ML17305A273

LER 89-005-01:on 890628,sample Flow Rate for Vent low-range Radioactive Effluent Monitor Below Low Flow Alarm Setpoint, Rendering Monitor Inoperable.Caused by Loose Set Screw on Coupling.Set Screw on Sample Pump tightened.W/890928 Ltr

ML17305A273
Person / Time
Site:	Palo Verde
Issue date:	09/28/1989
From:	James M. Levine, Shriver T ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
192-00529-JML-T, 192-529-JML-T, LER-89-005-01, LER-89-5-1, NUDOCS 8910110146
Download: ML17305A273 (16)

Text

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ACCESSION NBR:8910110146 DOC.DATE:

FACIL:STN-50-530 Palo Verde Nuclear Station, 89/09/28 NOTARIZED: NO Unit 3, Arizona Publi 05000530 DOCKET I AUTH. NAME AUTHOR AFFILIATION SHRIVER,T.D. ,Arizona Public Service Co. (formerly Arizona Nuclear Power LEVINE,J.M. Arizona Public'ervice Co. (formerly Arizona Nuclear Power RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 89-005-01:on 890628,plant vent low range effluent I. I monitor alarm not properly investigated.

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Arizona Public Service Company PALO VERDE NUCLEAR GENERATING STATION P O. 8OX 52034 ~ PHOENIX. ARIZONA 85072-2034 192-00529-JML/TDS/DAJ September 28, 1989 U. S. Nuclear Regulatory Commission NRC Document Control Desk Washington, D.C. 20555

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Unit 3 Docket No. STN 50-530 (License NPF-41)

Licensee Event Report 89-005-01 File: 89-020-404 Attached please find Supplement Number 1 to Licensee Event Report (LER) No.

89-005-00 prepared and submitted pursuant to the requirements of .10CFR 50.73.

In accordance with 10CFR 50.73(d), we are herewith forwarding a copy of this report to the Regional Administrator of the Region V Office.

If you have any questions, please contact T'. '0: Shriver, Compliance Manager at (602) 393-2521.

Very truly yours,

. H. Levine

'ice President Nuclear Production JGH/TOS/DAJ/kj Attachment CC: W. F. Conway (all w/a)

E. E. Van Brunt, Jr.

J. B. Hartin T,. J. Polich H'. J. Davis A. C. Gehr INPO Records Center 89i0iioi46 PDR 8905'28 ADOCK 05000530 PDC

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NRC FORM 355 US. NUCLEAR REGULATORY COMMISS APPROVEO OMB NO. 31504))04 P9) EXPIRES: 4I30I92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REGUESTt 500 HRS. FORWARD LICENSEE EVENT REPORT (LER) COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENT BRANCH (F530), V.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO THE PAPERWORK REDUCTION PROJECT 13(504104). OFFICE OF MANAGEMENTAND BUDGET. WASHINGTON, DC 20503.

FACILITY NAMK (I) DOCKET NUMBER (2) PA TITLE (4l Palo Verde Uni t 3 o 5 o o o 53 p>oF06 Plant Vent Low Range Effluent Monitor Alarm Not Properly Investigated KVENT DATE ISI LER NUMBER (Sl AFPORT DATE (7) OTHER FACILITIES INVOLVED (SI MONTH OAY YEAR YEAR stQUNNTIAL:%>i, ttsvtsKnt MONTH OAY YEAR FACILITYNAMES DOCKFT NUMBER(s)

NVMSEII (kC NVMSEA N/A 0 5 0 0 0 0 6 2 89 89 0 0 5 0 1 0 9 2 8 8 9 N/A 0 5 0 0 0 THIS REPORT IS SUBMITTED PURSUANT T0 THE RLDUIAEMKNTBoF 10 cFR (I: IciNck one ot mort of tnr folfornndl (11)

OPKRATHIG MODE IS) 20A02(b) 20.405(cl 50.734)(2) (It) 73.71(N)

POWER 20AOS(el(1)(B SOW Ic) III 50.734 I (2)(e) 73.7)(c)

