ML20071G373
| ML20071G373 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 05/19/1983 |
| From: | Schroeder C COMMONWEALTH EDISON CO. |
| To: | Schwencer A Office of Nuclear Reactor Regulation |
| References | |
| 6593N, NUDOCS 8305240110 | |
| Download: ML20071G373 (4) | |
Text
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Commonwealth Edison s
/
) One First National Plazt Chicano, lilanois T'
] Address Reply to: Post Othee Box 767
/ Chicago, lilinois 60690 May 19, 1983 Director of Nuclear Reactor Regulation Attention:
Mr.
A. Schwencer, Chief Licensing Branch No. 2 Division of Licensing U. S. Nuclear Regulatory Commission Washington, DC 20555
Subject:
LaSalle County Station Units 1 and 2 Fuel Lift Model and Results NRC Docket Nos. 50-373 and 50-374 Reference (a):
LaSalle County Station Unit 1 License NPF-11, Condition 2.C.(12).
Dear Sir:
Provided herewith are two Tables 3.9.4 and 3.9-4A for LaSalle Units 1 & 2 respectively.
These Tables compare the NRC load combinations in the horizontal plane and in the vertical plane and design basis loads resulting from the ABS of SSE + SRV + CO + peak pressure input loads (Load Case 2).
The indicated results confirm the earlier docketed LaSalle conclusions, and those in the NEDE-21175-3-P report.
From the maximum input loads, a maximum fuel assembly gap opening for the most limiting ABS load combination is derived and then compared to the 0.520 inch gap needed to initiate disengagement of the lower tie plate from the fuel support casting.
The decoupling results for LaSalle are:
Unit 1 Unit 2 Calculated gap 0.186 in.
0.160 in.
Acceptable gap 0.520 in.
0.520 in.
l Margin 2.8X 3.20X The results acknowledge the slight differences between Unit 1 and Unit 2 RPV pedestals and attachment positions for major nozzles; moreover, the results indicate acceptability and consistency with the generic report.
The LaSalle evaluations were made with the GE Model II fuel lift model represented in NEDE-21175-3-P.
Both units were treated equivalently by the model and by the input load definitions; these latest results supercede all others.
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Director of NRR May 19, 1983 Obviously, the generic treatment is adequate to obviate the need for any plant specific treatment because of the built-in conservatism in both the selection of loads and the method for load combinations.
A realistic estimate of margin is ten-fold greater.
There is no safety issue in this subject and all pertinent LaSalle data is already on the record except these Tables which will be included in FSAR Amendment 63.
That amendment is expected to be submitted to the NRC by June 30th, 1983.
To the best of my knowledge and belief the statements contained herein and in the attachment are true and correct.
In some respects these statements are not based on my personal knowledge but upon infor-mation furnished by other Commonwealth Edison employees and consultants.
Such information has been reviewed in accordance with Company practice and I believe it to be reliable.
One (1) signed original and forty (40) copies of this letter and the enclosure are provided for your use.
If there are any further questions regarding this matter, please contact this office.
Very truly yaurs, I
(
C.
Sch ceder /
Nuclear Licens ng Ad inistrator 1m cc:
Region III Inspector - LSCS Enclosure 6593N k
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l TABLB 3.9 t/
I FUEL _ ASSEMBLY (1HCLUDING CHANNEL)
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i Calculated U
Peak Evaluation Basis Acceptance criteria Londing
_ Primary Load Type Acceleration _
Acceleration i
Acceleration Envelope Horizontal. Direction:
Horizontal Acceleration J9G
- 3. (, C Profile i
1.
Peak Pressure 2.
Annulus Pressurization vertical Direction:
vertical Acceleratione d*,0 0 12.0 C 1.
Peak Prensure 2.
Safe Shutdown Entthquake 3.
Safety Ro11ef Valve 4.
Cent ontsAvtos.1 Orc t (.L AT to M 4
l HOTES6 (1) Evaluation Basta Accelerations and Evaluations are contained in NEDE-21175-3-P. The evaluation basis acceleration envelope f a defined by a coincident 8G vertical acceleration with the J4G horisorttal acceleration. The 34G horizontal value is reduced linearly to raro an the correspondir.g vertical j
acceleration increases from 8 to 12 G's.
1 (2) The esiculated maximura fuel assembly gap opening for the most limiting load combination is O.f SG inch.
This is leas'than the gap (0.52 inch) required to arnet the disengagement of the lower tie plate frors the fuel support casting.
(3) The fatigue analysia indicates that the fuel anacr:bly has adequate fit 1 Rue capebility to withstand the loadings resulting from multiple SRV actuationshWth-232CRII-wcr.c.
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TABLE 3.9- #42, a
. Y' FUEL ASSEMBLY (INCLUDINC CHANNEL)
Calculated Peak Evaluation Basis Acceptance Criteria Loading Primary Load Type Acceleration Acceleration Acceleration Envelope Horizontal Direction:
Horizontal Acceleration
/, 3 G
- 3. 6 C Profile 1.
Peak Pressure 2.
OFE*ItAT)oM AL 5AS S E+rrySprigd-3* $A F5TV EE LtC F VALVG 4
Offti6dri Ally Vertical Direction:
Vertical Accelerationa f
4, '/
G 12.0 0 1.
Peak Pressure 2.
Safe Shutdown Earthqunke 3.
Gr48Pr>fSkrle M CJtts U Art o d NOTES:
(1) Evaluation Basis Acceleratione and Evaluations are contained in MEDE-21175-3-P. The evaluation basin acceleration envalope is defined by a coincident 80 vertical acceleration with theJ.44 horizontal acceleration. The 544 horizontal value is reduced linearly to zero as the corresponding vertien!
acceleration increases from 8 to 12 C's.
l (2) The calculated anzimum fuel eseeably gap opening for the most Ifuiting load combination fa O./6 inch.
This is less than the gap (0.52 inch) required to start the disengagement of the lower tie pinte from the fuel support casting.
(3)
The fatigue analysis indicates that the fuel annenhly has adequate fatigue capability to withotand the loadinga resulting frbs multiple SRV actuations and the OBE+SRV cvent.
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