ML20011E229

LER 89-039-01:on 891116,discovered That Door for Upper North Electrical Penetration Room Open & Latch Mechanism Missing. Caused by Abnormally High Differential Pressure Across Door. Ventilation Sys Flow Balance performed.W/900131 Ltr

ML20011E229
Person / Time
Site:	Arkansas Nuclear
Issue date:	01/31/1990
From:	Ewing E, Taylor L ARKANSAS POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
1CAN019019, 1CAN19019, LER-89-039, LER-89-39, NUDOCS 9002120094
Download: ML20011E229 (4)

Text

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', \' Arkansas Power & UgM Company

-\ .) Amant.at, Nacleat One

'-- Ja' RaJe 3. Bax 137 G Rtssellvdic, AR 7MQ1 Tel 531964 3100 L

January 31, 1990 1CAN019019 U. S. Nuclear Regulatory Commission L Document Control Desk

! Mail Station PI-137 Washington, D. C. 20555

SUBJECT:

Arkansas Nuclear One - Unit 1 Docket No. 50-313 License No. DPR-51 ,

Licensee Event Report No. 50-313/89-039-01 I

Gentimen:

In accordance with 10CFR50.73(a)(2)(v), attached is a revision to the subject report concerning the Penetration Room Ventilation System being rendered inoperable due to the failure of the access door to the upper i north electrical penetration room.

Very truly yours, f <

/ E. C. Ewing

• General Manager, Technical Support ,

and Assessment ]

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attachment cc: Regional Administrator Region IV .

U. S. Nuclear Regulatory Commission l 611 Ryan Plaza Drive, Suite 1000 l Arlington, TX 76011 1 INPO Records Center 1500 Circle 75 Parkway  :

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FACILITY KAME (1) Arkansas Nuclear One Unit One IDOCALT NOMBLR (2) l& AGE (3) 10151010101 31 il 31110Fl013 TITLL (4) Penetration Room Ventilation $ystem Rendered inoperable Due to the Failure of the Access Door to the Upper North Ilectrical Penetration Room f VENT DATI (b) i L[P NUMBER (6) l &[ PORT DATl (7) l OTHf R F ACILITlf 5 INVOLV(D (6) l l l l l$pquentiell lkevisioni l 1 l l Monthi Div lYear IYear i i Number 1. I Number luonthi Day lYear i Facility hames IDocket Numbeefs) l l l l l l t l l l l 101 il01010i I ,j_,,

il It il 6! 81 91 81 91- I 01 31 91--! Of 11 Of 11 31 11 91 Of t0131010101 1 I OPikA11NG l jfMI6 REPORT 15 50BMITTLD PUR$UANT TO THE REQUIREMEN15 0F 10 CFR 6:

MODI (9) i WI (Check one or more of the followino) (11) f POWERI l I 20.402(b) l I 20.40b(c) I,_1 60.73(a)(2)(iv) l I 73.71(b)

LEYCLI l l 20.405(a)(1)(1) l I 60.36(c)(1) l_11 60.73(a)(2)(v) l_,1 73.71(c)

(10) 1010161 ,1 20.405(e)(1)(11) l I 6n.36(c)(2) 1._l 60.73(a)(2)(v11) 1,_l Other (Specify in 1 _l 20.405(a)(1)(111) l I 50.73(a)(2)(1) l I 60.73(a)(2)(v111)(A)l Abstract below and l_.1 20.406(a)(1)(tv) I I 60.73(a)(2)(11) l I 60.73(a)(2)(v111)(8)l in Tekt. NRC Fore I I 20.406(a)(1)(v) i I $0.73(e)(2)(iii) i i 50.73(a)(2)(m) i 366A)

LICfN5ff CONTACT FOR THIS Ltk (12) _ _ _

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lArea i L;rry A. Taylor Nuclear Safety and Licensing Specialist ICode i 1510111916141 13111010 COMPLffE ONE LINE FOR [ACH COMPONENT FAILURE DISCRlttD IN THl$ Rf>0RT (13) l l l lReportabiel 1 l i l IReportablel Spusel$ystes! Component IManufactureel to NPRDS I Itausel5ysteel Component INanufacturert to NPRDS 1 i l I i i l 1 l i i l i I I i i i I I I I I I I I I I I l i I i i i I I l l l l i i l i i l I I I I i i ! I I I I I I i l I I I I i l i l i I

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On November 16,1D89, at approximately 0130, it was 1dertified by plant personnel that the door (DR-78) for the Upper North Electrical Penetration Room (UN(PR) was open and that its latch mechanism was missing. In addition, the door's weather stt !pping was severely degraded. This door is required to be closed to allow the Penetration Room Ventilation System (PRVS) to perfore its design function of maintaining a slightly negative pressure in the penetration rooms during osergency conditions. Upon discovery that DR-78 was inoperable, a job request was f amediately initiated to have it repaired.

The door was returned to operable status at 1D45 on November 16, 1989. DR*78 receives extensive usspo during ANO-1 and ANO-2 outages because it provides access to the Not Tool Room as well as the UNEPR.

Since ANO 2 was in the 1stter stages of a fifty six day refueling outage, DR 78 had received extensive usspe. The cause of the failure of this door was determined to be the extensive use it was subjected te during the outape. An abnormally high differential pressure across the door contributed to its degradation. DR 78 was added to the Operations daily rounds log to be inspected daily. Additionally, a ventilation system flow balance will be performed to reduce the differential pressure across the door.

