ML20044B240

LER 90-012-00:on 900612,control Room Ventilation Emergency Air Filtration Unit Declared Inoperable.Caused by Heater Malfunction.Work Request initiated.W/900712 Ltr

ML20044B240
Person / Time
Site:	Quad Cities
Issue date:	07/12/1990
From:	Bax R, Michael Brown COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-90-012-02, LER-90-12-2, RLB-90-181, NUDOCS 9007180189
Download: ML20044B240 (5)

Text

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,- 1 v Commonwealth' Edison -l

. Omd Citam Nuclear Power Station - l

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. 22710 206 Avenue North  ;

. Coroova, menos 61242 9740 Telephone 30B$$4 2241 l

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I RLB-90-181

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.._- i July 12, 1990 l 4

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U. S. Nuclear Regulatory Commission Document Control Desk Hashington, DC 20555 l

Reference:

Quad Cities Nuclear Power Station  :

Docket Number 50-254 DPR-29. Unit One ,

i-L Enclosed is Licensee Event Report (LER)90-012, Revision 00, for Quad Cities Nuclear Power Station.

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l- This report is submitted in accordance with the requirements of the Code of l Federal Regulations. Title 10, Part 50.73(a)(2)(v)(A): The licensee shall . i h report any event or condition that alone could have prevented the fulfillment l' of the safety function of structures or systems that are needed to shutdown i the reactor and maintain it in a safe shutdown condition.

Respectfully, COMMONHEALTH EDISON COMPANY QUAD CITIES NUCLEAR POWER STATION 1 rptB Station Manager l RLB/HJB/jlg Enclosure .

cc: R. Stols T. Taylor INPO Records Center NRC Region III 2899H 9007180189 900712 FDR ADOCK0500ig4 i

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LICENSEE EVENT REPORT (LER) rom Rev 2.0

, Facility Name (1) DockCt Number (2) Pane (3)

Ouad' Cities Unit one 01510101 O! 21 El 4 ~1lofl0l4 Title (4)

B Control Room HVAc Failed To Attain Reautred Tomoerature Differential. Believed To Be Due To Heater Problem.

Event Date (5) LER Number (6) Rooort Date (7) Other Facilities involved (B)

Month Day Year Year /jj// sequential /j/f Revision Month Day Year Facility Names Docket Numberft) f f

/// Number /// Number

_0und citiet 01Bf01010121615

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01 6 11 2 91 0 91 0 01112 010 017 11 2 91 0 01 Sl 01 Of Of f I OPERATING

(( heck one er more of the followino) (11) 4 20.402(b) 20.405(c) 50.73(a)(2)(iv) 73.71(b) power _ 20.405(a)(1)(1) . 50.36(c)(1) _K. 50.73(a)(2)(v) 73.71(c)

LEVEL 20.405(a)(1)(ti) 50.36(c)(2) 50.73(a)(2)(vil) _ Other (specify (10) 0l9l8 20.405(a)(1)(iii) 50.73(a)(2)(1) 50.73(a)(2)(viii)(A) in Abstract

/,// /,/,// /,/,/,/,/,/,// / // / /,//,/ / //

20.405(a)(1)(iv) 50.73(a)(2)(ti) 50.73(a)(2)(viii)(B) below and in

///}/'///}/}/'

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jjjj 20.405(a)(1)(v) _ 50.73(a)(2)(iii) 50.73(a)(2)(x) Text)

LICENSEE CONTACT FOR THIS LER (12)

Name TELEPHONE NUMBER AREA c0DE p Brown. Reaulaterv Assurance. Ent. 3102 131019lI61$l41-l212141 COMPLETE ONE LINE FOR EACH COMPON NT FAILURE DFSCRIBED IN TH!s REPORT (13)

CAusE SYSTEM COMPONENT MANuFAC- REPORTABLE / CAusE SYSTEM COMPONENT MANuFAC- REPORTABLE j

TURER 70 NPRDS_ / TURER TO NPRDs 1

1 I I I I I I I I I I I I f

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i I-l 1 I I i I I l l l l l l SUPPLEMENTAL REPORT EXPECTED (14) Espected Month i Dav l Year Submission lyes (If vet. complete EXPECTED SUBM15$10N DATE) X l NO l !l !l ABSTRACT (Limit to 1400 spaces, i.e. approximately fif teen single-space typewritten lines) (16)

