ML17303A773

LER 88-005-00:on 880221,inadvertent Safety Injection from Safety Injection Tanks (Bp)(Acc) Occurred.Caused by Personnel Error.Appropriate Disciplinary Measures Will Be Taken.Malfunctioning Fuse replaced.W/880226 Ltr

ML17303A773
Person / Time
Site:	Palo Verde
Issue date:	02/26/1988
From:	Haynes J, Shriver T ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
192-00348-JGH-T, 192-348-JGH-T, LER-88-005-01, LER-88-5-1, NUDOCS 8802290358
Download: ML17303A773 (6)

Text

REGULATORY INFORMATION DISTRIBUTION SYSTEM (BIDS)

ACCESSION NBR:88022903'OC. DATE: 88/02/26 N IZED: NO DOCKET ¹ AUTH. NAME AUTHOR AFFILIATION

.

FACIL: STN-50-529 Palo Verde Nuclear Stations Unit 2i Arizona Pub li 05000529 SHR IVER'. D. *rizona Nuclear Poeer Prospect (fol merlg Arizona Public Serv HAYNES'. G. Arizona Nuclear Power Prospect (formerly Arizona Public Serv RECIP. NAME RECIPIENT AFFILIATION

SUBJECT:

LER 88-005-00: on 880221'nadvertent safety inJection from safety ingection tanks (BP) (ACC) occurred. Caused bg personnel error. Appropriate disciplinary measures mill be taken. Malfunctioning fuse replaced. W/88022b ltr.

DISTRIBUTION CODE: IE22D COPIES RECEIVED: LTR ~ ENCL ( SIZE TITLE: 50. 73 Licensee Event Report (LER)i Incident Rpti etc.

NOTES: Standardized plant. 05000529'EC IP IENT COPIES REC I P IENT COP IES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 1 PD5 PD 1 1 LICITRAiE 1 1 DAVIS. M 1 1 INTERNAL: ACRS MICHELSON 1 1 ACRS MOELLER 2 2 AEOD/DO* 1 1 *EOD/DSP/NAS 1 AEOD/DSP/ROAD 2 2 *EOD/DSP/TP*B 1 1 ARQ/DCTS/DAB 1 1 DEDRO 1 1 NRR/DEST/ADS7E4 1 0 NRR/DEST/CEBSH7 1 1 NRR/DEST/ESB 8D 1 1 NRR/DEST/ICSB7A 1 NRR/DEST/MEB9H3 1 NRR/DEST/MTB 9H 1 1 NRR/DEST/PSBSD1 1 NRR/DEST/RSB 8E 1 1 NRR/DEST/SGB 8D 1 NRR/DLPG/HFBiOD 1 1 NRR/DLPG/GABiOA 1 NRR/DOE*/EAB11E 1 1 NRR/DREP/RAB10A 1 1 NRR/DREP/RPB10A 2 2 NR~R.DR IZ/S I B9A1 1 1 NRR/PMAS/ ILRB 12 1 1

~REC FILM 02 1 1 RES TELFORDi J 1 RES/DE/EIB 1 1 RES/DRPS DIR 1 1 RGN5 FILE 01 1 1 EXTERNAL: EG8cG GROH. M 5 5 FORD BLDG HOYLE A 1 1 H ST LOBBY WARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC HARRIS' 1 1 NSIC MAYST G 1 1 NOTES:

TOT*L NUMBER OF COPIES REQUIRED: LTTR 48 ENCL 47

NRC Form 300 U.S. NUCLEAR REOULATOAY COMMISSlON

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APPAOVED 0MB NO. 315041St LICENSEE EVENT REPORT (LER) EXPIRES: 0/31/00 FACILITY NAME II) DOCKET NUMBER 12) PA S.

Palo Verde Unit TITLE I ~ I 2 o 5 o o o 52 910F04 Inadvertent Safety Injection Resulting From Personnel Error EVENT DATE IS) LER NUMBER LS) REPORT DATE (TI OTHER FACILITIES INVOLVED LEI MONTH DAY YEAR YEAR EEOVENTIAL RE YtEIQN DAY YEAR FACILITYNAMES DOCKET NUMBER(S)

NUMBER .s. o NUMBER MONTH N/A 0 5 0 0 0 0 2 2 1 8 8 8 8 0 05 0 0 N/A 0 5 0 0 0 THIS REPORT IS SUBMITTED PURSUANT T 0 THE REOUIREMENTS OF 10 CFR ('I t /Cnece one et mote ol the /oiiowIndl (11 OPF RAT I NO MODE ISI 20A02(4) 20A05(cl 50.73(s) 11)(lrl 7$ .7'I IE)

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LICENSEE CONTACT FOR THIS LER 02I NAME TELEPHONE NUMBER AREA CODE Timothy D. Shriver, Compliance Manager 6 0 2393 2521 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS AEPORT (1$ )

CAUSE SYSTEM COMPONENT MANVFAC. EPORTABLF. MANUFAC.

