ML20086R189

AO-S2-75-01:on 750109,discovered High Water Level Existed in Sump Area of High Pressure Heater Drain Pump.Caused by Turbine Bldg Sump Pumps Shut Off for Test.Test Instructions Revised to Require Surveillance

ML20086R189
Person / Time
Site:	Surry
Issue date:	01/24/1975
From:	Stallings C VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	Moseley N NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20086R145	List: ML20086R178 ML20086R184 ML20086R189
References
AO-S2-75-01, AO-S2-75-1, NUDOCS 8402280730
Download: ML20086R189 (10)

Text

c

- e ,

, , (- ,-

• Y , N ,) l t

i- '

,( , VJnoxx2A E I.E CT RIC A ND PO W E H C O h11'AN Y -

i RICIISI OND.YI ROINI A O O O 61  !

January 24, 197.> g i

F.r. .Nccan C. l'oscicy, Director

• Serial No. 399 Directorate of Regulatory Operations F0itt/JTB:civ United Statc3 Nuclear Rc;ulatory Cc=ission Region II - Seite 813 Dochet No. 50-281 230 Peachtree Straat. Northvast . License No. DPR-37

- Atlanta, Geor;;ia 30303 Daar Mr. Mcaeley:

Fursuant to Surry Power Station Technical Specificatica 6.6.3.1, tha Virginia Electric cnd ?cuer Cc=7say herchy subsita forty (40) copies of Abnornal Cccurre.t:c R2pcrt 1?o. AG-S2-75-01.

Tha subatance of this report has baen reviaved by the Station Nuclear

. Safety snd 0;eratin:; Ccmittee and vill be placed on the cacada for tha

\. next cactina of the System l'uclear Safety and Operatin;; Ccanittee.

Very truly yours, 7 -

h. 'l.h/Albo', 'V C." M. Stallings .

Vice President-?cwor Supply and . Production Operations T: closures .

40 copics of A0-S2-75-01 cc: M,r. K. R:.Collt.r' 873 i

• 8402280730 750124 '

PDR ADOCK 05000280 PDR s . .

a b

j

1 -

]

( .

1, i

4 ABNORMAL OCCURRENCE REPORT i RFFORT No. A0-S2-75-0_t, Tile FLOODING OF TilR VALVE PIT C0:lTAINING SERVICE VATER VALVES MOV-SW-2 03 A ,11, C , D

) .

i.

~

.IC . -

l

' JANUARY 9, 1975 m O- .

t DOCKET NO. 50-281_

LICENSE NO. DPR-37 ,

'I i .

! ShRRYPOWERSTATION 1

i VIRGINIA ELECTRIC AND Pd!ER COMPAN_Y

.,.-- e.. . . . . .

. * . ~

7 N

• e e

e Y

E 8.g e

. ,~ ~

. + =

W

'k e

~b T

e g

s. , ,m ,,.p, 5 . ,

'a f

',,[',

• +_m~

'41=1 C., s. . eew .u% . _ _

m .

1. INTRODUCTION-(_) (j

. In accordance with Technical Specification 6.6.B.1 for Surry Power-Station, Operating License Number DPR-37, this report describes an abnormal occurrence which occurred on January 9, 1975. The Directorate of Regulatory Operations, Region II, was notified on January 9, 1975.

The occurrence reported herein is classified as an abnormal. occurrence pursuant to Technical Specification 1.0.I.6 which states, "An abnormal occurrence is defined as: Engineered safeguard system malfunction or other component or system malfunction which rendered or could render the engineered safeguard system incapable of performing its intended function."

The occurrence described herein involved the inoperability of the flow paths of the service water to the recirculation spray system heat exchangers, during power operation of Unit No. 2.

II. SUMLiRY OF OCCURRENCE On January 9,1975 at approximately 1215 hours0.0141 days <br />0.338 hours <br />0.00201 weeks <br />4.623075e-4 months <br />, with Unit No. 2 at 80 per cent power, it was discovered that a high water icvel existed in the sump area of the high pressure heater drain pumps. Using a portable sump pump,' station personnel began to pump this water to a floor drain.

When the Shif t Supervisor learned of the high level in the high pressure 3.,.... -

heater drain; pump sump, he . checked the. recirculation . spray s.orvice uater balve' pit' (RS ' valve cit') .

