ML20084U392

Ro:On 720519,during HPCI Monthly Surveillance,Turbine Would Not Reset from Control Room.Caused by Broken Wire Off Turbine Reset Solenoid Discovered on 720520.Further Investigation Underway

ML20084U392
Person / Time
Site:	Dresden
Issue date:	05/25/1972
From:	Worden W COMMONWEALTH EDISON CO.
To:	Bloch E US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20084U394	List: ML20084U392 ML20084U978
References
NUDOCS 8306280660
Download: ML20084U392 (2)

Text

l'

..'e -

(3 v' Q .

l 4

i Commonwealth Edison Company

% - ONE F1RST NATlONAL PLAZA

• C H I C A G O. ILLINO35 w 6.. , ...

3* POST OFFICE SOX 767

• C H I C A G O, ILLINO15 60690 m

W.

- ,._.! Dresden Nuclear Power Station C N[.3 I 9 fj',"[ 'j R. R. #1

- ,-:' Morris, Illinois 60450

- ..- May 25, 1972 Q,._. ,

N _ ..

Mr. E. J. Bloch, Director Division of Reactor Licensing U.S. Atomic Energy Commission Washington, D. C. 20545 50-249

SUBJECT:

LICENSE DPR-25, DRESDEN NUCLEAR POWER STATION UNIT #3 SECTIONS 6.6.A.1 AND 6.6.B.2 0F TECHNICAL SPECIFICATIONS.

Dear Mr. E. J. Bloch:

This is to report a condition relating to the operation of the station in which during monthly surveillance, the High Pressure Coolant Injection (HPCI) turbine would not reset. Failure of the turbine to reset rendered the system incapable of providing coolant injection as required by Section 3.5.C.1 of the Dresden Unit #3 Technical Specifica-tions.

PROBLEM AND INVESTIGATIO_']

HPCI monthly surveillance was being conducted on May 19,.19'i2, and it was found that the turbine would not reset from the Control Room.

The turbine was reset locally and the turbine surveillance test was s

satisfactorily ecmpleted. On Saturday, May 20, 1972, an electrician

• } f found a wire broken off the turbine reset solenoid. This wire was recon-4 'nidtod'and a new solenoid was ordered. The new solenoid will be installed QL when received. This surveillance test was last conducted on April 20, 1972, (p; and the turbine reset satisfactorily at this time. In addition, during the plant trip of May 4, 1972, the HPCI turbine was called upon to operate and ,

the turbine reset satisfactorily.

CONCLUSION AND CORRECTIVE ACTION

/ The cause of the failure appears to be a brittle failure of a f terminal on the solenoid. New solenoids have been ordered to replace *

, this solenoid and the similar one on the D-2 HPCI turbine. , ,

nO i n, j

a 8306280660 720525 f" PDR ADOCK 05000 8

t COPY SENT REGION % ---

srwra w

A..* P Q

(/

Mr. E. J. Bloch May 25, 1972 l Further investigation of the failure mechanism will be conducted by the Cor:r.onwealth Edison Engineering Department and further action will be taken. if required.

Sincerely,

. . NCIL.v W. P. Worden

- Superintendent WPW:do

-