ML20050D153
| ML20050D153 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 04/05/1982 |
| From: | ARKANSAS POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML20050D151 | List: |
| References | |
| NUDOCS 8204120078 | |
| Download: ML20050D153 (8) | |
Text
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ARKAiSAS NUCLEAR ONE UNIT 1 LEAKING FUEL INVESTIGATION J
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ARKANSAS POWER & LIGHT COMPANY 1
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8204120078 820405 PDR ADOCK 05000313 p
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- HISTORY OF FAILURES AND DESCRIPTION OF INVESTIGATION PROGRAM
- CONCLUSIONS OBTAINED TO DATE 1
- AP&L PLANS FOR FUTURE EVALUATIONS e
_____________._______________m_,_
L
- CONCLUSIONS -
FAILURES NOT MAliUFACTURING RELATED NO INDICATION OF PELLET-CLAD INTERACTION RELATED PHENOMENA MOST PROBABLE CAUSE IS SOME FORM OF EXTERNAL CLAD ATTACK i
e s
RESULTS OF MANUFACTURING INVESTIGATION
. NO BURNUP DEPENDENCY
- TYPICAL MANUFACTURING RELATED FAILURES ARE SEEN EARLY IN FUEL LIFETIME
- SIMULTANEOUS NATURE OF FAILURES IS INCONSISTENT WITH MANUFACTURING CAUSES
, NO BATCH DEPENDENCY
- 9 BATCH 6
- 6 BATCH 5
- 9 BATCH 4
. NO CORRELATIONS BETWEEN ANY MANUFACTURING RELATED ATTRIBUTES
- NO UNUSUAL INFORMATION FOUND IN EXAMINATION OF RECORDS
- POWDER
- PELLETS
- CLADDING V
- RESULTS OF PCI EVALUATION -
. TYPICALLY PCI OCCURS AS A FUNCTION OF BURNUP AND POWER RAMPS
- ANO-1 LEAKER BURNUP DISTRIBUTION
<2 MWD /T 9
ASSM.
7.6 -
9.1 MWD /T 2
ASSM.
11.4 - 13.7 MWD /T 4
ASSM.
13.7 - 19.0 MWD /T 2
ASSM.
19.8 - 21.4 MWD /T 7
ASSM.
- NO UNUSUAL TRANSIENTS DURING OPERATION
- PLANT OPERATED CONTINUOUSLY 30 DAYS BEFORE LEAKS OCCURRED
- NO SIGNIFICANT ROD MOVEMENTS OR MAJOR SYSTEM IMBALANCES
- REACTOR STARTUPS WERE WITHIN ESTABLISHED SAFE GUIDELINES
. INSPECTION DID NOT REVEAL PCI EFFECTS
- NO UNEXPECTED RIDGING DETECTED FROM DIAMETER MEASUREMENTS
- VISUALLY OBSERVED CLADDING SPLITS WERE NOT INDICATIVE OF PCI
- INTEGRITY OF BURNABLE POISON RODS INTACT l
IDENTICALLY DESIGNED B&W FUEL HAS NO IDENTIFIED PCI FAILURES UNDER SIMILAR OPERATING C0flDITIONS EXPERIMENTAL RAMPING PROGRAMS HAVE NOT RESULTED INPCIUllDERM6RESEVEREOPERATINGCONDITIONS 4
4 4
e e
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(
- CONSIDERATIONS INDICATING EXTERNAL ATTACK -
. NO EVIDENCE OF INTERNAL ATTACK
. NOT IMPOSSIBLE FOR TRANSIENT TO OCCUR OR AGENT TO HAVE ENTERED SYSTEM AT TIME OF FAILURE AND NOT BE DETECTED BY END OF CYCLE WHEN INSPECTIONS WERE PERFORMED
. SIMULTANEOUS NATURE OF FAILURES AND LACK OF BATCH OR BURNUP DEPENDENCE NOTE:
INSPECTIONS OF CHEMISTRY RECORDS HAVE NOT YIELDED ANY EVIDENCE OF ABNORMAL CONDITIONS, I
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FURTHER WORK TO ESTABLISH THE EXACT NATURE OF THE ATTACK IS UNWARRANTED
. PROBABILITY OF SUCCESS VERY LOW AFTER EXTENDED REACTOR AND FUEL RESIDENCE TIME
. THROUGH WALL CRACKS WOULD HAVE EXPERIENCED MASKING DUE TO OXIDIZING, HYDRIDING AND OTHER EFFECTS
. NO CERTAINTY AS TO PRIMARY OR SECONDARY DEFECTS
. INCIPIENT DEFECTS WOULD BE DIFFICULT TO LOCATE
, ADDITIONAL COST CANNOT BE JUSTIFIED
. ACTIVITY LEVELS WERE BELOW TECH SPEC LIMITS
. PRESENT ACTIVITY LEVELS INDICATE NO ADDITIONAL FAILURES
.I
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