05000278/LER-1980-007, Forwards LER 80-007/01T-0

Forwards LER 80-007/01T-0

ML19305A912
Person / Time
Site:	Peach Bottom
Issue date:	03/06/1980
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19305A913	List: 05000278/LER-1980-007, Forwards LER 80-007/01T-0 05000278/LER-1980-007-01, /01T-0:on 800221,during Routine Plant Equipment Insp,Seismically Qualified Backup Nitrogen Bottle Supplies to Five Containment Ventilation Valves Found Out of Svc. Caused by Lack of Operator Info & Equipment Identification
References
NUDOCS 8003180573
Download: ML19305A912 (3)

LER-1980-007, Forwards LER 80-007/01T-0

Event date:
Report date:
2781980007R00 - NRC Website

text

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l PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET P.O. BOX 8699 PHILADELPHIA. PA.19101 azisieai4ooo March 6, 1980 Hr. Boyse H.

Grier, Director Office of Inspection and Enforcement Region I US Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406

Dear Mr. Grier:

SUBJECT:

L i c e_n s e e _Ev_e n t Report Narrative Description The following occurrence was reported to Mr. Greenman, US Nuclear Regulatory Commission, Region I,

Office of Inspection and Enforcement on February 21, 1980.

Reference:

Docket No. 50-278 Report No.;

LER 3-80-7/IT Report Date:

March 6, 1980 Occurrence Date:

February 21, 1980 Facility:

Peach Bottom Atomic Power Station RD 1, Delta, PA 17314 Technical Specifications Reference:

Technical Specifications 6.9.2.a.(6) states in part

" Personnel arror or procedural inadequacy which prevents or could prevent, by itself, the fulfillment of the functional requirements of systems required to cope with a c c id e :i t s analyzed in the SAR" shall be reported.

Description of the Event a)

During a routine inspection of plant equipment, the back up seismically qualified, bottled nitrogen supply to five containment ventilation valves was found valved out of service.

The valves, however, were being supplied from the normal instrument air supply and therefore, the boot seals were inflated and containment integrity was maintained.

The normal instrument air supply is not seismically qualified. /9002 5

///

8003180 g

Mr. Bo y c e 11. Grior Page 2 LER 3-80-7/1T b)

When the first seismic back up bottle supply was found closed, an investigation into the cause and an inspection of all containment ventilation valves was inacdiately initiated.

Additionally, a blocking error was al"9 identified.

At approximately 3:20 a.m.

on 2/20/ts, ventilation valve A0-3512 was blocked for modification work.

The. operator applying the blocking permit incorrectly valved out the disc seal air supply to A0-3511 as well as A0-3512.

At the time the inspection was made, the disc seal pressure on these valves was 15 psig and 55 osig.

Normal seal pressure is greater than 75 psig.

The inspection of all other Unit 2 & 3 containment ventilation valves did not identify any other deficiencies.

Consequences of the Event:

a)

If a seismic event occurred which resulted in failure of.the instrument air system, the five valves involved could have permitted containment leakage after some time interval if corrective action was not taken.

If a seismic event had occur ed, the valves would have remained sealed for about 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> based on testing of a set of these valves.

If the disc seal pressure decayed to about 62 psig, an indicating light in the control room would indicate a deflated disc seal for four of the five valves involved.

(Pressure switch installation on ene fifth valve was not completed at chts date).

The required once per shift panel check by the operator would have identified the condition of four of the five valves and the seismic air supply would have been re-established prior to loss of containment integrity.

This occurrence could have resulted in loss of containment integrity following a postulated seismic event only if j

additional operator errors had occurred and if j

administrative controls were not adhered to.

i i

i b)

Leak tests performed to determine seal capability of A0-3511 I

and A0-3512 at the disc seal pressure existing wnen the I

blocking error was found indicated leakage well below the i j' acceptable level.

This occurrence could have resulted in loss of containment integrity if the disc seal pressure decayed without notice.

I t

Cause of the Event

a)

Investigation has shown that the back up, seismically qualified, bottled nitrogen supplies to the five containment ventilation valves have been valved out of service since December 23, 1979.

The containment ventilation valves are being modified to qualify them for operation during seismic l~

event.

Some of the valves have been modified, and some have not.

Those valves which are not modified have a seismically qualified nitrogen bottle supply to the valve disc seal which is manually actuated follo4ing the positioning of the valve in the closed position.

It order to ouen these i

Mr. Boyco H.

Grior Page 3 LER 3-80-7/lT 1

unmodified valves, an operator must valve out this bottle supply to the disc seal prior to operating the valve from the control room.

The same nitrogen bottles have a different purpose on the modified valves, and the nitrogen bottles on these five modified valves were valved out of service in-the mistaken belief that the bottles were no longer needed.

b)

The blocking error was caused by a lack of equipment identification and inadequate operator training.

Corrective Actionsi When the first seismic air suppif was found valved out, an inspection of all containment ventilation valves was immediately initiated.

This inspection identified four other bottled supplies which were valved out of service, along with the blocking error.

All problems were corrected immediately.

l The operators were instructed as to the status of all containment I

ventilation valves.

Tags were hung on all air supply valves, both seismic back-up and normal, indicating the normal valve position.

Applicable procedures and check-off lists have been revised to include the position of valves associated with the containment ventilation valves.

The bottle pressure round sheet has been converted to a surveillance test to ensure that the seismic back up supply is functional.

Previous Similar Occurrence:

I LER 2-80-1/IT Very truly yours,

/E'Y Qft

'A.

Coone Su erinten nt Generation Division - Nuclear Attachment l

cc:

Director, NRC - Office of Inspection and Enforcement Mr. Norman M.

Haller, NRC - Office of Hanagement &

li Program Analysis I

I