ML19326B753
| ML19326B753 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 05/25/1973 |
| From: | Phillips J ARKANSAS POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML19326B743 | List: |
| References | |
| 30357, NUDOCS 8004170581 | |
| Download: ML19326B753 (2) | |
Text
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4 H EL PIN G BUILO ARKANSAS A R K A N S A S P O W E R C. L.l G H T C O M P A N Y STPt AVENUE AND F INE STAEET
- PINE BLUFF. AAKANSAS 71801 e (5013 534-1330 May 25, 1973 Mr. Frank E. Kruesi Director of Regulatory Operations United States Atomic Energy Commission Washington, D. C.
20545
SUBJECT:
ARKANSAS POWER & LIGHT COMPANY ARKANSAS NUCLEAR ONE - UNIT 1 DCCKET No. 50-313
Dear Mr. Kruesi:
This letter is written to report the results of our investigation of an incident which occurred during hydrotesting of the reactor building spray system on March 27, 1973, and was subsequently identified to p)
Regulatory Operations, Region II, as required by 10 CFR 50.55(e).
(x.J During hydrotesting of the reactor building spray system piping, a leak developed in the shop fsbricated eight inch (8") spool BS-HCD-A5-118.
On examination, it was discovered that a crack extended about 30* on the pipe circumference; it is about one-half inch from shop weld No. 7 of the spool.
Repair was made by replacing an eighteen inch (18") section of the pipe (6" upstream and 12" downstream of weld) with a piece from eliminated spool BS-HCD-AS-117 (Heat #343860). The system has been satisfactorily re-hydrotested.
The failure piece has been subjected to extensive metallurgical examination, the report of which is in our files for review if desired.
The mode of failure was determined to be intergranular stress corrosion cracking and occurred from the inside of the pipe, only on one side of the weld, and in a relatively localized area. Flat spots were observed in this area, indicating hammering may have been done on the inside sur-face near the joint, possibly to facilitate fit-up, resulting in a local-ized area of high stress which can set up the conditions for stress corrosion in this area.
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I Mr. Frank E. Kruesi
. R.B. Spray System Piping May 25, 1973 Page Two i
I TLe facts in this failure indicate that this is an unusual occur-rence, resulting from a combination of events (from fabrication through fir ld installation) which are unlikely to recur, therefore, no further investigation is planned.
Very truly yours,
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' J. D. PHILLIPS i
Vice President & Chief Engineer JDF: NAM:mb cc:
N. C. Moseley, Director Directorate of Regulatory Operations j
Region II Atomic Energy Connission 230 Peachtree Street, N.W. Suite 818 Atlanta, Georgia 30303
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