ML20236U227
| ML20236U227 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 06/06/1975 |
| From: | Jennifer Davis, Thornburg H, Warnick R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | |
| References | |
| PN-75-033, PN-75-33, NUDOCS 9807290394 | |
| Download: ML20236U227 (1) | |
Text
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PRELIMINARY NOTIFICATION - NOT FOR PUBLIC DISCLOSURE Jt'ne 6,1975
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PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE
--PN-75-33 This preliminary notification constitutes EARLY notice of events of
..o POSSIBLE safety or public interest significance.
The information presented is as initially received without verification or evaluation and is basically all that is known by OIE staff as of 12:15 p.m. on date of this notification.
IT SHOULD BE SPECIFICALLY NOTED THAT THIS NOTIFICATION MAY CONTAIN INFORMATION THAT LATER MAY BE DETERMINED TO BE INACCURATE OR INCONSISTENT. AN OFFICE OF INSPECTION AND ENFORCDIENT NOTIFICATION OF AN INCIDENT OF OCCURRENCE (BLUE SHEET) SUBSEQUENTLY WILL BE ISSUED IF WARRANTED.
'~'
Facility: ' Commonwealth Edison Company (Zion Unit 1)
Subject:
ABNORMAL DEPRESSURIZATION OF PRIMARY COOLANT SYSTEM Commonwealth Edison Company notified the Office of Inspection and Enforcement, Region III, on June 6, 1975, that a rapid depressurization of Zion 1 occurred at about 8:20 a.m.
The pressure dropped from normal operating pressure (2100 psi) to approximately 1600 psi.
The cause of the depressurization has not yet been confirmed.
Safety Injection was manually initiated before system initiation ng
-levels were reached.
The D loop was isolated (because of a seal temper-ature alarm on the D loop reactor coolant pump) within 20 minutes follow-ing the pressure decrease and plant conditions then stabilir.ed.
Contain-
=
ment pressure increased to approximately 1 psi. No noticeable change in containment temperature was noted.
No' estimate of the volume of coolant pumped to containment is available at this time; however, preliminary information indicates the leak rate approached 500 gallons per minute.
The licensee's pre'liminary survey indicates that no radiological limits were exceeded.
The plant was in the process of starting up from an d
extended maintenance outage.
IE:III inspectors were dispatched promptly A
to the site.
O The State of Illinois has been informed of the occurrence.
Press releases are being issued by IE:III and Commonwealth Edison.
Contact:
RFWarnick, IE x7261 HDThornburg, IE x7353 JGDavis, IE x7541 Distribution :
~
Chairman pders Commissioner Mason S. J. Chilk, SECY Commissioner Gilinsky Commissioner Rowden G. F. Murphy, JCAE Commissioner Kennedy C. C. Kammerer, CA l
L. V. Gossick, EDO D. F. Knuth, IE J. A. Harris, PA B. C. Rusche, NRR H. H. Brown, ISP K. R. Chapman, NMSS H. K, Shapar, ELD Transmitted: P Bldg.2 r>
- H St J.
p
- MD Bldg 2 PRELIMINARY NOTIFICATION - NOT FOR PUBLIC DISCLOSURE 9807290394 750606 PDR I&E PN-75-033 PDR
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