ML20005F850

LER 89-034-00:on 891211,partial Train B Containment Depressurization Actuation Signal Generated During Slave Relay Testing.Caused by Personnel Error.Individual Counseled & Testing Procedures revised.W/900109 Ltr

ML20005F850
Person / Time
Site:	Millstone
Issue date:	01/09/1990
From:	Conway R, Scace S NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-89-034, LER-89-34, MP-90-024, MP-90-24, NUDOCS 9001170321
Download: ML20005F850 (4)

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l January 9. 1990 1l MP-90-024

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. Re: 10CFR50.73(a)(2)(iv)- ,

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Reference:

Facility Operating License No. NPF-49 Docket Noc 50-423

" Licensee Event Report 89-034-00 . ,,

g . Gentlemen:

This letter forwards Licensee Event Report 89-034-00, required to be submitted pursu .

L anteo 10CFR50.73(a)(2)(iv), any event or condition that resulted in the automatic actua-  ;

tion of any Engineered Safety Feature.

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" Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY a

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' A Station Superintendent Millstone Nuclear Power Station ,

-SES/RDC:tp' q TAttachinent: 'LER 89-034-00 cc: W. T. Russell, Region 1 Administrator W. L Raymond, Senior Resident inspector, Millstone Unit Nos.1, 2 and 3 D. H.'Jaffe, NRC Project Manager, Millstone Unit No. 3 j ,

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.1) i kd>cc NRc Form 366 ; U.6, NUCLE AR REGULATORY COMM2SSlON APPROVED 046 NO, 3160-0104 j3 t, O-89) 1 EXPIRES 4 /30/02 -

I Estimated Dumn per responsa to compiy with this R , mtormation conecuon reauest: 60.0 hrs. Forware

,e comments regrama euroen est. mate to tne Recoros y LICENSEE EVENT REPORT (LER) ano Reports Management Branen #630). U 6 Nuclea'

, , Reguiatory Commission. Washmgton. DC 20666. ene to V i tne Pape work Reduction Project (3160-0104). Office of

, Management anc Booget. Wasnmoton. DC 20603z y

F ACIUTY NAME O) 3 DMET NUMbik th "M j u Millstone Nuclear Power Station Unit 3' 015l 010109 l 2 l 3 1lOFl 0l 3- i TIT LE (d i i

Partial Containunt Depressurization Actuation Signal Due to Operator Error i EVENT DATE (61 LER NLNBER isi AFPORT DATE (7) OTHER F ACILITIE S INv0LVED 181 MONTr oAY YEAR YEAR MONTH DAY YEAR F ACUTY NAME6 01Sl0l0]of I l l

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OPERATING THIS REPORT IS BEINO $UBMiTTED DURSUANT TO THE Rf 0VIREMENTS 0810 CFR 5: (Cneck one or more of the following)(11) 20 402(b) 20 402tc) 7 3,71(b)

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OTHER (Specify m Abstract bwow and m Text, NRC Form 166 A) 20.406(a H 1 Hili) 60.73(a H2 H O 60.73 te H2)(viio t A) i 20 406(a)OHiv) 60.73(a) f2 Hil) 60. 73(a H2)(viit H B) 20 405tanttitiv) 60.73(a H2Hil0 60 73taH2Hx)

LICENSEE CONTACT FOR TH!S LER (12i NAME TELEPHONE NUMBER Robert P. Conway, Senior Engineer, Ext 5642 7l0l3 4[4l7l-l1l7l9l1 COMPLETE ONE UNE FOR F ACH COMDONENT FAILURE DESCRIBED IN TMS REPORT (13)

CAUSE SYSTEM COMPONENT M$MC- CAUSE SYSTEU COMPONENT N h 0* 7g >'

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. I II I I I I I III I I I SUPOL EMENT AL REDORT EXAECTED .14) MONTH DAY YEAR SUBM SiON l

] -YES fif yes. compiete EXPECTED SUBM:SSION DATE) NO DA E 06) l l l f ABSTRACT (umit to 1400 spaces. Le,, approximately tmeen smgie-scace hpewrmen hries) (16; L

1 . At 2236 hours0.0259 days <br />0.621 hours <br />0.0037 weeks <br />8.50798e-4 months <br /> on December 11, 1989 in Mode 1 at 100re power, 557 degrees and 2250 psia, a partial B Train Containment Depressurization Actuation (CDA) signal was generated by personnel error while F conducting Slave Relay Testing. Procedural inadequacy was a contributing factor since the step being h executed contained three specific actions not directly related to each other. The operator failed to execute l one of the actions in the step, to reset automatic test circuits prior to testing the Containment Spray Actuation circuit. When the test was initiated, the B Train Emergency Diesel Generator Load Sequencer (EGLS) generated a partial B Train CDA signal. Containment spray and water injection into the reactor l did not occur because only a partial CDA signal was generated. The operator conductmg the test

l. immediately reset the CDA Slave Relay. Operators verified that the CDA signal had occurred only on the B Train and that the CDA was not required. All equipment functioned as designed. The operator conducting the test was counselled on proper execution of procedures, and ieviewed operation of the EGLS. The A and B Train Slave Relay Testing procedures were revised to separate the single step, which i required three unrelated actions, into three separate steps, and to require positive verification that automatic test circuits have been reset.

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LICENSEE EVENT REPORT (LER) '",'"may;",g*,cy,onJg'L6,tf, "','g ,lfn*,yL, TEXT CONTINUATION ane Rooert, Management eranen to-530). u s. Nucioar Reputatory Commission. Washington. DC 20555. and to tne Paperwork Reduction Project (3160-0104L office of s

Management and Buonet Wasnington. DC 20503.

