ML19318A665

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Responds to IE Bulletin 80-05, Vacuum Condition Resulting in Damage to Chemical Vol Control Sys (CVCS) Holdup Tanks. Pressurizer Relief Tank,Vol Control Tank & One Primary Drain Transfer Tank Designed for Full Vacuum Conditions
ML19318A665
Person / Time
Site: Beaver Valley
Issue date: 06/16/1980
From: Dunn C
DUQUESNE LIGHT CO.
To: Grier B
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
IEB-80-05, IEB-80-5, NUDOCS 8006230660
Download: ML19318A665 (2)


Text

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15219 June 16,1980 United States Nuclear Regulatory Cocsission Office of Inspection and Enforcement Attn: Boyce H. Grier, Regional Director Region I 631 Park Avenue King of Prussia, Pennsylvania 19406

Reference:

Beaver Valley Power Station, Unit No. 1 i

l Docket No. 50-334, License No. DPR-66

{

I.E.Bulletin 80-05 Gentlemen:

i We have reviewed the referenced bulletin concerning vacuum condition <

resulting in damage to chemical volume control system holdup tanks. The following Systems and Tanks were reviewed for potential vacuum conditions as described in I.E.Bulletin 80-05.

SYSTDi TANKS MARK NO.

RCS Pressurizer Relief Tank RC-TK-2 V&DS Primary Drains Transfer Tank DG-TK-1 V&DS Primary Drains Transfer Tank DG-TK-2 BRS Coolant Recovery Tank BR-TK-4A BRS Coolant Recovery Tank BR-TK-4L CVCS Volume Control Tank CH-TK-2 The pressuriser relief tank, Volume control tank and one of the primary drains transfer tanks (DG-TK-1) are designed for full vacuum conditions.

The coolant recovery tanks are connected to the Sweep Gas System.

The Sweep Gas System is designed so that each servicable tank has an unobstructive vent. The J-Vent or unobstructive vent is the same size as the drain line. These design features ensure that a negative pres- -

sure cannot be placed on the tank, whether it be from valve misalignment ~

which leads to tank isolation or during normal operation of purging ~

down the tank. '

8.00623 0 Ob g

s o.

Beaver Valley Power Station, Unit No.1 Docket No. 50-334, License No. DPR-66 I.E.Bulletin 80-05 Page 2 The second primary drains transfer tank (DG-TK-2) has had several design. changes made to the systems associated with it. This tank is equipped with a nitrogen supply line and an inlet solenoid valve which opens on low pressure to maintain.a slightly positive pressure on the tank. Since the outlet solenoid valve has been removed, the potential for vacuum damage to the tank is further lessened since the cover gas supplied to the degassifiers is available to the tank. We plan to conduct a test to determine whether the present system arrangement is adequate to prevent vacuum damage to DG-TK-2. The results of this test will be reported to the NRC promptly upon completion.

If you have any questions concerning thir response, please contact my office.

Very truly yours, h

C. N. Dunn Vice President, Operations cc: Mr. D. A. Beckman, Resident Inspector U. S. Nuclear Regulatory Commission

- Beaver Valley Power Station Shippingport, Pennsylvania 15077

/ U.S. Nuclear Regulatory Commission c/o Document Management Branch Washington, D.C. 20555 U.S. Nuclear Regulatory Commission Director, Office of Inspection and Enforcement Washington, D.C. 20555

.