ML17305A732

LER 90-003-00:on 900331,power Supply to Alternate Plant Ventilation Effluent Radiation Monitor Deenergized.Caused by Personnel Error.Design Mod Issued to Supply Dedicated Power to loads.W/900429 Ltr

ML17305A732
Person / Time
Site:	Palo Verde
Issue date:	04/29/1990
From:	Bradish T, James M. Levine ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
192-00654-JML-T, 192-654-JML-T, LER-90-003-02, LER-90-3-2, NUDOCS 9005080228
Download: ML17305A732 (20)

Text

ACCELERATED DI'~HUBUTION DEMONSTIRATION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9005080228 DOC.DATE: 90/04/29 NOTARIZED: NO "

DOCKET FACIL:STN-50-529 Palo Verde Nuclear Station, Unit 2, Arizona Publi 05000529 AUTH. NAME r'UTHOR Public AFFILIATION Service Co. (formerly Arizona Nuclear Power BRADISH,T.R. Arizona LEVINE,J.M. Arizona Public Service Co. (formerly Arizona'uclear Power RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 90-003-00:on 900331,loss of power to alternate plant ventilation effluent radiation monitor.

W/9 'tr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE:

TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.

NOTES:Standardized plant. 05000529 RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 1 PD5 PD 1 1 PETERSON,S. 1 1 CHAN,T 1 1 INTERNAL: ACNW 2 2 ACRS 2 2 AEOD/DOA 1 1 AEOD/DSP/TPAB 1 1 AEOD/ROAB/DSP 2 2 DEDRO 1 1 NRR/DET/ECMB 9H 1 1 NRR/DET/EMEB9H3 1 1 NRR/DET/ESGB 8D 1 1 NRR/DLPQ/LHFB11 1' NRR/DLPQ/LPEB10 1 1 NRR/DOEA/OEABll 1 1 NRR/DREP/PRPB11 2 2 NRR/DST/SELB 8D 1 1 NRR/DST/SICB 7E 1 1 NRR/DST/SP>BS D1 1 1 NRR/DST/SRXB 8E 1 1 REG F-I-LE.~ 02 1 1 RES/DSIR/EIB 1 1 RGN5 FILE 01 1 1 EXTERNAL EG&G STUART i V A 4 4 L ST LOBBY WARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC MAYS,G 1 1 NSIC MURPHY'iG A 1 1 NUDOCS FULL TXT 1 1 NOTES: 1 1 NOTE TO ALL "RIDS" RECIPIEKIS:

PLEASE HELP US TO REDUCE WASTEl CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXI'. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 39 ENCL 39

i I

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Arizona Public Service Company PALO VERDE NUCLEAR GENERATING STATION P.O. BOX 52034 ~ PHOENIX( ARIZONA 85072-2034 JAMES M. LEVINE 192-00654-JML/TRB/RKR VICE PRESIDENT NUCLEAR PRODUCTION April 29, 1990 U. S. Nuclear Regulatory Commission Document Control Desk Washington, .DC 20555

Dear Sirs:

Subj ect: Palo Verde Nuclear Generating Station (PVNGS)

Unit 2 Docket No. STN 50-529 (License No. NPF-51)

Licensee Event Report 90-003-00 File'0-020-404 Attached please find Licensee Event Report (LER) No. 90-003-00 prepared and submitted pursuant to 10CFR50.73. In accordance with 10CFR50.73(d),

we are herewith forwarding a copy of the LER to the Regional Administrator of the Region V office.

I If you have any questions, please contact T. R. Bradish, Compl'iance Manager at (602) 393-2521.

Very truly yours, JML/TRB/RKR/tlg Attachment CC: W. F Conway (all with attachment)

E. E Van Brunt J. B Martin D. H Coe T. L Chan A. C Gehr A. L Gutterman INPO Records Center

it ~ '

NRC FORM 368 (669)

LICENSEE EVENT REPORT (LER)

U.S. NUCLEAR REGULATORY COMMISSION t APPAQVED OMB NO. 31504104 EXPIRES: 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ES'TIMATE TO THE RECORDS AND REPORTS MANAGEMENT BRANCH (P630). U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555. AND TO, THE PAPERWORK REDUCTION PROJECT (31500104). OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, DC20503.

