ML19289D576
| ML19289D576 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 02/09/1979 |
| From: | Olshan L Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7903080268 | |
| Download: ML19289D576 (4) | |
Text
[ p og*g UNITED STATES y-
/&
NUCLEAR REGULATORY COMMISSION 4.A WASHINGTON, D. C. 20555
%, ' w*+.../
February 9, 1979 Docket Nos. 50-295 and 50-304 LICENSEE: Commonwealth Edison Company FACILITY:
Zion Station, Units 1 and 2
SUBJECT:
SUMMARY
OF MEETING HELD ON JANUARY 18, 1979 TO DISCUSS ECCS REANALYSIS A meetirig was held on January 18, 1979 in Bethesda, Maryland with representatives of Commonwealth Edison Company (CECO), Westinghouse and the Nuclear Regulatory Commission (NRC). The purpose of the meeting was to discuss the ECCS reanalysis performed for Zion to correct the error in the metal-water reaction calculation.
On January 9,1979, CECO was informed by Westinghouse that the reanalysis performed for Zion Units 1 and 2 had yielded results which would limit the total nuclear peaking factor, F, to 1.86.
q Up to that time Zion Unit 1 had been restricted by an April 21, 1978 Order to an F limit of 2.02.
To accommodate the further n
restriction in peaRing factor while operating as a load following plant the licensee had reduced power to 93% of full power.
Since Zion, Unit 2 was presently in a coastdown mode in preparation for refueling, Cycle 4, it was not impacted by the administratively limit.
It was noted, however, that Zion Unit 2 imposed reduction in FO would probably be derated when it starts up from the Cycle 4 reload late in April 1979 for up to approximately 55% of cycle burnup.
Westinghouse said, that of all the Westinghouse plants reanalyzed using the newly approved February 1978 E/M, Zion was the only one required to reduce power as a result of the ECCS reanalysis. This was attributed to the Westinghouse high-powered 15 x 15 fuel, which for this plant resulted in the burst node becoming the limiting node once the Zr-water error was corrected.
To reduce the peaking penalty, Westinghouse and CECO proposed several "short-tenn" benefits which they believe would remove presently existing conservatisms in the analysis.
Incorporating these benefits could immediately justify the return of Zion 1 to full power, but both units would have to be, derated at the beginning of their next cycle.
780308c m g, I
9
t Meeting Summary for February 9, 1979 Commonwealth Edison Company
-2 Several "long-term" options being considered by Westinghouse were also discussed and include:
(1) Return the upper head temperature to cold leg temperature (required modification of the bypass flow nozzle from the downcomer to the upper head region);
(2) Replace the 15 x 15 fuel with 17 x 17 fuel; (3)
Improve the ECCS model (a) Incorporation of upper head injection (UHI) drift flux model in blowdown (SATAN) code, (b) New mechanistic reflood model (4) Seek exemptions from Appendix K based on conservatism in ECCS model in areas of:
(a) Fission product decay (1.2 times ANS)
(b) Metal-water reaction rate (Baker-Just)
The staff indicated that before any of the proposed options could be considered as a basis to raise the F limit above 1.86, the licensee n
must submit their specific request for review and approval by the NRC.
CECO was urged to submit the reanalysis and appropriate Technical Specifications for the F of 1.86 as soon as possible. CECO said the g
submittal will be made wYthin two weeks.
/N-(%
UL L. N.' Olshan, Project Manager Operating Reactors Branch #1
Attachment:
List of Attendees cc: w/ attachment See next page
a Meeting Sundary for 3-February 9, 1979 Commonwealth Edison Company Docket File NRC PDR Local PDR ORBI Reading NRR Reading H. Denton E. Case V. Stello D. Eisenhut B. Grimes D. Davis D. Ziemann P. Check G. Lainas A. Schwencer R. Reid T. Ippolito V. Noonan J. McGough Project Manager OELD OI&E(3)
ACRS (16)
C. Parrish NRC Participants TERA J. R. Buchanan Licensee 4
E ZION ECCS f1EETING JANUARY 18, 1979 LIST OF ATTENDEES Commonwealth Edison Nuclear Regulatory Commission W. Benjamin R. Audette*
A. Lippitt C. Berlinger J. Marianyi P. Check
- W. Naughton F. Coffman*
T. Rieck M. Dunnenfeld C. Schumann D. Fieno W. Wogsland J. Guttman
- P. Harmon Westinghouse D. Kirkpatrick R. Carter G. Lanik J. Johnson N. Lauben R. Muench R. Lobel*
C. Thompson D. Neighbors C. Tuley P. Norian L. Olshan K. Parzewski H. Richings J. Rosenthal*
Z. Rosztoczy*
A. Schwencer*
J. Voglewede*
S. Weiss *
- Part-time attendance