ML17305A294

Special Rept 1-SR-89-009:on 890910,plant Vent High Range Effluent Monitor Inoperable for Greater than 72 H Due to Nonfunctional Skid Mounted Instrumenting Control Unit for Low Range Monitor.Suppl Describing Cause Will Be Issued

ML17305A294
Person / Time
Site:	Palo Verde
Issue date:	10/10/1989
From:	James M. Levine ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
1-SR-89-009, 1-SR-89-9, 192-00536-JML, 192-536-JML, NUDOCS 8910200014
Download: ML17305A294 (8)

Text

A.C CELEBRATED D.i BUTI ON DEMONS g~ Oq ~STEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:8910200014 DOC.DATE: 89/10/10 NOTARIZED: NO DOCKET FACIL:STN-50-528 Palo Verde Nuclear Station, Unit 1, Arizona Publi 05000528 AUTH. NAME AUTHOR AFFILIATION LEVINE,J.M.'rizona Public Service Co. (formerly Arizona Nuclear Power RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

Special Rept 1-SR-89-009:on 890910,radiation monitoring unit inoperable for greater than 72 h.

DISTRIBUTION CODE: IE22D COPIES RECEIVED-LTR TITLE: 50.73/50.9 Licensee Event Report (LER),

2Incident ENCL I SIZE ~

Rpt, etc.

C NOTES: 05000528 RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 1 PD5 PD 1 1 CHAN,T 1 1 DAVIS,M. 1 1 INTERNAL ACRS MICHELSON 1 1 ACRS MOELLER 2 2 ACRS WYLIE 1 1 AEOD/DOA 1 1 AEOD/DSP/TPAB 1 1 AEOD/ROAB/DSP 2 2 DEDRO 1 1 NRR/DEST/ESB 8D 1 1 NRR/DEST/ICSB 7 1 1 NRR/DEST/MEB 9H 1 1 NRR/DEST/MTB 9H 1 1 NRR/DEST/PSB 8D 1 1 NRR/DEST/RSB 8E 1 1 NRR/DEST/SGB 8D 1 1 NRR/DLPQ/HFB 10 1 1 NRR/DLPQ/PEB 10 1 1

- NRR/DOEA/EAB 11 1 1 NRR DREP RPB 10 2 2 NUDOCS-ABSTRACT 1 1 EG FILE OQ 1 1 RES/DSIR/EIB 1 1 1 1 EXTERNAL: EG&G WILLIAMS,S 4 4 L ST LOBBY WARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC MAYS,G 1 1 NSIC MURPHYIG A ~ 1 NUDOCS FULL TXT 1 1 NOTES 1 1 NVZE 'IO ALL 'KIDS" RECIPIENIS:

PLEASE HELP US 'IO REDUCE HASTEl CXNZACT 'IHE DCXXlNEÃ7 CGNIBOL DESK LISTS ~

RXH Pl-37 (EXT. 20079) %0 ELIMINATE YOUR ?RATE PKR DISTRIHQTICN DOCUlmm'S YOU Zemi T NEHDt TOTAL NUMBER OF COPIES REQUIRED: LTTR 40 ENCL 40

n Arizona Public Service Company PALO VERDE NUCLEAR GENERATING STATION P,O BOX 52034 ~ PHOENIX. ARI2ONA 85072-2034 192-00536-JML/TDS/SBJ October 10, 1989 U. S. Nuclear Regulat'ory Commission NRC Document Control Desk Washington, D.C. 20555

Subject:

'alo Unit Verde Nuclear Generating 1

Station (PVNGS)

Docket No. STN 50-528 (License No. NPF-41)

Special Report 1-SR-89-009 File'9-020-404 Attached please find Special Report 1-SR-89-009 prepared and submitted pursuant to Technical Specification 3.3.3.8 ACTION 42(b) and 6.9.2. This report discusses a radiat'ion monitor inoperable for greater than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />; Additionally, a copy of this report is being sent to the Regional Administrator.