FACILITY NAME (II DOCKET NUMBER (2) PAGE 3>

TITLE (4)

Palo Verde Unit 2 05000529 1 QF 08 F

Loss of Power to Alternate Plant Ventilation Effluent Radiation Monitor EVENT DATE (6) LER NUMBER (5) AEPQRT DATE (1) OTHER FACILITIES INVOLVED (8)

MONTH DAY YEAR YEAR pm SEQVENTIAL NUMBER (cc REVISION MONTH OAY NUMBER YEAR FACILITYNAMES DOCKET NUMBER(SI N A 0 5 0 0 0 0 3 3 1 9 0 9 0 0 0 3 0 0 0 429 90 N/A 0 5 0 0 0 OPERATING THIS REPORT IS SUBMITTED PURSUANT T 0 THE RLQUIREMENTS OF 10 CFR (): ICneck one or more of III~ foifowinp/ (11)

MODE (9)

N 20.402 (8 I 20AOS(c) 60.73(e) (2) (N) 73.7((OI POWER 20A05( ~ )(\)5) 50.34(c) Ill 60.73(eH2)(rl 73.71(cl LEVEL p p p 20.405(e) (I) (Sl 50.38(c)(2) 60.73(e I (2) (rill OTHER ISpecifyin Aorrrect Oelow enrf in Text, IY/IC Form 20AOS( ~ ) (1)(iil) 50.73( ~ )l1)lll 60.73(e) l2) (riii)IAI 366A/

20.406( ~ I (1)(lr) 50.73(el(1)(il) 50.73(e)(2) (rlii)IB) 20.405 ( ~ I (I ) (r) 50.73(el(2) liil) 60.73( ~ ) (2 II x)

LICENSEE CONTACT FOR THIS LER (12I NAME TFLEPHONE NUMBER AREA CODE Thomas R. Bradish Com liance Mana er 602 393 -2 521 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPQAT (13) r ;prix Yxo"CI Rrpo 9 CAUSE SYSTEM COMPONENT MANUFAC. REPORTABLE 85@kgPM4NI COMPONENT MANUFAC.

TUREA TURER SUPPLEMENTAL AEPOAT EXPECTED (14) MONTH DAY YEAR EXPECTED SUBMISSION DATE (15)

YES III yn, complete EXPECTED SIISMISSIQrf DATE/ NQ ABsTRAcT ILimir ro te00 rpecn, I e., epproximeteiy lifreen Iinpie tpece typewrirren fined (16)

At approximately 1230 MST on March 31, 1990, Palo Verde Unit 2 was in a refueling outage with ehe reactor core offloaded to the Spent Fuel Pool when a Chemistry Effluent Technician and the Control Room Shift Supervisor discovered that the Preplanned Alternate Sampling Program (PASP) portable sample care for the Fuel Building Ventilation had been inoperable. At approximately 0620 MST on March 31, 1990, the load center supplying power eo ehe PASP portable sample care had been deenergized for a preplanned electrical outage. When the load center was deenergized', it was not recognized that it supplied power to the PASP portable sample cart. At approximately 0840 MST on March 31, 1990, the PASP portable sample cart was returned to OPERABLE status. With the PASP portable sample cart inoperable for approximately two hours and tweney minutes, Unit 2 operated in a condition contrary to Technical Specification 3.3.3.8.

The cause of the event was a personnel error due to inadequate identification of the loads on the load center prior to deenergization.

As corrective action a Design Modification has been issued to supply dedicated power to these loads.

Similar events were reported in LERs 529/87-14, 529/88-13, 530/88-07, 530/89-03, and 529/89-005.

