ML20085H059
| ML20085H059 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 01/03/1975 |
| From: | Eric Thomas TENNESSEE VALLEY AUTHORITY |
| To: | Case E US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML20085H060 | List: |
| References | |
| NUDOCS 8308300124 | |
| Download: ML20085H059 (2) | |
Text
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TENNESSEE VALLE CHATTANOCGA, TENNESSEEAUTHO AITY ""~" 'J "'\\
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% W (Un' Mr. Edson G. Case Y
Acting Director of Licensing s
2 Office of Regulation
",I5W U.S. Atonic Energy Corrission Washington, D. C.
20545 i
Dear Mr. Case:
Subject:
TOC;ESSEE VALLEY AUTEGRITY - BR0'aiS FERRY NUCLEAR PLAliT U?;IT 1 - DOCl;ET 50. 50-259 - FACILITY OPERATI;!G LICD SE DPR ABXORMAL CCCURRD;CE REPORT BFAO-50-259/7449U
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The abnorral occurrence report referenced above stated that a cctallur-gical exanination would be performed on a removed section of pipe to determine the techanisn of this failure. The notallurgical examination has been completed, and the follouing conclusion is quoted from the L-report:
" Evidence of the transgranular route of the crack, vhich gren
- f. on the outside in, and the cold vorking contiguous to the cr.'ch and the crack tip indicate the complete fissure developed due to fatigue. loading.
Srall branch cracks leading from the I'
rain fissure su2 gest that aggravated corrosion conditions may have developed in the fissure.
A secondary fissure was also detected at the fusion line of the wcld joining the pipe to ell.
This fissure could have developed at the same time as the fissure that produced the leak, but louer stress retarded the penetration into the weldcent and ell. The greater amount.
of branching in the crevice fissure from the water side indicates corrosion may have played a more significant role in the propagation of the crack than the one that caused the leak."
A copy of the conplete report is on file at the plant and available for your review at any time.
Very truly'yours, TECIESSEE VALLEY AUTUORITY
(, E. F. Thomas ]
LC irecter of Power Production 116 8308300124 7501d3 PDR ADOCK 05000259 S
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2 Mr. Edson G. Case January 3, 1975 CC: !!r. Uorman C. Moseley, Director Region II Regulatory Operations Office U.S Atotic Energy Co:=ission 230 Peachtree Street, L37., Suite 818 Atlanta, Coorgia 30303 9
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