ML19317H103
| ML19317H103 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear, Crane  |
| Issue date: | 07/14/1976 |
| From: | ARKANSAS POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML19317H098 | List: |
| References | |
| NUDOCS 8004140582 | |
| Download: ML19317H103 (2) | |
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FUEL DAMAGE DURING ANO-1 DEFUELING OPERATION
-D April 1976 1.-
SUNLUlY hree (3) fuel assemblies received potentially significant spacer grid damage during fuel handling. He Nuclear Steam Supply System Vendor, Babcock 6 Wilcox, reviewed the damage and made on-site repairs.
Based on their evaluation, which was supported by previous testing, the damaged assemblies were reinserted.
Corrective actions were taken to prevent recurrence of damage.
DISCUSSION During the defueling of the ANO-1 core in April 1976, a problem in fuel handling was encountered. It involved the interference of adjacent fuel assembly spacer grids as the assemblies were removed from the core. This problem was similar to that experienced at Metropolitan Edison's Bree Mile Island Unit 1.
The experience gained during the 'DfI-1 defueling was employed during the ANO-1 defueling. His resulted in adjustments to equipment and the addition of administrative controls to the fuel handling procedures to increase the detectability of interference during fuel handling operations.
These procedures resulted in the examination of sixty-three (63) fuel assemblies.
Of these, thirteen (13) showed some evidence of possible handling interferences; three of which had spacer grid damage serious enough to warrant a more detailed evaluation of their serviceability.
tabcock 6 Wilcox evaluated the damage to the three (3) assemblies and concluded that if all significant protrusions were removed, the fuel assemblies would Q
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be acceptable for continued service.
Babcock 6 Wilcox sent a repair team to
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the site to perfom a grinding operation on two (2) of the three as'semblies.
No identifiable protrusions were found on the third assembly; therefore, no grinding operations were required. All repair operations were successful.
The most serious potential threat in the further operation of the damaged assemblies was the possibility of increased fretting. Babcock 6 Wilcox concluded, and we concurred, that such a risk is low.
The basis for.the conclusion was a series of bundle flow tests that were perfomed using mechanically deformed spacer grid cells.
Tne test conditions were more severe than the condition of the damaged assemblies, yet there was no significant deviation (fretting, vibration, etc.) in the behavior of the fuel assembly. Thus, the conclusion was ma'de that the probability of failure for the fuel rods in the damaged assemblies is not significantly higher than for normal fuel rods. The slightly damaged assemblies were, therefore, reinserted in the core.
A more detailed report will be available in the near future for inspection at the plant site.
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