05000361/LER-1982-122, Forwards LER 82-122/03L-0.Detailed Event Analysis Submitted

Forwards LER 82-122/03L-0.Detailed Event Analysis Submitted

ML20065T512
Person / Time
Site:	San Onofre
Issue date:	10/21/1982
From:	Ray H SOUTHERN CALIFORNIA EDISON CO.
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
Shared Package
ML20065T514	List: 05000361/LER-1982-122, Forwards LER 82-122/03L-0.Detailed Event Analysis Submitted 05000361/LER-1982-122-03, /03L-0:on 820921,pilot Flames of Trains a & B Toxic Gas Isolation Sys Butane Monitors Extinguished.Caused by Low Bottle Pressure for Single Hydrogen Bottle Supplying Both Monitors.Bottle Replaced
References
NUDOCS 8211020554
Download: ML20065T512 (2)

LER-1982-122, Forwards LER 82-122/03L-0.Detailed Event Analysis Submitted

Event date:
Report date:
3611982122R00 - NRC Website

text

O PE gygg linc Southern California Edison Company 1992 OCT U y y S AN ONOFRE NUC LE AR GENER A TING S T A TION P.O. B O K 128 (FQ g S AN C LEMENTE, C A LIFORNI A 92672 H. B. R AY YELEPHONE October 21, 1982

.ranON - ANa E a

'""ar"a U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region V 1450 Maria Lane, Suite 210 Walnut Creek, California 94596-5368 Attention:

Mr. R. H. Engelken, Regional Administrator

Subject:

Docket No. 50-361 30-Day Report Licensee Event Report No.82-122 San Onofre Nuclear Generating Station, Unit 2 This submittal is in accordance with' the reporting requirements of Section 6.9.1.13b of Appendix A to Facility Operating License NPF-10.

It ciascribes a reportable occurrence involving Limiting Condition for Operation (LCO) 3.3.2 associated with the Toxic Gas Isolation System (TGIS). A completed copy of LER 82-122 is enclosed.

On September 21, 1982, while operating in Mode 2, a Control Room alarm I

was received indicating failure of TGIS, Trains "A" and "B".

Investigation revealed that the pilot flames associated with the butane monitors were extinguished. At 0530, Trains "A" and "B" butane monitors were declared inoperable and LCO 3.3.2, Table 3.3 Action Statement 15 was invoked. As required by this Action Statement, the Control Room Emergency Air Cleanup System (CREACUS) was placed in the isolation mode.

Subsequent investigation revealed that pilot flameout was due to low bottle pressure for the single hydrogen bottle supplying both monitors.

The bottle was replaced and the trains were declared operable at 0940 on September 21, 1982.

l 8211020554 821021 DR ADOCK 05000361 3 -) A PDR 00.Df

Mr. R. H. Engelken October 21, 1982 To avoid recurrence of such an event, a spare hydrogen bottle has been placed in the area allowing bottle replacement on a more timely basis when the pressure in the bottle in service drops to 200 psig.

In addition, maintenance personnel have been informed to assign high priority to procurement of new hydrogen bottles when needed. These instructions will remain in force until an on going investigation into the feasibility of installing a two bottle automatic system connected to a common header is completed.

Since the CREACUS was operated in the isolation mode throughout the event, there was no impact on the health and safety of plant personnel or the public.

If there are any questions regarding the above, please contact me.

Sincerely,

Enclosure:

IER 82-122 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 & Program Control Insititue of Nuclear Power Operations (INPO)