ML20010F609
| ML20010F609 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 09/01/1981 |
| From: | Delgeorge L COMMONWEALTH EDISON CO. |
| To: | Schwencer A Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8109100422 | |
| Download: ML20010F609 (5) | |
Text
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Commonwealth Edison one First National Ptars, Chicago, IISnois Address Reply to: Post Office Box 767 v
j Chicago, Illinois 60690 September 1, 1981 Mr.
A. Schwencer, Chief Licensing Branch 2 Division of Licensing U.S. Nuclear Regulatory Commission Washington, DC 20555
Subject:
LaSalle County Station Units 1 and 2 Supplemental Information Concerning Containment Leak Chase Channels NRC Docket Nos. 50-373/374 Reference (1):
L. O. DelGeorge letter to A. Schwencer dated August 10, 1981
Dear Mr. Schwencer:
The purpose of this submittal is to provide the report on the LaSalle County Containment Leak Chase Channels discussed in the telephone conference of August 12, 1981 with Mr.
A.
Bournia of your staff.
This report clarifies the codes used in the design, the load cases evaluated, combinations employed and resultant component stresses.
This information supplements that provided in Reference (1) and verifies the conclusion reached therein, that the integrated leak rate test performed at LaSalle County with leak chase channel plugs in is acceptable, and that future tests can be performed in the same manner.
This item remains as an unresolved issue with the regional of fice of inspection and enforcement pending completion of-the review of the attached report by your office.
Therefore, it is requested that this matter be given your prompt attention.
If there are any further questions.in this regard, please 1
direct them to this office.
-Very truly yours, L. O. DelGeorg [
Oirector of Nuclear Licensing Enclosure d)\\
cc:
NRC Resident Inspector - LSCS 2475N 8109100422 810901 PDR ADOCK 05000373 A
~.
LaSalle County 1 & 2 Project Nos. 4266/4267 Sheet 1 of 3 Design Assessment of Suppression Pool Leak Chase Channels
- The liner seams in the suppression pool area are enclosed by 2x1x3/16 stainless steel leak chase channels (ASTM A-276, Type 304). which are attached to the liner by 3/16 inch continu-ous fillet weld.
The loads and load combinations for which the channel and its weld are assessed, appl'icable codes and acceptance criteria are listed below.
Also included is a design margin table for the channel and its weld to the liner.
Loads and Load Combinations The applicable pc'l hydrodynamic loads as defined in Section 3 and Table 3.4-1 of the LSCS-DAR are:
1.
Safety / Relief Valve (SRV) Actuation Loadt In addition to the boundary loads, the SRV discharge loads include air bubble drag loads due to:
a)
All Valve, and b)
Single Valve Second Actuation.
2.
Loss-of-Coolant (LOCA) Accident Loads The LOCA loads considered for this assessment are:
a)
LOCA Water Jet Loads b)
LOCA Charging Air Bubble Loads c)
Pool Swell and Fallback Loads d)
Condensation Oscillation Loads e)
Chugging Loads f)
Accident Temperature, and g)
Jet Impingement Loads In addition to the pool hydrodynamic loads listed above, the leak chase channel is assessed for the effects of hydrostatic pressure including pool sloshing under seismic events (OBE, SSE).
These loads were combined using the appropriate load combinations from Table 4.3-2 of the LSCS-DAR.
Applicable Code and Acceptance Criteria The acceptance criterin used for this assessment is the same as outlined in Subsection 4.3.2 of LSCS-DAR.
Thus, stresses per 1969 AISC specification are used for load combinations 1 through 3 defined in Table 4.3-2.
For load combinations involving
--..=.. _==.- =; =_-
m LaSalle County 1 & 2
. Project Nos. 4266/4267 i
Sheet 2 of 3 I
s abnormal or extreme environmental loads (combinations 4 through 7a), the stresses are limited to 0.95 fy.
The allowable stress used for-the weld for all load combinations is 21000 psi.
I Margin Factors Margin factors, defined as the ratio between the allowable stress and the actual stress, were computed for the channel section and its weld to the liner for the governing load combinations of Table 4.3-2.
/
f
.m-m__--____.____.
_ ~.
c
~LaSalle County 1 & 2 Project Nos. 4266/4267 Shret 3 of 3 MARGIN TABLE FOR LEAK CHASE CHANNEL s
Load Combination
- Margin Factor Margin Factor Equation for Channel for Weld I
1 11.9 63.70 3
10.4 56.10 5.50 4a 1.30 Sa 1.30 5.50 1
7a 1.30 5.50 i
s
- Refer to Table 4.3-2 l
l l
l l
I f
l
O TABLE 4.3-2 LOCA AND SRV DESICN LOAD CCMBINATIONS STRUCTLRtAL STEEL ELASTIC DESIGN ASYN-e.
E D,_
g
, f,_
PO T
R E
E P
P T
R RR SRV**
ADS g, NET
- DESICM '
RICAL SINGLE S11tESS O
0 O
33 g
A A
g 1
Normal AISC 1.0 3
X X
Allowable w/o Temp 1.0 1.0 1.0 1.0 2
Normal AISC 1.0 0
X X
Allowable'
+
w/ Temp 1.0 1.0 1.0 1.0 1.0 1.0 3
Normal AISC 1.0 0
X X
Allowable 1.0 1.0 1.0 1.0 Sev. Env.
1.0 1.V 1.0 X
0 X
1.6 AISC 1.0 1.0 1.0 4
Abnormal 1.0 1.0 1.0
=
1.0 0
0 0
X Allowable 1.0 1.0 1.0 4a 1.0 1.0 1.0 i 95 Fy
{
5 Abnormal 1.0 1.0 1.0 X
0 X
1.6 AISC i
1.0 1.0 Sev. Env.
1.0 1.0 1.0 0
0 0
X Allowable 1.0 1.0 1.0 1.0 -
5a 1.0 1.0 i.95 Fy l
m 6
Normal 1.6 AISC l
1.0 0
X X
Allowable 1.0 1.0 1.0 1.0 w
1.0 Ext. Env.
1.0 1.95 Fy e
g i
n 1
7 Abnormal 1.6 AISC g
j 1.0 1.0
~ 1.0 1.0 1.'0 1.0 X
0 X
Allowable 88 Ext. Env.
1.0 1.0
=
=
=.-
1.0 1.0 1.0 1.0 1.0 0
0 0
X 1.95 Fy 1.0 7a 1.0 1.0 e
e LOAD DESCRIPTION Safe Shutdown Eartfiquake Dead Loads E
=
D
=
SS L
=
Live Loads P,
Pipe Break Temperature Load Stability Loads T
=
S
=
A Pipe Break Temperature Reactione g
E*""
E '" """
=
P
~
O A
Load Loads 4
DBA LOCA Loada Operating Pipe Reactions P
=
R
=
A O
=
eact ns an et orces Due to Openting henun kads R
P
=
R y
Pipe Break q
Only One SRV Should be Combined
=
Safety /Helief Valve LoaJe SRV =
at One Time Operdting Bnvis E.irthquaks EO =
e Varles in Hai,nitu.l., an.! Intaneity
=
l
.