ML20072A320
| ML20072A320 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 06/03/1983 |
| From: | Schroeder C COMMONWEALTH EDISON CO. |
| To: | Schwencer H Office of Nuclear Reactor Regulation |
| References | |
| 6703N, NUDOCS 8306100062 | |
| Download: ML20072A320 (3) | |
Text
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/D Commonwealth Edison j
- ) ona First Nationit Plaza. Chictgo, Ilhnois O '7 Address Reply to: Post Office Box 767 g
\\
/ Chicago, Illinois 60690 June 3, 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 & 2 License Condition 2.C.(12)
Fuel Lift, Clarification of Results NRC Docket Nos. 50-373 and 50-374 References (a):
C.W. Schroeder letter of May 19, 1983 to A. Schwencer, providing LaSalle Specific Fuel Lift Results.
(b):
GE BWR generic responses to NRC questions on NEDE 21175-3-P via letter of April 19, 1983 from J.F. Quirk to C.O.
Thomas (NRC).
(c):
Telecon between A. Bournia, et al, (NRC) and C.W. Schroeder/G.R. Crane (CECO) on May 31, 1983.
(d):
C.W.
Schroeder letter of June 1, 1983 to A. Schwencer, in response to Reference (c).
Dear Sir:
The multiple references for fuel lift at LaSalle have created some confusion due to the criteria differences used by GE Engineering and GE generic licensing groups and due to the continued refinements made in the generic model used to predict fuel lift.
Although none of these interpretations or improvements results in a changed conclusion with l
respect to closing the fuel lift issue, this letter provides a l
correlation index as to what the various LaSalle numbers mean and their origin or qualifications applicable to their derivation.
The attached Table illustrates the consistency of the results i
provided to the staff.
This information supercedes that provided in paragraph 1 of Reference (d) wherein the 0.160 inch value was erroneously identified as a result of the revised generic model.
That value is essentially a statistically adjusted number derived from the 0.120 value i
I via equation 5.4 of Reference (b) (I.4.3 of the NEDE Report).
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8306100062 830603 PDR ADOCK 05000373 P
PDR g
Director.of NRR June 3, 1983 I trust that this submittal provides sufficient clarification of the multiple fuel lif t values reported for LaSalle County Station Units 1 and 2.
Enclosed for your use are one (1) signed original and forty (40) copies of this letter and the attachment..
If there are any further questions concerning this matter, please contact this office.
Very truly yours, NM c h/n C. W. Schroeder Nuclear Licensing Administrator 1m Attachment cc:
NRC Resident Inspector - LSCS 1
1 6703N l
L
l LaSalle Fuel Lift Maximum Gap Results (inches)
(Calculated per GE Licensing Topical Report NEDE-21175-3-P)
Standard Model Modified Model*
Of*C Load Phasing:
Load Phasing:
/
Deterministic Monte Carlo Deterministic Monte Carlo Unit LaSalle 84/50 1
84/90 0.186 LaSalle 84/50 0.120 0.187 2
84/90 0.160
- Modified at nodes 6 and 9 as described in Reference 2, page 19.
84/50 represents 84% non-exceedance probability at 50% statistical confidence.
84/90 represents 84% non-exceedance, probability at 90% statistical confidence.
The governing equation is R t,dg-where t84/50 = l-
=
R
+
-