ML20028H683

LER 90-034-00:on 901223,high Chlorine Concentration Caused Control Room Ventilation Manual Isolation & ESF Actuation. Caused by Instrument Error Code & Misinterpretation of Analyzer Indication.Flow reduced.W/910121 Ltr

ML20028H683
Person / Time
Site:	Quad Cities
Issue date:	01/21/1991
From:	Bax R, Hamann R COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-90-034, LER-90-34, RLB-91-27, NUDOCS 9101280069
Download: ML20028H683 (5)

Text

3 Commonralth Edison

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O . etd Jxt Nocte dwer Station 02710 200 Avenut NMh

, C,orcova, l!hnois 012424740 7etophuse 309'654 2241 RLB-91-27 January 21, 1991 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

Reference:

Quad Cities Nuclear Power Station Docket Number 50-254, DPR-29, Unit One Docket Number 50-265, DPR-30, Unit Two Enclosed is Licensee Event Report (LER)90-034, Revision 00, for Quad Cities Nuclear Power Station.

This report is submitted in accordance with the requirements of the Code cf Federal Regulations, Title 10, Part S0.73(a)(2)(iv): The licensee shall report any event or condition that resulted in a manual or automatic actuation of any Engineered Safety Feature (ESF).

Respectfully, COMMONWEALTH EDISON COMPANY QUAD CITIES NUCLEAR POWER STATION R. bL. Bax Station Manager RLB/MJB/jmt Enclosure cc: R. Stols T. Taylor INPO Records Center NRC Region III 9101280069 910121

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PDR ADOCK 05000254 S PDR j g;gpp98H

9 LICEN5tt EVICT RIPORT (LtR) Form Rev_2.0 Facility Name (1) Docket Number (2) Page f31

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j Quad Cities Unit one of El 01 01 01 21 El 4 1 lof!0!4 Title (4)

Manual isolation Of Centrol Room HVAC bue To M11tnterotelation of _the CL Analv2er Indication. .

. Event Date (1) LtR Number (El Reoort Date (71 Other Fac11111et Involved fB1 _

I Month Day Year Year /p,/p

/ sequential ///j Revision Month Day Year . Facility Na:E,_,Dgket Number f s )

/// N umbg,t_,,__, ]jfff Number 0Jad Citiet 01 El 01 01 01 21 61 E

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i 11 2 fl 3 91 0 91 0 0l314 010 0 11 211 91 1 Q1 El 01 01 01 l l gpg THis REPORT Is sVBMITTED PUR$UANT TO THE RE0u!REMENTs 0F 10CFR (Check one or more of the followinej f111 1 20.402(b) 20.40$(c) .1. 50.73(a)(2)(iv) _, 73.71(b)

POWER _ 20.405(a)(1)(1) __,_ 60.36(c)(1) 50.73(a)(2)(v) , 73.71(c)

LEYtl 20.40$(a)(1)(11) _ $3.36(c)(2) _ 50.73{a)(2)(vit, Other (Specify

_(J 01 0!0l0 _ 20.40$(a)(1)(111) __ 50.73(a)(2)(1) 50.73(a)(2)(v111)(A) in Abstract

// /// /,/ /,/ /,//,/ ///,/,/,/,/ /////,/ ,. 20.405(a)(1)(iv) _,,._ 50.73(alt 2)(ii) $0.73(a)(2)(v111)(B) below and in

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// 0 20.405(a)(1)(v) _,. 60.73(a)(2)(111) _ 50.73(alt 2)(x) Text)

LICEN$tt CONTACT FOR THIS LER f121 Name T[tfPHONE NUMElp ARIA CODE Rachel Hamann. Tech $taff fxt. 2119 3 10l9 61 El 41 -l 21 Il 41 1 COMPLETE ONE LINE FOR [ACH COM N FAIL]JEs,,,pt$CRIBE0 IN THit REPORT (131 CAU$t sYsitM COMPONENT MANUFAC- REPORTABLE CAUSL sYsitM COMPONENT MANUFAC. REPORTABLE d

TURER TD NPRD1 Tufilt TO NPPDS l l i l i l l l l I 1 i l i I l I i l I I I i 1 1 1 I l '/

$UPPLEMENTAL REPORT EXPECTED f141 Expected Month i Day I Year '

submission X lYet fff ves. comolate [XPECTED $UBMISSION DATE) l NO (

of3l11$l911 A857RACT (Limit to 1400 spaces, i.e. approximately fifteen single-space typewritten lines) (16)

ABSTRACT:

On December 23, 1990, Unit One was in the shutdown mode for a refueling outage and Unit Two in the RUN mode at 96 percent of rated core thermal power. At 2055 hours0.0238 days <br />0.571 hours <br />0.0034 weeks <br />7.819275e-4 months <br />,

-an Operator reported during his rounds that a high chlorine concentration indication existed. The Control Room Ventilation (HVAC) was manually isolated which is an Engineered Safety feature (ESF) actuation. At 2330 hours0.027 days <br />0.647 hours <br />0.00385 weeks <br />8.86565e-4 months <br />, an Emergency Notification System (ENS) phone call was completed per 10CFR 50,72(b)(2)(ll).

