ML19329A676
| ML19329A676 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 03/23/1973 |
| From: | Schierling H US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Ross D US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 8001090660 | |
| Download: ML19329A676 (2) | |
Text
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Distribution:
Docket file PWR-2 Reading C. B Kim
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h,),3/g D. Davis ITY k 1
M D h J ub D. F. Ross, Chief, Core Perfomance Branch, L CLAD COLLAPSE TIME CALCULATIONS FOR OCONEE 1 i
4 B&W told us in Lynchburg that for oconee 1 fuel, they calculate a time to collapse of 26850 hrs using their CRECOL code. We calculated 19200 hre with BUCKLE using the same assumptions.
Both values are based on an increase of internal pressure due to gas release during that period. Using a constant BOL pressure of 775 poi throughout the operation, we calculate 15000 hrs, which probably will reduce to about 14500 hrs if we use as wall thickness = average - 2.
At present, we are looking at Oconee 1 first cycle only (about 7500 hrs). I think we can conclude that no co11spee will However, the next B&W cores we have to look at (Oconee 2, occur.
T-1) have a first cycle of 460 days (11000 hrs), which the l
applicants would present at about 15000 hrs to allow for uncertainties. BW is considering this operating time, also.
4 l
for ')conee 1; not necessarily as a first cycle, but sa a method to get it reviewed by us now and avoid delays for upcoming reviews. The approach seems reasonable. However, 15000 hrs is about what we calculate with BUCKLE. %at cal-culation is based on the conservative assumption of no pressure increase, and we could conclude that no collapse will occur during 12000 hrs of operation for Oconee 1 cladding and for other plants with similar cladding.
nis conclusion, however, would solely be based on our BUCKLE
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calculation since Sang finds the B&W CRECOL code at present
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not acceptable.
He, also, has reservations on the use of BUCKLE exclusively, particularly for predicted collapse times greater than about 12000 hrs. He feels that if we conclude no collapse for 12000 hre, B&W will not exert a major effort in revising CRECOL or developlog a new code.
I propose (1) that we find the first cycle of Oconee 1 with 7500 hrs acceptable, (2) that we find the cladding of the Oconee 1 type acceptable for a maximum of 12000 hrs, and (3) that we request 3GW to revise CRECOL or develop a new code
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that is acceptable to us.
For the last item, we should initiate action to get B&W moving.
Attached is a comparison of collapse times calculated for various conditions.
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PWata AEC.ata (Rev.D-63) uitostanutzt reintwas ortica.tese-o-as44es i
100L 09n f60 f\\
'o CODE
_t (wall)_
T (cladl P ~(internal)_
t (collapse) 775 BOL( )-
26850 hrs CRECOL
.0265 657 F 775 BOL( )
19200 hrs
+
BUCKLE
.0265 657 F 15000 hrs 6'57 F 775 Const
.0265 BUCKLE 14500 hrs
.02612( )
657 F 775 Const BUCKLE 9300 hrs 775 Const
.024(
657 F BUCKLE increased P internal over core life due to gas release i
(1)
.07612 =.0265 - 26".00019 (7)
.0265 = mean wall thickness
.00019 = standard deviation,
.024 = minimum wall, specified (3) f y.
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