ML20084J216

Ack Receipt of Re Vacuum Breaker Interim Surveillance Program.Program Believed to Meet Objectives Better than NRC Program Outlined in

ML20084J216
Person / Time
Site:	Quad Cities
Issue date:	11/17/1972
From:	Brian Lee COMMONWEALTH EDISON CO.
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20084J218	List: ML20084J216 ML20084J240 ML20084J296 ML20084J305
References
NUDOCS 8305120248
Download: ML20084J216 (2)

Text

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%j O 1 71 vommonweana Ecison Company ONE FIR S T NATIONAL PLAZA

• C H I C A G O. I L LI N O S S Addrene teolv ree POST OFFIC E toX 747

• C H I C A G O. O L &lNOIS 60490

(. '\' ,pa November 17, 1972 ,.

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Mr. Angelo Giambusso d jf7 / k.

Deputy Director of Reactor Projects y .bf.

Directorate of Licensing i ,# (Y [ffk [k['

$8 U.S. Atomic Energy Commission '

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Washington, D.C. 20545 g /

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Subject:

Vacuum Breaker Interim Surveillance Program for Quad-Cities, Units 1 & 2, AEC Dkts 50-254 and 50-265 D.2ar Mr. Giambusso:

9 The purpose of thi letter is to acknowledge and comment on your November 8 1972 letter regarding the Quad-Cities 1 and 2 vacuum breaker valves. We concur with the intent and objectives outlined in the letter. However, we believe that we have established a program that will meet these objectives better than the program outlined in your letter.

Valve position alarms are currently installed in the control room for both Units 1 and 2. The Unit 2 alarm will detect a 1/16" movement of the valvo disc. The Unit 1 alarms will not detect such a small movement because,

,as you stated, the improved position switches have not

[ yet been installed.

To compensate for the lack of having the improved i

position switches, the following approach is being used to assure proper vacuum breaker position.

N ' W2 are operating the Unit 1 drywell at a slight positive pressure (.15 to .25 psi) with respect to the

. suppression chamber. The pressure differential can be Oh[05h$((hP COPY SENT REGION _

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Camm:nwe:lth Edison Conhny

. 9 Mr. Angelo Giambusso November 17, 1972 determined by indicators in the control room, and in addition, N2 makeup is recorded in the control room. In effect we are continually monitoring the pressure decay to the limits described in 3.7.A.4.6 and 4.7.A.4.6 of our proposed techni-cal specification for these valves os discussed in Special Report No. 4 By operating in this manner, we have continual knowledge of vacuum breaker position on Unit 1 and can detect the equivalent of a 1/16" opening on one valve. Differential pressure, total containment pressure and N, makeup are being

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logged twice per shift.

In addition, a monthly exercising test is being conducted. Since the Unit 1 valves have the arm modification to provide the additional closing force, we believe a monthly test is sufficient, and the weekly test suggested in Item 1 of your letter seems unnecessary.

With respect to the next to last paragraph of your letter, we had been logging the position of the vacuum breaker valves of both units daily at the local panel. Since the position of the valves on Unit 2 is known in the control room from the alarms, a requirement to log position at the local panel sin times a day just because the alarm does not yet meet IEEE 279 standards seems unnecessary. Morcover, on Unit 1, since ralve position is known from the pressure and makeup instrunentation, a daily logging at the local panel also eppears adequate.

An directed, we are presently logging vacuum breaker position at the local panels twice per shift, and

,unless otherwise directed we will begin logging these positions daily starting on Decernber 1, 1972. We are also currently following the surveillance procedures outlined herein, in lieu of your suggested methods, and will continue to do so.

V5ry truly-yours,

-.kcaon "- 7 Byrbn Lee, Jr.

. Assistant to the President t

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