ML20151T969

Advises of Cycle 9 Reload Core Plans & Conclusions of Review.Prior to NRC Review & Approval of Reload Core Analysis & Application for Amend to License Not Required as Result of Cycle Specific Reload Design for Cycle 9

ML20151T969
Person / Time
Site:	Zion File:ZionSolutions icon.png
Issue date:	02/03/1986
From:	Leblond P COMMONWEALTH EDISON CO.
To:	Harold Denton Office of Nuclear Reactor Regulation
References
NUDOCS 8602100400
Download: ML20151T969 (4)

Text

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/^s Commonwealth Edison

[ O ) One First Nat,orti Ptra, Chygo Ithnog Address Reply to Post Office Bou 767

(- Chicago, lihnois 60690 February 3, 1986 Mr. d 'arold R. Denton, Director Offi:e of Nuclear Reactor Regulation U.S. Nuclear Regulatory Conunission Washington D.C. 20555

Subject:

Zion Station Unit 2 Cycle 9 Reload NRC Docket No. 50-304 References (a): F. G. Lentine letter to H. R. Denton dated August 22, 1983; titled " Zion ,

Station Units 1 and 2 Proposed Change to Facility Operating License i Nos. DPP-39 and DPR-48.

l (b): Ceco Amendment Numbers 83 and 73 to DPR-39 and DPR-48 respectively, l

Jan Norris letter to D. L. Farrar l dated December 23, 1983 and NRC SER l on OFA/WABA.

l l (c): NRC SER on Ceco's Revised ECCS Analysis l Performed for Zion 1 and 2 dated May 24, l 1985.

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(d): F. G. Lentine letter to H. R. Denton dated July 27, 1983; titled " Zion Station Units 1 and 2, Byron Station Units 1 and 2, l Braidwood Station Units 1 and 2, l Cosimonwealth Edison Company Topical Report on Benchmark of PWR Nuclear Design Methods.

(e): NRC's SER on Ceco's Neutronics Topical.

(Reference 5) dated December 13, 1983.

Dear Mr. Denton:

Zion Unit 2 has recently completed its eighth cycle of operation, and is presently undergoing a refueling outage which began on September 5, 1985. Cycle 8 terminated with a cycle burnup of approximately 13,930 IWD/NTU. Startup for Cycle 9 is expected to occur around the latter part of January, 1986. This letter is to advise you of Coninonwealth Edison Company's plans regarding the Zion Unit 2 Cycle 9 reload core and the

! conclusions of our review per 10 CFR 50.59. Q i

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l 0602100400 060203 PDR ADOCK 0D000304 p PDR

H.'R. Denton February 3,1986 The Zion Unit 2 Cycle 9 reload core was designed to perform under current nominal design parameters, Technical Specifications and related bases, and current setpoints such that:

1. Core characteristics will be less 'imiting than those previously reviewed and accepted; or

2. For those postulated incidents analyzed and reported in the Zion Final Safety Analysis Report (FSAR) which could potentially be affected by fuel reload, reanalysis has demonstrated that the results of the postulated events are within allowable limits.

Commonwealth Edison Company performed a detailed review with Westinghouse on the bases, including all the postulated incidents considered in the FSAR. of the Westinghouse Reload Safety Evaluation (RSE). Based cn this review and the Westinghouse RSE, safety evaluations were performed by Commonwealth Edison On-Site and Off-Site Review pursuant to the requirements of 10 CFR 50.59(a) and 10 CFR 50.59(b).

Although the reload fuel mechanical and thermal-hydraulic design for the Cycle 9 reload core has not significantly changed from that of the previously reviewed and accepted reload designs, this cycle now incorporates approximately two-thirds of a full core of Westinghouse's 15x15 Optimized Fuel Assemblies (0FA's) with Wet Annular Burnable Absorbers (WABA's).

OFA/WABA compatibility with the current L0 PAR fuel was addressed in the Commonwealth Edison Company's OFA Transition Licensing Submittal (Reference (a)) and was subsequently accepted in the related NRC SER (Reference (b)).

The current FWDH limit of less than 1.55 ensures that the DNB ratio remains above 1.30 for L0 PAR fuel and 1.48 for OFA fuel as described in Reference (a). In addition, based upon the performance of a three case subset FAC analysis, a total peaking factor (Fq) of 2.197 is the maximum which could occur for the full range of power distributions, including load follow maneuvers, allowable under Constant Axial Offset Control (CAOC). Therefore, with the recently approved Zion Unit 1 and 2 Fq limit of 2.32 (Reference (c))

ApDMS surveillance of Fq(z) is not required.

As in the past, the reload safety evaluation relied on previously reviewed and accepted analyses reported in the FSAR, fuel densification reports, and previous reload safety evaluation reporto (including Hoference (a)). A detailed review of the core characteristics was performed to determine those parameters affecting the postulated accident analyses reported in the Zion FSAR. For those incidents whose consequences could potentially be affected by the reload core characteristics, the incidents l

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H.'R. Denton February 3,1986 were reenalysed. Cossnonwealth Edison verified that the reanalyses were I performed in accordance with the Westinghouse reload safety evaluation methodology, as outlined in the March 1978 Westinghouse Topical Report entitled " Westinghouse Reload Safety Evaluation Methodology (WCAp-9272),

and were consistent with the PWR neutronic methods currently employed by Commonwealth Edison, as qualified in the Reference (d) topical report and related NRC SER (Reference (e)). Consnonwealth Edison also verifies that the results of these reanalyses were within previously reviewed and accepted limits.

The reload safety evaluation demonstrated that Technical l

Specification changes are not required for operation of Zion Unit 2 during '

Cycle 9. Commonwealth Edison On-Site and Off-Site Reviews concluded that no }

unreviewed safety questions, as defined by 10 CFR 50.59, are involved with  ;

this reload. More specifically with this reload:

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1. There is no increase in the probability of occurrence or the L consequences of an incident or malfunction of equipment important to safety previously evaluated in the safety  ;

analysis report;

2. No additional accident or malfunction of a different type than l

any evaluated previously in the safety analysis reported has I

been created; and

3. There has been no reduction in the margin of safety as defined in the basis for any Zion Unit 2 Technical Specification.

Therefore, prior NRC review and approval of the reload core analysis and application for amendment to the Zion Unit 2 operating license is not required as a result of the cycle specific reload design for Cycle 9.

Finally, verification of the reload core design will be performed per the standard startup phyrias tests normally performed at the start of each Zion reload cycle. These tests include, but are not limited to:  ;

l 1. A physical inventory of the fuel in the reactor by serial number j and location prior to the replacement of the reactor head;

2. Control rod drive tests and drop time; 1

3. Critical boron concentration measurements; I

4. Control bank worth measurements; t_ . .

H.'R. Denton February 3, 1986 i

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5. Moderator temperature coefficient measurements;

6. Power coefficient measurements; and I

7. Startup power distribution measurements using the incore flux mapping system.

Very truly yours, P. C. LeBlond Nuclear Licensing Adminstrator cc: Resident Inspector - Zion J. A. Norris - NRR l

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