ML17300A762

Special Rept 2-SR-87-004:on 870305,low & High Range Noble Gas Activity Monitors Inoperable for More than 72 H.Caused by Failure of Flow Control Valve Coupling to Perform Intended Function.Coupling Replaced

ML17300A762
Person / Time
Site:	Palo Verde
Issue date:	03/30/1987
From:	Haynes J ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
192-00169-JGH-T, 192-169-JGH-T, 2-SR-87-004, 2-SR-87-4, NUDOCS 8704210333
Download: ML17300A762 (4)

Text

REGULATOR i FORMATION DISTRIBUTION S M (RIDS)

ACCESSION NBR: 8704210333 DOC. DATE: 87/03/30 NOTARIZED: NO DOCKET 0

'ACIL:STN-50-529 AUTH. NAME Palo Vev de Nuclear Stationi Unit 2> Av izona Pub AUTHOR AFFILIATION li 05000529 HAYNES> J. G. Av i zona Nucleav'ou;er Prospect (formerly Av i zona Public Serv I

R E C P. NAME RECIPIENT AFFILIATION MARTIN> J. B. OFFice oP Inspection 5 Enfov cement> Div'ectov (62020}-8704}1

SUBJECT:

Special v ept 2-sr-87-004: on 870305> lou 5 high v ange noble gas activity monitov s inoperable For mov e than 72 h. Caused bg failure of floe contv ol valve coupling to pev form intended function. Coup ling replaced.

DISTRIBUTION CODE: IEO}D COPIES RECEIVED: LTR ENCL SIZE:

TITLE: General (50 Dk t)-Insp Rept/Notice o{'iolation Respon se NOTES: Standav'dized plant. M. Davis NRR: }Cg. 05000529 REC IP IENT COPIES RECIPIENT COP IES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 0 PD5 PD 1 LICITRAiE 1 DAVIS' 1 INTERNAL: ACRS 2 2 AEOD 1 1 DEDRQ ENF LIEBERMAN } 1 NRR ROE !'!. L NRR/ADT 1 1 NRR/DOEA DIR 1 NRR/DREP/EPB }

NRR/DREP/RPB 2 2 t'!RR/DRIS DIR 1 1 P .S LRB } OGC/HDS} 1 E FIL 1 RES SPEISi T 1 1 RG 5 FILE 01 1 EXTERNAL: LPDR 1 1 NRC PDR 1 1 NSIC 1 1 NOTES:

TOTAL NUMBER OF COPIES REQUIRED LT1R 25 ENCL 24

Arizona Nucfear Power Project P.o. BOX 52034 ~ PHOENIX. ARIZONA85072-2034

'I 192-00169-JGH/TRB/ESP March 30, 1987 Mr. John B. Martin, gegional Administrator Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Region V 1450 Maria Lane, Suite 210 Walnut Creek, CA 94596-5368

Subject:

Palo Verde Nuclear Generating Station Unit 2 Docket No. STN 50-529 (License NPF-51)

Special Report 2-SR-87-004 File: 87-020-404

Dear Mr. Martin:

Attached please find a Special Report 2-SR-87-004 prepared and submitted pursuant to Technical Specifications 3.3.3.9 and 6.9.2. This report discusses Radiation Monitors Inoperable for greater than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

lf you have any questions, please contact Tom Bradish, Compliance Supervisor at (602) 932-5300, Ext. 6936.

Very tru yours, J. G. Ha nes Vice President Nuclear Production JGH/TRB/ESP/cld Attachment cc: 0. M. DeMichele (all w/a)

E. E. Van Brunt, Jr.

R. P. Zimmerman R. C. Sorenson E. A. Licitra A. C. Gehr 0 rn INFO Records Center R(

C3 3704210333 870330 PDR ADOCK 05000529 8 PDR ~g g/t'

PALO VERDE NUCLEAR GENERATING STATION RADIATION MONITORS INOPERABLE FOR GREATER THAN 72 HOURS License No. NPF-51 Docket No. STN 50-529 Special Report No. 2-SR-87-004 This Special Report is being submitted pursuant to Technical Specification (T.S.)

3.3.3.9 ACTION 42b and T.S. 6.9.2 to report an event in which low and hi range noble gas activity monitors (RU-141 and RU-142) were 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 monitors were initially declared inoperable on March 5, 1987 at 0101 while the unit was in Mode 5 (COLD SHUTDOWN) due to continuous low flow alarms. At 0607 on March 5, 1987 the unit entered Mode 4 (HOT STANDBY) and the monitors are required by Technical Specifications to be operable. The 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> limit for returning the monitors to operability was exceeded at approximately 0607 MST on March 8, 1987.

Pursuant to T.S. 3.3.3.9 ACTION 42a the Preplanne'd Alternate Sampling Program was initiated to monitor the plant ventilation system.

Troubleshooting conducted under an authorized work document revealed that the flow control valve coupling was not performing its intended function. The coupling device transmits rotational movement of the motor to the valve stem. It also has a limit switch arm that through threading actuates the limit switches. This threaded portion

'became galled (thread stripped) and the limit switch arm would not move preventing valve movement. As immediate corrective action, the coupling was replaced. A root cause of failure request has been initiated and will address the potential of similar cases in other monitors encompassing all three units.

To return RU-141 and RU-142 to service,,Quarterly Functional Test (36ST-9SQ04) was successfully performed. The monitor was declared operable at 1355 on March 10, 1987.

The monitor was unavailable for 5 days, 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> and 48 minutes.