LEVEL le)(2) p p p 20AOS(el(1)(NI SOM(c)(2) 50.73(a l(2) (rNI OTHER ISprcify in Apttrect Oriow rmf In Trit, HRC Form 20.405(al(1) (Ni) 50.73(e)l2) (I) 50.734) l2)(rNII(A) 3EEAI 20AOS(e I (I) I Iel 50.73(e) l2) IN) 50.73(el(2) (riN)IS)

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LICENSEE CONTACT FOA THIS LER (12I NAME TELEPHONE NUMBER AREA COOS Timothy D. Shriver, Compliance Manager 60 23 93 -2 52 1 COMPLFTK ONK LINE FOR EACH COMPONENT FAILURE DESCRIBEO IN THIS REPORT (13)

CAUSE SYSTEM COMPONENT MANUFAC. EPOATABLE: MANUFAC. EPOATABLE TUAER TO NPADS SYSTEM COMPONENT TVREA TO NPADS N>p!... n.~.

SVPPLKMKNTAL REPORT EXPECTED (14) MONTH DAY YEAA EXPECTFD SUBMISSION DATE D5)

YKS Iifyrt. compirtr EXPECTED SVSMISSIOH OATEI X NO AssTRAcT ILimit to Icdd tpacrt, I r., rpptoelmetrly fifteen tfnrirrprcr typrwrtttrn Iinrtf 0 sl At approximately 1115 MST on June 28, 1989, Palo Verde Unit 3 was in a refueling outage with the core off-loaded to the Spent Fuel Pool when a Unit 3 Technician discovered that the sample flow rate for the Plant Vent Low Range Radioactive Effluent Monitor (RU-143) was below the low flow alarm setpoint rendering the monitor inoperable. Investigation determined that the low flow alarm had occurred at approximately 0531 MST on June 28, 1989; however, the alarm was not properly investigated. This resulted in not meeting ACTION requirements 36 and 40 of Technical Specification (T.S.) 3.3.3.8.

The cause of the low flow condition on RU-143 was a loose set screw on the coupling between the monitor's sample pump and its drive motor. The cause of the improper follow-up action for the low flow alarm was inadequate communication between control room personnel and personnel responsible for investigating the cause of -th(; alarm condition.

As corrective action, the Pre-Planned Alternate Sampling Program was implemented by 1150 MST on June 28, 1989, fulfilling T.S. 3.3.3.8 ACTION requirements. The loose set screw was tightened and RU-143 was returned to service at approximately 1558 MST on June 24, 1989.

A previous similar event was reported in Unit 1 LER 528/85-067.

NRC Form 355 (559)

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NRC FOAM 3SSA ILS. NUCLEAR REGULATOAY COMMISSION (5 SS) APPROVED OMS NO. 3I50010i EXPI RESI 8/30/02 ESTIMATED SURDEN PER AESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT ILER) INFORMATION COLLECTION AEQUESTI 503) HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION ANO REPORTS MANAGEMENT SRANCH IP430), U.S. NUCLEAR REGULATOAY COMMISSION, WASHINGTON, DC 20555, ANO TO THE PAPERWORK REDUCTION PROJECT (3150410i). OFFICE OF MANAGEMENTAND BUDGET,WASHINGTON, DC 20503.

FACILITYNAME (l) DOCKET NUMSER (2) LER NUMBER (5) PAGE (3I SEQUENTIAL jan@

IISVISION NUMSSII NUMSSII Palo Verde Unit 3 o 6 o o o 53 089 0 05 0 1 0 2 OF 0 6 TECT ///more spece /8 rrrFr/rer/ eee eAN/Oone///RC %%dmr 35SA'8/ (lt)

I. DESCRIPTION OF WHAT OCCURRED:

A. Initial Conditions:

At approximately 0631 HST on June 28, 1989, Palo Verde Unit 3 was in a refueling outage with the core (AC) off-loaded to the Spent Fuel Pool (ND).

B. Reportable Event Description (Including Dates and Approximate Times of Major Occurrences):

Event Classification: Condition prohibited by the plant's Technical Specifications.

