ML20086D910

AO 73-29:on 731002,drywell High Pressure Switch Failed to Actuate at Required Setpoint.Switch Reset,Functionally Tested & Declared Operable

ML20086D910
Person / Time
Site:	Vermont Yankee
Issue date:	10/03/1973
From:	Riley B VERMONT YANKEE NUCLEAR POWER CORP.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20086D909	List: ML20086D905 ML20086D910
References
AO-73-29, VYV-3039, NUDOCS 8312050656
Download: ML20086D910 (2)

Text

____ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ .

O O

.? VERMONT YANKEE NUCLEAR POWER CORPORATION

, SEVENTY SEVCN OROVC STRCCT RUTLAND,Yi:IO10NT 05701 VYV-3039 "'

P. O. DOX 157 VCRNON, VERMONT 05354 October 3, 1973 United States Atomic Energy Commission Directorate of Regulatory Operations, Region I 631 Park Avenue King of Prussia, Pennsylvania 19406

REFERENCE:

Operating License DPR-28 Docket No. 50-271 Abnormal Occurrence No. A0-73-29 Gentlenen:

As defined by Technical Specifications for the Vermont Yankee Nuclear Power Station, Section 6.7.B.1, we are reporting tha following Abnormal Occurrence as A0-73-29.and confirming our telephone conversation with your office.

At approximately 0900 on October 2, 1973, while performing a monthly functional test of the Reactor Protection System, a Drywell High Pressure suitch (PS5-12A) failed to actuate at the required setpoint of <2 PSIG as specified in Table 3.1.1 of the Technical Specifications. The reactor was shutdown at the time of the incident. Functionally, this switch operates in a one-out-of-two twice type logic and in a deenergized state actuates the Reactor Protection System. The three additional sensors monitoring drywell pressure were immediately tested and found to be actuating properly indicating that the system would have functioned if an actual high pressure existed in the drywell. 1 The switch was reset, functionally tested, and declared operable at 0930 on October 2, 1973.

Very truly yours, 8312050656 731010 VERMONT YANKEE NUCLEAR POWER CORPORATION PDR ADOCK ODOOO271 q PDR i

B.W. Riley f

_i ,

Plant Superintendent T S

WFC/rbh . h

r WMU ROM RE'>

e..,,n Ai r..n e n,, si., i 4. es in Ai us cr ia l L'o ** **si ta-

n,,,. ..,,,,,o,.

2 ' .','

e .

'ic o . .. . .. Z r' .','

i t

"ec'*, a-

- . i me.

] O (Pd t rfte 3 86tl knilj litlIl Oll M S AN S

1. M Licensee: Vemont_ Yankee nucienr Power Cornoration

11. D. Thornburg, cars Docket No.: 50 271 Chief, FS6EB "

Abnomal Occurrence: 73-29 IO (fdame ariJ unit) l Nil Ag.$ pluAng)

R0:11Q (5)

DR Central "iles (1) cart The attached report from the subject licensee is Regulatory Standards :3)

Dir. of Licensing (13 i forwarded in accordance with RO Manuni chanter 1000.

T o (N ari.e ami w<uti g INinALS REMARR$

RO Files /

The action taken by the licensee is_ considered cair appropriate. Followup will be perfomed during the next inspection as appronrinte. conies of F HOM (Name ato un.is P.tuaans t.<-

/ - , ~~ f' ' the report have been forwarded to the PDR, Local I L.

• r D/."L. C'a hthn, Seniolr PDR, NSIC, DTIE and State representatives. The Reictor Inspector, BWR Section licensee will su,bmit a 10 day written report to PHO? I fe0, DATE 10/16/73 Licensing.

USE OTHER LIM TOR ADDittumaL RCM ARKS g gg , g ,3 3 o , ,, g . ,

I , .

9 h * ,9 % ,

)E -

y e

4 s

-e, G

+ +- ^ -o w -m.+ -w -

%-. .. ., , -,.%