05000280/LER-1981-018-03, Ler 81-018/03L-0:on 810702,power Operated Relief Valves Lifted to Mitigate Overpressurization Transient.Caused by Unisolated Charging Flow Control Valve.Valve Isolated. RCS Pressure Reduced Below Setpoint

From kanterella
(Redirected from ML20009H643)
Jump to navigation Jump to search
Ler 81-018/03L-0:on 810702,power Operated Relief Valves Lifted to Mitigate Overpressurization Transient.Caused by Unisolated Charging Flow Control Valve.Valve Isolated. RCS Pressure Reduced Below Setpoint
ML20009H643
Person / Time
Site: Surry Dominion icon.png
Issue date: 07/29/1981
From: Joshua Wilson
VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20009H621 List:
References
LER-81-018-03L, NUDOCS 8108100317
Download: ML20009H643 (2)
v • d • e


LER-1981-018, Ler 81-018/03L-0:on 810702,power Operated Relief Valves Lifted to Mitigate Overpressurization Transient.Caused by Unisolated Charging Flow Control Valve.Valve Isolated. RCS Pressure Reduced Below Setpoint
Event date:
Report date:
2801981018R03 - NRC Website
v • d • e

text

'.

"JRC FORM 366 U. S. NUCLEAR REGULATORY OOMMIsSION

.7.T7:

LICENSEE EVENT REPORT 00NTAOL ELOCK. I I

l I

! lh (PLEASE PRINT OR TYPE ALL REQUIRED INFORf.1ATION) 1 6

c

- l i VI Al Sl Pl Sl 1l@l 01 O! -l 01 01 01 010 l -l Ol O l@l 4 l 1 l I i 1 ! 1 l@lo ar u @

l l

4 e uCENSEE :::E i.

a

.i:E ~st ~uM E-

s a

uCENsE Tv.E ao

. '[,,

,g*J l L jg 0 BoIgl0[71 01218;1Jgl0l7l2l9i8;1l@

1 5 ;0 : Oi 0; 2; i

s s

si

=cCxtTNUMeER a

EvtNT cATE 2'

a Reno =T c4TE SC E'.'ENT OESOAl' TION

  • NO
  • ROB ABLE 00NSEOUENCES

,;,;jl During Unit I startup, wi th the reactor coolant system (RCS) solid at 190 degrees F 1

3;3,, and 350 psig, power operated relief valves (PORV) lifted in order to mitigate an oved-

,3i,,

pressurization transient. The transient occurred when the charaina flow control valde j e i s ; ; (FCV) Inadvertantly ope. -d when being out in service. The ooeration of the PORVs.

l l c is i ! isolation of the FCV. and subsecuent lowerino of RCS oressure below the setcoint I

oi

,I terminated the transient:

therefore. the health and safety of the nublic were not I

iaffected. This item is reportable per T.S.6.6.4.g.

as required by T.S.3.1.G.3 I

,3,g, 80 g 9 SYSTEM AUSE

CAUSE

COMP.

VALVE CODE 000E SUBCODE COMPONENT COOE SUBCODE SU8 CODE 10ist i Cl-Jl@ l El@ l B j@ l V l Al Ll VI El Xl@ l Fl@ l Gl@

7 8

9 10 11 12 13 18 19 20 SE QU E NTI AL OCOU R R E NCE RE* ORT REvtsiCN ga EVENTvtAR RE*CRT NC.

COCE Tv*E NC.

@ a,,sg,no l 81 1l l-l l 0 l 118l

]/l l013l lLl 1,---J l0 l 7

_1 23 24 26

7
S 29 30 31

'2 AO* ION SU UmE Essg:*

SMU*DCwN ATTACNMENT N8RC 4 PRIME COV8 COM'ONENT TAKEN ACTION ONDUANT METMCO MOURS SU8MITTED PORM SUIS.

