ML19329C713

Notifies That Review of ECCS Flow Test Cannot Be Completed. Requests Addl Info Re Sufficient Justification of Sump Design to Assure Vortexing Will Not Occur & Test Results of Four Pumps Used to Determine NPSH

ML19329C713
Person / Time
Site:	Davis Besse
Issue date:	03/08/1976
From:	Mazetis G Office of Nuclear Reactor Regulation
To:	Engle L Office of Nuclear Reactor Regulation
References
NUDOCS 8002180206
Download: ML19329C713 (2)

Text

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Leon Engle, Project Manager, light Water Reactor Br. 4. DPM THRU: Sanford Israel, Section Leader, Reactor Systems Sr., DSS DAVIS-BESSE 1 PROPOSED SUMP TEST Our review of the 1500 gpm ECCS flow test pronosed by Toledo Edison for Davis-Besse 1 cannot be comoleted at this time for the following reasons:

1.

Sufficient justification of the sumo design to assure that vortexing would not occur has not been given. No studies or test data have been offered.

The design of the anti-vortexina device is not sucported by test data. What additional reduction, i

in available head in feet, does this device im;ose on the cums?

Availaole information (H. Uoodhouse, 00'?ER, May 1965) indicates that less than 3 feet of margin exists to minimun recomended pioe submergences. The anplicant will be recuired to either orovide a full-flow onsite vortex test, or conduct odel tests to show that their surn configuration is not subject to vortex fonnation after a LCCA.

2.

In resconse to a cluestion pertaininq to 1PSH the atolicant raised tne 2redicted flood level inside thf c,ontainment G.i feet over the credicted level used for.1PSH calculations in the FS,'i.

Tlia reason offered was one of several errors discovered in tne FSAR calculations.

Provide a corsarison of current calculations of predicted flood height with tne crevious calculations, clearly showina the original error.

State the basis for the 1SM10 gallons of water from the BWST and indicate the r;uantity of water still remaining in the B'lST at the tine of the shift to the recirculation mcde.

Provide the calculations of pressure losses in the suction lines for each of the four nunps, including the values of all L/3's, areas, Reynolds ' lumbers, and friction factors. Clearly sm where each value was derived, including all fittings in the suction Diping. Wat pressura loss is attributed to tne sco screens?

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Provide the manufacturar's test results (data / curves) for the four pumps used to determine the required MPSH. Confim that these tests were donducted on the Davis-Sesse 1 pumps (i.e.,

not prototypes).

4 Iten 4 in the 1/0/75 letter from the apolicant is not clear.

The indication is that some rneans are provided te event excessive ficws. Describe how the required ECCS s will be established durino the preon tests. State the flow crit 6eia and describe its basis.

Indicate the approorfateness of the flow criteria for both the injection mode and the recirculation mode.

Discuss the potential for these settings beconing chanced.

Include a discussion of the uncertainties involved in the final established flow (in tems of i gpn).

5.

With the proposed test setup consisting of a connector in the sumo between the two suction lines. it accears that the means exist to achieve the maximun flow rate capability of nne train (DH nump plus spray ourp). The obiect of the test would be to confim that the pressure losses submitted in the 1/5/76 letter from the aoplicant.

Differences should only be due to entrance losses an.1 temoerature. Discuss mans to confim predicted entrance losses.

Provide all calculatiens utilized to predict the' exoected oressure losses for the cold sump test. Describe the criteria which will be used to satisfy yourself that the test verified the exoected post-LOCA conditions and discuss the capability to vary flow to obtain cara than one point on a plot of iGS:i versus ficw.

Describe the instrurent to be used foe-the cressure droo measure-monts, include a diagran of its scale. er.d specify the instrument uncertainty involved.

wMem: t d G. R. Mazetis Reactor Systens Branch Division of Systems Safety cc:

T. Novak D. Ross S. Israel W. Minners J. Watt G. ia:etis f

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