05000361/LER-1982-136, Forwards LER 82-136/01T-0.Detailed Event Analysis Submitted

Forwards LER 82-136/01T-0.Detailed Event Analysis Submitted

ML20070L566
Person / Time
Site:	San Onofre
Issue date:	12/09/1982
From:	Ray H SOUTHERN CALIFORNIA EDISON CO.
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
Shared Package
ML20070L568	List: 05000361/LER-1982-136, Forwards LER 82-136/01T-0.Detailed Event Analysis Submitted 05000361/LER-1982-136-01, /01T-0:on 821109,while in Mode 1,momentary Loss of Power of Feedwater Control Sys Experienced.Caused by Inadvertent Dislodging of Power Cord.Reactor Manual Trip Initiated
References
NUDOCS 8301030184
Download: ML20070L566 (2)

LER-1982-136, Forwards LER 82-136/01T-0.Detailed Event Analysis Submitted

Event date:
Report date:
3611982136R00 - NRC Website

text

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Southern Californie Edison Company

,$M S AN ONOFRE NUCLE AR GENER ATING ST A TSON P.O. B O X 128 S AN C LEMENTE. C ALIFORNI A 92672 December 9, 1982

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U. S. Nuclear Regulatory Commission

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Attention:

Mr. R. H. Engelken, Regional Administrator q

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Dear Sir:

Subject: Docket No. 50-361 30-Day Report Licensee Event Report No.82-136 San Onofre Nuclear Generating Station, Unit 2

References:

1)

Letter, H.B. Ray (SCE) to R.H. Engelken (NRC),

dated November 10,1982, " Prompt Report -

Licensee Event Report No.82-138" 2)

Letter, H.B. Ray (SCE) to R.H. Engelken (NRC),

dated November 24, 1982, "14-Day follow-up Report - Licensee Event Report No.82-138" Pursuant to Appendix A Technical Specification 6.9.1.12g to 6perating License NPF-10 for San Onofre, Unit 2, reference (1) confirmed our prompt notification to the NRC on November 95 1982 of a reportable occurrence involving a manual trip of the reactor and initiation of the Emergency Core Cooling System (ECCS).

Reference (2) provided the required follow-up report with a completed Licensee Event Report (LER) for this occurrence.

Pursuant to section 6.9.1.13b, this submittal provides the required 30-day written report and copy of LER 82-136 involving Limiting Condition for Operation (LCO) 3.4.8.lb resulting from the same occurre ce. LC0 3.4.8.lb limits the maximum cooldown of the Reactor Coolant System (RCS) to 100*F in any one hour period.

On November 9,1982, while in Mode 1, momentary loss of power to the Feedwater Control System was experienced. As a precaution, the reactor was manually tripped. The ECCS was automatically initiated during the resulting cooldown and RCS temperature dropped more than 100 F in less than one hour. This violated LC0 3.4.8.lb.

The associated Action Statement requires restoration of the LC0 limits within 30 minutes, and an engineering evaluation to be performed to determine the effects of the out-of-limit condition on the structural integrity of the RCS or be in Hot Standby (Mode 3) condition within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and cooldown to below 200 F within the next 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

8301030184 821209

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a R. H. Engelken December 9,1982 i

Corrective actions associated with this LC0 were ininediately implemented.

The plant was maintained in a stable Hot Standby condition until the engineering evaluation was completed. The engineering evaluation was performed and results were provided to the operators at 0230 on November 10,1982 (approximately 101/2 hours after the initiation of the event).

1 The conclusion of the engineering evaluation was that the severity of this -transient on the RCS was less than the previously analyzed RCS transient for a Main Steam Line (MSL) break as reported in the Final Safety Analysis Report (FSAR). Since the SONGS 2 RCS design basis allows for five (5) MSL break transients during the life of the plant, it was concluded that the RCS integrity was not affected and that the plant was safe for continued operations. Further cooldown was not necessary and the LC0 was satisfied.

Further corrective actions to prevent recurrence are identified in reference (2).

Also, as stated in reference (2), a detailed engineering evaluation of the ECCS initiation is underway and will be the subject of a Special Report to be submitted before February 8,1983 as required by Technical Specification Sections 3.5.2 (Action b) and 6.9.2.

The public health and safety were not affected by this occurrence since all safety systems performed as required.

If there are 'any questions, please contact me.

Sincerely, Enclosure: LER 82-136 I

cc:

A. E. Chaffee (USNRC Resident Inspector, San Onofre Unit 2)

U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Office of Management Information and Program Control Institute of Nuclear Power Operations