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) %~>Neg@j SUPPLEMENTAL REPORT EXPECTED Ils) MONTH DAY YEAR EXPECTED SU 5 M I SS I ON II/ yn, complete DATE (I SI YES EXPECTED SIISSIISSION DATE/ NO ABSTRACT /Limit tO IC00 /peen, I A, eoptos/mstelp lifteen tinlie.spree tTPewntnn linn/ (10)

On February 21, 1988, Palo Verde Unit 2 was in Mode 5 (COLD SHUTDOWN) at approximately 170'F and 125 psia being cooled-down and depressurized to begin a refueling outage. At approximately 0719 MST an inadvertent safety injection (JE) from the Safety Injection Tanks (BP)(ACC) occurred as a result of low pressurizer pressure signals not being properly bypassed. The safety injection was accompanied by a containment isolation (BP) (JE) engineered safety features (ESF) actuation. There were no other ESF actuations and none were necessary. During the event a high pressure safety injection (HPSI) valve (INV) did not fully open. All other equipment operated per design.

The root cause of the event was a cognitive personnel error on the part of utility, licensed personnel. Additionally during the event, the HPSI loop injection valve did not open due to a blown fuse (FU).

As corrective action, appropriate disciplinary measures will be taken. The HPSI loop injection valve was verified to operate properly after replacing the malfunctioning fuse. A root cause of failure has been initiated for the blown fuse.

There have been no previous similar occurrences.

8802290358 880226 PDR ADOCK 05000529 8 PDR NRC Sotm 300

NAC Form 3SSA 19431 U.S. SIUCLEAR AEOULATOAYCOMMISSION LICENSEE EVENT REPORT ILER) TEXT CONTINUATION APPROVEO OMS NO 3150M)04 EXPIAESI SI31/SS s FACILITY NAME (I) DOCKET NUMSER )1)

LER NUMSER IS) PACE I3) rsm SEOVENTIAL REVISION NVMSEII NVM SR Pal o Verde Uni t 2 o 5 o o o 5 29 88 00 5 0 0 0 2 oF0 4 TEXT )I/more a>>co is e))rr'red. use akrinr'or>>PHPIC Fonrr 3OSA's) ))3)

At approximately 0719 NST on February 21, 1988, Palo Verde Unit 2 was in Mode 5 (COLD SHUTDOWN) at approximately 170'F and 125 psia when a low pressurizer (PZR) pressure trip signal caused an inadvertent Safety Injection Actuation Signal (SIAS)(BP)(JE) and Containment Isolation Actuation Signal (CIAS)(JE).

This resulted in an inadvertent safety injection into the reactor coolant system (RCS)(AB) from the Safety Injection Tanks (SIT)(ACC). At approximately 0802 MST a Notification of Unusual Event was declared due to the injection of water into the RCS. The Notification of Unusual Event was terminated at the time of declaration (0802 flST). There were no other Engineered Safety Features (ESF)(JE) actuations and none were necessary.

On February 21, 1988, Palo Verde Unit 2 was in the process of being cooled-down and depressurized for the start of a refueling outage. The cooldown/depressurization was being conducted in accordance with procedure 420P-2ZZ10, "Hot Standby to Cold Shutdown - Node 3 to Node 5RR In accordance with 420P-2ZZ10, the high pressure safety injection pumps (HPSI)(Bg)(P) had been removed from service (electrical power disabled), the low pressure safety injection pumps (LPSI)(BP) had been aligned for shutdown cooling, and the SIT isolation valves ( ISV) closed (but not disabled). No safety injection flowpaths were required to be operable in accordance with Technical Specifications after Unit 2 entered Node 5 at approximately 03'16 NST on February 21, 1988.

On the shift prior to the one during which the ESF actuation occurred, identified that the low pressurizer pressure channel "C" trip was not it was operating properly. The channel was bypassed and a work request document was initiated to have the channel repaired. During a subsequent investigation into the problems with pressurizer pressure channel "C", control room personnel (utility, licensed) observed the bypass indication for channel "CR and incorrectly noted that all four (i.e. 4 of 4) low pressurizer pressure trip channels were bypassed. The requirement for bypassing the four pressurizer pressure trip channels was then documented as being complete in 420P-2ZZ10.

At 0700 NST on February 21, 1988, on-coming shift personnel (utility, licensed) continued the cooldown/depressurization in accordance with 420P-2ZZ06, ANode 5 Operations." At approximately 0713 Low Pressurizer Pressure Channel A, B, and D pre-trips were received. The cooldown/depressur ization continued as it had previously been documented that the four low pressurizer pressure trips were bypassed. At approximately 0719 NST, Low Pressurizer Pressure Channel B and D trips were received and SIAS and CIAS were initiated.

Containment isolation (CIAS) is required to minimize the release of radioactive material during a loss-of-coolant-accident (LOCA) or main steamline break. The CIAS initiates 'isolation of the process lines penetrating the containment by actuating the appropriate valves when 2-out-of-4 high containment pressure initiation signals or 2-out-of-4 low pressurizer pressure initiation signals are received by CIAS actuation logic.

