ML20207R645
| ML20207R645 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 03/12/1987 |
| From: | Leblond P COMMONWEALTH EDISON CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8703170499 | |
| Download: ML20207R645 (3) | |
Text
. - _.
A } CONNRenwealth h
-s One Fret Nebonel Plaza, Cheogo, Illinois
) Address Reply to: Poet Omco Box 767 l.
Nd Chce00. Illinois 60800 0767 March 12, 1987 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission j
Washington, D.C.
20555
).
Subject:
Zion Nuclear Power Station Unit 1 Cycle 10 Reload NRC Docket No. 50-295 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 l
Operating License Nos. DPR-39 and DPR-48.
j (b): Ceco Amendment Numbers 83 & 73 to DPR-39 and DPR-48 respectively, J.A. Norris to D.L. Farrar dated December 23, 1983 and NRC SER on OFA/WABA.
(c):
F. G. Lentine letter to H. R. Denton dated July 27, 1983; titled " Zion Stations Units 1 4
and 2, Byron Station Units 1 and 2, Braidwood Station Units 1 and 2, Commonwealth Edison Company Topical, Report on Benchmark of PWR Nuclear Design Methods.
(d): NRC SER on CECO's Neutronics Topical (Ref. 3) dated December 13, 1983.
Dear Mr. Denton:
4 Zion Unit I has recently completed its ninth cycle of operation, and is presently undergoing a refueling outage which began on September 4, 1986.
Cycle 9' terminated with a cycle burnup of approximately 13,992 MWD /MTU.
Startup for Cycle 10 is expected to occur early in the first part of March 1987. This letter is for your information and to advise you of Commonwealth i
Edison Company's plans regarding the Zion Unit 1 Cycle 10 reload core and the conclusions of our review per 10 CFR 50.59.
l The Zion Unit 1, cycle 10 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 l
reviewed and accepted; or f
l 8703170499 B70312
~
Ob PDR ADOCK 05000295 l
P.
PDR 4
9 H. R. Denton March 12 1987 2.
For those postulated incidents analyzed and reported in the Zion Final Safety Analysis Report (PSAR) 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 PSAR, of the Westinghouse Reload Safety Evaluation (RSE). Based on 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 CPR 50.59(a) and 10 CPR 50.59(b).
Although the reload fuel mechanical and thermal-hydraulic design for the Cycle 10 reload core has not significantly changed from that of the previously reviewed and accepted reload designs, this cycle now incorporates nearly (96%) a full core of Westinghouse's 15x15 Optimized Fuel Assemblies (OFA's) with Wet Annular Burnable Absorbers (WABA's). OFA/WABA compatibility with the LOPAR fuel was addressed in the Commonwealth Edison Company's OPA Transition Licensing Submittal (Reference (a)) and was accepted in the related NRC SER (Reference (b)). The current FNDH limit of less than 1.55 ensures that the DNB ratio remains above 1.30 for LOPAR fuel and 1.48 for OFA fuel as described in Reference (a).
In addition, based on Westinghouse's three case subset FAC analyses, a total peaking factor (Fq) of 2.211 could occur for the full range of power distributions, including load follow maneuvers allowable under Constant Axial Offset Control (CAOC). Therefore, with the current Zion Unit 1 Pq limit of 2.32, APDMS surveillance of F (Z) is not required.
q 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 reports (including Reference (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 were reanalyzed.
Commonwealth Edison verified that the reanalyses were performed in accordance I
with the Westinghouse reload safety evaluation methodology, as outlined on the l
March 1978 Westinghouse Topical Report entitled " Westinghouse Reload Safety Evaluatirn Methodology" (WCAP-9272), and were consistent with the PWR l
neutronic methods currently employed by Commonwealth Edison, as qualified in l
the Reference 3 topical report and related NRC SER (Reference (d)).
l Commonwealth Edison also verifies that the results of these reanalyses were l
within previously reviewed and accepted limits.
l l
The reload safety evaluation demonstrated that reload related Technical Specification changes are not required for operation of Zion Unit i during Cycle 10.
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:
1.
There is no increase in the probability of occurrence or the consequences of an incident or malfunction of equipment important to safety previously evaluated in the safety analysis report; l
H. R. Denton March 12, 1987 2.
No additional accident or malfunction of a different type than any evaluated previously in the safety analysis report 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.
Therefore, prior NRC review and approval of the reload core analyses and application for amendment to the Zion Unit 1 operating license is not required as a result of the cycle specific reload design for Cycle 10.
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 include, but are not limited to:
1.
A physical inventory of the fuel in the reactor by serial number and location prior to the replacement of the reactor head; 2.
Control rod drive tests and drop times; 3.
Critical boron concentration measurements; 4.
Control bank worth measurements using the rod swap technique; j
5.
Moderator temperature coefficient measurements; 6.
power coefficient measurements; and 7.
Startup power distribution measurements using the incore flux mapping system.
Very truly yours, t
- p. C. LeBlond i
Nuclear Licensing Administrator Im
(
cc: Resident Inspector - Zion J. A. Norris - NRR l
2835K
!