ML20197A461

Forwards Supplemental Response to SER Open Issue 9(d) Re Relief Valve Testing,Per 860206 & 0428 Requests.Flow Rate Assumed in Accidental Analysis Far Exceeds Critical Flow Rate

ML20197A461
Person / Time
Site:	Beaver Valley
Issue date:	05/06/1986
From:	Carey J DUQUESNE LIGHT CO.
To:	Harold Denton, Tam P Office of Nuclear Reactor Regulation
References
2NRC-6-045, 2NRC-6-45, TAC-62878, NUDOCS 8605120327
Download: ML20197A461 (3)

Text

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May 6, 1986

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Mr. Harold R. Denton, Director .

Office of Nuclear Reactor Regulation

United States Nuclear Regulatory Commission i Washington, DC 20555

ATTENTION

Mr. Peter Tam, Project Manager i Division of PWR Licensing - A Office of Nuclear Reactor Regulation l

SUBJECT:

Beaver Valley Power Station - Unit No. 2 Docket No. 50-412 .

SER Open Issue 9(d), Relief Valve Testing ,

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REFERENCE:

a) Initial Test Program Response, Letter No. 2NRC-5-110, Dated July 29, 1985.

GENTLEMEN

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' Attached is a supplement to previous responses to open issue 9(d).

This response addresses the reviewer's basic concern described in a telephone conversation on February 6, 1986. The attached response was subsequently discussed in another conversation on April 28, 1986.

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DUQUESNE LIGHT COMPANY By _ _ _J./J(J6 rey/ '

Vice President GLB/jdw Attachment

AR/NAR j cc: Mr. P. Tam, Project Manager (w/a) i Mr. J. M. Taylor, Director (3) (w/a) l Mr. W. Troskoski, Sr. Resident inspector (w/a)

! Mr. L. Prividy NRC Resident In<pector (w/a)

INPO Records Center (w/a)

NRC Document Control Desk (w/ j)

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- United States Nuclear Regulatory Comission

• Mr. Peter Ta.m, Project Manager SER Open issue 9(d), .9clicf h lvc Tcsting Page 2 SU ORN TO BEFORE ME THIS gT)//} SCRIBED DAY OF( AND_. . , 1986.

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COUNTY OF ALLEGHENY On this 8 ] day of Sk////p/r _ , /[(k,beforeme,a Notary Public in and for said Comondalth and County, personally appeared J. J. Carey, who being duly sworn, deposed and said that (1) he is Vice President of Duquesne Light, (2) he is duly authorized to execute and file the foregoing Submittal on behalf of said Company, and (3) the statements set forth in the Sut>mittal are true and correct to the best of his knowledge.

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, RESPONSE TO SER OPEN ISSUE 9(d)

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QUESTION 640.18:

FSAR Subsection 14.2.12 test abstracts should be modified to demon-strate that capacities of pressurizer PORV's and main steam line at-mospheric pump valves are consistent with the accident analysis assumptions for both minimum and maximum valve capacities.

PREVI0'JS RESPONSE (REFERENCE a):

In regard to the pressurizer PORV's, Table 5.4-20 of the FSAR de-scribes a capacity of 210,000 lb/hr. The accident analysis assumed a flow at least equal to the safety valve maximum capacity (345,000 lb/hr. from Table 5.4-20). Therefore, since the rcident analysis assumes a flow which is roughly 164f. of the PORV capacity, sufficient margin exists to preclude the need for a test.

In regard to the atmospheric steam dump valves (steam generator PORVs), FSAR 15.1.4 indicates a flow of 225 lb/sec. at 1,000 PSIA (810,000 lb/hr.) was assumed in the accident analysis Using the j 26,200 lb/hr. at 100 PSIA is roughly 270,000 lb/hr. Since this is only 1/3 of the flow assumed in the accident analysis , sufficient margin exists to preclude the need for a test.

SUPPLEMENTARY RESPONSE:

In a telephone conversation to discuss this and other issues, the i reviewer described his basic concern. DLC was asked to describe how it is known that flow cannot exceed the values assumed in the acclent analyses.

In a later conversation it was indicated that the reviewer's concern was now limited to the atmospheric steam dump valves.

The general response to this question is that the flow rate assumed in the accident anaylysis far exceeds the critical flow rate.

With regard to atmospheric steam dump valves, a calculation was per-formed for effluent monitoring equipment design purposes. It assumed

1,000 PSI A at the valve inlet and a 10 inch inlet line. Using the valve capacity factor and the diffuser capacity factor, a flow of

270,000 lb/hr was calculated. But, since the actual inlet line is only 4 inch expanded to 10 inch, it can be seen that the 270,00 lb/hr.

flow rate cannot be achieved through the 4 inch line regardless of valve characteristics. Since the 810.000 lb/hr. assumed in the

, accident analysis is several hundred percent more conservative than

, the unachievable flow rate of 270,000 lb/hr. testing cannot be justified.

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