At approximately 1115 HST on June 28, 1989, during the performance of Radiation Monitoring System (IL) daily surveillance testing, a Unit 3 Chemistry Technician (utility, non-licensed) discovered that the indicated sample flow rate for the Plant Vent Low Range Radioactive Effluent Monitor (RU-143)(VL)(RI)(IL). was below the alarm setpoint. Investigation determined that a low flow alarm had occurred at approximately 0531. HST on June 28, 1989 and acknowledged in the Control Room; however, the alarm was not properly investigated. Since an actual low flow condition existed, the monitor had been inoperable since approximatey 0531 HST and ACTION requirements 36 and 40 of Technical Specification 3.3.3.8 were not met within the allowable interval.

With RU-143 inoperable, Technical Specification 3.3.3.8 ACTIONS 36 and 40 require that effluent releases via the Plant Vent may continue provided the flow rate is estimated at least once per four (4) hours and auxiliary sampling equipment is installed within one hour after the monitor is declared inoperable (i.e., implement Pre-Planned Alternate Sampling Program).

Prior to event discovery, at approximately 0530 MST on June 28, 1989, Unit 3 Operations personnel (utility, licensed and non-licensed) were in the process of preparing for a planned maintenance outage on the Train RAH Class lE electrical power system (EB). During the process, several alarms were received as components were de-energized. At approximately the same time (0531 HST, per computer logs) the low flow alarm for RU-143 occurred.

Control Room personnel (utility, licensed) acknowledged the low flow alarm and contacted Radiation Protection personnel (utility, non-licensed) per procedural requirements. No further followup action was taken. Pursuant to Technical Specification 3.3.3.8 ACTIONS 36, 37, and 40, the Pre-Planned Alternate Sampling Program should have been implemented by 0631 MST on June 28, 1989.

NRC Fomr 3SSA (SSS)

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NRC FORM 35BA (LS. NUCLEAR REGULATORY COMMISSION (SBB) APPROVED OMB NO 3(500104 EXPIRES: O)30/02 ESTIMATED BURDEN PFR RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT (LER) INFORMATION-COLLECTION REQUEST( 500 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENT BRANCH (P430), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, OC 20555, ANO TO THE PAPERWORK REDUCTION PRO)ECT (31504(OO). OFFICE OF MANAGEMENTANO BUDGET, WASHINGTON. DC 20503.

FACILITY NAME (11 DOCKET NUMBER (2) LER NUMBER (5) PAGE (3)

YEAR Iso

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sEGUSNTIAL NUMSSR REVISION NUMBER Palo Verde Unit 3 o s o o o 53 089 0 05 0 1 03o"0 6 TEXT IJF more <<>>ce 1s)rrr)rNf. 1>>o adWabnal NRC Form 355ABI ( 17)

At approximately 1115 HST on June 28, 1989, Unit 3 Chemistry personnel were performing daily Radiation Monitoring System surveillance testing and noted the low flow condition for RU-143.

Control Room personnel were contacted and the applicable ACTION requirements of Specification 3.3.3.8 were implemented by approximately 1150 HST on June 28, 1989 in accordance with the Pre-Planned Alternate Sampling Program.

C. Status of structures, systems, or components that were inoperable at the start of the event that contributed to the event:

Except as described in Section I.B, no other structures, systems or components were inoperable at the start of the event which contributed to the event.

0. Cause of each component or system failure, if known:

Not'pplicable - no component or system failures were involved.

E. Failure known:

mode, mechanism, and effect of each failed component, if Not applicable - no component failures were involved.

F. for failures of components with multiple functions, list of systems or secondary functions that were also affected:

Not applicable - no component failures were involved.

G. For failures that rendered a train of a safety system inoperable, estimated time elapsed from the discovery of the failure until the train was returned to service:

Not applicable - no component failures were involved. However, the Plant Vent Low Range Radioactive Effluent Monitor (RU-143) became inoperable at approximately 0531 HST on June 28, 1989, due to the low flow conditions. Following appropriate repairs, RU-143 was returned to service at approximately 1558 NST on June 29, 1989.

RU-143 was inoperable for approximately'4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> and 27. minutes; H. Method of discovery of each component or system failure or procedural error:

There were no component or system failures. The procedural errors discussed in Section I. I were discovered during the post event investigation conducted in accordance, with the PVNGS Incident Investigation, Process.

