ML17252B002
| ML17252B002 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 01/09/1973 |
| From: | Worden W Commonwealth Edison Co |
| To: | Anthony Giambusso US Atomic Energy Commission (AEC) |
| References | |
| Download: ML17252B002 (2) | |
Text
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I Regulatory::
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Commonwealth Edison Company 72 WEST ADAMS STREET
- CHICAGO, ILLINOIS DOCKETED USA£~
. O'AN 171973 fl>
REGULATORV
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MAIL SECTIOM 0 V DOCKf( Cl.ERi(
I Mr. A.
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Deputy Director Directorate of Licensing U. s. Atomic Energy Connnission Washington, D. C.
20545
- CHICAGO, ILLINOIS 60690 Dresden Nuclear Power Station R. R. Ill Morris, Illinois January 9, 1973 SUBJ~CT:
LICENSE DPR-25, DRESDEN NUCLEAR POWER STATION, UNIT 113.
SECTION 6.6.B.* 3.
Dear Mr. Giambusso:
50-249 This is fo report a condition relating to the operation of the
- unit. in which, on. January 3, 1973, the Standby Liquid Control System tank did not satisfy the volume-concentration requirements established in Figure 3.4.l of the Technical Specifications.
PROBLEM AND INVESTIGATION On January 3, 1973, the Unit 3 equipment attendant valved the sparging air into the boron tank at 0631 hours0.0073 days <br />0.175 hours <br />0.00104 weeks <br />2.400955e-4 months <br />.
This was in preparation for a routine monthly boron concentration analysis as required by the Technical Specifications.
At 0810 hours0.00938 days <br />0.225 hours <br />0.00134 weeks <br />3.08205e-4 months <br />, the shift engineer received word that the boron tank was overflowing.
During this time the unit was increasing load after the completion of routine surveillance tests.
Upon aotif ication of the overflow condition, the load pickup was terminated at' 746 MWe.
Investiga-tion showed that 'the sparging air was valved in as it should have been, buLthe demineralized water was also valved in.
Both valves, 3-1101-6 (clean demineralized. water) and 3-1101-36 (sparging air)' are normally locked closed.
The equipment attendant mistak!ngly unlocked and opened both valves, which he thought were in series in the air sparge line.
As soon as the problem was reviewed, the Standby Liquid Control System was declared inoperable and the unit began an orderly shutdown.
The shutdown was initiated at 0905 hours0.0105 days <br />0.251 hours <br />0.0015 weeks <br />3.443525e-4 months <br /> at 8 MWe/hr.
The unit was brought down at this rate because of the station IOMR (Interim *operating Management Reconnnendations) which are normally used during the weekend load drops.
I I
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Mr. A. Giambusso
- January 9, 1973 During the orderly shutdown, a boron analysis was conducted to determine the concentration. It was 7.4% which is approximately one-half of the normal concentration.
The tank level was consequently drained until 3700 gallons remained.
Part of the boron solution which was removed from the tank was batch mixed with boron bearing chemicals and then returned to the tank to bring it back within concentration and volume limits.
As required by 4.4.C.l of the Technical Specification, a boron concentration analysis was conducted.
The final tank volume was 3840 gallons at a sodium pentaborate concentration of 14.7% which is within the.limits ofFigure 3.4.1 of the Technical Specifications.
At 1500 on January 4, the Standby Liquid Control *system was declared operab'l-e and the orderly shutdown was terminat~d. The loa_d was subsequently increased at 8 MWe/hr. to full power.
CORRECTIVE ACTION The valve checkoff sheets will be revised so that a second valve on the clean demineralized line will have to be open before water can be added to the boron tank.
This should preclude the possibility of this type of incident from reoccurring.
The individual that made this error was informed of his mistake and made aware of the consequences.
In anticipation of a Dresden license change to coincide with the Quad Cities licenses, an operating order has been issued which states that, until a Technical Specification revision is issued, an orderly shutdown shall be initiated and the reactor placed in cold shutdown within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> whenever the Units 2 or 3 Standby Liquid Control System becomes inoperable.
WPW:do
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Sincerely, W. P. Worden Superintendent
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