ML20033G502
| ML20033G502 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 03/29/1990 |
| From: | Schuster T COMMONWEALTH EDISON CO. |
| To: | Murley T NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 9004100113 | |
| Download: ML20033G502 (4) | |
Text
'm\\
Conunonwealth Edison i
f _ ) 1400 Opus Place
.,- (
Downers Crove, Illinois 00515 j
- /
N
)
s--
p.
March 29, 1990 Dr. Thomas E. Murley Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555 i
Attn Document Control Desk
Subject:
Byron Station Units 1 and 2 Braidwood Station Units 1 and 2 Response to Station Blackout (SBO) Questions HEC Docket Nns.
50-454/455 and 50-456/457 Dear Dr. Murley On February 26, 1990, a teleconference was held between Commonwealth Edison (CECO) Nuclear Engineering, its Architect Engineer and members of the Electrical Systems Branch including Paul Gill.
The discussion centered around Byron and Braidwood SBO questions from SAIC, to which CECO personnel provided verbal answers.
At the conclusion of the call, four questions required further research and CECO response.
The following discussion summarizes the questions and the respective answers:
1.
Why is Braidwood categorized as "1" instead of "3" for ESW7 Braidwood ESW Characterization is correctly shown as "1"
in our April 1989 submittal. The attached record of a telephone conversation between Mr. A. Rubin and Mr. J. Flack NkC is submitted as supporting evidence in concluding that the NUMARC 87-00 Table 3-2, Extremely Severe Weather Data is incorrect by an l
order of magnitude in'the direction of increased frequency of occurrence of extremely severe weather.
Therefore NUMARC 87-00, Table 3-2, is incorrect in categorizing Braidwood as ESW Group 3.
2.
Document the loading of the Alternate AC (AAC) source, including the blacked out unit and non-blacked-out unit loads.
The analysis which supports our April 1989 submittal includes the following AAC loads:
Non-Blacked out unit All normally auto-sequenced loads for loss of offsite power (non-accident) except for the Component Cooling pump and motor driven aux feedwater pump.
O(0 9004100113 900329 PDR ADOCK 05000454 p
PDC (i\\
Dr. Thomas E. Murley MIrch.29, 1990
.a p,
Riacked out Unit All normally auto-sequenced loads for loss of offsite power (non-accident) except for a component cooling pump, motor driven aux feedwater pump, and diesel generator ventilation..
Based on the 2/26/90 teleconference we understand the NRC's position to bei shedding of any auto-sequenced loads is not permissible on the non-blacked out unit. The analysis which supports our April 1989 submittal concludes that a diesel generator margin of 656KW remains af ter shedding.
Adding in an 1165HP motor driven aux feedwater pump and a 518 HP component cooling pump would overload the diesel generator to the extent that shedding of a charging pump of 550HP on the blacked out unit would not sufficiently unload the diesel generator.
A more detailed and lengthy analysis will be required to determine what blacked out unit loads could be shed.
We are currently seeking clarification of the industry position on this item through NUMARC.
We will promptly notify you of subsequent actions and a schedule for completion when.this position is determined.
3.
Demonstrute that non-operation of component cooling pump on the blacked out unit is acceptable by considering the impact of the loss of penetration cooling.
Component cooling functions to perform long term cooling of concrete at the penetrations, no adverse short term affects are anticipated.
Detailed analysis in underway to demonstrate this. This analysis will be completed by May 30, 1990.
4.
Perform a detailed review of containment isolation valves to determine that containment isolation can be achieved with either control room or local indication of valve status.
A review of cont'inmen't isolation valves has been performed.
a All valves requiring closure arc capable of being closed from i
the control room or locally, with indication of status available in the control rbom or locally.-
Very truly yours, M.O.k T. K. Schuster Nuclear Licensing Administrator Attachment cc:
Braidwood Resident Inspector Byron Resident Inspector P. C. Shemanski - NRR S. Sands - NRR Region III Offico 0847T/TKSewj
f/
Arncasca v (men O H,NERA s
-s -
November 28, 1988 Mr. C. A. Moerke Byron /Braidwood Station Project Engineer Power Engineering Department Commonwealth Edison Company Room 35 West P.O. Box 767 One First National Plaza Chicago, IL 60690
Subject:
Extremely Severe Weather Group for Braidwood
Dear Mr. Moerke:
A question was raised at the meeting on November 15th in Ceco offices regarding the extremely severe weather data tabulated in NUMARC 87-00 for Braidwood.
Enclosed is a record of a telephone conversation that I had with John Flack of NRC regarding this table. He confirmed that the NUMARC table is incorrect. The frequency of extremely severe weather (ESW) for Braidwood is an order of magnitude less than that shown in Table 3-2 of NUMARC 87-00 (i.e., 0.0001 events l
per year, D.0.1 0.001 per year). Therefore, Braidwood is in ESW Group 1 instead of ESW Group 3 for determining the station blackout coping duration per Regulatory Guide 1.155, Station Black'out.
Sincerely yours, A h.RJ4 Alan M. Rubin, Ph.D.
Senior Project Manager Enclosure ec: GECA:
Mr. J. Abel Mr. Z. Boxer Mr. W. B. Fancher Mr. M. Kluge Mr. T. Kriz Mr. B. Rybak Mr. N. Smith Mr. L. Stern Mr. L. Tate Mr. D. Wozniak IEM:
Mr. W. Larson AMR/ds
/
\\
p 5
Attochment B, ECP-2.4, Rev. I s.
1 EE in. con Doc. NO.
soluTung "l"'"
O enc a.ocArios) oisTa=.
Da.TE l
PAE I
0F PROJECT: MM Ph -
M PROJECT NO. ? ** # * '
SUBJECT:
W h 'vA b.ts pW PARTICIPANTS (NAME/ORG ANIZATION)-
GA
% / T ud#A
%L r)~.L / N R C
SUMMARY
7M 8-? '
N" F 7-6 h
4Mh a
v i
A (A 9
td M A&&
s_ru b L + 4 J b 025 &
v v
% dm & M em Aha U. C.
Th k = - m $ 6n*Lxvel E JtSo s
a r y
$ slAJ 4
% tNLk k&A & )ths Akt S & CECO &&
/klar
[J.,
0.00i (L[.u, wA 0.000i e
- 0. 0
- O L J.,4.Ar #
L x, A.24., i c~ua ~ (A r Aa A 4 ;uta 4
(
.o _
M V
y Ws & N&
w in h *% v4 A$4 W3E& : ^ m v
N4 h kn. D N 4Ala u b M e.
d M AA.A N A/wMA4C 0
.f edJ r 4,, e1
- Tb M
.tal M AA,&w M
.i v
y V
V i
hm && &A A
O. Os o i Ww &&
O.00l.
TL v
w J
~A A
%kds % > n Ks w %
k AG Atts s c t c i$.se v
i ACTION ITEMS:
b i
A
____-__--