ML20040C625

Final Deficiency Rept Re Water Leakage Into Five ECCS Pump Suction Barrel Pits,Originally Reported on 810826. Cylindrical Liners Will Be Installed in Each Pit by 821206

ML20040C625
Person / Time
Site:	Nine Mile Point
Issue date:	01/15/1982
From:	Rhode G NIAGARA MOHAWK POWER CORP.
To:	Starostecki R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
10CFR-050.55E, 10CFR-50.55E, NUDOCS 8201290095
Download: ML20040C625 (2)

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' Y NIAGARA NuMOHAWK NIAGARA MOHAWK POWER CORPORATION /300 rRIE BOULEVARD WEST. SYRACUSE N Y.13202/ TELEPHONE (315) 474-1511

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January 15, 1982 /+ s g- \.,

Office of Inspection and Enforcement RECEIVED 1 Attention: Mr. R.W. Starostecki, Df rector 6}

"M y $ g ]3 i$f;.[j?lj*!Ntr,~

Division of Resident and Project Inspection 9 me Q U.S. Nuclear Regulatory Connission 631 Park Avenue N f "'

e King of Prussia, PA 19406 Re: Nine Mile Point Unit 2 Docket No. 50-410

Dear fir. Starostecki:

Enclosed is the final report in accordance with 10CFR50.55(e) for the deficiency regarding vater leakage into the five energency core cooling systen pump suction barrel pits. This condition was originally reported to ifr. R.

l Feil of your staff an August 26, 1981.

Very truly yours, NIAGARA H0H fK POWER, RPORATION m ./> ,,

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Kf g L erald K. Rh e Vice President Systen Project flanagement Xc: Director of Inspection and Enforcenent U. S. Nuclear Regulatory Cormission Washington, D. C. 20555 8201290095gg@hio PDR ADOCK PDR S 6

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e-f HIAGARA f10 HAWK POWER CORPORATION NINE MILE POINT - UNIT 2 DOCKET NO. 50-410 FINAL REPORT FOR THE DEFICIENCY REGARDING LEAKAGE INTO THE FIVE ECCS PUMP SUCTION BARREL PITS Description of the Deficieng As described in the interin report dated September 23, 1981, groundwater was found to be leaking into the pits which will house the suction barrels of the five energency core cooling systen (ECCS) punps. These pumps are located in pump compartments at elevation 175 feet of the reactor building and auxiliary  :

bays. The leakage is believed to be the result of the absence of water stops at the junction between the containment nat and the porous concrete underneath the nat.

Analysis of Safety Implications Under nornal operating conditions, the ground water around the reactor building and auxiliary bays is drained by a nonsafety-related dewatering systen. The punp compartments are also provided with nonsafety-related sump pumps. During a sef snic event, if the dewatering systen is rendered inoperable and the sunp pump fails, there is a renote possibility that all pump suction pits could be flooded sinultaneously. However, even if this problen were to have remained uncorrected, i' would not have adversely affected the safe operation of the plant. This conclusion is based on the following analysis. ,

The pump flange is bolted to the reactor building nat through a grouted in-place annular base plate. Since there are no sealt between the pump flange and base plate or base plate and grout, there is a possibility of seepage of ground water under the pump flange and/or base plate into the pump compartment. However even if the water entered the conpartnents and the nonsafety-related sump pump systen located in each compartment were also rendered inoperable, Category I level switches, nounted approxinately 6 inches above the top of the nat inside each ECCS pump compartment, would signal the plant operator of the flooded condition. Since the ground water inflow rate ,

into the conpartments would be very low, it would be several weeks before the water would reach the pump r40 tors, which cre located more than 7 feet above the top of the nat. Therefore, there would be sufficient time to install and activate p9rtable pumps to drain water from the conpartments; thus, the ECCS pump operation would not be affected.-

Corrective Action 7

In order to provide a leaktight housing for each of the five ECCS punp suction barrels, a cylindrical liner will be installed in each pit. The liner is scheduled for installation by December 1,1982.

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