ML20072J942
| ML20072J942 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 06/28/1983 |
| From: | Bradley E PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Schwencer A Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8307010093 | |
| Download: ML20072J942 (3) | |
Text
___ _____ - __ - ---_- - -
60- M.2 m,, e n
.)
PHILADELPHIA ELECTRIC COMPANY 2301 M ARKET STREET P.O. BOX 8699 PHILADELPHI A. PA.19101 EDw ARD o, a AU ER. J R.
Q 151841-4000
- '*::":ll.*.i".'
...s EUGENE J. BR ADLEY a ssociav..eas..nb cowsess6 DON ALD mLANKEN RUDOLPH A. CHILLEMI E. C. KIR K H A LL T. H. M AM ER CORNELL PAUL AUERB ACH
.ss,s...............s.,
EDW ARD J. CULLEN. JR.
June 28, 1983 THOM AS H, MILLER. JR, B R E M E A. M c K Ee4 N A Assista-T C4*u o.h Mr.
A.
Schwencer, Chief Licensing Branch No. 2 i
Division of Licensing U.
S. Nuclear Regulatory Commission Washington, D.C.
20555 l
Subject:
Limerick Generating Station, Units l&2 l
Response to Core Performance Branch and Reactor System Branch Re ference :
PECO and NRC Conference Calls dated June 14 and 27, 1983 File:
GOVT l-l (NRC)
Dear Mr. Schwencer:
The attached document provides additional information addressing the differences in pressurization transient results between Limerick and other BWR 4 plants of s imilar design as requested by both Core Performance and Reactor System Branch reviewers in the referenced conference calls.
Sincerel Ff. B E.
adley RJS/gra/70 Copy to:
See Attached Service List I
l 8307010093 830628 PDR ADOCK 05000352 A
o e
cc: Judge Lawrence Brenner (w/ enclosure)
Judge Richard F. Cole (w/ enclosure)
Judge Peter A. Morris (w/ enclosure)
Troy B. Conner, Jr., Esq.
(w/ enclosure)
Ann P. Fodgdon (w/ enclosure)
Mr. Frank R. Romano (w/ enclosure)
Mr. Robert L. Anthony (w/ enclosure)
Mr. Marvin I. Lewis (w/ enclosure)
Judith A. Dorsey, Esq.
(w/ enclosure)
Charles W. Elliott, Esq.
(w/ enclosure)
Jacqueline I. Ruttenberg (w/ enclosure)
Thomas Y. Au, Esq.
(w/ enclosure)
Mr. Thomas Gerusky (w/ enclosure)
Director, Pennsylvania Emergency Management Agency (w/ enclosure)
Mr. Steven P. Hershey (w/ enclosure)
Donald S. Bronstein, Esq.
(w/ enclosure)
Mr. Joseph H. White, III (w/ enclosure)
David Wersan, Esq.
(w/ enclosure)
Robert J. Sugarman, Esq.
(w/ enclosure)
Martha W. Bush, Esq.
(w/ enclosure)
Spence W. Perry, Esq.
(w/ enclosure)
Atomic Safety and Licensing Appeal Board (w/ enclosure)
Atomic Safety and Licensing Board Panel (w/ enclosure)
Docket and Service Section (w/ enclosure) s
O s
Additional Informalion Addressing Limerick Pressurization Transient Results The majoe factors resulting in Limerick's having less severe effects of pressurization transient than a typical BWR 4 are (1) the control cell core design,
( 2 ),.t he larger steam line volume, and (3) the end of cycle I (EOC !) nuclear characteristics.
(a)
Control Cell Core (CCC) Design Due to different loading patterns, control blade history, and control rod patterns, the axial power shape in a control cell core design at the end of cycle is more bottom peaked than that in a conventional core.
Therefore, with the same technical specification scram speed, the negative scram reactivity in a CCC is significantly larger to mitigate tha positive void reactivity feedback caused by pressurization.
i (b)
Steam Line Volume The Limerick plant configuration provides a much larger steam line volume that other BWR 4s.
(For example, the difference is as much as 50% over another BWR 4).
This results in a lower vessel pressurization rate.
Therefore, generally milder.
Limerick's pressurization transients are (c)
End of Cycle 1 Nuclear Characteristics analyzed with the EOC 1 nuclear The Limerick transients are characteristics.
More typically, BWR 4s have used the end of equilibrium cycle conditions.
Core design evaluations have shown that, at EOC 1,
the void coefficient is less negative and the scram reactivity is larger than that at E0EC.
Therefore, the change in Critical Power Ratio (CPR) for Limerick is significantly less."
t