ML17306B272

Special Rept 3-SR-004-03:on 920817,PASS Inoperable for More than 7 Days.On 920902,discovered That PASS Unable to Draw Vacuum on Gaseous Sample Bomb.Vent Line Reworked & Procedure Revised

ML17306B272
Person / Time
Site:	Palo Verde
Issue date:	01/27/1993
From:	James M. Levine ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
192-00825-JML-T, 192-825-JML-T, 3-SR-92-004-03, 3-SR-92-4-3, NUDOCS 9302100025
Download: ML17306B272 (7)

Text

ACCELERA~JOCUMENT DISTA+ION SYSTEM ACCESS'ON NBR:9302100025 DOC.DATE: 93/01/27 NOTARIZED: NO DOCKET FACIL:STN-50-530 Palo Verde Nuclear Station, Unit 3, Arizona Publi 05000530 AUTH. NAME AUTHOR AFFILIATION LEVINEgJ.H. Arizona Public Service Co. (formerly Arizona Nuclear Power RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

Special Rept 3-SR-004-03:on 920817,PASS inoperable for more than 7 days. On 920902,discovered that PASS unable to draw vacuum on gaseous sample bomb. Vent line reworked &

D procedure revised.

DISTRIBUTION CODE: IE22D COPIES RECEIVED:LTR ENCL SIZE:

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

/

NOTES:Standardized plant. 05000530 RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL D PD5 LA 1 1 PD5 PD 1 l.

TRAMMELL,C 1 1 D INTERNAL: ACNW 2 2 ACRS 2 2 AEOD/DOA 1 1 AEOD/DSP/TPAB ~ 1 1 AEOD/ROAB/DSP 2 2 NRR/DET/EMEB 7E 1 1 NRR/DLPQ/LHFB10 1 1 NRR/DLPQ/LPEB10 1 1 NRR/DOEA/OEAB 1 1 NRR/DREP/PRPBll 2 2 NRR/DST/SELB 8D 1 1 NRR/DST/SICB8H3 1 1 NRR/DST/SPLB8D1 1 1 NRR/DST/SRXB 8E 1 1 RgG FT5R~ 02 1 1 RES/DSIR/EIB 1 1 RGN5 FILE Ol 1 1 EXTERNAL: EG&G BRYCEgJ.H 2 2 L ST LOBBY WARD 1 1 NRC PDR 1 1 NSIC MURPHY,G.A 1 1 NSIC POOREiW. 1 1 NUDOCS FULL TXT 1 1 D

NOTE TO ALL"RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM PI-37 (EXT. 504-2065) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED: LTTR 31 ENCL 31

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Arizona Public Service Company PALO VERDE NUCLEAR GENERATING STATION P,O, BOX 52034 ~ PHOENIX. ARIZONA 85072-2034 I

192 -00825- JML/TRB/J J M JAMES M LEVINE January 27, 1993 VICE'AE$ IIIENT NUCI CAA f'AOI)UCf ION U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station P1-37 Washington, DC 20555

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Unit 3 Docket No. STN 50-530 (Ucense No. NPF-74)

Special Report 3-SR-9240443 File: 93-020-404 Enclosed please find Supplement 3 to.Special Report 3-SR-92-004 prepared and-submitted pursuant to Technical Specification (TS) 3.3.3.1 ACTION 28 and TS 6.9.2. This report discusses the Post Accident Sampling System being inoperable for greater than seven days. This supplement is being submitted to provide additional information regarding the cause of the event and the corrective action. A copy of the Special Report is being forwarded to the Regional Administrator, NRC Region V.

If you have any questions, please contact Thomas R. Bradish at (602) 393-5421.

Sincerely, JML/TRB/JJN Enclosure cc J. B. Martin (all w/enclosure)

J. A. Sloan W. F. Conway OBOI) 2(",

9302i00025 930i27 PDR ADOCK 05000530 S PDR

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ENCLOSURE POST ACCIDENT SAMPLING SYSTEM INOPERABLE GREATER THAN,SEVEN DAYS

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PALO VERDE NUCLEAR GENERATING STATION UNIT 3 POST ACCIDENT SAMPLING SYSTEM INOPERABLE GREATER THAN SEVEN =DAYS LICENSE NO. NPF-74 DOCKET NO. 50-530 SPECIAL REPORT 3-SR-92-004-03 INITIALCONDITIONS:

This Special Report is being submitted pursuant to Technical Specification (TS) 3.3.3.1 ACTION 28 and TS 6.9.2 to report an event in which the Post Accident Sampling System (PASS) was inoperable for a period greater than seven days'. The seven-day period for returning PASS to service.was exceeded at approximately 1005 MST on August 17, 1992.

BACKGROUND INFORMATION:

PASS is designed to sample reactor coolant and containment atmosphere under post accident conditions. The liquid sample portion of the system provides pressurized and depressurized reactor coolant samples as-required for analysis. The gas sample portion of the system provides containment atmosphere samples as required for analysis.

ACTIONS TAKEN:

On August 10, 1992, Palo Verde Unit 3 was in Mode 1 (power operation) when PASS was declared inoperable at approximately 1000 MST for maintenance. The maintenance involved rerouting field tubing to permit easier access for future maintenance. The tubing was a vent line for an eductor. Following the completion of work at approximately 1503 MST on August 10, 1992, PASS was declared operable.

On September 2, 1992, Chemistry Technicians discovered that the PASS was unable to draw a vacuum on the gaseous sample bomb. Initial troubleshooting on September 4, 1992, determined that the maintenance performed on August 10, 1992, may have caused the PASS to be inoperable. The vent line for the PASS eductor was reworked and operability was restored on September 5, 1992.

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CAUSE OF THE INOPERABILITY:

The investigation determined that the PASS eductor vent tubing was rerouted using additional 1/4 inch tubing and modifying the existing 1/2 inch tubing. The additional 1/4 inch tubing was installed between the same diameter tubing that extended from the PASS station and the rerouted 1/2 inch tubing. Due to the additional length and number of turns in the rerouted vent line, the eductor could not draw sufficient vacuum.

The root cause for PASS being inoperable was that a critical parameter (i.e., vent line backpressure/flow rate for the eductor) was not identified in plant documentation.

Therefore, the effect of rerouting the field routed tubing on operability was not recognized by the individuals involved.

In addition to the work which resulted in the PASS being inoperable, an appropriate retest was not conducted prior'to declaring the PASS operable. Appendix A of the (30DP-9WP04) lists parameters (pressure, temperature, flow) to be checked retest'rocedure for work involving tubing. An Inservice Leak Test was incorrectly specified but later deleted since the tubing was open ended and could not have been readily pressurized.

Operations, Chemistry, and the Work Group Supervisor concurred with the decision to delete the retest requirement and determined that no further testing was required.

However, flow requirements could have been checked by attempting to draw a vacuum.

CORRECTIVE ACTIONS:

The Chemistry System Status procedure, 74DP-9ZZ04, was revised to direct Chemistry personnel to ensure that a functional test is performed following maintenance which may affect the sampling capability.

The PASS piping and instrument drawing will'be revised/amended to denote the critical nature of the vent line for the eductor. This is expected to be completed by April '15, 1993.

This event will be included in the next available industry events training for Work Control Personnel. This training is expected to be completed by October 15, 1993.

PLANS AND SCHEDULE FOR RESTORING THE SYSTEM TO SERVICE:

Following satisfactory completion of repairs and required surveillance testing, PASS was returned to operable status at approximately 2137 on September 5, 1992.

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