ML17303A442

LER 87-017-00:on 870608,discovered That 4-h Samples of Gaseous Radwaste Sys Had Not Been Taken as Required.Caused by Improper Communication Between Chemist & Control Room Operator.Night Order initiated.W/870702 Ltr

ML17303A442
Person / Time
Site:	Palo Verde
Issue date:	07/02/1987
From:	Bradish T, Haynes J ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
192-00242-JGH-T, 192-242-JGH-T, LER-87-017, LER-87-17, NUDOCS 8707090257
Download: ML17303A442 (6)

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REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:87070'ZP0257 DOC. DATE: 87/07/02 NOTARIZED: NO DOCYET 5 FACIL: STN-50-529 Palo Verde Nuclear Stationp Unit 2p Arizona Publi 05000529 AUTH. NAME AUTHOR AFFILIATION BRADISHI T. R. Ari zona Nuclear Poeer Pro Ject (Formerly Arizona Public Serv HAYNESI J. G. Arizona Nuclear PouJer ProJect (formerly Arizona Public Serv RECIP. NAME RECIPIENT AFFILIATION

SUBJECT:

LER 87-017-00: on 870608p discovered that 4-h samples of.

gaseous radeaste sos had not been taken as required. Caused bg improper communication betujeen chemist 4 control room operator. Night order hae been implemented. N/270702 Itr.

DISTRIBUTION CODE: IE22D COPIES RECEIVED: LTR / ENCL Q etc.SIZE:

TITLE: 50. 73 Licensee Event Report (LER) p Incident Rptp NOTES: Standardized p lant. M. Davi si NRR: 1Cg. 05000529 REC IP IENT COPIES REC IP IENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 1 PD5 PD 1 1 LICITRAiE 1 1 DAVISI M 1 1 INTERNAL: ACRS MICHELSON ACRS MOELLER 2 2 AEOD/DOA 1 1 AEOD/DSP/ROAB 2 2 ~

AEOD/DSP/TPAB 1 1 DEDRO NRR/DEST/ADE 1 0 NRR/DEST/ADS 1 0 NRR/DEST/CEB 1 1 NRR/DEST/ELB 1 NRR/DEST/I CSB 1 1 NRR/DEST/MEB 1 1 NRR/DEST/MTB 1 NRR/DEST/PSB 1 1 NRR/DEST/RSB 1 1 NRR/DEST/SGB 1 1 NRR/DLPG/HFB 1 1 NRR/DLPG/GAB 1 NRR/DOEA/EAB 1 1 NRR/DREP/RAB 1 1 NRR/DREP/RPB 2 2 1 NRR/PMAS/PTSB 1 1 ~RE~CEIL 02 1 1 RES DEPY GI 1 1 RES TELFORDp J 1 RES/DE/EIB 1 1 RGN5 FILE 01 1 EXTERNAL: EG5G GROHi M 5 5 H ST LOBBY WARD 1 LPDR 1 1 NRC PDR 1 1 NSIC HARRISI J 1 1 NSIC MAYSp G 1 1 NOTES:

TOTAL NUMBER OF COP IES REQUIRED: LTTR 46 ENCL 44

NRC Forth 300 US. NUCLEAR REOULATORY COMMISSION 19 43 I APPROVED OM 5 NO. 3)504104 LICENSEE EVENT REPORT (LER) EXPIRES: 4/31/44 FACILITY NAME (II DOCKET NUMSER (2) PA 3 Palo Verde Unit 2 0 5 0 0 0 5 2 1 OF 03 TITLE Iet Inade uate Monitorin of Gaseous Radwaste Durin De assin of Primar Coolant EVENT DATE (5) LER NUMBER (4) REPORT DATE (7) OTHER FACILITIES INVOLVED (0)

MONTH OAY YEAR YEAR re/+

SEQUENTIAL NUMSER nc~

NCI NUMSER MONTH OAY YEAR FACILITYNAMES DOCKET NUMSERISI 0 5 0 0 0 0 6 0 5 0 0 0 THIS REPORT IS SVSMITTED PURSUANT 7 0 THE REQUIREMENTE oF 10 cFR III /chrch onr or metr o/ thr /ollowlnF/ (11 OFF RATING MOOS (Sl 20.402(0) 20A05(c) 50.73(el l2)(lvl 73.71(III (1)(ill)

POWER 20.405( ~ I II I (I) 40M(c)III 50.73(e) (2)(rl 73.71(c)

LEUEL 0 3 5 20.405 (I )(1)(0 I 50.34(c)(2) 50.73(e) (2)(rS) OTHER /Sprclly /n Aoto rct hrtow rnt/ln yreL NFIC Form 20.405 41 40.73(e l(2) (I) 50.73(e) (2)(r(II)(A) 3FFA/