NRC Form 355A (BBO)

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NRC FORM SSSA (559)

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ILLNUCLEAR REGULATORY COMMISSION APPROV ED 0 M 5 NO. 31500104 EXPIRES: S/30/92 ESTIMATED BURDEN PEA RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT ILER) INFORMATION COLLECTION REQUEST: 50A) HAS. FORWARD COMMENTS AEGARDINC BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPOATS MANACEMENT BRANCH (P430), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO THE PAPERWOAK REDUCTION PROJECT (3)504)104), OFFICE OF MANAGEMENTANO BUDGET,WASHINGTON, OC 20503.

fACILITYNAME ('I) DOCKET NUMBER (2) LER NUMBER (Sl PACE 13)

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'Qw. SEQUENTIAL REVISION NVMSSR NVMSSR Palo Verde Unit 3 o s o o o 53 08 9 005 01 04 o"0 6 TEXT //l'IIXPP SPSCP /S neireC VSP 5/S/PRs/I/RC FORR 35//AS/ (17)

Cause of Event:

The cause of the low flow on the Plant Vent Low Range Monitor (RU-143) was a loose set screw on the coupl:ing between the monitor's air sample pump (P) and its drive motor (HO). The loose set screw resulted in a loose coupling and the motor would not adequately turn the sample pump.

The cause of the inadequate followup for the RU-143 low flow alarm was that the appropriate on-shift personnel (utility, non-licensed) responsible for investigating problems occurring with the gaseous effluent monitors were not contacted by control room personnel (utility, licensed) and instructed to investigate the cause of the alarm. Responsibility for investigating Radiation Honitoring System (RHS)(IL) problems is shared by unit Chemistry and Radiation Protection (RP) Departments, depending upon the type of monitor involved. Chemistry is responsible for the operation of gaseous effluent radiation monitors which includes RU-143. In response to the alarm on RU-143, which occurred in the control room, control room personnel contacted an individual in the RP area. However, this individual was"n'of responsible"for effluent monitors,;

therefore, proper investigation of the alarm condition was not performed.

Also contributing to this event, PVNGS alarm response procedures for RHS alarms provide instruction that control room personnel are to contact RP for all RHS alarms. Therefore, the procedures utilized by control room personnel in response to the RU-143 alarm were incorrect in that .instruction should'ave been provided to contact Chemistry effluents personnel.

There were no unusual characteristics of the work location which contributed to this event.

Safety System Response:

There were no automatic or manual safety system responses and none were necessary.

K. Failed Component Information:

Not applicable - no component failures were involved.

II. ASSESSHENT OF THE SAFETY CONSE(UENCES AND IHPLICATIONS OF THIS EVENT:

Plant Vent gaseous effluent instrumentation is provided to monitor for radioactive materials released during normal plant operations or NRC form SSSA (559)

Il NRC FORMSSSA ILLNUCLEAR REGULATORY COMMISSION APPROVEO OMS NO. 31504104 1889)

E xpIR Es: SI30/92 ESTIMATEO'BUROEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT ILER) INFORMATION COLLECTION REOUEST: 500 HRS. FORWARO COMMENTS REGAROING BUROEN ESTIMATE TO THE RECOROS TEXT CONTINUATION ANO REPORTS MANAGEMENT BRANCH IP830), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, OC 20555, ANO TO THE PAPERWORK REOUCTION PROJECT I3150010S). OFFICE OF MANAGEMENTANO BUOGET, WASHINGTON, DC 20503.

FACILITY NAME Il) COCKET NUMBER I2) LER NUMBER (51 PAGE (3) vip SEQUENTIAL REVISION NVMSSR NVMSSR Palo Verde Unit 3 o s o o o 5 30 89 0 0 5 01 0 5 QF 0 6 TEXT (Ilmore TJNoe ls rerFdred. u Je edrddorNJ FVRC Form 35SABI 117) postulated accident conditions. There are two separate radioactive gaseous effluent monitoring channels for the Plant Vent: the low range effluent monitor (RU-143) for normal plant radioactive gaseous effluents and the high range effluent monitor (RU-144) for post-accident plant radioactive gaseous effluents. The low range monitor continuously operates until the concentration of radioactivity in the effluent is above a pre-determined setpoint. At this setpoint, sample flow is re-directed to the high range monitor and the low range monitor is secured.