If you have any questions on this matter, please contact Mr. Timothy Shriver, Compliance Manager at (602) 393-2521.

Very truly, yours, J. M. Levine Vice President Nuclear Production JML/TDS/SBJ/kj Attachment cc: W. F. Conway (w/attachment)

J. B. Martin T. J. Polich M. J. Davis A. C. Gehr INPO Records Center

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PALO VERDE NUCLEAR GENERATING STATION Radiation Monitoring Unit Inoperable for Greater Than 72 Hours License No. NPF-41 Docket No. STN 50-528 Special Report 1--SR-89-009 This Special Report is submitted in accordance with Technical Specifications 3.3.3.8 ACTION 42(b) and 6.9.2 for an event in which the plant vent high range effluent monitor (RU-144) was inoperable for greater than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. The 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> limit for inoperability was exceeded at approximately 0623 MST on September 10, 1989.

Palo Verde Unit 1 was in a refueling outage with the core unloaded at the time of this event. At approximately 0623 on September 7, 1989, the plant vent low and- high range effluent monitors (RU-143 and RU-144) were declared inoperable because the skid mounted instrumenting control (SMIC) unit for the low range monitor was not functional. Pursuant to Technical Specification 3.3.3.8 ACTION 37, the Preplanned Alternate Sampling Program (PASP) was initiated at approximately 0705 MST on September 9, 1989 and will continue until the radiation monitors are declared operable.

These radiation monitors work as a pair, with the low range monitor normally operating and the high range monitor in standby. When the low range monitor reaches a predetermined setpoint, the high range monitor starts and the low range monitor goes to standby. The high range monitor provides tracking of radioactive effluents during postulated accident scenarios. The high range monitor must be declared inoperable when the low range monitor is inoperable.

Each radiation monitor has a detector communicating with a microcomputer. The microcomputer for RU-143 is located in the post accident monitoring unit (PAMU).

Routine radiation info'rmation in the microcomputer can be accessed locally using the SMIC unit. A portable indication and control (PIC) unit can be plugged into the microcomputer to locally access information.

Remote access to the microcomputer is through the minicomputer. Annunciations of the radiation monitor are processed by the minicomputer.

The SMIC's inability to communicate with the microcomputer did not affect the ability of the radiation monitor to provide annunciation and actuations (see attached drawing). Additionally, an engineering evaluation is being performed to determine what equipment is required to be functional for a radiation monit'or to be operable. This evaluation should be completed by January 5, 1990.

The SMIC inability to communicate with the microcomputer is intermittent, making identification of the cause of the problem difficult. Maintenance monitored RU-143 SMIC performance daily after the radiation monitor was declared inoperable. Based on indications, the CPU board and system board for the SMIC were replaced. SMIC continued to operate intermittently following the board changeouts. A supplement to this Special Report will be issued describing the cause of the SMIC malfunction. Maintenance will continue to pursue resolution

.of the problem.

,I RADAR AT N MONK TOR ZNG YSTEM BLOCK DZ AGRAM SMIC MONITORS Mounted

'kid Indicating Unit Ru-141/142 located at Ru-143/144 m'oni tor s Ru-145/146 MICRO-COMPUTER

.Controller/Brains of the RMS system (1 per monitor)

KEPIC- Ru-,141/142/143/144 located in PAMU For'. Ru-141/142 Cabinet Ru- 143/ 144 Indicating unit, Ru-145/146 connect.ed to located on 120'f MERIC micro in PAMU Control Bldg'.

For'. Ru-145/146 only, Indicating unit located outside I

Control Room SYSTEM Console MINI-COMPUTER (DECMRITER) (DEC) 140'ccesses the Receives and Mini for shut- stores info from down/reboot each micro and operations and sends data to trend data, DCU terminal and located in the printer, located EFF. Off'ice in Eff. Office SYSTEM PRINTER (TERMINET)

Provides hard DCU Console copy of all RMS events, CRT 8 keyboard for located in C.R.

accessing mini -computer and providing alarm display and acknowledge