ML17303A840

LER 88-008-00:on 880212,RCS Leakage Monitor Declared Inoperable Due to Notification of Particulate change-out Excess.Caused by Personnel error.Change-out Periodicity Revised to Once Per 24 h.W/880311 Ltr

ML17303A840
Person / Time
Site:	Palo Verde
Issue date:	03/11/1988
From:	Haynes J, Shriver T ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
LER-88-008, LER-88-8, R92-00352-JGH-T, R92-352-JGH-T, NUDOCS 8803150141
Download: ML17303A840 (15)

Text

' C CELE RATED DIERIBUTION DEMONSTRATION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:8803150141 DOC-DATE-'8/03/11 NOTARIZED: NO DOCKET FACIL:STN-50-528 Palo Verde Nuclear Station, Unit 1, Arizona Publi 05000528 AUTH. NAME AUTHOR AFFILIATION SHRIVER,T.D. Arizona Nuclear Power Project (formerly Arizona Public Serv HAYNES,J.G. Arizona Nuclear Power Project (formerly Arizona Public Serv, RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

ler 88-008-00:on 880212,reactor coolant sys leakage monitor inoperable due to personnel error.

W/8 ltr.

DISTRIBUTION CODE: IE22D COPIES RECEIVED: LTR i ENCL Letc.SIZE:

TITLE: 50.73 Licensee Event Report (LER), Incident Rpt, . D NOTES:Standardized plant. 05000528 8 RECIPIENT COPIES COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL h PD5 LA 1 1 PD5 PD 1 1 LICITRA,E 1 1 DAVIS,M 1 1 INTERNAL: ACRS MICHELSON AEOD/DOA 1

1 1

1 1'ECIPIENT ACRS MOELLER AEOD/DSP/NAS 2

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1 AEOD/DSP/ROAB 2 2 AEOD/ DS P/TPAB 1 1 ARM/DCTS/DAB 1 1 DEDRO 1 -

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, NRR/DEST/ADS7E4 1 0 NRR/DEST/CEB8H7 1 1 NRR/DEST/ESB 8D 1 1 NRR/DEST/ICSB7A 1 1 NRR/DEST/MEB9H3 1 1 NRR/DEST/MTB 9H 1 1 NRR/DEST/PSB8D1 1 1 NRR/DEST/RSB 8E 1 1 NRR/DEST/SGB 8D 1 1 NRR/DLPQ/HFB10D 1 1 NRR/DLPQ/QAB10A 1 1 NRR/DOEA/EAB11E 1 1 NRR/DREP/RABlOA 1 1 NRR/DREP/RPB10A 2 2 N DRY/SIB9A1 1 1 NRR/PMAS/ILRB12 1 1 EG 02 1 1 RES TELFORD,J 1 1 RES/DE/EIB 1 1 RES/DRPS DIR 1 1 RGN5 FILE 01 1 1 EXTERNAL: EG&G GROH,M 5 5 FORD BLDG HOY,A 1 1 H ST LOBBY WARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC HARRIS,J 1 1 NSIC MAYS,G 1 1 NOTES: 1 S

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TOTAL NUMBER OF COPIES REQUIRED: LTTR 48 ENCL 47

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LICENSEE EVENT REPORT ILERI EXPIRES: 5/31/55 FACILITY NAME 11) DOCKET NUMBER 12) PA E Palo Verde Unit 1 p s p p p 5 2 8 i oFD TITLE I ~ I Reactor Coolant System Leakage Monitor Inoperable Due to Personnel Error EVENT DATE 15l LER NUMBER ISI REPORT DATE (7) O'THER FACILITIES INVOLVED ( ~ I MONTH DAY YEAR YEAR "$(c SEQVEtertIL R E VISIOrt SS) NUMSER MONTH OAY YEAR FACILITYNAMES DOCKE'1 NUMBER(SI R UM 5 E R Palo Verde Unit 2 o s o o o529 0 2 1 2 8 8 8 8 0 0 8 0 0 03 11 8 8 Palo Verde Unit 3 p 5 p p p 5 3 0 THIS REPORT IS SUBMITTED PURSUANT T 0 THE REOUIREMENTS OF 10 CF R ('I: ICnrce one ot morr of tnr foiiowinf) (11)