ABSTRACT:

On June 12, 1990 at lill . lours, Unit One and Unit Two were in the RUN mode at 98 and 100 percent of rated core thermal power respectively. At this time, the Shift Engineer (SE) declared the control room (CR) ventilation (HVAC) emergency air filtration unit (AFU) inoperable. While performing procedure QOS 5750-2, Control Room Emergency Filtration System Monthly Test, the required 15 degree Fahrenheit

(*F) temperature difference across the heater could not be attained. The CR HVAC was declared inoperable and an outage report was initiated. An Emergency Notification System (ENS) phone notification was completed in accordance with 10 CFR 50.72(b)(2)(iii)(A).

The cause of this event is believed to be due to the heater, however, it is not known why the heater could not produce the required temperature difference.

Corrective actions included decreasing the flow rate within the allowable range,

, checking heater current, and retesting the system. On June 13, 1990, the system

, was successfully tested.

This report is being submitted in accordance with 10 CFR 50.73(a)(2)(v)(A).

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LICElst(( EVENT ktPORT (LER) TEXT CONTIIA1ATION Form Rev 2.0

, FACILITY NAME (1) DOCKET NUMBER (2) Ltk IUMBER (6) Pane (3) j Year /// Sequential /j/j/ Revision jj/j

// M er j//

/ Nus6er Quad cities Unit one 0 l $ 1010 l 0121 $14 910 - 011l2 - 0I0 012 0F 014 TEXT Ent ey Incustry Identification system (E!!s) codes are identified in the tout as (XXj PLANT AND SYSTEM IDENTIFICATION:

General Electric - Boiling Water Reactor - 2511 MHt rated core thermal power.

EVENT IDENTIFICATION: B Control Room HVAC Failed To Attain Required Temperature 4 Differential, Believed To Be Due To Heater Problem.  !

1 A. CONDITIONS PRIOR TO EVENT: 1

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Unit: One Event Date: June 12, 1990 Event Time: lill I Reactor Mode: 4 Mode Name: RUN Power Level: 981  ;

This report was initiated by Deviation Report D-4-1-90-048 RUN Mode (4) - In this position the reactor system pressure is at or above 825 ,

psig, and the reactor protection system is energized, with APRM protection and RBM -

interlocks in service (excluding the 151 high flux scram).

B. DESCRIPTION OF EVENT:

On June 12, 1990 at lill hours Unit One and Unit Two were in the RUN mode at 98 and 100 percent of rated core thermal power respectively. Procedure 005 5750-2, -

Control Room Emergency Filtration System Monthly Test had been completed for the B train and a heater temperature difference (delta t) of 12 degrees Fahrenheit (*F) had been observed in lieu of the required 15'F or greater. The B control room (CR) emergency air filtration Unit (AFU) system [VI) was declared inoperable and 005 5750-02, Control Room Emergency Filtration System Inoperable Outage Report, was initiated.

An Emergency Notification System (ENS) phone notification was completed at 1126 [

hours in accordance with 10 CFR 50.72(b)(2)(iii)(A).

Operating (0P) Instrument Maintenance (IM), and Electrical Maintenance (EM) were dispatched to investigate and work request Q85295 was initiated. At 1400 hours0.0162 days <br />0.389 hours <br />0.00231 weeks <br />5.327e-4 months <br />, the B train was started to check AFU system flow rate. The AFU flow was verified normal, but at the high end of the acceptable range at 2200 cubic feet per minute (CFM). The ems verified heater [EHTR) operation by checking current draw to be l within normal value. The Shift Engineer (SE) after discussions with the IMs and l

ems had the AFU flow reduced to 1800 CFM to obtain a higher delta t across the l heater. The IMs noted that the B AFU booster fan discharge flow control valve

' (FCV) [FCV), 1/2-5741-329, would not respond when attempting to adjust flow. Work request Q85286 was written to repair the B FCV.

On June 13, 1990 at 1035 hours0.012 days <br />0.288 hours <br />0.00171 weeks <br />3.938175e-4 months <br /> the B train was restarted. At 2035 hours0.0236 days <br />0.565 hours <br />0.00336 weeks <br />7.743175e-4 months <br />, the required ten hour operability test was successfully completed for the B train with an acceptable 17 'F delta t recorded. The CR emergency AFU system was declared i operable and the outage report terminated.