NRC Form 385 (669)

I+I NRC FORM355A ILS. NUCLEAR REGULATORY COMMISSION APPROVED OMB NO, 3150010O (549)

E XPIR ES: O/30l92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT ILER) INFORMATION COLLECTION REOUEST: 50J> HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENT BRANCH IP430). U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO THE PAPERWORK REDUCTION PROJECT (31500104>. OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON. DC 20503.

FACILITY NAME (I) DOCKET NUMBER (2), LER NUMBER (5) PAGE (3)

YEAR I:

~N SEOUENTIAL NUMBER

>IIEET REVISION NUM 54 Palo Verde Unit 2 0 5 0 0'0 5 990 0 03 0 0 02oF 08 TEXT (llmoro AOoco ls IPOohd, ooo a5Ãonol HRC Form 35543) (IT)

I. DESCRIPTION OF WHAT OCCURRED:

Initial Conditions:

At approximately 0620 MST on March. 31, 1990, 'Palo Verde Unit 2. was in a refueli'ng outage with the reactor core (AC) offloaded to the Spent Fuel Pool (ND).

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

Event Classification: Condition Prohibited'by the Plant's Technical Specifications (TS)

At approximately 1230 MST on March 31, 1990, a Chemistry Effluent Technician (utility, non-licensed) and the Control Room Shift Supervisor (utility, licensed) discovered that the Preplanned Alternate Sampling Program (PASP)(IL) portable sample cart for the Fuel Building ventilation (VL) had been inoperable. The power supply for the PASP portable sample cart had been deenergized for' preplanned electrical outage at approximately 0620 MST on March 31, 1990. The power supply was reenergized at approximately 0802 MST.

Prior to the event discovery, at approximately 0840 MST on March 31, 1990, the PASP portable sample cart flow had been verified to confirm proper operation. With the PASP portable sample cart inoperable for approximately two hours and twenty minutes, Unit 2 operated in a condition contrary to TS 3.3.'3.8.

Prior to the event, at approximately 1700 MST on March 23, 1990, the Fuel Building Ventilation System Low and High Range Radioactive Gaseous Effluent Monitors (RU-145 and RU-146)(MON)(IL) were removed from service when their power supply was deenergized for scheduled maintenance during the refueling outage'his was reported in Special Report 2-SR-90-001 dated April 12, 1990, in accordance with TS 3.3.3.8 ACTION 42b and TS 6.9.2. Appropriate .actions were initiated in accordance with approved procedures. These actions included the installation of the PASP portable sample cart within one hour in accordance with TS 3.3.3.8 ACTIONS 37 and 40. .The portable sample cart taps into the Fuel Building ventilation and uses a particulate and charcoal cartridge for sample collection with an inline flow gauge and sampling pump. The portable sample cart is electrically powered from a local outlet. The Portable Area Monitor (PAM) was also installed. The 'PAM is located on the Fuel Building roof to monitor the Fuel Building Ventilation discharge pipe. The output from the PAM is connected to the Radiation Monitoring System NR C Form 355A (539)

NRC FOAM355A U.S. NUCLEAR REGULATORY COI4MISSION APPAOVED OMB NO. 31500104 (589) EXPIRE5; 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT ILER) INFORMATION COLLECTION AEOUESTI 508) HRS. FORWARD COMMENTS REGAADING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENT BRANCH (P530). U.S. NUCLEAR REGULATORY COMMISSION. WASHINGTON, DC 20555. AND TO THE PAPERWORK REDUCTION PROJECT (31500104). OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (5) PAGE (3)

YEAR SEOVENW*L REVISION NUMBER NVMSER Palo Verde Unit 2 o s o o o 52 990 0 0 3 0 0 0 3 oF0 8 TEXT ///mom <<>>44/I moo/md, o44 odI//oor>>/HRC FomI 3/JSAS/OT)

(RMS) mini computer (CPU)(IL) in the Chemistry Lab. The PAM is also powered from a local outlet.

