ML19318A863

Responds to IE Bulletin 80-05, Vacuum Conditions Resulting in Damage to Chemical Vol Control Sys Holdup Tanks. Lists Low Pressure & Holdup Tanks Which Are Normally Valved to Contain Primary Sys Water

ML19318A863
Person / Time
Site:	Catawba
Issue date:	06/09/1980
From:	Parker W DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
IEB-80-05, IEB-80-5, NUDOCS 8006240282
Download: ML19318A863 (2)

Text

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Duxu POWER COMPANY & 973 Powra Dutt.oswo WY 422 Socrn Cavacu Stazzr, CruntorTz, N. C.asa4a v$c". p. .$ Y '

June 9, 1980 * * " * *j,","3,', o 3 sesau P.oowcwon i

Mr. James P. O'Reilly, Director U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303 Re: RII:JPO Catawba Nuclear Station Docket Nos. 50-413 and 50-414

Dear Mr. O'Reilly:

In response to your letter of March 10, 1980, which transmitted IE Bulletin h,

80-05, we wish to advise that a review of the design of all Catawba Nuclear Station's systems that contain low pressure or hold-up tanks that can be valved to contain primary systen water has been conducted.

The following low pressure or hold-up tanks are those which are normally valved to contain primary system water.

1. The Pressurizer Relief Tank in the Reactor Coolant Systec is designed for a full vacuum, 15 psig external design pressure.

2. The Volume Control Tank in the Chemical and Volume Control System is designed for a full vacuum, 15 psig external design pressure.

3. The Recycle Hold-up Tank in the Boron Recycle System is designed for I

atmospheric conditions (0 psid). It is vented through a normally open, fail open butterfly valve in a 12 inch line to the Auxiliary Building Ventilation System.

4. The Reactor Ccolant Drain Tank in the Liquid Radwaste System is Jesigned for greater than full vacuus. External design pressure is 60 psig.

I 5. The Waste Drain Tank in the Liquid Radwaste System is designed for full vacuum, 15 psig external design pressure.

i 6. Failure of the Refueling Water Storage Tank in the Refueling Water System due to vacuum in the tank could hinder supply of borated water to the containment spray pumps. Following a LOCA, this situation would cause excessive pressures inside containment. To preclude this situation, tank 8006240 $ %

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• o 4 Mr. James P. O'Reilly, Director

~ June 9, 1980 Page Two vents have been included. The tank is locally vented to atmosphere through one.open 6-inch vent line and one open 12-inch vent line.

Since this tank is outside, vents are redundantly heat traced to avoid freezing in winter.

The Liquid Radwaste System has several other low pressure tanks which do not normally contain unprocessed primary system water, but may potentially contain radioactive water. All of these tanks are protected by venting through a i

normally open valve to the Auxiliary Building Ventilation System or through a local vent to atmosphere.

Each of the above tanks is protected against failure under vacuum conditions either by structural design or venting.

Very truly yours, h b d. F A k William O. Parker, Jr. NA M RWO:scs cc: Director Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Mr. G. F. Maxwell Nuclear Regulatory Commission - Construction Catawba Nuclear Station l

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