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MODE ( ~ I 20A02(b) 20.e05(cl 60.73(el(2) lirl 73.71PFI POWER 20.C05 (~ Ill)(i) 50.35(cl(1) 50.734)(2)lvl 13.7((cl LEYEL 0 0 0 20.405( ~ ) 50.35(cl(2) 50.73(e I I 2) lviiI O'THER (Specify in Abttfrct below entf in Test, ffRC Form 20.405(vill))till 50.7 3(e I (2) Ill 50.73(el(2)(rill l)AI 36SAI 20A05 Ie) III (iv) 50.73le)(2)(E) 60.73(el(2)(rill IIBI Special Report

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NAME TELEPHONE NUMBER AREA CODE Timothy D. Shriver, Compliance Manager 60 23 93 -2 52 1 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COMPONENT MANUFAC.

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EBL 55 SUPPLEMENTAL REPORT EXPECTED ((1) MONTH DAY YEAR EXPECTED SUBMISSION DATE (15)

YES Iif yrr, compirte EXPECTED $ (iBMISSION DATE) X tto ABSTRACT ILimit to tc00 coecn, I.r., rppfoeimrtrfy hftren tinfle corer typewritten finn) (15)

On February 12, 1988, ANPP was notified by the manufacturer of the PVNGS Units', 2, and 3 containment building radiation monitors (IJ)(MON) that pareiculate filter change-out frequencies in excess of 48 hours could adversely affect the performance of the monitors. ANPP was changing the particulate filters on a weekly basis; therefore, the monitors were declared inoperable in Units 2 and 3 on February 12, 1988. At the time of the notification, RU-1 was not required to be operable in Unit 1. The channels have potentially been periodically inoperable in Unies 1 monitors'articulate and 3 since June 1987 and in Unit 2 since May 1987 when ANPP started changing the filter media on a weekly basis. The monitors are required for RCS leakage deteceion in accordance with Technical Specifications 3.3.3.1 and 3.4.5.1.

The root cause of this event is a cognitive personnel 'error in that ehe original equipment manufacturer (OEM) did not recognize the effect that exeended filter change-out frequencies had on monitor operation.

As immediate corrective action, the filter change-out periodicity was revised to once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> in Units 2 and 3. ANPP is conducting an extensive review and test of the radiation monitor software utilized at PVNGS as described herein.

A previous similar occurrence was reporeed in Unit 1 LER 86-046-00.

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This report also contains information for a special report.

NRC eorm 355 SS03150141 380311 PDR ADOCK 05000528 8 DCD

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LICENSEE EVENT REPORT {LERI TEXT CONTINUATION t U 8, NUCLEAR REOULATORV COMMISSiON APPROVFO OM8 NQ 3188 PIOt EXPIRES: 8/3'I/88 FACILITY NAME (I I OOCKET NUMSER Ill LER NUMSER ISI PAOE ISI YEAR . ~F1. SSOI/SNrt*L REVISION NUM SR NUMSS4 Palo Verde Unit 1 p p p p p 5 2 8 8 8 0 0 8 0 0 0 2 oF 0 6 TEXT llfmotP tPtct/t NRt/itetL tttP ate%'Ons/H/IC FOnn JRSA't/ IITI On, February 12, 1988 ANPP was advised by Kaman Instrumentation Corporation that the containment building radiation monitors'IJ)(MON) particulate channel may not be able to perform its intended function. The affected channel provides indication of potential reactor coolant pressure boundary (AB) leakage. These monitors are utilized in all three (3) units. At the time of the notification, Unit 1 was in Mode 6 (REFUELING), Unit 2 was in Mode 1 (POWER OPERATION) at approximately 98 percent power, and Unit 3 was in Mode 1 at approximately 100 percent power. As immediate corrective action, the Unit Shift Supervisors (utility, licensed) were notified and the channels were declared inoperable at approximately 1505 and 1450 monitors'articulate MST in Units 2 and 3 respectively. RU-1 was not required to be operable in Unit 1 pursuant to Technical Specifications at the time of notification. The appropriate ACTION requirements for Limiting Conditions for Operation (LCO) 3.4.5.1 and 3.3.3.1 were entered and required action taken.