Finding it full'of wa'ter, he manually stir'ted

. the Unit No. 2 turbine building sump pumps, and dispatched electricians.

to check the motor control centers for the service water valves in the

~

recirculation spray system to determine if a ground fault existed. Upon receipt of the information that a ground did exist, an orderly shutdown was begun at 150 N'Je/hr. f

.a

'j

a i- .

..

• l- '

(

The water level in the RS valve pit was reduced using a portable ,

A pump and the valves we're manually opened. The reactor power decrease has then halted and power was escalated. The valve pit was completely emptied and new notor operators installed. ,

III. ANALYSIS OF OCCURRENCE The RS valve pit containing the recirculation spray valves MOV-SW-203A, I

B',C,D has an overflow connection to the turbine building sump, as does i the high pressure drain pump sump. .The turbine building sump pumps had been shut off in connection with a test in which the flow rate to the sump is calculated by means of monitoring the change in sump level over one (1) hour. The personnel conducting this test were dispatched to handle a station emergency and were not availabic to conitor the sump level.

( The sumo filled and overflowed to the RS valve pit and high pressure drain pump sump through the respective connecting overflow pipes.

The action of the Shift Supervisor in starting the sump pumps stopped the, flow to the RS valve pit and drained the RS valve pit to the level of the overflow pipe.

_It was then necessary to use the portable pump to uncover the cotor operators on the valves.

~

1

, , * . ~. . .. . :7

, - ,. e r ., . . . .. .

.c

., ,IV . ORRECTIVE XCTION TO PREVENT RECURRENCE .

The occurrence would not have happened if the level in tha turbine building sump had been visually conitored during tha flow test. The instructions for this test have been~ revised to require such surveillance.

I l ,

l' . . i .

4

.. 4 e . .

j 4-V.

.o .

M'tLYSIS M.'D EVALUATION OF SAFETY IMPLICATIONS OF Tile OCCURRENCE O

',~~ ,

l The MOV-SW-203A,B,C,D are normally closed, and are automatically opened on a containment high-high pressure signal. Thes,e valves allow service water tc flow through the recirculation spray heat exchangers, i

and open as part of the unit response to a loss of coolant accident.

Once these valves had been opened and flow to the recirculation spray heat exchangers had been established, the reactor power cr.uld be safely escalated.

During the cime interval in which the motor operators were submerged and the valves were closed, it is possible that the valves would have

failed to open during a LOCA of sufficient magnitude to cause a containment ,

high-high pressure. Operator action would have been required'to manually open the valves. This could have been accomplished even with the pit filled with water,

(.s. ,

VI. CONCLUSIONS The licensee concludes that:

1. The occurrence described herein was caused by the failure of station personnel to monitor the level of the sump during a flow calculation test. .

. .c * *. . . . :- . . ..... . .. . . ..

/

2/ . T.he occurrence' reported herein 'd'i'd not af fdSt 'the.

' ' . safe operation of the station. ,

3. The occurrence described herein did not adverselv affect tha health or safety of the general public.

e l t

• e e ,

~~ -n - . .s- e .+ pe-n. _ . - __ __ , __

O.N'*'12

-- ,p

\' s . .

' ~'

VIMO1NIA Ex.ncrrezc ann Pownn COM1'ANY , , , , _ _

H a cian oxn.Vx uaix A enuot I\MN!f ,

January 24, 1975 V JANOEC$v[$' 30 ,yg. .

g, g

~

E3. McT: tsu3y u C33I;S;a ~

d) se:recri hill Secus &

9 Mr. Norman C. Moseley, Director Serial No. 399 Directorate of Regulatcry Operations P0&M/JTB:clw United States Nuclear Regulatory Commission Regica II - Suite 818 Docket No. 50-281 230 Peachtree Street, Northwest License No. DPR-37 Atlanta, Georgia 30303

Dear Mr. Moseley:

Pursuant to Surry Power Station Technical Specification 6.6.B.1, the Virginia Electric and Power Company hereby submits forty (40) copies of Abnormal Occurrence Report No. A0-S2-75-01.

The substance of this report has been reviewed by the Station Nuc1 car I Safety and Operating Committee and will be placed on the agenda for the next meeting of the System Nuc1 car Safety and Operating Committee. ,

l Very truly yours,.

. 4[0b C. M. Stallings-Vice President-Power Supply and Production Operations Enclosures 40 copics of A0-S2-75-01 cc: Mr. K. R. Goller fI O f ,-

[0

o <

Y l 1046 i

(

r T- .