SUP'U E R MANUFACTURER lAlgl34 Zg l5 Zlg lZl@

l 010 l 0 _

l l Ylg l N jg l Nj@

lCl6]3l5l@

33 3

06 3e 40 41 42 43 de 47 CAUSE CESOAIPTION AND COA AECTivE ACTIONS

.,,a;;This event was initiated when the charging FCV was unisolated. The valve controller i g.i.jtoutput signal implied the valve was in the closed position but failure of the valve ;

,,,;,tresulted in nearly full flow. Th*s resulted in a soike in charoina flow causino an

(

}RCS pressure increase.

Corrective action was to isolate the FCV and reduce-RCS l

,,,3, 11

,4 i t pressure below the setooint.

I s 9 8e TA

%powtR QTHER STATUS Of RV DISCCV E RY ESCRIPTION

! 5 l l G l@ l 01 01 0l@L N/A l

l l@l Operator Observation l

I1 AbVITY CO TENT ogggasg-at AMCUNT OF ACTIVtTY LOCATION QF RELEASE I Is j l Z l h ]mELEASEgl N/A l

l N/A

]

4 3 1C 11 As 45 80 agasyNNgg gxeO5URES i

NUvSE*

  • v

O E 50 R f '*10N l

ls i : t j 0 ; O l 0 l@l Z'l@l N/A l

11 SC l

4 9

  • ESSONNE $ NJu'niES q

%USg a OESCRt'T+0N\\'*/

- i.t101010l@l 1

i-e n

i:

to

,055 Cr On OauACE 70 SAC;uTv

.Tv'E O E30 R 6 *?!cN N/A l

I' LEI !

?

4 7 10 3G I'"*:$:

NO n/p N AC usE ONLv R,,Ti:

,$st E i 0 i : # I N l@l i

II IIiiII IiiIl;

'($d4)357-3184 l

8108100317 810729 J. L. Wiison PDR ADOCK 05000200

E

. O :E PDR i

S w~

- m

---w

-+

ATTACHMENT I SURRY POWER STATION, UNIT 1 DOCKET NO:

50-280 REPORT NO:

81-018/03L-0 EVENT DATE:

07-02-81 TITLE OF EVENT:

RCS OVERPRESSURIZATION 1.

DESCRIPTION OF EVENT

On July 2, 1981, during Unit I startup following the unit's steam generator replacement project, with the reactor coolant system solid at 190 degrees F and 350 psig, the pressurizer power operated relief valves lif ted in order to limit an overpressure condition. This is reportable per T.S. 6.6.4.g as required by T.S.-3.1.G.3 2.

PROBABLE CONSEQUENCES AND STATUS OF REDUNDANT SYSTEMS:

Since the power operated relief valves and the other components of the over-pressure mitigation system acted promptly and without failure to mitigate the RCS pressure transient, the health and safety of the public were not affected.

3

CAUSE OF EVENT

The overpressure condition was caused by an inadvertant increase in charging flow. The flow increase occurred when the charging flow control valve was unisolated when being placed in service. The valve controller output signal implied the FCV to be in the fully closed position, but when the FCV was un-isolated, the charging flow increased sufficiently to raise the RCS pressure to the lift pressure of the PORV.

Subsequent investigatinn revealed failure of the charging FCV.

4.

IMMEDIATE CORRECTIVE ACTION

The immediate action was to isolate the FCV and depressurize the RCS to less than the pressure requi red for lif ting.the PORV's.

5 SUBSEQUENT CORRECTIVE ACT!0N:

The FCV was repaired, tested, and satisfactorily returned to service.

6.

ACTIONS TAKEN TO PREVENT RECURRENCE:

No further action is required.

7.

GENERIC IMPLICATIONS:

There are no generic implications form this event.

Retrieved from "https://kanterella.com/w/index.php?title=05000280/LER-1981-018-03,_Ler_81-018/03L-0:on_810702,power_Operated_Relief_Valves_Lifted_to_Mitigate_Overpressurization_Transient.Caused_by_Unisolated_Charging_Flow_Control_Valve.Valve_Isolated._RCS_Pressure_Reduced_Below_Setpoint&oldid=4650742"