ML17312A951

LER 96-003-00:on 960809,open Auxiliary Bldg Door Caused Full Bldg Essential Filtration Inoperability.Caused by Personnel Error.C/As Under consideration.W/960904 Ltr

ML17312A951
Person / Time
Site:	Palo Verde
Issue date:	09/04/1996
From:	James M. Levine, Marks D ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
192-00980-JML-D, 192-980-JML-D, LER-96-003-01, LER-96-3-1, NUDOCS 9609130076
Download: ML17312A951 (14)

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ACCESSION NBR:9609130076 DOC.DATE: 96/09/04 NOTARIZED': NO DOCKET I FACIL:STN-50-528 Palo Verde Nuclear Station, Unit 1, Arizona Publi 05000528 AUTH. NAME AUTHOR AFFILIATION MARKSiD.G. Arizona Public Service Co. (formerly Arizona Nuclear Power LEVINE,J.M Arizona Public Service Co. (formerly Arizona Nuclear Power RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 96-003-00:on 960809,open auxiliary bldg door caused full bldg essential filtration inoperability. Cause by personnel error.C/As under consideration.W/960904 ltr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR t ENCL I SIZE:

TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.

E NOTES:STANDARDIZED PLANT 05000528 G

RECIPIENT COPIES RECIPIENT COPIES 0 ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD4-2 'PD 1 1 CLIFFORD,J 1 1 R INTERNAL: ACRS 1 1 2 2 AEOD/SPD/RRAB 1 1 LE CENT R 1 1 NRR/DE/ECGB 1 1 NRR DE EELB 1 1 NRR/DE/EMEB 1 1 NRR/DRCH/HHFB 1 1 NRR/DRCH/HICB 1 1 NRR/DRCH/HOLB 1 1 NRR/DRCH/HQMB 1 1 NRR/DRPM/PECB 1 1 NRR/DSSA/SPLB 1 1 NRR/DSSA/SRXB 1 1 RES/DSIR/EIB 1 1 RGN4 FILE 01 1 1 EXTERNAL: L ST LOBBY WARD 1 1 LITCO BRYCE,J H 2 2 NOAC MURPHYiG.A 1 1 NOAC POORE,W. 1 1

-NRC PDR 1 1 NUDOCS FULL TXT 1 1 N

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Jamei M. Levine TEL (602g934300 Matt Station 7602 Peto Verde Nuctear Vce President FAX (602P934077 P.O. Box 52034 Generating Station NeAear Producthn http JNyww.apse.corn Phoenbt, AZ 85072-2034 192-00980-JML/DGNI/RAS September 4, 1996 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station P1-37 Washington, DC 20555-0001

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Unit1 Docket No. STN 50-528 License No. NPFQ1, Licensee Event Report 9640340 Attached please find Licensee Event Report (LER) 96-003-00 prepared and submitted pursuant to 10CFR50.73. This LER reports the August 9, 1996 discovery that Trains A and B Fuel Building. Essential Filtration units were rendered inoperable w'hen a control door in the Auxiliary Building was propped open. In accordance with 10CFR50.73(d), a copy of this LER is being forwarded'to the Regional Administrator, NRC Region IV.

If you have any questions, please contact Daniel G. Marks, Section Leader, Nuclear Regulatory Affairs, at (602) 393-6492.

Sincerely, JMUDGM/RAS/pv cc: L. J. Callan K. E. Perkins,.

K.'E. Johnston INPO Records Center w pgg/

9609i30076 960904 PDR ADOCK 05000528 8 PDR.

Ck LICENSEE EVENT REPORT (LER)

ACILITT NAME (1) DOCKET NUMBER (2) PAGE(3)

Palo Verde Unit 1 ,0 5 0 0 0'5 2'8,10FO 5 0 en Auxilia Buildin Door Causes Fuel Buildin Essential Filtration lno erabilit EVENT DATE 5 LER NUMBER 8 R EPOR'T DATE OTHER FACIUTIES INVOLVED 8 MONTH OAY YEAR YEAR SEQVENTIAL REVISION FACIUTYNAMES NUMBERS NUMBER NUMBER NA 0 5 0 0 0 0 8 0 9 6 9 6 - 0 0 3 - 0 0 0 9 0 4 9 6 NA 0 5 0 0 0 IS REPORT IS SUBMiTTED PURSUANT TO THE REQUIREMENTs QF 10 cFR C (checlr one ot more ot the following) (11) 20A02(b) 20.45(c) 50.73(a)(2)(h) 73.71(b) 20.45(a)(1)(r) 50.38(c)(1)

X 50.73(a)P)(r) 73.71(c)

LEVEL(10) g 0 0 20.45(a)(I)(s) 50~c)P) X 50.73(a)(2)(ni) OTHER (Specgy in Absbacf 20.45(a)(1)(gi) 50.73(a)P)(r) 5073(a)P)YAWNY bekwr and kr TrrrL NRC Form 20.45(a)(1)(h) 5073(a)P)(s) 5073(aN2)Y)(B) 388A) 20.45(a)(1)(r) 50.73(a)P)(iii) 5073(a)P)03 UCENSEE CONTACT FOR TI8S LER (I 2)