The containment building atmosphere monitors (RU-1) are non-redundant monitors supplied by Kaman Instrumentation Corporation. The function of each monitor is to measure four containment (CTMT) atmosphere parameters that provide indication of reactor coolant pressure boundary (RCPB) leakage. These parameters are: particulate, iodine, and gaseous radioactivity, and dew point temperature. The particulate and gas channels provide two of the three means of detecting increased leakage from the RCPB in accordance with Regulatory Guide 1.45. The third method utilized is the containment sump level and flow monitoring-system (IJ). The dew point and iodine channels provide an additional supportive means of verifying potential leakage.

RU-1 is required to be OPERABLE in accordance with PVNGS Technical Specifications Section 3/4.3.3 and 3/4.4.5 as follows:

a ~ The RCS leakage detection systems shall be operable in modes 1, 2, 3, and 4: (a) containment air particulate monitoring system (RU-1), (b) containment sump level and flow monitoring system, and (c) containment gaseous monitoring system (RU-1). When the required gaseous or particulate radioactivity monitoring system (RU-1) is inoperable, plant operation may continue for 30 days provided grab samples of containment atmosphere are obtained and analyzed once every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The RCS leakage"" is limited to (a) one gpm unidentified leakage and (b) ten gpm identified leakage in modes 1, 2, 3 and 4. The operator determines whether the RCS leakages are within these limits by monitoring the containment atmosphere gaseous and particulate radioactivity at least once every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and by using the other leakage detection methods.

The particulate channel alarm/trip setpoint shall be less than or equal to 2.'3E-6 uCi/cc with a measurement range of 1.0E-9 to 1.0E-4 uCi/cc.

The gaseous channel alarm/trip setpoint shall be less than or equal to 6 'E-2 uCi/cc with a measurement range of 1.0E-6 to 1.0E-1 uCi/cc.

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~ ~ V.S. NUCLEAR REGULATORY COMM/SS/ON LICENSEE EVENT REPORT ILERI TEXT CONTINUATION APPROYEO OMS NO 3/50M/04 EXPIRES: d/31/dd FACILITY NAME 111 DOCKET NUMRER 131 LER NVMSER ldl PACE 131 YEAR SSQVSNTIAL f>IO A t V IS IO Ic

~ IUMSTR I/VM TA Palo Verde Unit'.1 0 5 0 0 0 5 2 8 8 8 0 0 8 00 03 OF 0 6 TEXT /// moro tpoco it n/II/'/OIL vto o4REMO/ R//TC for/II3/NA'tl llll RU-1 calculates the containment particulate activity by utilizing a rate of change algorithm. Containment atmosphere is constantly drawn through RU-1 and passes first through the particulate channel where the particulate is deposited on a paper filter (FLT). A beta scintillation detector (DET) measures gross activity of the deposit. As the activity on the paper increases, the count rate from the detector also increases. The measurement is transmitted to a microprocessor which is pre-programmed with the flowrate and detector efficiency. The algorithm in the microprocessor of RU-1 calculates the slope of the increase in counts per unit time and uses this slope to calculate the containment particulate activity which is utilized for display and alarm functions.

RU-1 was supplied to PVNGS in late 1982. At that time, the particulate monitoring channel was provided with an adjustable automatic particulate filter stepping device. The default stepping time was set at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The stepping interval was variable with no operational limits provided by the OEM. Operational problems were experienced with the automatic stepping device which adversely affected the reliability and availability of the particulate channel. In order to increase the reliability of the monitor, it was determined (in conjunction with the manufacturer) that the filter stepping device could be removed and the filter media manually changed on a periodic basis. It was determined that the removal of the automatic filter stepping device did not impact the calculation of particulate activity as there was no operational difference between adjusting the automatic stepping device to step at weekly intervals or manually changing the filter media weekly. The stepping device was removed and manual change-out of the filter media every week was implemented in May 1987 in Unit 2 and in June 1987 in Units 1 and 3.

It should be noted that RU-1 was not required to be October operable in Unit 3 prior to the initial entry into Mode 4 (HOT SHUTDOWN) on 1, 1987

