ML17285A528

LER 89-012-00:on 890505,unplanned Reactor Scram Occurred During Performance of Reactor Protection Sys Logic Sys Functional Test.Caused by Procedural Inadequacy.Procedure Will Be Revised to Provide Specific resetting.W/890605 Ltr

ML17285A528
Person / Time
Site:	Columbia
Issue date:	06/05/1989
From:	Arbuckle J, Powers C WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-89-012, LER-89-12, NUDOCS 8906140197
Download: ML17285A528 (6)

Text

D1S1BUTl0.'i DEMOhilP~0.'i SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:8906140197, DOC.DATE: 89/06/05 NOTARIZED: NO DOCKET FACIL:50-397 WPPSS Nuclear Project, Unit 2, Washington Public Powe 05000397 AUTH. NAME AUTHOR AFFILIATION ARBUCKLE,J.D. Washington Public Power Supply System POWERS,C.M. Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION 89-012-00:on 890505,reactor scram during reactor

SUBJECT:

LER protection sys logic sys functional test.'/8 DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE:

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

NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA i 1 1 PD5 PD 1 1 SAMWORTH, R 1 1 INTERNAL: ACRS MICHELSON 1 1 ACRS MOELLER 2 2 ACRS WYLIE 1 1 AEOD/DOA 1 1 AEOD/DS P/TPAB 1 1 AEOD/ROAB/DS P 2 2 DEDRO 1 1 IRM/DCTS/DAB 1 1 NRR/DEST/ADE SH 1 1 NRR/DEST/ADS 7E 1 0 NRR/DEST/CEB SH 1 1 NRR/DEST/ESB SD 9H 1.

1 1

1 NRR/DEST/ICSB 7 1 1 NRR/DEST/MEB NRR/DEST/MTB 9H 1 1 NRR/DEST/PSB SD 1 1 NRR/DEST/RSB 8E 1 1 NRR/DEST/SGB SD 1 1 NRR/DLPQ/HFB 10 1 1 NRR/DLPQ/PEB 10 1 1 NRR/DOEA/EAB 11 NUDOCS-ABSTRACT RES/DSIR/EIB 1

1 1

1 1

1 L~

hJRR/DREE REEF

~PB 10 RES jjDSR/PRAB 2

1 1

2 1

1 RGN5 FILE 01 1 -

1 EXTERNAL: EG&G WILLIAMS,S 4 4 FORD BLDG HOY I A 1 1 R L ST LOBBY WARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC MAYS,G 1 1, I NSIC MURPHY,G.A 1 1 S

D D

NOTE 'rO ALL "RIDS" RECIPIENTS ~

S PLEASE HELP US TO REDUCE WASTE! CONI'ACT 'IHE DOCU~'Z CONTROL DM',

ROC'l-37 (EXF. 20079) P3 ELQGNATE YOUR NME FR% DISTRIBVZIGN LISTS FOR DOCUt~S YOU DON'T NEEDt TOTAL NUMBER OF. COPIES REQUIRED: LTTR 43 ENCL 42

WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O. Box 968 ~ 3000 George N'ashinglon Way ~ Richland, 11'ashinglon 99352 Docket No. 50-397 June 5, 1989 Document Control nesk U.S. Nuclear Regulatory Commission Washington, D.C . 20555

Subject:

NUCLEAR PLANT NO. 2 LICENSEE EVENT REPORT NO.89-012

Dear Sir:

Transmitted herewith is Licensee Event Report No.88-012 for the WNP-2 Plant.

This report is submitted in response to the report requirements of 10CFR50.73 and discusses the items of reportability, corrective action taken, and action taken to preclude recurrence.

Very truly yours,

(//>(, 0"u~~

C.M. Powers (tl/D 927ll)

WNP-2 Plant Manager CMP: 1 g

Enclosure:

Licensee Event Report No.89-012 cc: Mr. John B. Martin, NRC - Region V Mr. C.J. Bosted, NRC Site (M/D 901A)

INPO Records Center - Atlanta, GA Ms. Dottie Sherman, ANI Mr. D.L. Williams, BPA (M/D 399)

NRC Fotm 366 U.S. NUCLEAR REGULATORY COMMISSION (9 83)

APPROVED OMB NO. 31504104 LICENSEE EVENT REPORT (LER) EXPIRES'BI31ISS FACILITY NAME Ill DOCKET NUMBER (2) PAGE. 3I ea P ant - Unit 2

"'" "'Reactor Scram During Reactor Protection System Logic System Functional Test 0 5 0 0 0 9 7 1 OFO 4 while Plant was Shutdown for Refuelin and Maintenance Outa e-Inade uate Procedure EVENT DATE (5) LEA NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)

