ML20009E922

LER 81-058/03L-0:on 810622,during steady-state Operation at 2,194 Mw,Reactor Bldg to Torus Vacuum Breaker Isolation Valve 2T48-F310 Failed Open.Cause Attributed to Torus Differential Pressure Switch Setpoint Drift.Switch Recalibr

ML20009E922
Person / Time
Site:	Hatch
Issue date:	07/15/1981
From:	Nix R GEORGIA POWER CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20009E910	List: ML20009E909 ML20009E922
References
LER-81-058-03L, LER-81-58-3L, NUDOCS 8107280546
Download: ML20009E922 (2)

Text

' '

NRC FOIM 366 U. Lk MELGA] RTGULATE.Y COMMIO31oM (7-77)

LICENSEE EVENT REPORT CONTROL BLOCK: l i

l l l l l 6

lh (PLEASE PRINT CR TYPE ALL REQUlr.ED INFCr.MATloN) lo IiI8 I9al AlLICENSEE 7

El Il CODE Hl 2l@l 0 15l 0l -l 0 l 0l 0 le l 0 I O I - l 0 l 0 l@l LICENSE NUMBER 25 426l 1 LICENSE l 1 l 1TYPE l l 1JOl@l5 7 CAT 58 l@

CON'T IoI1]

/ 8 ZR$ dl 60 Ol 5101 ODOCKET 61 l 01316 NUVBER I 6 l@l68 0 69l 6 l EVENT2 l 2DATE l 8 l 1 l@l 01711 14 75 REPORT 151811 DATE 80l@

EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h IO I2I I While the olant was in steadv state coeration at 7194 MWt. Reactnr Ruild- 1 10i3 1 ing to Torus Vacuum Breaker Isolation Valve. 2T48-F310. failed open. I IO I4 l l Tech Specs 3.6.3 reauires that Primary Containment Isolation Valves be l lo isi l operable. Redundant Reactor Building to Torus Vacuum Breaker Isolation l 10isl l Valve, 2T48-F311 was operable. Neither olant ooeration nor oublic health 1 10171I and safety were affected. This is a repetitive event as reported on l l 0 ia i l Reportable Occurrence Report 50 ^66/1981-051. I DE CODE SLBCO E COMPONENT CODE SUBCODE SU DE lTJ il l S l Dl @ [E_j @ (_E_j @ l I l N l S l T l R l U l@ l_Sj @ l Z l @

7 8 9 to 11 12 13 18 19 20 SEQUENTI AL OCCURRENCE REPORT REVISION EVENT YE AR REPORT NO. CODE TYPE N O.

LER RO

@ yu RE T 1811 l l--J l015l8l l/l l 01 31 LLJ l-l [_gj

,,,_ 21 22 23 24 26 27 28 29 30 31 32 T K N AC N ON PLANT MET HOURS S8 i FOR 8. SUPPLIER MANUFACTURER LE 33 J@LLl@

J4 LLl@

35 llj@

36 l010l010i 3/ 40 LY 41 J@ l_nJ@

42 1 a_l@

43 lsI316I2l@

44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS lilOIl The cause of the event has been attributed to Reactor Buildino to Torus I i i I Differential Pressure Switch. 2T48-N210_ setonint drift. The switch wac I yl recalibrated as per HNP-2-5240. Static "0" Rino Pressure Switch Calibra- I Li_,L_j l tion, and functionally tested successfully. A new switch has been ordered I li14l l and will be installed when received. I 7 8 9 80 SA S  % POWER OTHER STATUS DIS O RY DISCOVERY DESCRIPTION W lEl@

l0l9I0l@l NA l l Al@l Operator observation

8 l

ACTIVITY CO0 TENT RELEASE AMOUNT OF ACTIVITY LOCATION OF RELEASE L'_L J l_Z.J @D OF RELEASE [_Z_j@l NA l l NA l PERSONNEt exPOSSES NuveER TYPE DESCRIPTION NA l l i l 71 1 0l 0 l 0 l@l Zl@l PERSONNE L INJU IES NuM8ER oESCRi= TION @

W l8 0l 7 9 0l Ol@l 11 12 NA 80 l

LOSS OF OR DAMAGE TO FACillTY TYPE DESCRIPTION NA l i 9 l Zl@l' 80 8107280546 810715 NRC U"81 ONLY

@ PDR ADOCK 05000366 PDR 12lOl ISSUEl @ DESCRIPTION 3 y y,,,,,y , ,y,l 7 8 9 10 68 69 80 r, l * * '

• OO

• PHONE. 912-367-7781 2 GTME OF MEBARER

LER No.: 50-366/1981-058 Licensee: Georgia Power Company Facility: Edwin I. Hatch Docket No. : 50-366 Narrative Report for LER 50-366/1981-058.

On June 22, 1981, while the plant was in steady state operation at 2194 MWt, Reactor Building to Torus Vacuum Breaker Isolation Valve, 2T48-F310, failed open. Tech Specs 3.6.3 requires that primary containment isolation valves be operable. Redundant Reactor Building to Torus Vacuum Breaker Isolation Valve, 2T48-F311, was operable. Neither plant operation nor public health and safety were affected. This is a repetitive event as reported on Reportable Occurrence Report No. 50-366/1981-051.

The cause of the event has been attributed to Reactor Building to Torus Differential Pressure Switch, 2T48-N210, setpoint drift. The switch was found to actuate at 5" water column and 'it should be 14" water column. The switch was recalibrated as per HNP-2-5240, Static "0" Ring Pressure Switch Calibration, and functionally tested successfully. The switch was returned to service. A new switch has been ordered and will be installed when received.

A generic review revealed no inherent problems with this type switch, i

a

.