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20.404(e I (1)(vl 50.73(e)(2) (III) 50.73( ~ l(2)(el LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMSER AREA CODE Thomas R. Bradish, Compliance Supervisor (Ext. 6936) 60 39 50 00 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE OESCRI4EO IN THIS REPORT (13)

MANUFAC. REPORTASLE MANUFAC EPORTASL CAUSE SYSTEM COMPONENT CAUSE SYSTEM COMPONENT TURER TO NPRDS TVRER TO NPRDS RV~~ %

SUPPLEMENTAL REPORT EXPECTED (14) MONTH DAY YEAR EXPECTED SVSMISSION DATE (15)

YEs /I/ yN, co plrte ExpfcyED svsM/ss/DIY DATE/ NO AbsTRAGT /Limit to /400 tptcn, /r., rpproeimrtrly httrrn I/nplr./petr typrwnttrn hnrt/ (14)

At approximately 0100 on June 8, 1987, Palo Verde Unit 2 was in Mode 1, POWER OPERATION, at 35 percent power, when it was discovered that four (4) hour samples of the Gaseous Radwaste System had not been taken as required during Gas Stripper operation. Technical Specifications require sampling of the Gaseous Radwaste System either continuously by the Explosive Gas Monitor, or manually every four hours during degassing operations and daily during system operation, when automatic sampling of the Gaseous Radwaste System is not available.

Degassing operaeions which is used to remove dissolved gases from the Reactor Coolant System, had been in progress since 1725 on June 7, 1987. The four hour sample was not taken until 0140, June 8, 1987.

The root cause of this event was improper communications between Operations and Chemistry personnel on the status of the gas stripper. The operators on-shift assumed that the Chemistry technicians were performing the necessary samples.

As a corrective action, a night order was initiated requiring a chemistry department representative to initial the control room log entry for any change in gas stripp'er seatus.

Similar events occurred in Unit 1 on September 13, 1985 and January 11, 1986 and in Unit 2 on July 29, 1986. These events were reported on LERS 85-072-00, 86-005-01, and 86-019-00, respectively.

8707090257 870702 PDR ADOCK 05000529 S PDR NRC totm 300

NRC Perm 3$ 5A l94>3)

US. NUCLEAR REOULATORY COMMISSION LICENSEE EVENT REPORT {LER) TEXT CONTINUATION APPROVEO OMS NO.3150M>05 EXPIRES. S/31/SS PACILITY NAME 11> POCKET NUMSER IEI LER NUMSER ISI PAPE 131 55ovENT/AL AIVI5ION NVM IR rrvMPIA Palo Verde Unit2 o s o o o 52 987 0 0 2 oF 0 TEXT /I/ more aoece

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At approximately 0100 on June 8, 1987, Palo Verde Unit 2 was in Mode 1, POWER OPERATION at 35 percent power, when i.t was discovered by a control room operator (utility-licensed) that four (4) hour samples of the Gaseous Radwaste System (WE) had not been taken as required during Gas Stripper operation. The operation of the gas stripper results in the removal of dissolved gases from the reactor coolant, and directs the gasses to the Waste Gas Decay Tanks (WE)'f the Gaseous Radwaste System.

The Gaseous Radwaste System is required to be monitored for buildup of an explosive gas mixture during operation of the Gaseous Radwaste System. This is done through the use of Hydrogen/Oxygen monitors which measure the relative concentrations of these gasses. The monitors are currently inoperable pending completion of a design change to alleviate moisture buildup in the sample lines which affects the monitoring capabilities.

With the Hydrogen/Oxygen monitors inoperable, Technical Specification 3.3.3.8 ACTION 39 allows continued operation of the Gaseous Radwaste System provided grab samples are taken and analyzed every four hours during degassing operations, and daily during system operation.

At approximately 1550 on June 5, 1987 gas stripper operation was initiated which started degassing of the Reactor Coolant System. Chemistry personnel (utility non-licensed) signed the Control Room log at that time to acknowledge the requirement to take grab samples every 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> during degassing operations.

During the morning of June 7, 1987 control room operators were involved in a plant startup. At approximately 1000 the Gas Stripper was placed in the standby (or recirculation) mode to allow performance of the Reactor Coolant System (RCS)(AB) Water Inventory Balance. Chemistry personnel stopped taking grab samples at this time. At 1405, after the completion of the water inventory balance, the Gas Stripper was again placed on line processing Equipment Drain Tank (EDT)(SE) water which was being pumped to the Holdup Tank (HUT)(CB). The EDT pumpdown was completed at 1725, on June 7, 1987, at which time degassing operations recommenced when RCS letdown flow was routed through the Gas Stripper to the Volume Control Tank (VCT)(WK). Although degassing operations had restarted at 1725, June 7, 1987, no further grab samples were taken until 0140 on June 8, 1987. Four hour sampling should have commenced at 2125, June 7, 1987.

