ML20112C647
| ML20112C647 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 01/03/1984 |
| From: | ARKANSAS POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML20112C642 | List: |
| References | |
| PROC-840103, NUDOCS 8501110312 | |
| Download: ML20112C647 (5) | |
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ATTACHMENT 4
1 ANO-2 SHOULDER GAP INSPECTION PLAN FOR THE FOURTH REFUELING OUTAGE
.h January 3, 1985 5
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fANO-2 Shoulder Gap Inspection Plan For The Fourth Refueling Outage
' 1.--
Introduction Shoulder gap is the distance from the top of a fuel rod to the bottom of the l upper flow plate.. Measurements _of this gap have been made on select ANO-2 fuel assemblies after each cycle of operation to date.
At the end of cycle 2, after being exposed to two full cycles of operation, the ga' closure p
- rate measured.on some Batch C assemblies indicated that rod to plate contact imight1 occur during their third-cycle of exposure.
Accordingly, a modification
.using shims was devised to increase the available gap.
In all, 30. Batch C
. assemblies were shimmed'before cycle ~3 exposure.
References'l and 2 present
- further information on the measured gaps and the modification procedure.
To assure adequate gap would be available for Batch D assemblies, which were scheduled for their third exposure during cycle 4 an inspection plan for theexaminationoftheseassembliesduringthethIrdrefuelingoutagewas
- prepared and submitted to the NRC (Reference 3).
The results of the in.spection indicated that none of the assemblies in the cycle 4 core would experience gap closure.
However, since a fourth cycle of exposure was tplanned for a batch D test assembly (AKD040), as part of a DOE high burnup test, this assembly was shimmed during the 2R3 refueling.
References 4, 5,
- and 6 present further details on the measurements and our analyses.
The NRC concurred that_ shoulder gap spacing would remain adequate for cycle 4 operation; however, they requested that refueling outage surveillance continue until.such time as an approved analytical model for shoulder gap prediction was available (Reference 7).
2.'
Cycle 5 Core Composition The' cycle 5 core will be composed of 8 Batch A, 1. Batch D, 52 Batch E, 56
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Batch F and 60 Batch G assemblies.
Prior to cycle 5 operation the Batch ti "assemb1Ieswillhavetwocyclesofoperation,-theBatchAandFassemblies and the Batch G assemblies will'be Jwill have a single cycle of operation,ign exist between the batches.
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Some differences in assembly des Table I
- D
- 1C lists the major improvements that have been incorporated into the assemblies l'
design to assure adequate shoulder gap.-
3.
' Shoulder Gap Inspection Plan For The Fourth Refueling Outage g
The peripheral rods'on all four faces of five Batch D assemblies and ten Batch'E assemblies will'be measured for shoulder. gap.
The assemblies in
' Batch'D to be measured will be those which have previously been measured after their first and second cycles of operation. 'Of the ten Batch E~
' assemblies to be selected,'seven will have been previously measured after
.their first exposure cycle. -The remaining three Batch E assemblies will be selected from a group of eight assemblies that will have high fluence exposures.
Batch A and F assemblies do not require measurement this outage since they have only been exposed to a single cycle of operation, tn
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Analysis Procedure With their previous measurements, the Batch D data will cover three exposure cycles. The Batch E data will cover two exposure cycles and will be compared to the Batch D data to determine the extent that the Batch E shoulder gap behavior is characterized by the Batch D behavior. The data base of Batch D and E data will be used to project end-of-cycle 5 shoulder gaps for AKD040 and the Batch E assemblies. All assemblies to be used in cycle 5 will pass the following criterion:
At a 95% probability, the worst rod in the assembly will not have gap closure at the end of cycle.
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- 3 TABLE I DESIGN DIFFERENCES'BETWEEN BATCHES Increase:in Batch Shoulder Gap.From Guide Tube Designation' Orginal Ref.(in.)
Fabrication
- A" REFERENCE Annealed (RXA)1 2
DL
+0.302 Annealed (RXA)
E
+0.15 Cold Worked (SRA)
F
+0.85 Cold Worked.(SRA)
-G
+0.85 Cold Worked (SRA)
'1-Ten Batch A assemblies had cold worked, stress-relief annealed (SRA)
- guide tubes.
One of these 10, AKA104, is a candidate-for cycle 5.
2 The'O assembly, AKD040, was shimmed to provide an additional 0.4 inches during the cycle 3 outage. Therefore, the total' change from the reference. gap is +0.70 inches.
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REFERENCES e.
'1.
ohn R. Marshall to Robert A. Clark, Docket No. 50-368, Letter Number J
2CAN128297, dated December 10, 1982.
2.
John R. Marshall to Robert A. Clark, Docket No. 50-368, Letter Number
,, J,, s 2CAN938397, dated March 30, 1983.
3.
-. John R. Marshall to Robert A. Clark, Docket No. 50-368 Letter Number 2CAH98398, dated August 19, 1983.
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John R.' Marshall to J. E. Gagliardo, Docket No. 50-368, Letter Number 2CAN118319, dated December 2,1983 (transniittal of report CEN-260(A)-P).
5.
John R. Marshall to J.~E. Gagliardo, Docket Ni 50-368, Letter number 2CAN128386, dated December 16, 1983 (transmittal of report CEN-261(A)).
6.
John R. Marshall to James R. Miller, Docket No. 50-368, Letter Number
- 2CAN948493, aated April 18, 1984.
7.
James R. Miller to John H. Griffin, Docket No. 50-368, Letter Number
~2CMA928491, dated Februa'ry 24, 1984 (transmittal of Safety Evaluation Report).
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