On December 31, 1990, the IM's determined the high concentration reading was actually an instrument error code, and the indicated chlorine concentration had been well below the trip setpoint.

The cause of the event was a manual ESF actuation due to a misinterpretation of the C1' Analyzer indication. The indication was believed to be a high chlorine concentration. It was later discovered that a high-chlorine concentration was not 4 present.

It is unknown what caused the alarm which was believed to be a high chlorine concentration. As part of corrective action, the manufacturer was contacted and an inspection of the system was completed. The inspection results are pending. A revised report will be submitted.

This report is submitted in'accordance with 10CFR 50.73(a)(2)(iv).

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44 LittMitt EV[b? kiPOR7 (LER) ftKT Cf W TION Fare Rav 2.0 FAe!LITV NAME (1) 00CKE7 NUMBER (2) . LER A ER f61 Pana (1)

Year j/,j/

/ sequential //j/j Revision j///

a /// humber Number h d cities unit ona 0 l E l o I o I o 1 21 E l 4 910 - oI114 - 0 I o of 2 or ol_4 TEXT Energy Industry Identification system (E!!s) codes are identified in the text as (XX1 PLANT AND SYSTEM IDENTIFICATION:

General Electric - Bolling Water Reactor - 2511 MWt rated core thermal power. ,

EVENT IDENTIFICATION: Manual Isolation Of Control Room HVAC Due To Misinterpretation of the C1 Analyzer Indication.

A. CONDITIONS PRIOR TO EVENTJ Unit: One Event Date: December 23, 1990 Event Time: 2055 Reactor Mode: 1 Mode Name: SHUTDOWN Power Level: 007.

-This report was initiated by Deviation Report D-4-1-90-150 SHUTDOWN Mode (1) - In this position, a reactor scram is initiated, power to the control rod drives is removed, and the reactor protection trip systems have been deenergized for 10 seconds prior to permissive for manual reset.

B. DESCRIPTION OF EVENT:

On December 23, 1990, Unit One was in a refueling outage with the mode switch in the shutdown position. Unit Two was in the RUN mode at 96 percent of-rated core thermal power. At 0754 hours0.00873 days <br />0.209 hours <br />0.00125 weeks <br />2.86897e-4 months <br />, an event (D4-1-90-149, LER 254/90-033)'had occurred which caused Reactor Building (NG)(VA) and Control Room [NA) Ventilation (HVAC)(VI) to isolate and Standby Gas Treatment (SBGT)[BH) to auto start. Repairs were made to the systems.: _At 1835 hours0.0212 days <br />0.51 hours <br />0.00303 weeks <br />6.982175e-4 months <br />, the reactor building _ ventilation was reset and the fans [ FAN) turned back on. At 1900 hours0.022 days <br />0.528 hours <br />0.00314 weeks <br />7.2295e-4 months <br />, control room ventilation was reset and toxic gas sample point A was selected. At 2055 hours0.0238 days <br />0.571 hours <br />0.0034 weeks <br />7.819275e-4 months <br />, the Unit One Equipment Attendant (EA) reported during his operating rounds that a Toxic = Gas Chlorine (C1) indication of 2.8 to 3.3 ppm existed. -This is above the trip setpoint of the Toxic

-Gas Analyzer. Control Room HVAC was manually-isolated and toxic gas sample point C was selected for the recirculation mode. At 2200 hours0.0255 days <br />0.611 hours <br />0.00364 weeks <br />8.371e-4 months <br />, the Instrument Maintenance (IM) Department reported that the Control Room chlorine' detector had-dried out.(a loss of electrolyte solution).- At 2330 hours0.027 days <br />0.647 hours <br />0.00385 weeks <br />8.86565e-4 months <br />, an Emergency Notification System (ENS) phone call was completed per 10CFR 50.72(b)(2)(11).

After further. investigation, the IM's discovered that the Toxic Gas Chlorine indication of 2.8 to 3.3 ppm was not an actual c'oncentration indication but rather an operational error code. The chlorine gas concentration was measured by the Chemistry. Department and found to be well below the trip setpoint.