'n early 1988 ANPP engineering personnel (contractor, non-licensed) were investigating the feasibility of changing the filter media monthly vice weekly. During this investigation, it was identified that extended filter change-out periods could potentially prevent the monitor from responding to radiation increases. The manufacturer was contacted on February 11, 1988 to review ANPP's findings. On February 12, 1988 the manufacturer contacted ANPP and identified that, based upon initial testing results, filter change-out periods in excess of 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> could adversely affect the ability of the particulate channel to provide the required alarm function following increases in containment activity. As immediate corrective action, control room personnel (utility, licensed) were notified and the monitors'. particulate channels declared inoperable on February 12, 1988 at approximately 1505 MST, and 1450 MST in Units 2 and 3 respectively. The approximate elapsed time from the time of discovery until the monitoring systems were returned to service was 1.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> for Unit 2 and 44 hours5.092593e-4 days <br />0.0122 hours <br />7.275132e-5 weeks <br />1.6742e-5 months <br /> for Unit 3. In Units 2 and 3 the filter media was replaced and, after appropriate surveillance testing, the monitors were returned to service at approximately 1627 MST on February 12, 1988, and approximately 1100 MST on February 14, 1988, respectively. In Unit 1, the filter media will be replaced and the monitor returned to service prior to an operational mode for which RU-1 is required. The filter media change-out interval has been reduced to once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> in all three units.

N/IC I 0/IM 3SOA IS dlr

'l NAC FRNR 844A U 4 NUCLEAR AEGULATOAYCOMMISSION 19M I LICENSEE EVENT REPORT ILER) TEXT CONTINUATION APPAOVEO OM8 NO 4 ISO~)OS EXPIRES'IS)i88 FACILITY NAME 11) DOCKET NUMSEA I?I LEA NUMEEA 14) ~ AOE ISI YEAR Cij' SEQVENTIAL '.n REVISION NVM ER:NR NVMSER Palo Verde Unit 1 scen ie sp4MRNE vsp Assiicvel lYAC Foms 888A's) l)T) o s o o o 5 c) 8 8 0 0 8 00 04 OF 0 6 TE)CT IIT ssesp The root cause of this event has been determi'ned to be a cognitive personnel error on the part of the original equipment manufacturer (OEM). The OEM did not provide limitations or precautions for the filter stepping interval which would have forewarned ANPP that extended filter change-out intervals could have impacted the ability of the monitor to operate per design. Additionally, when the automatic stepping device was removed and weekly change-out of the filter media implemented, the OEM did not specify that extended filter change-out intervals would impact the ability of the monitor to operate per design.

As corrective action, the monitors were declared inoperable in Units 2 and 3 and a reduced filter change-out interval implemented. The filter change-out interval will be maintained at less than or equal to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> in all three units until appropriate software modifications are made which would allow extended filter change-out intervals.

There were no unusual characteristics of the work location, which contributed to the event. ANPP procedures were evaluated and determined to be adequate.

There were no automatic or manually initiated safety responses and none were necessary. Other than discussed herein, there were no structures, systems, or components inoperable at the start of the event which contributed to the event. No safety limits were approached and no fission product barriers were challenged. During the period that the filter was being replaced on a weekly basis, the particulate channel of RU-1 was capable of detecting changes in containment activity levels, and thus providing indication of possible RCS leakage. The affect of the extended filter change-out intervals was to reduce particulate channel sensitivity such that it may not have alarmed per design requirements. However, control room personnel (utility, licensed) periodically monitor the activity levels detected by RU-1 and would have perceived unexplained increases in indicated activity as potential RCS leakage.

If the containment atmosphere particulate channel insufficiently indicated increases in containment radiation level as a result of increases in RCS leakage, then either (1) the gaseous channel would have responded to increasing radiation levels and alerted the operators of a potential problem and/or (2) the containment radwaste sump flow alarm would have been initiated in the main control room (NA) alerting control room personnel (utility, licensed) that the containment sump flow had increased by one gpm above normal flow for one hour. If indications occur that a potential leak exists, control room personnel are required to verify the rate and take the appropriate actions.

Based upon the above, there were no safety consequences resulting from this event.

NRC S I) RM )44A I9 8) I

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NRC FPN>> 355A U.5. NUCLEAR REGULATORY COMM>55>ON

>9431 LICENSEE EVENT REPORT {LERI TEXT CONTINUATION APPROVEO OMS NO 3(50 GIC4 EXPIRES: EI311(8 FACILITY NAME (11 OOCKET NUMEER (11 LER NUMEER (5) PAGE I31 YEAR g~i' 55GUENTIAL NUM 58 AEV >5>ON NUM55>l Pa 1 o Verde Uni t 1 0 5 0 0 0 5 P 8 8 0 0 800 05 0 6 TEXT IIP>>>>>>p solace >5 newed, I>5p CCkio'>el HPC F>>m> 3(((A3( (131 Palo Verde Unit 1 LER 86-046-00 reported a previous similar event wherein ANPP personnel (utility, non-licensed) discovered that software conversion constants supplied by Kaman for RU-1 were in error. This resulted in a reduced alarm capability due to the incorrect conversion of activity levels detected (i.e. counts) into displayed activity. This problem was also addressed in Deficiency Evaluation Report (DER) 86-25 and Notice of Violation (NOV) 528/86-28-01.

