ML20084L564

AO 50-237/1974-39:on 740810,during Weekly Surveillance Testing,Control Valve Fast Acting Solenoid 1 Failed to Give one-half Scram Signal.Cause Undetermined.Power Reduced to 40%.Sys Being Monitored

ML20084L564
Person / Time
Site:	Dresden
Issue date:	08/16/1974
From:	Stephenson B COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20084L568	List: ML20084L564 ML20084L569 ML20084L578 ML20084L585 ML20084L599
References
595-74, NUDOCS 8305230378
Download: ML20084L564 (3)

Text

__ __. _ _ . _ _ _ _

' ~

j

.ma C mmanbalth Edis:n One First Nat6cna! Piaza Chicago. !!iancis

(

Address Reply to: Post Off:ce Box 767 Chicago, I;Iinois 60690 BBS Ltr.4595-74 Dresden Nuclear Power Station R. R. #1 Morris, Illinois 60450 August 16, 1974 o N 50-237 0 mnmO 9%

~

9

~

U J ., ,l .LU s\

Mr. James G. Keppler, Regional Director 2 gggg g $sg Directorate of Regulatory Operations-Region III U. S. Atomic Energy Coassission fi U.S. ATW:C meg ec,magg It yy,/

Replatery 799 Roosevelt Road Glen Ellyn, Illinois 60137 4

"W p'f

SUBJECT:

REPORT OF ABNORMAL OCCURRENCE PER SECTION 6.6.B 0F THE TECHN SPECIFICATIONS.

WEEKLY TURBINE CONTROL VALVE SURVEILLANCE.

References:

1) Regulatory Cuide 1.16 Rev.1 Appendi:4A

2) Notification of Region III of AEC Regulatory Operations Telephone: Mr. F. Maura, 1340 hours0.0155 days <br />0.372 hours <br />0.00222 weeks <br />5.0987e-4 months <br /> on August 12, 1974 Telegram: Mr. J. Keppler,1350 hours0.0156 days <br />0.375 hours <br />0.00223 weeks <br />5.13675e-4 months <br /> on August 12, 1974

3) Drawing Number: P&ID M-12 Report Number: 50-237/1974-39 Report Date: August 16, 1974 Occurrence Date: August 10, 1974 Facility: Dresden Nuclear Power Station, Morris, Illinois IDEttrIFICATION OF OCCURRENCE _

At 2220 hours0.0257 days <br />0.617 hours <br />0.00367 weeks <br />8.4471e-4 months <br /> on August 10, 1974, il control valve failed to give a % scram during surveillance testing. The valve operated satisfactorily.

CONDITIONS PRIOR TO OCCURRENCE At 2220 hours0.0257 days <br />0.617 hours <br />0.00367 weeks <br />8.4471e-4 months <br /> on August 10,1974, Unit 2 was in the run mode producing 1758 MWt and 549 MWe.

DESCRIPTION OF CCCURREMCE At 2220 hours0.0257 days <br />0.617 hours <br />0.00367 weeks <br />8.4471e-4 months <br /> on August 10, 1974, weekly turbine control valve surveillance was being ccnducted on Unit 2. #1 control valve fast acting solenoid failed to give a % scram signal. The load drop was continued to

%9 Altc . p ,

5. >N: P' /

8305230378 740s

• gDRADDCK05000

~ -vn: w

[C

F.r.J:mesG.Kepp{.or { Augu:t 16, 1974 below the point where the scram is required. . An electrician inspected the switch and found no obvious problem. The control valve was then tested again and the switch operated satisfactorily.

DESIGNATION OF APPARElff CAUSE OF OCCURRENCE (Other)

No apparent cause could be found.

ANALYSIS OF OCCURRENCE

. There were no safety consequences to the public or plant personnel as a result of this occurrence because the remainder of the trip logic was operating correctly and the unit would have scranmed on a generator trip.

OORRECTIVE ACTION The immediate corrective action was to reduce power below 407.;

inspect the switch, relays, and connecting wires; and functionally test the system two more times. The system operated satisfactorily each time, so no further immediate corrective action was deemed necessary.

This system is tested weekly and is being monitored for similar problems.

EAILURE DATA Review of station records has found no failures of this type in this or similar systems.

< Since the cause of the malfunction could not be determined, no

. component data can be given. -

' Sincerely,

. c.'M B. B Step enson .

Superint4adent BBS:LTD:do L- _

. ?,

ce*G' r ' .

m UNITED CTATE3 I e . ATOMIC ENERGY COMMISSION g DIRECTORATE OF REGULATORY CPERATIONS REGION Ill

%rtso'"f 799 ROOSEVELT ROAD mg GLEN ELLYN. ILLINOIS 6o137 (312) 858-2460 A. RO Inspection Report No.

Transmittal Date  :

Distribution: Distribution:

R0 Chief, FS&EB R0 Chief, FS&EB RO:HQ (5) RO:HQ (4)

DR Central Files L:D/D for Fuels & Materials Regulatory Standards (3) DR Central Files Licensing (13) RO Files RO Files B. RO Inquiry Report No.

Transmittal Date  :

Distribution: Distribution:

R0 Chief, FS&EB R0 Chief, FS&EB RO:HQ (5) RO:HQ DR Central Files DR Central Files Regulatory Standards (3) RO Files Licensing (13)

RO Files .

, C. Incident Notification From: Commonwealth Edison Co. . Docket No. 50-237

. (Licensee & Docket No. (or License No.)

Transmittal Date  : October 23, 1974 Distribution: Distribution:

EQ_ Chief..lS&EB R0 Chief, FS&EB RO:HQ (4) RO:HQ (4)

Licensing (4) L:D/D for Fuels & Materials DR Central Files DR Central Files RO Files RO Files I

3. -9,4 ( v5 4

b /,e s N

j 's

--- 1 3 %

. c .- .. p-y-e- e.- w.. ,,.c ,,

I t