COPY 8tNf REGION # _ --

( m

• 's e s , .

~

O ABNORMAL OCCURRENClj REPOR'll REPORT NO. A0-S2-75-0_1, Tile FLOODING OF THE _ VALVE l'IT <

CONTAINING SERVICE WATER VALVES MOV-SW-203A,B,C,D JANUARY 9, 1975 DOCKET NO. 50-281 LICENSE NO. DPR-37 SURRY POWER STATION VIRGINIA ELECTRIC AND' POWER COMPANY pms wy-n...,r* , , , , , , .

-v

1. INTRODUCTION  ;

In accordance with Technical Specification 6.6.B.1 for Surry Power Station, Operating License Number DPR-37, this report describes an abnormal occurrence which occurred on January 9, 1975. The Directorate f of Regulatory Operations, Region II, was notified on January 9, 1975.

1 i

The occurrence reported herein is classified as an abnormal occurrence pursuant to Technical Specification 1.0.1.6 which statee, "An abnormal occurrence is defined as: Engineered safeguard system malfunction or other component or system malfunction which rendered or could render the engineered safeguard system incapable of performing its intended function."

i The occurrence described herein involved the inoperability of the flow paths of the service water to the recirculation spray system heat exchangers, during power operation of Unit No. 2.

4

) II.

SUMMARY

OF OCCURRENCE On January 9, 1975 at approximately 1215. hours, with Unit No. 2 at 80 per cent power, it was discovered that a high water level existed in the sump area of the high pressure heater drain pumps. Using a portable sump pump, station personnel began to pump this water to a floor drain.

When the Shift Supervisor learned of the high level in the high pressure heater drain pump sump, he checked the recirculation spray service water I

. valve pit (RS valve pit) . Finding it full of water, he manually started I

i the Unit No. 2 turbine building sump pumps, and dispatched electricians j- to check the motor control centers for the service water valves.in the recirculation spray system to. determine if a ground fault existed. .Upon

~

receipt of the information that a ground did exist, an orderly shutdown i was begun at 150 MWe/hr.

i r

4

- _1_

,,- - i r . ie,,- r., , - - - - . . ,, _ , - - , .-. , . .m-J4 .... .

r 3 The water level in the RS valve pit was reduced using a portable pump and the valves were manually opened. The reactor power decrease was then halted and power was escalated. The valve pit was completely emptied and new motor operators installed.

III. ANALYSIS OF OCCURRENCE Thc RS valve pit containing the recirculation spray valves MOV-SK-203A, B,C,D has an overflow connection to the turbine building sump, as does the high pressure drain pump sump. The turbine building sump pumps had been shut off in connection with a test in which the flow rate to the sump is calculated by means of monitoring the change in sump level over one (1) hour. The personnel conducting this test were dispatched to handle a station emergency and were not available to monitor the sump level.

The sump filled and overflowed to the RS valve pit and high pressure drain pump sump through the respective connecting overflow pipes.

The action of the Shift Supervisor in starting the sump pumps stopped the flow to the RS valve pit and drained the RS valve pit to the level of the overflow pipe.

It was then necessary to use the portable pump to uncover the motor operators on the valves.

IV. CORRECTIVE ACTION TO PREVENT RECURRENCE The occurrence would not have happened if the level in the turbine building sump had been visually monitored during the flow test. The instructions for this test have been revised to require such surveillance.

r o

/ 8

.. (

v

)

V. ANALYSIS AND EVALUATION OF SAFETY IMPLICATIONS OF THE OCCURRENCE The MOV-SW-203A,B,C,D are normally closed, and are automatically opened on a containment high-high pressure signal. These valves allow service water to flow through the recirculation spray heat exchangers, and open as part of the unit response to a loss of coolant accident.

Once these valves had been opened and flow to the recirculation spray heat exchangers had been established, the reactor power could be safely escalated.

During the time interval in which the motor operators were submerged and the valves were closed, it is possible that the valves would have failed to open during a LOCA of sufficient magnitude to cause a containment high-high pressure. Operator action would have been required to manually open the valves. This could have been accomplished even with the pit filled with water.

VI. CONCLUSIONS The licensee concludes that:

1. The occurrence described herein was caused by the failure of station personnel to monitor the level of the sump during a flow calculation test.

2. The occurrence reported herein did not affect the safe operation of the station.

3. The occurrence described herein did not adversely affect the health or safety of the general public.

_3