Following the installation of the portable sample cart, the process and sample flow rates were verified a minimum of every four hours pursuant to TS 3.3.3.8 ACTION 36. At approximately 0615 MST on March 31, 1990, a portable sample cart flow check was performed. At that time, the portable sample cart was energized and operable. At approximately 0620 MST on March 31, 1990, a non-class IE 480 Volt load center (NGN-L17) (XFMR) (EC), which normally supplies nonessential lighting and outlets, was deenergized to permit connection of a temporary power supply to allow its normal power supply to be deenergized for a preplanned electrical outage. The load center was providing power to the local outlets for the portable sample cart and PAM. During the next scheduled tour, at approximately 0711 MST, a Chemistry Effluent Technician discovered that the PAM was not operating and notified the Control Room Shift Supervisor (utility, licensed).

At approximately 0750 MST while investigating the PAM inoperability, the Chemistry Effluent Technician discovered that the PAM was deenergized and notified the Control Room Shift Supervisor. The Control Room Shift Supervisor determined that the PAM was inoperable due to its load center being deenergized. At approximately 0802 MST, the PAM was returned to service when the load center was reenergized.

The PAM had been inoperable from approximately 0620 MST to approximately 0802 MST on March 31, 1990, a period of approximately 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and 42 minutes. The PAM was not required to be OPERABLE during thi.s time period to meet TS requirements.

At approximately 1230 MST on March 31, 1990, while reviewing the loads supplied by the load center, the Chemistry Effluent Technician and the Control Room Shift Supervisor discovered that the portable sample cart was powered by the same load center as the PAM. Prior to this discovery, at approximately 0840 MST on March 31, 1990 (after the load center had been reenergized), proper operation of the portable sample cart flow had been verified during the regularly scheduled surveillance. The portable sample cart was inoperable from approximately 0620 MST to 0840 MST on March 31, 1990, for approximately 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> and 20 minutes. This is contrary to TS 3.3.3.8 ACTION 40 which requires that "effluent releases via the affected pathway may continue provided samples are continuously collected with auxiliary sampling equipment".

NRC Form 35SA (5/)9)

i IS NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (64)9) APPROVED 0MB NO. 31500104 EXPIRES: 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT {LERI INFORMATION COLLECTION REQUESTI 500 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENT BRANCH (P430). U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO THE PAPERWORK REDUCTION PROJECT (31500104). OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, DC 20503.

FACILITYNAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

YEAR 2 SEQUENTIAL A~i 4)( REVISION NUMSTR NUMFER Palo Verde Unit 2 0 5 0 0 0 5 2 9 0 0 0 3 0 0 04OF 0 8 TEXT ///moru 4puru /4 rrqu/rrd, uru udd44mr/ SRC Form 3664'4/ (17)

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

As stated in.Section I.B, the Fuel Building Ventilation System Radioactive Gaseous Effluent Monitors, RU-145 and RU-146, were inoperable due to deenergization of their power supply for scheduled maintenance during the refueling outage. The PASP portable sample cart and PAM became inoperable as described in Section I.B. No other structures, systems, or components were inoperable at the start of the event that contributed to the event.

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

Not applicable - no component or system failures were involved.

Failure mode, mechanism, and effect of each failed component, if known:

Not applicable - no failures were noted.

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

Not applicable - no component failures were involved.

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 failures were involved.

H. Method of discovery of each component or system failure or procedural error:

Not applicable - no component or system failures or procedural errors were involved.

Cause of Event:

The cause of the event was a personnel error (SALP Cause Code A) by chemistry personnel (utility, non-licensed). Interim corrective action from a previous similar event (LER 529/89-005) required that PASP equipment be electrically powered such that a loss of power would provide an alarm in the control room, Preplanned bus outages during the refueling resulted 'in loss of power to several radiation NRC F omI 366A (64)9)

i 0 NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION APPROVED OMB NO. 31500104 (609)

EXPIRES; 4/30/62 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT ILER1 INFORMATION COLLECTION REOUEST: 500 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENT BRANCH (P4r30). U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO THE PAPERWORK REDUCTION PROJECT (31504104). OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3I r >(/sE BEDUENTIAL:,j~% RfvorON YEAR NUMBER F.'6 NUMBEA Palo Verde Unit 2 0 5 0 0 0 5 2 9 9 0 003. 00 0 5 QF TEXT ///mort tpttt /4 rttvttd, vtt tddidont/NRC Form3//SA'4/(17) monitors. In accordance with TS ACTION requirements, PASP equipment was placed in service to provide alternate sampling for the monitors out of service. Since the alarm computer in the control room could not accept all of the alarms, the alternate sample cart for Radiation Monitor RU-145 was not connected to the alarm computer in the control room. Other higher priority PASP equipment was connected instead.

