ML20053B450
| ML20053B450 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 05/21/1982 |
| From: | Lentine F COMMONWEALTH EDISON CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| 4177N, NUDOCS 8205280415 | |
| Download: ML20053B450 (3) | |
Text
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j{]/ one First N;tionit Pina. Chictgo_. tilinois Commonwealth Edison V
Address Reply to: Post Office Box 767 Chicago. Illinois 60690 Ma y 21, 1982 Mr. Harold R. Denton, Director Of fice o f Nuclear Reactor Regulation U.S.
Nuclear Regulatory Commission Washington, D.C.
20555
Subject:
Zion Station Unit 1 Cycle 7 Reload NRC Docke t No. 50-295 Reference (a):
May 21, 1982, letter from F. G.
Lentine to H. R. Denton
Dear Mr. Denton:
Zion Unit I has recently completed its sixth cycle of operation, and is presently undergoing a refueling outage which began on February 13, 1982.
Cycle 6 terminated with a cycle burnup o f approximately 10,464 MWD /MTU.
Startup for Cycle 7 is expected to occur in June,1982.
This letter is to advise you of Commonwealth Edison Company's review of and plans regarding the Zion Unit 1 Cycle 7 reload core.
The Zion Unit 1, Cycle 7 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 limiting 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 o f the postulated events are within allowable limits.
Commonwealth Edison Company performed a detailed review at Westinghouse on the bases, including all the postulated incidents considered in the FSAR, of the Westinghouse Reload Safety Evaluation Report C2g) /
(RSER).
Based on this review and the Westinghouse A
RSER, safety evaluations were performed by Common-f#
wealth Edison On-Site and Off-Site Review pursuant to the requirements o f 10 CFR 50.59(a) and 10 CFR 50.59(b).
/
Ab) 820 5 280 L{ ( }
9
w H. R. Denton May 21, 1982 The reload fuel mechanical and thermal-hydraulic design for the Cycle 7 reload core is unchanged from that of the previously reviewed and accepted reload designs.
The current FN limit o f H
less than 1.55 ensures that the DNB ratio remains above 1.30.
In addition, based on the Westinghouse FAC analysis, a total peaking factor (Fo) o f 2.091 could occur for the full range of power distributions, including load follow maneuvers (which are currently prohibited per the NRC Order o f February 29, 1980), allowable under Constant Axial Of fset Control (CAOC).
Therefore, with the revised Zion Station Fg peaking factor limit o f 2.13 (Reference (a)),
axial power distribution type surveillance is not required for Cycle 7.
As in the past, the reload safety evaluation relied on previously reviewed and accepted analyses repoit?d in the FSAR, fuel densification reports and previous reload safety evaluation reports.
A detailed review of the core characteristics was performed to determine those parameters a ffecting the postulated accident analyses reported in the Zion FSAR.
For those incidents whose consequences could potentially be a f fected by the reload core characteristics, the incidents were reanalyzed.
Commonwealth Edison verified that the reanalyses were 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).
Commonwealth Edison also verified that the results of these reanalyses were within previously reviewed and accepted limits.
The reload safety evaluation demonstrated that Technical Specification changes are not required for operation of Zjon Unit 1 during Cycle 7, except for the change to the power peaking f actor, Fg),)which resulted from steam generator tube plugging (Reference (a
during the refueling outage.
Commonwealth Edison On-Site and Of f-Site Review concluded that no unreviewed safety questions as defined by 10 CFR 50.59 are involved with this reload.
More speci-fically with this reload:
- 1. There is no increase in the probability of occurrence or the consequences o f 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 any evaluated previously in the safety analysis reported has been created; and 3.
There has been no reduction in the margin of safety as defined in the basis for any Zion Unit 1 Technical Specification.
H. R. Denton May 21, 1982 Therefore, based on this review, application for amendment to the Zion Unit 1 operating license is not required for the Cycle 7 reload design.
Finally, verification of the reload core design will be performed per the standard startup physics tests normally performed at the start of each Zion reload cycle.
These tests will include, but not be limited to:
- 1. Control rod drive tests and drop time;
- 2. Critical boron concentration measurements;
- 3. Control rod bank worth measurements;
- 4. Moderator temperature coef ficient measurements;
- 5. Power coef ficient measurement; and
- 6. Startup power distribution measurements using the incore flux mapping system.
If there are any questions concerning this matter, please contact this o f fice.
Very truly yours, fkw
^^kN F. G.
Lentine Nuclear Licensing Administrator Zion Station im cc: Zion Resident Inspector 4177N