ML19211D370

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Responds to NRC 790928 Ltr & 791211 Telex Re Auxiliary Feedwater Requirements.Discusses Mod to Emergency Condensate Storage Tank,Endurance Test on Auxiliary Feedwater Pumps & Design Basis for Sys Flow Requirements
ML19211D370
Person / Time
Site: North Anna Dominion icon.png
Issue date: 01/15/1980
From: Stallings C
VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To: Eisenhut D
Office of Nuclear Reactor Regulation
References
016, 16, NUDOCS 8001180285
Download: ML19211D370 (2)


Text

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Vrrto rsrA ELECTICIC AND Pow eit C O M 1*A N Y RxcxzMoxo,Vasora zA con 61 January 15, 1980 Mr. Harold R. Denton, Director Serial No. 016 Office of Inspection and Enforcement P0/FHT:sej Attn: Mr. Darrell G. Eisenhut Docket No. 50-338 Acting Director, License No. NPF-4 Division of Operating Reactors U. S. Nuclear Regulatory Commission Washington, D. C. 20555

Dear Mr. Denton:

, North Anna Unit 1 Auxiliary Feedwater Requirements Supplemental Response In response to your letter of September 28, 1979, Docket No. 50-338, and your telecopy of December 11, 1979, Virginia Electric and Power Company plans the following actions:

1. An additional level transmitter will be installed on the Emergency Con-densate Storage Tank (ECST). This instrument will provide the operator with both ECST level indication and a low level alarm in the main control room. The alarm will be set to alert the operator of ECST low level at least twenty (20) minutes before the ECST could be emptied by the largest auxiliary feedwater (AT4) pump. This modification should be fully implement-ed by March 31, 1980. Delays in equipment procurement could impact this date.

Until the additional level transmitter is installed, operating personnel will be instructed on how to correlate pump suction pressure with ECST level. The operation of the AFW pump distorts suction pressure such that accurate level indication is dif ficult; however the suction pressure indicator is still useful to allow the operator to anticipate the need to make up water or transfer to an alternate water supply and prevent a low pump suction pressure condition from occurring.

2. Your letter of Scutember 28, 1979, Requirements for Auxiliary Feedwater Svsre=s, requested that an endurance test be performed on all auxiliary feedwater pumps. In our response, Serial 825/092879, dated November 2,1979, we stated that, an endurance test of the turbine-driven auxiliary feedwater pu=p could be performed af ter the unit returned to power and steam was available.

In our letter to Mr. James P. O'Reilly, Serial No. 1179, dated December 28, 1979, we incorrectly stated that the endurance test would be performed while the unit is in Mode 3 during the post-refueling. return to power.

1765 280 8001180 W g

v MulNIA EuCTRIC AND POWEle TOM PANY TO Mr. Harold R. Denton 2 At this time we wish to inform you that the steam turbine-driven AFW pump will be endurance tested for 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> after North Anna 1 has started up.

We expect the test run to be performed with the unit at appfoximately 25 percent power, during the steam generator boric acid soak described in our letter Serial No. 1003 dated December 10, 1979. A report of the test will be forwarded as soon as it becomes available.

3. With regards to the "D" Basis for AFW System Flow Requirements, this in-formation is not presently available. 'Ihe information is being assembled by both Westinghouse Electric Corporation and Stone and Webster Engineering Corporation. After this information is assembled and reviewed by VEPCO, it vill be submitted to the NRC. We expect to submit this information by March 31, 1980.

Very truly yours, h.h db2dd n C. M. Stallings Vice President-Power Supply and Production Operations 1765 281