ML20009C361

Forwards LER 81-003/01T-0.Detailed Event Analysis Encl

ML20009C361
Person / Time
Site:	Oconee
Issue date:	03/12/1981
From:	Parker W DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20009C362	List: ML20009C361 ML20009C368
References
NUDOCS 8107200486
Download: ML20009C361 (2)

Text

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DUKE POWER COMPm ^b COPY' Powca Buzu: xo 422 Socin Cat'ucu S'azzr, CitAutorre N. C. 2e242

.)?-6//<6f WILLIAM O. PA R M E R. J R.

W atS60rNT 7 t'.t ***C N E; As t a 7 0 4 seta= P=oowevioN March 12, 1981 .na..ces Mr. James P, O'Reilly, Director QCl U.S. Nuclear Regulatory Comraission 4W P,9 N g Region II ( '

101 Marietta Street, Suite 3100 Atlanta, Georgia 30303 .

Q ' N jDa f' J y -

JUL I 7 mat. -

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Re: Oconee Nuclear Station ,

Docket No. 50-287  % ,, .  %$

Dear Mr. O'Reilly:

Please find attached Reportable Occurrence Report R0-287/81-3. This report is submitted pursuant to Oconee Nuclear Station Technical Specification 6.6.2.1(2),

which concerns operation in a mode less consarvative than the least conserva-tive aspect of a LCO. and describes an incident which is considered to be of no significance with resroct to its effect on the health and safety of the public.

Ve truly yours,' -

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<0.s t Lll ! -

/ Willine 0. Parker, Jr.

JLJ:pw Attachment cc: Director Mr. Bill Lavallee Office of Management & Program Analysis Nuclear Safety Analysis Center U.S. Nuclear 'legulatory Commission P. O. Box 10412 Washington, D. C. 20355 Palo Alto, California 94303 6ffi 8107200486 810312 PDR ADOCK 05000287 S PDR

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4 DUKE POWER COMPANY OCONEE UNIT 3 Report Number: R0-287/81-3 Report Date: March 12, 1981 Occurrence Date: February 26, 1931 Facility: Oc.aee Unit 3, Seneca, South Carolina Identification of Occurrence: Over-Pressurization of "B" OtSG Secondary Side Conditions Prior to Ocgurrence: Cold shetdown 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" Steam Generator was pressurized to 550 psig. The Steam l

Generator was overfilled, and water got in the main steam line. This was a violation of Technical Specification 3.1.2.4 and is thus reportable pur-suant 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 v11ve either electrically or mechanically, the reason for the excess valve leakage is un-known. However, the leakage through the control valve is not inconsistent with the desiga of the valve. (i.e. The valve is not designed to shut off flow completely). Thus the major cause of the incident was the result of a precedural deficiency in that the block valves are not specified as shut in that particu,lar mode of operation.

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

The integrity of the main steam liaes, hangers, inspection and the OTSG itscif were verified by inspection and analyses. Thus, this incident was af 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 l 3SD-5 and 3Sd-290 in order to lower the OTSG pressure. Procedures will be l

revised to specify that the startup block valves be shut prior to entering feedwater on condenser cleanup mode.

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