ML20059G496

Submits Voluntary Rept of Svc Water HX Testing During Sixth Refueling Outage.Expected Flow Rates Not Achieved.Periodic Tests Developed to Check Efficiency of Containment Air Coolers

ML20059G496
Person / Time
Site:	Davis Besse
Issue date:	09/06/1990
From:	Storz L TOLEDO EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
AB-90-0020, AB-90-20, GL-89-13, NP-33-90-16, NUDOCS 9009130003
Download: ML20059G496 (2)

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BISON Eo: SON PLAZA 300 MADISON AVENUE j Docket Number 50-346 WDO. OHO 43%24001 j i

License Number NPF-3 ,

l September 6, 1990 l AB-90-0020 United States Nuclear Regulatory Commission NP 33-90-16 Document Control Desk Vashington, D.C. 20555. i l

Subject:

Voluntsry Report of Service Water Heat Exchanger Testing during the m ? nefi' ding Outage.

1 Gentlemen During the sixth refuelin outage, while performing a flow balance test of service water train 1-1, .t was determined that the expected flow rates through  ;

several heat exchangers were not being achieved. Although the flows were belov those listed in the USAR, engineering evaluation determined there was no impact i on the plant's response to the accidents analyzed in the USAR.- The test was  !

being performed to verify balanced flow following implementation of a system modification. Under Modification 87-1315 a butterfly valve was replaced with a  ;

ball valve to improve control. Vith this new type valve full open, the flow through the CCW heat exchanger was greater than expected which resulted in less than expected flov through the other system loads. The other loads include a' ,

containment air cooler, an ECCS room cooler, a hydrogen dilution blower and a (

control room EVS condenser unit. The flows were evaluated and determined to be .

adequate with the exception of ECCS Room Cooler 1-5.  !

i ECCS Room Cooler 1-5 is one of two 100 percent capacity coolers in Room 105. i Only one is necessary to support the equipment in the room after a LOCA. The  !

I flow through this cooler was found to be less than required. The other cooler I in the room ( No. 1-4) was found to have adequate flow. Through engineering ,

evaluation, an appropriate valve position that vould provide CCV cooling (while j still leaving adequate flov for the other loads) vas determined. The pre-modification configuration from the previous operating cycle was also I l

evaluated, and it was determined that the corresponding flows were adequate with ,

the exception of ECCS Room Cooler No. 1-5. ECCS Room Cooler No. 1-4 is >

currently in service. Cooler No. 1-5 vill be inspected to determine the cause of its reduced flow.  ;

i l Toledo Edison is developing its inspection and preventive maintenance program j for all service water coolers and piping per its response to Generic Letter  !

l 89-13 on January 30, 1990, Serial Number 1-904. l t

9009130003 900906 CIC 0\

PDR ADOCK 05000346 '

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. Docket No. 346 License No. NPF-3 i Page 2 l

-l During the sixth refueling outage, efficiency testing of Containment Air. Cooler  ;

(CAC) 1-2 determined that the air side of the cooler was excessively fouled.  !

CAC 1-2 is one of three 50 percent capacity units. Only two are mechanically ,

and electrically aligned to be. operated, simultaneously. An evaluation of past.  ;

operating history of CAC 1-2 has revealed that it accumulates more dirt than the i other two units. This appears to be due to the air flow pattern around it. The  ;

fouling was excessive due to the type and volume of vork in containment during i the previous refueling outages.

The CAC 1-2 vas thoroughly cleaned and retested which verified an acceptable level of efficiency. Periodic. tests have been developed to check the efficiancy of the CACs. Preventive maintenance work orders are also being written to l provide for the air-side cleaning of the CACs during refueling outages.

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Very truly yours, s,

~w Gr .

C'Y l L. F. Storz '

Plant Manager JCS/ eld cc A. B. Davis, Regional Administrator, NRC Region III I P. H. Byron, DB-1 NRC Senior Resident Inspector M. D. Lynch, DB-1 NRC Senior Project Manager Utility Radiological Safety Board of Ohio

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