212J172
References
NUDOCS 8703060336
Download: ML20212J172 (2)

Text

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j NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555

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SAFETY EVALUATION BY THF 0FFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.100 TO FACILITY OPERATING LICENSE NO. DPR-39 AND AMENDMENT N0. 90 TO FACILITY OPERATING LICENSE NO. DPR-48 COMMONWEALTH EDISON COMPANY ZION NUCLEAR POWER STATION, UNITS 1 AND 2 DOCKET NOS. 50-295 AND 50-304 g INTRODUCTION I

• By letter dated October 10, 1986 to H. R. Denton (NRC) from P. LeBlond (CEC 01 C'omonwealth Edison proposed an amendment to Facility Operating Licenses Nos.

DPR-39 and DPR-48, Appendix A, Figure 3.2-4, Hot Channel Factor Normalized Operating Envelope (K(Z)) for Zion Units 1 and 2. The proposed chance will correct an error in the existing Technical Specifications. The error iiivolves the calculated value for KfZ) at the 12 foot level.

EVALUATION Peaking factor limits for Westinghouse reactors are governed by the LOCA accident analysis. There is an axial shaping to the limits which consist of a flat portion up to the core midolane (commonly referred to as the peaking or hot channel factor limit, FO) with reduced allowable values up to about the ten foot level, and further reduced values for the uppermost portion of the core. The latter is called the third line segment, and is governed by the small break LOCA analysis. The curve of the axial shape limits is referred to as the X(Z) curve, and is normalized to the peaking factor limit; that is, the curve in peaking factor coordinates is divided by the Fn value. Thus the K(Z) curve has a value of unity in the bottom half of the core, and smaller values at higher axial elevations.

The existing Zion Technical Specifications have an Fo of 2.32 and a VIZ) curve upper core segment end point coordinate = (12 feet. 0.647). This cor~ responds to a core peaking factor of 1.5 (2.32*0.647). The peaking factor of 1.5 at 12 feet is a k'estinghouse generic value for the small break LOCA, but the Zion limit at the 12 foot elevation is 1.42. The value of 1.42 was approved, in part, in an NRC/SER dated May 12, 1976 supporting Amendment Nos. 20/17 to Facility Operating Licenses DPR-79 and 48. Accordingly, the proper K(Z) value at the 12 foot elevation is 1.42/2.32 = 0.612. The proposed Technicel Specification change contains this value and is, therefore, acceptable. There are no problems with the remainder of the K(Z) curve.

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. TECHNICAL FINDING The proposed Technical Specification change corrects an error in the uppermost As shown above the chance will provide the correc, i point on the K(2) curve. l coordinates for the point and is, therefore, acceptable.

ENVIRONMENTAL CONSIDERATION These amendments involve a change in the installation or use of the facilities components located within the restricted areas as defined in 10 CFR 20. The staff has determined that these amendments involve no significant increase in the amounts, and no significant change in the types, J of any effluents that may be released offsite and that there is no i significant increase in individual or cumulative. occupational radiation l expnsure. The Commission has previously issued a proposed finding that these amendments involve no significant hazards consideration and there has l Accordingly, these arendments meet been no public comment on such finding.

the eliaibility criteria for categorical exclusion set forth in 10 CFR Sec  !

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51.22(c)(9). Pursuant to 10 CFP 51.22(b) no environmental impact statement l or environmental assessment need be prepared in connection with the issuance ic of these amendments.

CONCLUSION We have concluded, based on the considerations discussed above, that:

(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compMonce with the Commission's regulations and the issuance of these amendments will not be inimical to the common defense and security or to the health and safety of the public.

Dated: February 26, 1987 PRINCIPAL CONTRIBUTOR:

M. Dunenfeld

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