, C- APPARENT CAUSE OF EVENT:

-This event is being' reported according to 10CFR 50.73(a)(2)(1v) which requires the

_ licensee. report any event or condition that resulted in manual or automatic actuation of'any Engineered Safety Feature (ESF).

l The cause of the event was a manual ESF isolation of the Control Room HVAC caused I by a misinterpretation of the C1 analyzer indication. The operator read the  ;

sporadic indication as a high concentration, but the monitor was actually giving an

( operational error code; therefore, an automatic isolation was not required.

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c Lit [N$tt [ YIN 7 REPOR7 QtR) 7 EXT fjg MMUA RQN Form Rev 2.0 ,

3 FACILITY hAME (1) DOCKET NUMBER (2) LtR NUMBER (6) Paae f31 4 , Year sequential / Revision g/// Number /// Nunsber Quad [1 ties unit one 0l $ 101010121 El 4 910 - 01314 - 01 0 01 3 0F DI 4 i VEXT Energy Industry Identi/1 cation system (E!!s) codes are identified in the text as (xx]

The cause for the system malfunction is unknown at this time and is under investigation. The manufacturer has completed an inspection of the system and the inspection results are pending. The probe tip was found to have dried out and was refilled. The ventilation system will remain-in the recirculation mode until all 4 appropriate corrective actions identified from the manufacturer's report are 4

implemented. A revised report will be submitted.

i.

D. SAFETY ANALYSIS OF EVENT:

The safety consequences of this event are minimal. The high toxic gas chlorine concentration read by the operator was actually an operational error code. The j measured chlorine concentration was found to be well below the trip setpoint.

Therefore, the Control Room Ventilation did not require isolation. The manual isolation of Control Room Ventilation was conservative in nature and represents the

, proper system alignment had the chlorine concentration exceeded the trip setpoint, which the operator originally believed to be the case. Sargent & Lundy cumpleted a study in May 1988 which showed that the possibility of a chlorine toxicity accident was minimal. With this information, the station is pursuing a Technical Specification revision to remove the Chlorine and Sulfur Dioxide Analyzers as a l required Control Room HVAC isolation signal.

E. CORRECTIVE ACTIONS: ~

The chlorine concentration was measured and found to be below the alarm setpoint.

Work request, 089087, was written to investigate. The Chlorine analyzer probe was filled with solution. The Control Room HVAC is being kept in the recirculation mode to observe the performance of the chlorine analyzer and to perform further investigation.

As recomr inded by Anacon, the manufacturer of the Chlorine Analyzer, system flow was reduced with the flow control valve (FCV)(FCV). The manufacturer performed an inspection of'the system on January 15,1991. The results of the inspection, when received, will be reviewed. System improvements will be initiated as appropriate.

A revised report will be submitted. (NTS 2542009015001).

, The training lesson plant for the C1 analyzer will be enhanced to include the operational self-checks of the analyzer. (NTS 2542009015002)

F. PREVIOUS EVENTS:

In the past five years there have been numerous events involving-the Toxic Gas Analyzers. The following is s list of_DVR's and LER's written on the Toxic Gas Analyzer problems

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104-1-87-014 1/25/87 CR Vent C1 Monitor Inop due to low electrolyte level.

D4-1-87-042 5/20/87 CR Vent Ammonia and C1 analyzer failure due to corroded solder joint on probe wire.

04-1-87-060 6/29/87 , CR Vent Isol due to Cl Monitor problem 3847H

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Lit [g11E EVENT REPORT fLER1 TEXT CONTINUATION Forni Rev 2.0 .

g FACILITY NAME (1) DOCKET NUMetR (2) Ltt NUMa[R f61 Fane (3)

YC'ar Sequential / Revision M ar /,/j/j/

/ htenbar thud Citiet Unit One 0 l 1 1 0 1 0 l 0 l fl El 4 910 - 0l3 l4 - 01 0 01 4 0F 014 TEXT Energy Industry Identification system (t!!S) codes are identified in the text as [XX)

LER 90-13 7/9/87 due to condensation, physical defects, and 7/14/87 sample line contamination problems D4-1-87-106 1/28/87 CR HVAC C1 and sulfur dioxide analyzer failure due to unresponsive Cl detector, and sporadic Operation.

04-2-88-0001 1/1/88 CR HVAC C1 and sulfur dioxide analyzer failure due to probe seeing too much flew.

D4-1-89-128 12/25/89 CR Vent Isol due to dried out C1 probe LER 89-26 D4-1-90-146 12/20/90 CR Vent Isol due to dried out C1 probe LER 90-26 Five of the above events were caused by a dried out chlorine probe, which occurred during cold, dry weather.

G. COMPONENT FAILURE DATA:

The Toxic Gas Monitor is made by Anacon, Inc.

Part #1 15002-05 Model #: M-17 The Toxic Gas Monitor is not NPRDS reportable.

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