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< FAcOTY NAME (1) DOCKET NUMBER (2) LF A NUMBF A + - PAGE (3)

YEAR Millstone Nuclear Power Station Unit 3 - ~ ~

ol 5l ol ol old l2 l3 Sl9 0 ] 3 l -l 0l0 0l 2 OF 0l3 TEXT (tf more space is required. use modationat NRC Form 366A's) (17)

1. Descrintion nf Event -

, _ At 2236! hours on December 11, 1989 while operating in Mode I at 100G power, 557 degrees Fahrenheit and 2250 psia, a partial B Train Containment Depressurization Actuation (CDA) signal was initiated by personnel error while conducting B Train Slave Relay Testing at the B Train Emergency Diesel Generator Load Sequencer (EGLS). The operator failed to properly execute the

, " .~ procedure step which resets automatic test circuits, prior to testing the Containment Spray Actuation circuit. When the test was initiated, the B Train EGLS generated a partial B Train CDA signal..

Engineered Safety Features (ESP) equipment automatically started including the B (Train) l

' Emergency Diesel Generator, (B) Quench Spray pump, (B) Safety injection pump, (B) Auxiliary ,

Feedwater pump, (B) Residual Heat Removal pump, and the standby (C) Charging pump. These equipment actions were proper for the partial CDA signal transmitted by the EGLS, Because only a partial CDA signal was generated, Containment spray and water injection into the reactor did not occur. The operator conducting the test immediately reset the CDA Slave Relay being tested.

Immediate a' ctions by control room operators included verifying that the Containment i Depressuritation Actuation signal had occurred on only the B Train and that a CDA was not  !

required. ESF equipment which automatically started was stopped, and all plant equipment was -I

' restored to the proper configuration. Equipment operation was reviewed, and found to be satisfactory.

111.  : Catne of Event

'1 Root cause of the event was personnel error, in that the operator did not properly execute one step l in the procedure. Procedural inadequacy was a contributing factor since the step contained three specific actions not directly related to each other. This contributed to the event by requiring the operator to simultaneously complete several tasks within one procedural step. This allowed completion of one or more actions without accomplishing the entire step.

1 III. AnahO of Event  !

. This event is reportable under 10CFR50.73(a)(2)(iv) as an event that resulted in the automati:

actuation of an Engineered Safety Feature. Immediate notifications were made in accordance with 10CFR50.72(b)(2)(ii). There were no significant safety considerations since the inherently safe I design of the ESF actuations system produced a conservative action: generation of a partial CDA signal. This did not affect plant operations or the ability of safety systems to respond to actual plant conditions. Because only a partial CDA signal was generated, containment spray and water injection into the reactor did not occur. ,

IV. Corrective Action The operator conducting the test was counselled on proper execution of procedures, and reviewed operation of the Emergency Diesel Generator Load Sequencer. To prevent recurrence, the A and 3 Train Slave Relay Testmg procedures were revised to separate the single step which required three unrelated actions, into three separate steps, and to require posiuve verification that the EGLS automatic test circuits have been reset. Yellow warning signs stating " CAUTION: THE SEQUENCER WILL NOT STAY IN TEST UNLESS THE AUTO TEST IS RESET" are permanently mounted in the EGLS cabinets. Adequacy of these warmng signs was reviewed and found to be satisfactory.

NRC Form 366A (6-80;

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s N8tc Fortn 5t,6A U.S,. NUCLEAR REGULATORY coMMISSloN . APPROVED OMB NO. 3150-0104 i?

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(6-89) E XPIRE S: 4f30/92 Estimated buroen per response te comply with this

' '***2'" comOm 'oou * : 50 0 " " Fo'** c -

LICENSEE EVENT REPORT (LER) c"omments regarding buruen'* estimate 'to ine Rec'oros .

o'- TEXT CONTINUATION and Reports unnagement eranen ip-sao). o s. twem l t - Regulatory commission. Wasnington Oc 20555. anc to l tne Paperwork Reduction Pro;ect (3150-0104). Office of

[' : i Manacemant and Buopet. Wash'ncton. De 20503 FACILfTY NAME (1) DOCKET NUMBER (2) LFA NUMPEA @ PAGE (3)

YEAR n . Millstone Nuclear Power Station L Unit 3 ~ ~

0l 6l 0l 0l 0l4 l2 l3 8l9 0l 3l I 0]0 0l 3 OF 0l3 TEXT (11 more soace is reouired. use accational NRc Form 366A s) (17) ,

V. Mditionni information Three similar events of ESF actuations due to personnel error are described in Licensee Event Reports (LER) 88-019-00 (inadsertent Control Buildmg isolation Due to Personnel Error) and 89-005-00.(Inadvenent Safety injection Due to Personnel Error by Switch Mispositioning), and

' 89-013-00 ("A" Train Loss of Power Signal Due to Personnel Error). LER 88-019-00 reported a '

Control Building Isolation ESF actuation due to personnel error in entering a radiation monitor setpoint. - Corrective actions were adequate to prevent future ESF actuations from the radiation monitoring system, but were not applicable to the event reported herein. LER 89-005-00 and LER 89-013-00 reported ESF ac:uations due to personnel error by failing to be fully cognizant of the total impact of their actions, and failing to follow detailed procedures. While these events are similar in their root- cause and affected equipment, there were significant differences in the i

sequence of actions during each event. The corrective actions were adequate to prevent recurrence i

of the same events, but due to unique circumstances in each case, these previous corrective actions l

could not have prevented this event.

Ell 9 Codes Systems JE - Engineered Safety Features Actuation System

- comnonents None .

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NRc Form 366A (6-89)