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LICENSEE EVENT REPORT (LER) TEXT c0NTINLIAT10N Form Rev 2.0

. FACILITY NAME (1) DOCKET NUMBER (2) LER NLIMBER (6) Pane (3)

Year /// Sequential /j/j/ Revision j/j/j

/ Number f

/// Number _

_ound Cities Unit one 0 I $ 1 0 1 0 1 0 1 21 $1 4 910 - 0!1l2 - 010 01 3 oF 01 4 TEXT Energy Industry Identification system (E!!s) codes are identified in the tout as (XX)

No structures, systems, or components were known inoperable or degraded at the start of this event that could have contributed to the event.

C. APPARENT CAUSE OF EVENT:

This report is being sobmitted in accordance with 10 CFR 50.73(a)(2)(v)(A): The licensee shall report any event or condition that alone could have prevented the fulfillment of the safety function of structures or systems that are needed to shutdown the reactor and maintain it in a safe shutdown condition.

Technical Specification 3.8.H.1 requires that the control room emergency filtration system, including at least one booster fan shall be operable at all times when secondary containment integrity is required. Technical specification 4.8.H.2 requires that the AFU inlet heater demonstrate a heater delta t of IS*F.

The cause of this event is believed to be due to the heater. It has not been determined why the heater could not attain the required delta t at the higher flow. Initial checks of current draw indicated heater performance was acceptable in this area.

D. SAFETY ANALYSIS OF EVENT:

Technical Specification 4.8.H.2.b requires that at least once per operating cycle, the operability of the AFU inlet heater demonstrate a heater delta t of 15'F. The heaters purpose is to maintain incoming air humidity to the charcoal filter less than 70 percent (%) relative humidity. This is necessary because higher humidity conditions tend to deposit free water in the charcoal filters, loading the beds and reducing their ability to remove radio-iodine gases.

Assuming a worse case humidity of 100% and the recorded inlet temperature of 73'F, a 12'F delta t was calculated to yield a 68% humidity to the charcoal filter.

Thus, the safety consequences of this event were minimal.

Also, in accordance with Technical Specifications, the carbon sample analysis for methyl iodide removal efficiency is performed at 130' Centrigrade (*C) and 95%

relative humidity. The calculated humidity of 68% was far below this requirement.

E. CORRECTIVE ACTIONS:

Immediate corrective actions included: declaring the system inoperable, initiating the appropriate outage report, and dispatching personnel to investigate the AFU. A work request was initiated.

Heater current draw was found to be normal and flow was acceptable. However, the flow was reduced to obtain a better delta t across the heater. The B train was restarted and successfully tested.

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• • Fate Rev 2.0 Littwitt EVENT..aIPoRT (LER) TEXT coWTiltlAT10N l DOCKET NupeER (1) Ltk laaett (6) Pane (3)

,, FACILITY % (1)

. Year /// sequentist ///j Revillon fff ff

/// Wa r /// Maer ound citian unit one 015101010 i fl 514 910 - 0l112 - 010 Old 0F 0l4 TEXT Energy Industry Identification system (E!!s) codes are identified in the text 4s (XX)

Hork request 085295 was written to further investigate the AFU heater-(NTS 2542009004801).

Work request 085286 was written to have the B AFU booster fan discharge damper actuator repaired (NTS 2542009004802).

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' A Site Engineering Services Request, QAP 1100-T2, was submitted on June 13,1990 to review the 15' delta t Technical Specification requirement and, investigate the

heater size. (NTS 2542009004803).

F. AREVIOUS EVENTS:

A review of reportable events did not reveal any previous occurrences were the required 15'F delta t across the AFU heater could not be attained.

Based on the actions in process, no further corrective action is deemed necessary at this time. A supplemental report will be submitted if the cause is found to be other than a heater problem.

G.- COMPONENT FAILURE DATA:

The electric resistance heater is manufactured by Teledyne-Stillman, Part #611759 Serial #A-1175-2, 9 kilowatt (Kw). 10.8 amps, 480 volts (power), 3 phase, 60 hertz, EPN-1/2-9400-101.

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