The Plant Vent low and high range monitors measure particulate and gaseous gross beta activity as well as volatile I-131. The particulate beta channel uses a beta scintillator to count deposited activity on a fixed filter paper. A second beta scintillator counts the filtered gas for gaseous beta activity. The I-131 channel uses a single channel analyzer to discriminate and count volatile I-131 decay photon-.generated electrical pulses. The monitors sample isokinetically per ANSI

13. 1-1969. This is, done through receiving either a manual or automatic input of Plant Vent flow rate to a microcomputer (CPU) which in turn sets the correct radiation monitor sample flow rate. With the incorrect sample flow rate described'n Sect%on I.8, the Plant Vent effluent was not being sampled isokinetically by the low range monitor (RU-143).

At, the time of the event, Unit 3 was shut down during a refueling outage with the core off-loaded to the spent fuel pool. No fuel movement was in progress. Radioactive effluent levels before and after the period of monitor. inoperability were normal. There were no accidents or plant activities in progress which would have resulted in abnormal effluent radioactivity levels during the period of monitor inoperability.

Therefore, there were no safety consequences or implications resulting from this event.

I I I. CORRECTIVE ACTIONS:

A. Immediate:

The Pre-Planned Alternate Sampling Program was implemented to comply with the ACTION requirements of Technical Specification 3.3.3.8.

The set screw on RU-143's sample pump was tightened and the monitor was returned to service as described in Section I.C.

B. Action to Prevent Recurrence:

The Unit 1, 2, and 3 Radiation Monitoring System (RMS) alarm response procedures will be revised to require that the proper NRC Fo 3SSA 1889)

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NACFORMSSSA ILS. NUCLEAR REGULATORY COMMISSION (S4(R' APPAOVED OMB NO. 3(500(04 EXPIRES:

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~ ~ BURDEN PER RESPONSE TO (X)MPLY WTH THIS LICENSEE EVENT REPORT (LERI INFORMATION COLLECTION REQUEST: 500 HAS. FOAWARD COMMENTS REGARDING BUADEN FSTIMATE TO THE RECORDS TEXT CONTINUATION ANO REPORTS MANAGEMENT BRANCH (P430). U.S. NUCLEAR AEGULATOAY COMMISSION, WASHINGTON, OC 20555, AND TO THE PAPERWORK AEDUCTION PROJECT (3)504(04), OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON. OC 20503.

ACILITYNAME ( 1 ) DOCKET NUMBER l2) LER NUMBEA (5) PAGE (3) gjIj SSQVCNZIAL NUMBER REVISION NVMSSR Palo Verde Unit 3 o s o o o 5 3 0 8 9 0 0 501 06 OF 0 6 (IP more Speoe ls erFekeeL oee aAWonel HRC Form 3554'4) ((7) personel be contacted for investigating problems occurring with the monitors. The procedure revisions are expected to be completed by November 1, 1989. Also, this event has been reviewed and discussed with Unit 1, 2, and 3 Chemistry personnel to ensure that they are aware of the importance of prompt RHS alarm response.

The loose set screw has not been identified as a recurring problem at PVNGS. In accordance with an APS program, Engineering reviews work order trends. If the loose set screw were identified as a recurring occurrence, additional corrective action would be developed. Additionally, the low flow alarm provides indication that a problem has occurred and enables prompt corrective action and/or compensatory measures.

IV. PREVIOUS SIMILAR EVENTS:

A previous similar event was reported in Unit 1 LER 528/85-067. A low flow alarm for the Plant Vent low range monitor (RU-143) was received in the Control Room and acknowledged by Control Room personnel (utility, licensed). However, Radiation Protection personnel were not notified contrary to procedural requirementf. Previous corrective actions consisted of counseling control room personnel about the necessity to properly acknowledge and respond to alarms.

As discussed in Section I. I of this LER (530/89-005), control room personnel acknowledged the alarm and contacted an individual in the RP area. Furthermore, the current procedures were not correct in providing instruction for contacting the proper department to have the alarm investigated. Since the corrective actions taken for the previous event (530/85-067) addressed the problem of not contacting an individual to investigate the alarm, the corrective actions would not have prevented recurrence of, this event. Additionally, this is the first recurrence of this type of event in approximately three (3) years and the first occurrence of this problem in Unit 3.

NRC Feem 35BA (5 SS)

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