Since the PASP equipment could not be connected to the alarm computer, chemistry personnel should have taken additional action and notified the control room that the PASP equipment was being supplied from a specific outlet and that additional measures were required to prevent a loss of power to the PASP equipment (e.g.,

caution tag power supplies for the PASP equipment)'. Chemistry personnel did not inform the control room which electrical outlets were supplying power to the PASP equipment resulting in operations personnel (utility, licensed) not performing an adequate review of the loads on the non class 1E load center prior to deenergizing the load center. There were no administrative controls which recommended that chemistry personnel inform the control room which outlets were supplying power to the PASP equipment. 'There were no unusual characteristics of the work location that directly contributed to this event.

Safety System Response:

Not applicable - no safety system responses occurred and none were necessary.

Failed Component Information:

Not applicable - no component failures were involved.

II. ASSESSMENT OF THE SAFETY CONSEQUENCES AND IMPLICATIONS OF THIS EVENT:

The portable sample cart was determined to be inoperable for approximately 2 hours and 20 minutes. There was no fuel movement or crane movement over the spent fuel pool during this event. The Fuel Building Area Radiation Monitors (RU-19 and RU-31) did not indi'cate any change in radiation levels during this event. The PASP sample from the portable sample cart and the PAM did not indicate any significant radiation levels prior to and after this event. Therefore, there were no safety consequences or implications as a result of this event. This event did not adversely effect the health and safety of the public.

NR C Form 366A (BBB)

i5 V NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (64)9) APPROVED OMB NO. 31500104 EXPIRES: 4/30/92 ESTIMATED'BURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT (LER) INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENT BRANCH (F430), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555. AND TO THE PAPERWORK REDUCTION PROJECT (31504104). OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (II DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

YE4 R pig SEQUENTIAL %SFI REVISION NOUS ER ~P?i NUMSER Palo Verde Unit 2 5 0 0 0 5 2 9 90 003 0 0 06oF 08 TEXT /lfmoru 4/?444 /4 mqu/Iud, u44 Pdde'on4//VRC Fum? 3//643/ 07)

III. CORRECTIVE ACTIONS' A. Immediate:

Power was returned to the alternate sampling system and PAM.

B. Action to Prevent Recurrence:

A Design Modification has been issued to supply dedicated power to the portable sample cart in all three units. Implementation of the design modification in Units 1, 2, and 3 is expected by September 1990.

A procedure change has been initiated to the RMS Sample Collection Procedure for all three units to require that when PASP equipment cannot be connected to the alarm computer in the control room, chemistry personnel inform the control room which electrical outlets PASP equipment is powered from and request that the power supplies it for the PASP equipment (when is in use) be caution tagged to alert personnel that Technical Specification required equipment is connected to these power supplies. The procedure change is expected to be implemented by June 30, 1990'. As interim corrective action until the procedure change is implemented, when PASP equipment cannot be connected to the alarm computer in the control room,, chemistry personnel in all three units will notify the control room when the PASP is being implemented, identify the electrical outlets PASP equipment is being powered from, and request that the power supplies for the PASP equipment can be caution tagged to alert personnel that Technical Specification required equipment is connected to these power supplies.

IV. PREVIOUS SIMILAR EVENTS:

Five previous events have occurred which are similar to this event:

LER'529/87-014 described an event where the alternate sampling system for the Fuel Building Ventilation Radiation Monitor (RU-145) had been turned off and rendered inoperable. As corrective action to prevent recurrence, a placard was installed on the cart which identifies the cart as Technical Specification required equipment. Since the event described in this LER involves deenergizing the power supply for the PASP equipment, the corrective action described in LER 87-014 would not have been expected to prevent the event described in this LER.