E Daniel G. Marks, Section Leader, Nuclear Regulatory Affairs 6 0 2 3 9 3 - 6 4 9 2 COMPLETE ONE UNE FOR EACH COMPONENT FALVRE DESCRIBED IN TI8S REPORT (1 3)

MANUFAG. REPORTABLE MANVFAC. REPORTABLE TURER TO NPROS TURER TO NPRDS SUPPLEMENTAL REPORT EXPECTED (54) EXPIATED DATE (15)

TRACT (Umn IO TS00 SpaCea, I.e., appmrrknarely friteen SinglaeprC>> peWeraren lee@) (I 8)

On August 9, 1996, at approximatelv 1220 MST, Unit 1 was in Mode 1 (POWER OPERATIONS), operating at 100 percent power when APS engineering personnel determined that a coYIdition which exi.sted on August 2, 1996, had rendered both trains of the Fuel Building Essential Filtration system inoperable.

Specifically, it was determined that on August 2f 1996f at approximately 0830 MST, maintenance workers propped open a door on the 100'levation of the auxiliary building whi.ch created a flow path which could not be compensated for by the Fuel Building Essential Filtration units. This condition was corrected at approximately 0930 MST, August 2g 1996f but while the door was open, the Fuel Building Essential Filtration units would not have been able to maintain a measurable negative pressure under loss of coolant accident conditions as specifi.ed in the Updated Final Safety Analysis Report.

Calculations have demonstrated the offsite dose consequences would have remained within 10CFR100 limits under postulated LOCA conditions .while the door was open. The cause of the condition was attributed to personnel error, and various corrective actions are under consideration at this time.

There have been no previous similar events reported pursuant to 10CFR50.73 within the past three years. See section 7 for additional information.

0 4k LICENSEE EVENT REPORT (LER) TEXT CONTINUATION AGILITYNAME DOCKETNUMBER LER NUMBER PAGE SEQUENTIAL SIO NUMBER NUMBER Palo Verde Unit 1 0 5 0 0 0 5 2 8 9 6 - 0 0 3 - 0 0 0 2 of 0 5

1. EVENT CLASSIFICATION:

This LER (528/96-003-00) is being submitted to report a condition in which both Trains A and B Fuel Building Essential Filtration units (VG)(AHU) would not have been able to maintain a measurable negative pressure under Loss of Coolant Accident (LOCA) conditions as specified in the Updated Final Safety Analysis Report (UFSAR).

This condition is reportable pursuant to 10CFR50.73(a)(2)(v)(C) (any event or condition that alone could have prevented the fulfillment of a safety function) and 10CFR50.73(a)(2)(vii)(C) (a single cause or condition which caused two independent trains or channels to become inoperable in a single system).

This condition was initially reported to the NRC via the Emergency Notification System as a 1-Hour Non-Emergency event (ENS ID 30860, August 9, 1996) pursuant to 10CFR50.72(b) (1) (ii) (B) . Although subsequent evaluation revealed that the condition did not meet this reporting criteria, the ENS notification was not retracted because the condition was determined to be reportable under other 50.72 requirements.

2. EVENT DESCRIPTION On August 9, 1996, at approximately 1220 MST, Unit 1 was in Mode 1 (POWER OPERATIONS), operating at 100 percent power when APS engineering personnel (other utility personnel) determined that a condition which existed on August 2, 1996, had rendered both trains of the Fuel Building Essential Filtration system inoperable.

On August 2, 1996, at approximately 0800 MST, maintenance technicians (contractor personnel) were preparing to begin work on the 100'levation of the Auxiliary Building (NF) . While setting up, the technicians noted that it would be necessary to prop open a door in order to route an electrical cable for their welder. One of the technicians returned to the foreman and requested an open door permit. The technicians'oreman (contractor personnel) instructed the technician to return to the work location and retrieve the door number. Arriving at the door, the technician noted a large black-on-yellow sign in the center of the door which stated that Shift Supervisor permission was required to prop open the door. Immediately below the sign was the number "A-131" and under the number was another label which said "Sta' Down."'he technician

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LICENSEE EVENT REPORT (LER) TEXT CONTINUATION, AGILITYNAME DOCKET NUMBER LER NUMBER PAGE

, YEAR SEQUENTIAL EVISIO NUMBER NUMBER Palo Verde Unit 1 0 5 0 0 0 5 2 8 9 6 0 0 3 - 0 0 0 30f0 5 EXT telephoned the foreman and reported the door number as "A-131" and also informed the foreman of the other postings. The technician did not see the additional number at the top of the door.

The foreman reported to the Work Control Senior Reactor Operator (SRO)(utility, licensed) and requested an Open Door Permit. The. SRO looked up "A-131" in the controlling procedure (40DP-9ZZ17, Control of Doors, Hatches and Floor Plugs) and found there was no Security, Fire, HVAC, or HELB applicability to door "A-131" and informed the foreman that an open door permit was not needed.