MONTH DAY YEAR YEAR SSOVSNTIAL Rl VISiON DAY FACILITYNAMES DOCKET NUMBERIS)

NVMSER NVMSER MONTH YEAR 0 5 0 0 0 0 505 8 9 9 0 1 0 06 058 9 0 5 0 0 0 ORE RATING THIS REPORT IS SUBMITTED PURSUANT T 0 THE AEOUIREMENTS OF 10 CFR 5: ICneck one or mort of tne Ioiiorv npf lll MODE (9) 5 20.402(a) 20.405(cl 50,73(el (2) (ivl 73.71(S)

POWER 20,405( ~ l(1 I (il 60.36(cl(l I 50,73( ~ ) (2)(v) 73.71(n Text, NRC Form 20.405( ~ ) Ill(iii) 50.73( ~ I (2) I I) 60.73(e ) (2)(xiii)(A) 366AI 20.405 (e) I I II iv I 60,73( ~ l(2)(SI 60,73(el(2)(viiil(8) 20AOS(e l(1 l(v) 50,73(e)(21(iiil 50,73( ~ II2)Iel LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER AREA CODE COMPLETE ONE LINE FOR EACH COMPONENT FAILUAE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COMPOrvENT MAfx'FAC REPORTABLE MANUFAC REPORTABLE TVRER TO NPRDS CAUSE SYSTEM COMPONEIIT TURER TO NPADS SUPPLEMENTAL REPORT EXPECTED (1 ~ I MO'xT xx DAY YEAR EXPECTED SUBMISSION DATE I15i YES Iff yn tompien EXPECTED $ (f84IISSIOIY DATEI ABSTRACT ILimit to I400 Ipttn rt epproximettfy frfrttn trap'etpett typtxyrrtttn Anni IIS)

On May 5, 1989 at 2215 hours an unplanned reactor scram occurred during the performance of a Reactor Protection System (RPS) Logic System Functional Test (LSFT). However, no control rod movement occurred because the Plant was in a shutdown condition (annual maintenance and refueling outage) with all control rods inserted.

At the time of the event, Plant personnel were performing the mode switch shutdown scram interlocks section of the LSFT procedure. This part of the LSFT, which initiates a full scram, tested the timeout of a scram reset timing relay (RPS-RLY-K16A). After it was verified that the relay timed out and energized as required, the Test Engineer directed Plant Control Room Operators to reset the scram. The Operators, reset the scram as directed, but failed to bypass the Scram Discharge Volume (SDV) high level trip during this process. The procedure did not provide direction to bypass the SDV high level trip.

In addition, the SDV had previously been isolated for maintenance and, as a result, the automatic function (draining/isolation) was not operational during the event. This condition allowed the SDV to continue filling even after the scram had been reset.

Because the SDV high level trip was not reset, this resulted in the unplanned SDV high level scram.

NRC Farm 356 (9 83)

NRC Form 36BA U.S. NUCLEAR REGULATORY COMMISSION (84)3)

LICENSEE EV REPORT ILER) TEXT CONTINUATIO APPROVED OMS NO. 3160-0104 EXPIRES: 8/31/88 FACILITY NAME (1) OOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

YEAR 111@ SSQVSNTrAL gM REVrSION NVMSSII Xio: NUMSSrr Washington Nuclear Plant - Unit 2 o s o o o 397 89 01 2 000 2 QF 0 4 TEXT /IImore e/reee /e rer)o/red, ore eddi t/one NRC Form 366A'e/ (ll)

Abstract (continued)

The cause of this event is procedural inadequacy in that the procedure did not provide specific direction on resetting the full scram signals generated during the performance of the LSFT. Immediate corrective action consisted of Plant Operators bypassing the SDV high level trip and successfully resetting the scram. As a further corrective action, the RPS LSFT procedure will be revised to provide specific direction on resetting the full scram signals generated by the procedure.

This event posed no threat to the .health and safety of either the public or Plant personnel.

Plant Conditions a) Power Level - OX b) Plant Hode - 5 (Refueling)

Event Descri tion On Hay 5, 1989 at 2215 hours an unplanned reactor scram occurred during the performance of a Reactor Protection System (RPS) Logic System Functional Test (LSFT). It should be noted that no actual control rod movement occurred because the Plant was in a shutdown condition (annual maintenance and refueling outage) with all control rods inserted.

At the time of the event, Plant personnel were performing Plant Procedure (PPH) 7.4.3. 1.2. 1, Section E, RHode Switch Shutdown Scram Interlocks." This part of the LSFT tested the timeout of a relay (RPS-RLY-K16A) associated with the mode switch shutdown scram interlock. The test involves moving the reactor mode s'witch to the shutdown position (which initiates a full scram) and measuring the time it takes for the scram reset timing relay to close. Following the test, Plant Operators then reset the RPS logic. This section of the test is performed four times, once for each of the four RPS subchannels.

