ML19276H215
| ML19276H215 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 06/22/1979 |
| From: | Klingler G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | |
| References | |
| PNO-79-181, NUDOCS 7910150813 | |
| Download: ML19276H215 (1) | |
Text
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PRELIMINARY NOTIFICATION.
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June 22, 1979 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--P50-79-181 This preliminary notification constitutes EARLY notir' of event of POSSIBLI safety or public interest significance. The information presented is as initially received without verification or evaluation and is basically all that is known by IE staff on this date.
Facility: Metropolitan Edison Company Three Mile Island Unit 1 Middletown, Pennsylvania Docket No. 50-289
Subject:
PIPING CRACKS IN DECAY HEAT SYSTEM SUCTION PIPING While performing ultrasonic examinations of the Decay Heat System piping on June 20, 1979, leakage was discovered on the 10 inch suction piping from the Borated Water Storage Tank to the Decay Heat and Makeup Systems.
Cracking was confirmed by ultrasonic examination to be in the heat affected zone adjacent to the pipe weld and was estimated to extend a total of about 6 inches of the circumference.
The leaking pipe was 10 inch Schedule 40S piping of Type 304 Stainless Steel.
Because of the similarity of piping material and system environment to that found associated with previous pipe cracking, it is suspected that intergran-ular stress corrosion cracking produced by residual weld stresses is the cause of this failure.
The licensee is continuing inspection and examination of the affected piping.
The leakage observed was minor weepage resulting in no release or exposure to the public.
Inspection and Enforcement personnel on site are providing continuing followup of this occurrence.
The Commonwealth of Pennsylvania has been informed.
A press release vas made by Region I.
NRC, Region I, (Philadelphia) received notification of this occurrence by telephone from onsite inspection pei.mnnel at 2:15 p.m.,
June 21, 1979.
Contact:
GKlingler, IE x28019 FNolan, IE x28019 SEBryan, IE x28019 Distribution:
Transmitted H St j; e.?
Chairman Hendrie Commissioner Bradford S. J. Chilk, SECY Commissioner Kennedy Commissioner Ahearne C. C. Kammerer, CA.
Commissioner Gilinsky ACRS (For Distribution)
Transmitted:
MNBB /2 '/6 P. Bldg /,2#.5' V.Stello[IEj /l/O L. V. Gossick, EDO H. R. Denton, NRR Region H. L. Ornstein, EDO R. C. DeYoung, NRR J. J. Fouchard, PA R. J. Mattson, NRR l4ld j N. M. Haller, MPA R. S. Boyd, NRR (MAIL)- R. G. Ryan, OSP SS Bldg /A,'f[ J. J. Cummings. OIA H. K. Shapar, ELD W. J. Dircks, NMSS R. Minogue, SD S. Levine, RES 7910150hgj PRELIMINARY NOTIFICATION + .}}