NRC-97-0128, Forwards Figure for Updated Crack Growth Results as Requested in
| ML20202D029 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 12/01/1997 |
| From: | Gipson D DETROIT EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| CON-NRC-97-0128, CON-NRC-97-128 NUDOCS 9712040127 | |
| Download: ML20202D029 (3) | |
Text
4 Douglas IL Gimon Sender Vice l' resident Nuclear Generati"n 1
Fenni '2 f+io North Dnie lla)., Nev.p3rt, Whigan 4Nlr,r, Teh 3115%i@l Fat alU,% 4172 Detroit Edison December 1,1997 NRC-97 0128 U. S, Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555
References:
- 1) Fermi 2 NI<C Docket No. 50-341 NRC License No. NPF-43
- 2) Detroit Edison Letter to NRC," Revised Feedwater Nozzle Crack Growth Analysis", NRC-92-0092, dated July 29,1992
- 3) NRC Letter to Detroit Edison," Fermi-2 Revised Feedwater Nozzle Crack Growth Analysis Per Generic Letter 81-11 (TAC No. M84140)", dated December 8,1992 StGject:
Confirmation of Feedwater Nozzle Crack Growth Analysis in Reference 3 the NRC rec uested a revised analysis of the Fermi 2 feedwater nozzle crack growth, considering t 2e number thermal cycles from plant startups, shutdowns and Scrams over the remaining years of operation and submit the analysis for NRC review six months prior to the end of 12 operating years. At Fermi 2, the number of feedwater nozzle thermal cycles were 45 startups and shutdowns, and 79 Scrams for a total of 124 thermal cycles over the first 10 years of operation. Conservatively assuming the number of thennal cycles for the first ten years is repeated four times for a total of 496 thermal cycles, an initial crack depth of 0.25 inches is estimated to grow to approximately 0.8 inches depth in forty years of plant operation. This is below the maximum depth of 1.0 inch. Please refer to the attached figure for the updated crack growth results.
If you should have any questions plcase contact Mr. Michael Williams, Principal Engineer at (313)586-1066.
Sincerely,
/
l Attachment c6vI cc:
A. B. Beach U G V v b,,,
B. L. Burgess 4
G. A. Harris A. J. Kugler b,bllhbk!b b b
~
9712040127 971201 PDR ADOCK 05000341 P
PDR 3 p.nhre' nnem
.y.
Attachment to NRC-97-0128 Attachment
l i
r 1.0 t
Alowable Crack Depth - 1.0*
i l
0.8 Ieians o.e ut.
l i
- - 40 yens O.8 i
i R
l 1
8 I
r 0.4 b
l
=
I 6
I I
0.2 i
I t
i
'I 0.0
)
t 162 324 486 648 Number of l
e m al ycles
{
496 Updated Crack Growth Results (Revised Projected 40 Year Cycle Count)
L