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f Form 1D62.018 r NRC Form 366A U.S. Nuclear Regulatory Commission (9-83) Approved DM8 No. 31bO 0104 i Espires: 8/31/86 LICEN5ft (VENT REPORT (LER) TEXT CONTINUATION iACILITV NAML (1) l DOCA [i NUMBER (2) l ((R NUMBE R (6) l PAGE (3) ,

I l l 15equentiell IRevisionl Arkansas Nuclear One, Unit one l l Yeart i Number I i Number l 10161010101 3! Il 31 el 91--I of 31 91 I 01 110lF10Fl013 j TtKT (If more space is required, use additional NRC f orm 366a's) (17) >

A. Plant $tatus At the time this condition was discovered. Arkansas Nuclear One, Unit 1 (AND 1) was operating at approximately 6 percent of rated power and was in the process of increasing PD*er to 74 percent.

B. Event Description On November 16, 1989, at approximately 0130, it was identified by plant personnel that the door (DR 78) for the Upper North (1ectrical Penetration Room (UNEPR) was open and that its latch mechanism was missing. In addition, the door's weather stripping was severely degraded. This door is required to be closed to allow the Penetration Room Ventilation System (PRV$) [VF) to '

perform its design function.

The PRV$ is an E$ actuated system designed to collect and filter a portion of the postulated Containment Building (CB) penetratibn leakage following a posign basis accident to minimite the ,

activity which could be released to the environment. One-half of the maximum allowable CB penetration leakage is assumed to be processed by the PRVS. The 6esign features of the PRV$

include six sealed penetration rooms, two redundant filter trains, two redundant fans, isolation control valves, suction check valves, and instrumentation and controls. Each of the two redundant fans takes suction from each of the six separate penetration rooms which are isolated from their normal ventilation systems by control valves upon t$ actuation. To ensure that any leakage into the penetration rooms is processed by the PRY $, the system is designed to achieve  ;

and maintain a slight negative pressure in the penetration rooms.

Dpon discovering that DR-78 was inoperable, the PRV$ was declared inoperable and a Technical Specifications Limiting Condition for Operation action statement was entered which requires the reactor to be placed in cold shutdown within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> if the condition can not be corrected. A job request was immediately initiated to have it repaired. The door was returned to operable status at 1D46 on November 16, 1989.

C. Safety Significance PRVS air flow rate and penetration tres pressure tan be monitored in the Controi Room and annunciation is provided for inadequate penetration room vacuum and low system flow. Although the ocgraded condition of DR-78 could have degraded the capability of the sys'em to perform its design function I

of maintaining a slightly negative pressure in the penettetion rooms, ave 11ahle instrumentation l

wnutd have alertad the operators of the degraded system conditions and appropriate corrective l actions could have toen initiated. Additionally, the PRY $ had passed its monthly surveillance on l November 10, 1889, indicating that it had not been in a degraded condition for en extended period of time. Based on these f actors, the safety significance of this condition is cons 16ered minimal.

D. Root Cause

,, DR 78 receives extensive usage during ANO 1 and ANO 2 outages because it provides access to the l Hot Tool Room as well as the UNEPR. Since AN0*! was in the letter stages of a fif ty six day outage, DR 78 had received extensive usage. The cause of the f ailure of this door was determined to be the extensive use it was subjected to during the outage. Additionally, the ventilation system flows in the vicinity of DR 78 create a significant differential pressure across the door which contributes t3 its degradation. '

[. Basis for Reportability The degraoed condition of DR-78 could have rendered the PRV5 incapable of performing its design function of saintaining a slightly negative pressure in the penetration rooms during emergency conditions. Therefore, this event is reportable pursuant to 10CFR50.73(a)(2)(v) as a condition that alone could have prevented the fulfillment of the safety function of a system that is needed to control the release of radioactive material.

This condition was also reported via the Emergency Notification $ystem at 0838 on November 16, 1989.

l This notification was made late because it was not initially realized that the degraded condition l of DR-78 which rendered the PRVS inoperable was reportable pursuant to 20CFR50.72.

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O Fom M6A Form 1062.015  !

U.S. Nuclear Regulatory Commission ]

(9 83) Approved OMB No. 3160-0104 Expires: 8/31/85 LICEh5EI [ VENT REPORT (LER) Ttxt CONTINUATION FACILITY NAMt (1) lDDCKET NUPELR (2) l ,IR NLag4[R (6) . l FAGE (3) <

l l l l Jequential ! : Revision l Arkansas Nuclear One, Unit One l I Year Number l

Number l )

10151010101 31 11 31 el 9 --

01 31 9 -

01 1101310Fl013 i T[KT (If more 6 pace is required, use additional NRC Fore 366A's) (17) '

F. Corrective Actions A job request was initiated upon discovery of the inoperable door. The latch and weather stripping were repaired and the door was returned to operable status at 1045 on November 16,1989. )

l The feasibility of relocating the Hot Tool Room in order to reduce traffic through DR*78 during cutages was evaluated. However, it was detemined not to be feasible et the present time. 1 1

In order to prevent DR*78 from degrading to the point of inoperability, more frequent inspections of the coor's condition were initiated by adding it to the Operations daily rounds log. $1nce the l j

ether penetration room doors are not located in high traffic areas, the monthly FRV5 surveillance is considered adequate to assure their continued operability. i I

An engineering evaluation was performed to determine any further corrective actions which could be taken to prevent excessive degradation of DR 78. This evaluation determined that reducing the differential pressure across the door should significantly reduce its degradation rate. A flow balance of the ventilation system in the vicinity of DR-78 is scheduled to begin on February 1,1990.

To enhance the current process used in evaluating events or plant conditions for reportability, additional guidance will be provided by Plant Licensing to Operations personnel regarding '

10CFR50.72 notification. Additionally, training will be provided for Operations personnel on 20CFR50.72 reporting criteria. This training will be completed by June 22, 1990.

C. Additional Information There have been no previous similar events reported by ANO.

Energy Industry Identification System ([!!$) codes are indicated in the text as (XX).

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