After it was verified that the scram reset timing relay (RPS-RLY-K16A) timed out and energized as required, the Test Engineer directed Plant Control Room Operators to reset the scram. The Operators reset the scram as direct'ed, but failed to bypass the Scram Discharge Volume (SDV) high level trip during this process. The SDV had previously been isolated (vent and drain valves closed) due to maintenance on the air supply solenoid pilot valves. These pilot valves allow air to the SDV vent/drain valves, during the period. of time when a scram is reset, causing them to open and drain water from the SDV to the radioactive drain system. When a fu'il scram signal is generated, these pilot valves vent air from the SDV vent/drain valves which causes them to close on spring pressure, isolating the SDV. However, because the SDV was isolated, the automatic function (draining/isolation) was not operational during the event and, as a result, this condition allowed the SDV to continue filling because the vent and drain valves did not open following scram reset. This filling was due to drainage of the scram discharge header into the instrument volume.

NRC FORM SBBA ~U~ S. CI'Or 1968 520 589r00010 (0 83) r

NRC Form 366A U.S. NUCLEAR REOULATORY COMMISSION IB43)

LICENSEE EV REPORT (LER) TEXT CONTINUATIOI APPROVED OMB NO. 3150M)04 EXPIRES: 8/31/68 FACILITY NAME 111 DOCKET NUMBER 12) LER NUMBER 16) PACE 13)

~" 'EOUENTIAL r/RN REVISION NUMSER i'>?/I NUMSER Washington Nuclear Plant - Unit 2 o s o o o 97 89 0 1 2 0 0 3 oF 0 4 TEXT /ilmoro sirsss ls rsqodrsd, oss sddi)loss/l/RC Form 36&4's/1)7)

However, if the SDV high level trip had been bypassed prior to resetting the scram, this event would not have occurred. It should be noted that the procedure did not 4

provide dir ection to- bypass the SDV high level trip.

The following is a sequence of events associated with this LER:

22:14:50 hours - Reactor mode switch to shutdown. Full RPS scram as planned.

22: 15:22 hours - SDV not drained alarm (indicative of filling the SDV due to leakage past control rods).

~ ZZ: 15:32 hours - SDV high level rod block (due to continued filling'of the SDV from leakage).

~ 22:15:36 hours - SDV high level scram (unplanned).

Immediate Cori ective Action Plant Control Room Operators bypassed the SDV high level trip and reset the scram without further incident.

Further Evaluation and Corrective Action A. Further Evaluation

1. This event is being reported per the requirements of 10CFR50.73 (a)(2)(iv) as an "event or condition that resulted in manual or automatic actuation of any Engineered Safety Feature e (ESF), including the Reactor Protection System (RPS).

2. With the exception of the Scram Discharge Volume, there were no structures, components or systems that were inoperable at the start of this event that contributed to the event.

3. The root cause of this event is procedural inadequacy in that PPI1 7.4.3. 1.2. did not provide specific direction on resetting the scram 1

condition during the performance of this LSFT.

B. Further Corrective Action

1. PPH 7.4.3. 1.2.1- "Reactor Protection System LSFT," will be rev,ised to provide specific direction on resetting the full scram signa'Is generated by the procedure.

Safet Si nificance There is no safety significance associated with this event in that the reactor was in a cold shutdown condition, there was no control rod movement, there was no actual initiating condition and the RPS functioned as designed to cause a reactor scram. Accordingly, this event posed no threat to the health and safety of either the public or Plant personnel.

NRC CORM 366A AU.S. CPOr Ised-62O-SSP OOO)n IB 83r

NRC Form 368A U.S. NUCLEAR REGULATORY COMMISSION (943) r~

LICENSEE EV REPORT (LER) TEXT CONTINUATIO APPROVED OMB ND. 3I50-0104 EXPIRES: 8/31/88 FACILITY NAME I'I) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

(f YEAR gPg SEOUENTIAL

?  ?'UM884 REVISION v??8 NUMSE4 Washin ton Nuclear Plant - Unit 2 0 5 0 0 03 97 89 0 1 2 0 0 0 4 OF 0 TEXT fifmore speoe ls required. use eddiu'orrel NRC Form 3IMA'sf (IT)

Similar Events Hone EIIS Information Text Reference EI IS Reference System Component

.Reactor Protection System (RPS) JC Scram Discharge Volume (Control Rod Drive System) AA Scram Reset Timing Relay (RPS-RLY-K16A) JC NRC FORM 388A re 8 'PGr )988-820-589 00020 (9S)3)