ML20155B752

Forwards LERs 98-020-00 & 98-021-00 Re Two Separate Occurrences of One Train of Ecw Sys Being Inoperable.Repts for Unit 2 Are Being Submitted IAW NUREG-1022,Rev 1 Because Ecw Is Shared Sys & Conditions Are Applicable to Both Units

ML20155B752
Person / Time
Site:	San Onofre
Issue date:	10/26/1998
From:	Krieger R SOUTHERN CALIFORNIA EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20155B756	List: 05000361/LER-1998-020, :on 980806,determined That Ecw Sys Was Inoperable.Caused by Faulty Temp Control Unit.Temp Control Unit Was Replaced & Chiller Performed Satisfactorily 05000361/LER-1998-021, :on 980903,train B Ecw Chiller Failed to Start Using CR Start Push Button.Caused by Incorrect Wiring of Switch by Personnel.Wiring Was Corrected & Chiller Was Declared Operable on 980926 ML20155B752
References
RTR-NUREG-1022, RTR-REGGD-01.174, RTR-REGGD-1.174 NUDOCS 9810300263
Download: ML20155B752 (1)

Text

_ _ _ _ _.. _ _ __

h i

SOUTHERN Calif 0RNIA '

R. W. Krieger t

EDISON "O h I

An EDISON INTERNATIONAL Company 1

October 26,1998 U. S. Nuclear Regulatory. Commission

-1 Document Control Desk Washington, D.C. 20555 1

' Gentlemen:

Subject:

Docket No. 50-361 and 50-362 -

l 30-Day Report -

Licensee Event Reports No. 1998-020 and 1998-021 San Onofre Nuclear' Generating Station, Unit 2 and 3

' This letter provides Licensee Event Reports (LER) 1998-020 and 1998-021 in accordance with 10CFR50.73(a)(2)(i) for two separate occurrences of one train of Emergency Chilled Water (ECW) System being inoperable. Because ECW is a shared

. system and the conditions are applicable to both Units 2 and 3, reports for Unit 2 are being submitted in accordance with NUREG-1022, Rev 1.

Both reports involve the same component (the ECW Train B chiller unit ME335), have similar consequences, and the event dates are within 30 days of each other. However, the two events occurred during separata activities, and have different methods of l

' discovery, causes, and corrective actions. Therefore, according to the guidance provided by NUREG-1022, Rev 1, the two events are being reported separately. Using the guidelines in Regulatory Guide 1.174, the risk significance of each event, and the combined risk for both events together, was calculated to be small.

The health and safety of neither the public nor plant personnel were affected by either occurrence.

Any actions listed are intended to ensure continued compliance with existing commitments as discussed in applicable licensing documents; neither LER contains any new commitments. If you require any additional information, please so advise,

rely, f

Mim W102C gDR ADOCK 0 1

(

LERs No. 1998-020 and 1998-021 E. W. Merschoff, Regional Administrator, NRC Regiong g&

cc:

L J. A. Sloan, NRC Senior Resident inspector, Units 2 and 3 L

Institute of Nuclear Power Operations (INPO) l P.O.Ikx 128 San Clemente. CA 92674 0128 714-368-6255 Fax 714 3684183

..