4RC IORM )OSO 19 S)I

NRC Fe>I>> 344A I9.83 I U.S. NUCLEAR REOULATORY COMMISSION LICENSEE EVENT REPORT HLER) TEXT CONTINUATION APPROVED OM8 NO. 3)50-0104 EXPIRES: 8/3l/88 FACILITY NAME ))) DOCKET NUMSER )1)

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The Safety Injection System provides emergency core cooling by injecting borated water into the reactor coolant system. This limits core damage and assures an adequate shutdown margin should a LOCA or steamline break occur.

The SIAS is initiated by receipt of 2-out-of-4 low pressurizer pressure or 2-out-of-4 high containment pressure signals. Following an incident which results in a SIAS, the high pressure safety injection pumps, low pressure safety injection pumps, and high and low pressure injection valves (INV) (including the SIT isolation valves (ISV) ) receive actuation signals.

During the safety injection described herein, approximately 10 percent safety injection tank volume was injected into the reactor coolant system (approximately 962 cubic feet). This increased RCS pressure to approximately 250 psig and pressurizer level to approximately 100 percent. The HPSI pumps did not actuate since they had been electrically disconnected prior to entering Mode 5 and the LPSI pumps were already operating for shutdown cooling. All other equipment operated as designed except as discussed below.

Following the SIAS/CIAS, control room personnel (utility, licensed) in accordance with approved procedural controls, responded to the event and determined that the SIAS/CIAS was inadvertent. Control room personnel verified that all equipment operated as designed for the current plant conditions with the exception of a high pressure safety injection loop isolation valve ( ISV) not fully opening. By approximately 0830 MST the actuated equipment had been restored to normal configuration for Mode 5 operations and the event was terminated.

The root cause of this event has been determined to be a sequence of two cognitive personnel errors. The first personnel error was as a result of the pressurizer low pressure trips being documented as being place in bypass by control room personnel (utility, licensed) when only channel UCU was in bypass. The second cognitive personnel error was a result of control room personnel (utility, licensed) not properly responding to the low pressurizer pressure pre-trip alarms and terminating the cooldown/depressurization until the cause of the pre-trip alarms was investigated. Procedural controls were evaluated and it was determined that the personnel errors were not as a result of an error in approved procedures or the activities not being covered by approved procedures. There were no unusual characteristics of the work location which contributed to the event.

The cause of the high pressure safety injection valve not fully opening was determined to be a blown fuse (FU). The fuse was replaced and the valve was verified to function normally. A root cause of failure has been initiated to determine why the fuse opened.

As corrective action to prevent recurrence, appropriate disciplinary measures will be taken. Additionally this event will be reviewed by control room personnel in all three units as additional training. The results of the investigation did not identify any contributory causes therefore ANPP believes

'>I>C I OIIM Sssa I9 831

NAC Form SSSA U.S. NUCLEAR AEOULATORY COMMISSION (982 I LICENSEE EVENT REPORT {LERI TEXT CONTINUATION AI'PAOVEO OM8 NO, 2I50~18d EXPIRES: 8/21/88 FACILITY NAME (II OOCKET NUMSER (2l LER NUMSER ( ~ I SSOUSNTIAL IIEVIS IO 4 NUM (II NUM EA Palo Verde Unit 2 o s o o o 8 8 0 0 5 00 04 OF 0 4 TEXT /I/IINvoIooco lr raywed, I/w akron@ H/IC Fom/ 288A8/ (17)

The corrective actions described should be sufficient to prevent recurrence.

However, personnel errors such as those described above are closely monitored. If a trend is identified additional corrective actions will be initiated.

No safety limits were approached and no fission product barriers were challenged. There were no structures, systems, or components inoperable at the start of the event which contributed to the event other than described above. The Safety Injection Tanks, Low Pressure Safety Injection System, and High Pressure Safety Injection System are not required to be operable in Node

5. The malfunctioning high pressure safety injection valve did not affect the capability of the safety injection system to perform its intended function since there are other flowpaths available to inject borated water into the RCS (for example, redundant injection flowpaths into alternate RCS loop penetrations). All other components operated per design. Other than the personnel errors described above, the operators'ctions were correct and in accordance with procedural controls. Based upon the above, there were no safety consequences or implications resulting from this event and there was no threat to the health and safety of the public.

There have been no previous similar occurrences.

This report is also provided in accordance with Emergency Plan Implementing Procedure (EPIP)-03 for the Notification of Unusual Event described herein.

4IIC I OIIM Sddo (9 8(I

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~ ~

Arizona Nuclear Power Project P.O. BOX 52034 ~ PHOENIX, ARIZONA85072-2034 192-00348-JGH/TDS/DAJ February 26, 1988 NRC Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

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

Licensee Event Report 88-005-00 File: 88-020-404 Attached please find Licensee Event Report (LER) No. 88-005-00 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 trul yours, J. G. Hayn s Vice President Nuclear Production JGH/TDS/DAJ/kj Attachment cc: 0. H. Deflichele (all w/a)

E. E. Van Brunt, Jr.

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