At 0100 a control room operator (utility-licensed) notified chemistry that they were shifting gas stripper operations. At this time, the error was identified since chemistry personnel were unaware that gas stripping operations had been in progress. As an immediate corrective action, a chemistry technician collected the sample at 0140. Results of the sample indicated that the concentration of the gases were within specification during the entire event.

NAC /0AM 555A 19 9>I

NRC Foun 344A U.E. NUCLEAR REOULATDRY CDMMIEEIDN 19 $3 I LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVED OMS ND 31 SOLI 04 EXPIRES: 9/31/99 PACILITY NAME 111 DOCKET NUMEER I3)

LER NUMEER IEI PACE I3l jc::. 44OVENT/AL gp< AEVOKIN NVM 4A mix NVM444 Palo Verde Unit 2 0 5 0 0 0 5 2 9 87 01 7 00. 0 3 0 TEXT ///mo/4 44444 /4 oo//PP/f, voo I///io'on@ HRC Po/m 3/IEAO/1131 The root cause" of this event has been determined to be improper communcation between Chemistry personnel and the Control Room operators as to the status of the Gas Stripper. The Chemistry technician believed that he had communicated to the Control Room that he had stopped his sampling and would resume sampling when directed to do so by the Control Room. The Operators believed that they had not informed Chemistry that the Gas Stripper was to be shut down or that sampling was no longer necessary. The duration of the event was approximately 4 hours and 15 minutes.

This event did not affect the safe operation of the facility since samples after the event showed that the concentration of gases did not approach combustible limits. Therefore, there was no threat to the health and safety of the public.

There were no component, system, or safety train failures, other than the inoperable portion of the automated Hydrogen/Oxygen monitors that contributed to the event. There were no unusual characteristics of the work location that contributed to the event.

As corrective action to prevent recurrence, a night order has been implemented in Units 1 and 2 requiring Chemistry personnel to sign the Control Room Log

. whenever Gas Stripper operations are started or stopped (and the Explosive Gas

. Monitor is out of service). Additionally, this requirement will be added to the Operating Department Guideline (ODG) for Gas Stripper Operation which is applicable to all three units. As discussed below, a procedure change was implemented as a result of a previous event to require notification of chemistry personnel when gas stripper operation was started. The procedure was followed in this event however, the procedure change did not address instances where the system was in operation and the gas stripper was placed in a standby mode and then restarted.

Similar events occurred in Unit 1 on September 13, 1985 and January ll, 1986 and July 29, 1986 in Unit 2. These events were reported in LERs 85-072-00, 86-005-01, and 86-019-00, respectively.

The corrective action taken in the previous events resulted in a procedure change and the requirement for concurrent sign off by Chemistry personnel acknowledging initiation of gas stripper operation. This corrective action has proven effective since the last reported missed sample was July 29, 1986.

However, in this event, the interruption of degassing operations and placement of the gas stripper in a standby mode to perform the RCS water inventory balance startup created an unusual circumstance not foreseen when the procedure change was implemented.

Long term corrective action is to return the automatic gas monitoring system to operation. Preoperational testing was successfully completed on June 5, 1987.

The system is expected to be returned to service by July 31, 1987.

VAC 4ORV 3444 I9 43i

Arizona Nuclear Power Project P.O. BOX 52034 ~ PHOENIX, ARIZONA85072-2034 192-00242-JGH/TRB/ESP July 2, 1987 Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Unit 2 Docket No. 50-529

'icensee Event Report 87-017-00 File: 87-020-404

Dear Sirs:

Attached please find Licensee Event Report (LER) No. 87-017-00 prepared and submitted pursuant to 10CFR 50.73. In accordance with 10CFR 50.73(d), we are herewith forwarding a copy of the LER to the Regional Administrator of the Region V Office.

If you have any questions,'lease contact T. R. Bradish, Compliance Supervisor at (602) 393-5000, Ext. 6936.

Very truly yours, G. ay es Vice President Nuclear Production JGH/ESP/cld Attachment cc: O. M. DeMichele (all w/a)

E. E. Van Brunt, Jr.

J. B. Martin R. P. Zimmerman R. C. Sorenson E. A. Licitra A. C. Gehr INPO Records Center