As a result of the previous software problem, ANPP implemented the following programmatic corrective actions to prevent recurrence:

1. A software control evaluation program for Kaman radiation monitors was initiated.

2. An independent validation and verification on Radiation Monitoring System (RMS) software in use was initiated.

3. A procedure was developed to require proper documentation and testing of software activities in the RMS system.

As previously discussed, the problem with the manner in which RU-1 calculates containment activity was discovered by ANPP personnel. This discovery was a result of the programs described above. ANPP believes that these programs are sufficient. However as an additional measure, ANPP had initiated a Reliability Improvement Project for the ANPP radiation monitoring system prior to this event. This is intended to evaluate methods for improving the operability and reliability of the radiation monitoring systems.

RU-1 INFORMATION:

Manufacturer: Kaman Instrumentation Corporation Model No: 952140-002 Tra s ortabilit The deficiency-.with the manner in which RU-1 calculates activity levels is also applicable to other radiation monitors utilized at PVNGS. The following monitors are affected:

RU-51, 52, 53 - Moveable Airborne Monitors (utilized as backups for RU-1)

RU-8 - Auxiliary Building (NF) Ventilation Exhaust Filter Inlet Monitor RU- 14 - Radwaste Building (NE) Ventilation Exhaust Filter Inlet Monitor RU-13A - Technical Support Center Monitor RU-13B - Emergency Operations Facility (NC) Monitor RU-143 - Plant'Vent (VL) Monitor N>IC IO>IM 555A IQ 53>

NRC Eorm 344A V.S. NUCLEAR REGULATORY COMM/SS/QN IS 831 LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVEQ OM8 NQ 3/EQW/84 EXP/RES; 8/31/88 FACILITY NAME 111 OOCKET NVMEER 131 LER NVMEER IS) PAGE 131 SEQUENTIAL YEAR NUM ER .'rr. REVISION NUMEER Pa1o Verde Unit 1 o s o o o 6 2 8 8 8 0 0 8 00 06 oF 0 6 tEXT l/lrnn/4 EPPce /I IPEIRRNE PSP 8//Pi'encl P/RC P4nn 38%4 3/ 1111 r Monitors RU-8, 13A, 13B, 14, 51, 52, and 53 are not required pursuant to Technical Specifications and are not considered reportable. When RU-51, 52, and 53 are utilized as replacements for RU-1, the corrective actions described herein will be implemented (i.e., reduced filter change-out intervals). The affected particulate channel in RU-143 is required by Technical Specification 3.3.3.1 only to collect particulate samples. Therefore RU-143's operability is not affected by the algorithm deficiency described herein. A corrective action plan for the other affected monitors is currently being developed. If additional information which could change the readers perception or understanding of the event is identified during the development of this corrective action plan, a supplement to this report will be provided.

Based upon the problem described herein, an evaluation for 10CFR Part 21 reportability is being conducted.

This report also contains information for a special report required pursuant to Units 1, 2, and 3 Technical Specifications 3.3.3.1 and 6.9.2 for RU-1 being periodically inoperable for greater than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

'IRC I ORM 3444 IS 83I

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Arizona Nuclear Power Project P.O. BOX 52034 ~ PHOENIX. ARIZONA 85072-2034 192-00352-JGH/TDS/DAJ March 11, 1988 NRC Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Unit 1 Docket No. STN 50-528 (License No. NPF-41)

Licensee Event Report 88-008-00 File: 88-020-404 Attached please find Licensee Event Report (LER) No. 88-008-00 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, please contact T. D. Shriver, Compliance Manager at (602) 393-2521.

Very truly yours, J. G. Haynes Vice President Nuclear Production JGH/TDS/DAJ/kj Attachment'c:

0. M. DeMichele (all w/a)

E. E. Van Brunt, Jr.

J. B. Martin T. J. Polich R. C. Sorenson E. A. Licitra A. C. Gehr INPO Records Center

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