ML20009C127

Forwards LER 81-003/01X-1.Detailed Event Analysis Encl

ML20009C127
Person / Time
Site:	Oconee
Issue date:	06/10/1981
From:	Parker W DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20009C128	List: ML20009C127 ML20009C136
References
NUDOCS 8107200307
Download: ML20009C127 (2)

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, DUKE POWER COMPANY OFFICIAL COWN "

Powdi fluimawo 422 Socru Cucacu Srazzt, CuanwrTz. N. C. asa-sa 9/ all 03b 1.m u < d : 36 w n.U A,4 O. PA R M O. J R. Jung lQ, 1981 Vice PettictNT ItttPwoNE: AetA 704 373-4083 Steam PeoowevioN Mr. James P. O'Reilly, Director U. S. Nuclear Regulatory Commission -

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Region II -g-101 Marietta Street, Suite 3100 f/

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Atlanta, Georgia 30303 J gi u pp, p1 .3 y

J JUL 171981m 1 Re: Oconee Nuclear Station i". us.RCIARUGUWO4 }

emucu 6 Docket No. 50-287 h' J. D

Dear Mr. O'Reilly:

Please find attached Reportable Occurrence Report R0-287/81-03, Revision 1, which contains a change to the Corrective Action section of the original submittal.

This report is submitted pursuant to Oconee Nuclear Station Technical Specification 6.6.2.1(2), which concerns operation in a mode less conserva-tive than the least conservative aspect of a LCO, and describes an incident which is considered to be of no significance with respect to its effect on the health and safety of the public. The original report was submitted to your office on March 12, 1981.

Very truly yours, h hm  ? -

William O. Parker, Jr.

[9 JLJ/djs Attachment cc: Director Mr. Bill Lavallee Office of Management & Program Analysis Nuclear Safety Analysis Center U. S. Nuclear Regulatory Commission P. O. Box 10412 Washington, D. C. 20555 Falo Alto, California 94303 8107200307 810610

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gDRADOCK 05000287 PDR . .

• DUKE POWER COMPANY OCONEE UNIT 3 Report Number: R0-287/81-03, Rev. 1 Report Date: June 10, 1981 Occurrence'Dite: February 26, 1981 Facility: Oconee_ Unit 3, Seneca, South Carolina Identification._of Occurrence: Over-Pressurization of "B" OTSG Secondary Side Conditions Prior to Occurrence: Cold shutdown Description of Occurrence: At approximately 1600 hours0.0185 days <br />0.444 hours <br />0.00265 weeks <br />6.088e-4 months <br /> on February 26, 1981, the Unit 3 "B" Sceam Generator was pressurized to 550 psig. The Steam Generator was overfilled, and water got in the main steam line. Thia was a violation of Technical Specification 3.1.2.4 and is thus reportable pursuant to Technical Specification 6.6.2.1.a(2).

Apparent Cause of Occurrence: This incident was apparently caused by the startup control valve leaking through and filling the "B" OTSG and main steam line. Since nothing could be found wrong with the control valve either electrically or mechanically, the reason for the excess valve leakage is unknown. However, the leakage through the control valve is not inconsistent with the design of the valve. (i.e. The valve is not designed to shut off ficw completely). Thus the major cause of the incident was the result of a procedural deficiency in that the block valves are not specified as shut in that particular mode of operation.

Analysis of Occurrence: No systems or piping were damaged by this incident.

The integrity of the main steam lines, hangers, inspection and the OTSG itself were verified by inspection and analyses. Thus, this incident was of no significance with respect to safe operation, and the health and safety of the public were not affected.

Corrective Action: The immediate corrective action was to open valves 3SD-5 and 3SD-290 in order to lower the OTSG pressure. The Condensate and Feedwater Procedure will be revised to Icwer OTSG level to between 60% and 80% on the operating range prior to initiating FDW recirculation.

A note will also be added to close the start-up block valves if the control valves la.tak.

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