NRC FOIRI 366A (669)

iS NRC FORM 366A VS. NUCLEAR REGULATORY COMMISSION APPROVED OMB NO. 3)504)104 (64)9)

EXPIRES: 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT'(LERI INFORMATION COLLECTION REQUEST: 500 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENT BRANCH (P430). V.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO THE PAPERWOAK REDUCTION PROJECT (31504))04). OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (I) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

YEAR SrPr'EQUENTrAL glor r(svrsloN NUMBED .. /t NUMSso Palo Verde Unit 0 5 0 0 0 529 0 0 3 0 0 7 QF 0 TEXT ///mors ttrttt/4 rosrr/rtd, rrto tddr(4rrrt/HRC Form 3664'4/<17)

LER 529/88-013 described an event where the alternate sampling system for Normal Plant Ventilation Radiation Monitor (RU-143) had been rendered inoperable when the circuit breaker opened. As corrective action to prevent recurrence, an Engineering Evaluation Request was issued to evaluate the feasibility of supplying alternate power to the loads. Based on this. evaluation, a design modification was issued to supply dedicated power to the sample cart. Implementation of this change is expected by September 1990. Since this change has not been installed in the unit, it did not prevent the event described in this LER.

LER 530/88-007 described an event where the alternate sampling system for the Condenser Vacuum Pump/Gland Seal Exhaust Radiation Monitor (RU-141) became electrically disconnected from a nearby electrical outlet and thus, rendered inoperable. As action to prevent recurrence, the involved individual was counseled, additional training was performed, and enhanced labeling for the sample cart was developed. The counseling, training, and labeling would not have prevented the event described in this LER.

LER 528/89-003 described an event where the alternate sampling system for the Fuel Building Exhaust Radiation Monitor (RU-145) became inoperable when, the circuit breaker opened. As corrective action to prevent recurrence, a Design Modification was issued to supply dedicated power to the sample cart. Implementation of this change is expected by September 1990. Since this change has not been installed in the unit, it did not prevent this event.

LER 529/89-005 described an event where the alternate sampling system for the Normal Plant Ventilation Radiation Monitor (RU-143) became inoperable when the circuit breaker opened due to an overload condition. As corrective action to prevent recurrence, a Design Modification was issued to supply dedicated power to the sample cart. Implementation of this change is expected by September 1990.

Since this change has not been installed in the unit, it did not prevent this event. Additionally as an interim corrective action in LER 89-005, PASP equipment was to be electrically powered such that a loss of this power would provide an alarm in the control room.

Preplanned bus outages during the refueling outage resulted in loss of power to several radiation monitors. In accordance with TS ACTION requirements, PASP equipment was placed in service to provide alternate sampling for the monitors out of service. However, the alarm computer in the control room has limited capacity and could not accept all of the'larms. The alternate sample cart for radiation monitor RU-145 was not connected to the alarm computer in HAC Form 366A (669)

NRC FORM 366A U.S, NUCLEAR REGULATORY COMMISSION APPROVED OMB NO. 31500104 (64)9)

EXPIRES: 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT ILERI INFORMATION COLLECTION REOUESTI 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND RE'PORTS MANAGEMENT BRANCH (P430), U.S. NUCLEAR REGULATORY COMMISSION. WASHINGTON, OC 20555, AND TO THE PAPERWORK REDUCTION PROJECT (31500104), OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (11 DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

<jd) SSOUSNTIAL <4?: REVISION YEAR ) 4 NUMSSR NVMSER Palo Verde Unit 2 o s o o o 52 990 003 0 0 os>> os TEXT lllnels spsss is srquirsd, pss sdd/IloIMI/VRC Form 36//A'4/(17) the control room since other higher priority PASP equipment were connected instead. Therefore, this corrective action did'not prevent this event.

NRC FOIIII 366A (689)

il l