The technician, who by now had arrived at the Work Control SRO's office, was informed that an open door permit was not required. The technician reiterated that there was a large black-on-yellow sign in the center of the door which stated that the Shift Supervisor's permission was required in order to prop open the door. The Work Control SRO verified with the technician that the door number was A-131 and then rechecked the procedure. After checking the second time, the Work Control SRO assumed the door was incorrectly posted and did no further research. The maintenance technicians returned to work on the 100'levation of the Auxiliary building.

At approximately 0930 MST, an Auxiliary Operator (AO)(utility, non-licensed) was performing routine rounds and noted door A-123 was propped open with an electrical cable routed through it. The AO immediately advised the Shift Supervisor (utility, licensed), who directed the AO to remove the cable and close the door.

3. ASSESSMENT OF THE SAFETY CONSEQUENCES AND ZMPLZCATZONS OF THE EVENT Door A-123 opens to a stairway which opens into the pipe chase area of the 88'oot elevation of the Auxiliary Building. This opening then serves as a non-ducted flow path from the 100'levation of the Auxiliary Building to the Fuel Building (ND). This non-ducted flow path could have circumvented the Fuel Building Air Filtration units'bility to maintain a measurable negative pressure in the 88'levation of the Auxiliary Building during LOCA conditions.

While door A-123 was open (approximately 1.25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br />), the Fuel Building Essential Filtration units would not have been able to maintain a measurable negative pressure under T.~CA conditions as requi~ed by the

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION AGILITYNAME DOCKETNUMBER LER NUMBER PAGE SEQUENTIAL EVISIO NUMBER NUMBER Palo Verde Unit 1 0 5 0 0 0 5 2 8 9 6 0 0 3 - 0 0 04of 0 5 EXT UFSAR. Section 9.4.2.2 of the UFSAR states: "areas with safety injection piping [BP/BQ] and equipment shall be kept under measurable pressure in relation to ambient during emergency conditions by exhausting through Engineered Safety Features [ESF] [JE] filtration systems.."

Calculations completed by Design Engineering personnel (other utility personnel) have demonstrated that had a negative pressure not been maintained in the Unit 1 Auxiliary Building under LOCA conditions, the limitations of 10CFR100 would not have been exceeded. The loss of the Fuel Building Essential Filtration system would result in minute increases in the calculated recirculation leakage as specified by the UFSAR but would not increase the calculated doses beyond 10CFR100 limits.

4. CAUSE OF THE EVENT An investigation performed in accordance with the APS corrective action program revealed that the cause of the event was personnel error (SALP code A). Specifically, the responsible contractor maintenance technician provided an incorrect door number when requesting an open door permit.

Also, Work Control personnel did not question or verify the door number when informed of the cautionary sign posted to it. These personnel errors were cognitive and not the result of a procedural error or deficiency.

The investigation also revealed that the manner in which doors are identified contributed to the event and door numbering system ergonomics could be improved. There were no unusual work location characteristics (e.g., heat, noise) which contributed to the personnel error.

5. STRUCTURES, SYSTEMS AND COMPONENTS Door A-123, which was propped open and initiated the event, is a non-quality related, 3'y 7'y 1.75" hollow metal door with a pressed metal frame.

The Fuel Building Heating Ventilation and, Air Conditioning (HVAC) System consists of normal and essential HVAC systems. The normal HVAC system is designed to maintain environmental conditions suitable for personnel comfort and safe operation of equipment during normal plant operation.

The essential filtration system functions only in the event of a fuel handling accident, a LOCA or during required testing. The essential filtration system exhausts throvah the fuel building vent, minimizing the

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LICENSEE EVENT REPORT (LER) TEXT CONTINUATION AGILITYNAME DOCKET NUMBER LER NUMBER PAGE

'fEAR 'EQUENTIAL BIO NUMBER NUMBER Palo Verde Unit 1 0 5 0 00 5 2 8 9 6 -' 0 3 - 0 0 0 50f0 5 EXT release of airborne radioactivity to the surrounding areas in case of a fuel handling accident. The essential exhaust system also creates a negative pressure in the areas below the 100'levation of the auxiliary building in the case of a LOCA. The negative pressure ensures that air leakage is into this area of the auxiliary building and ensures leaks associated with Safety Injection system piping and components are filtered prior to release. A tunnel connects the 88'levation of the auxiliary building with the fuel building essential filtration units.

The essential filtration units are actuated upon a Safety Injection Actuation Signal (BIAS) .

There were no systems or components which were inoperable prior to the event which contributed to the event. Likewise, there were no automatic or manually initiated safety system responses and none were required as a result of the event.

6. CORRECTIVE ACTIONS TO PREVENT RECURRENCE The open door was secured by Operations personnel and the contract maintenance technicians'oreman was notified of the event.

Controlled doors in Units 1, 2 and 3 will be reworked to remove room numbers and other non-essential labeling.

7. PREVIOUS SIMILAR EVENTS There have been no previous similar events reported pursuant to 10CFR50.73 which have resulted in the inoperability of the Fuel Building Essential Filtration due to open doors. However, there have been previous occurrences where area numbers have been confused with door numbers.

These other previous occurrences are being considered in the investigation of this event.