ML13333A308
| ML13333A308 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 10/18/1978 |
| From: | Baskin K Southern California Edison Co |
| To: | Ziemann D Office of Nuclear Reactor Regulation |
| References | |
| TAC-48143 NUDOCS 7810230155 | |
| Download: ML13333A308 (30) | |
Text
c R REGUZ UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 M4ORANDUM FOR:
TERA Corp.
FROM:
US NRC/TIDC/Distribution Services Branch
SUBJECT:
Special Document Handling Requirements
- 1.
Please use the following special distribution list for the attached document.
- 2.
The attached document requires the following special considerations:
Do not send oversize enclosure to the NRC PDR.
Only one oversize enclosure was received -
please return for Regulatory File storage.
M Proprietary information -
send affidavit only to the NRC PDR Other: (specify)
SBd4Files
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Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROV.E AVENUE ROSEMEAD, CALIFORNIA 91770 K. P. BASKIN October 18, 1978 TELEPHONE
- MANAGER, GENERATION ENGINEERING 213-572-1401 Director, Office of Nuclear Reactor Regulation Attention:
Mr. D. L. Ziemann, Chief Operating Reactors Branch #2 Division of Operating Reactors U. S. Nuclear Regulatory Commission Washington, D.C.
20555 Gentlemen:
Subject:
Docket No. 50-206 Provisional Operating License No. DPR-13 Fire Protection Program Review San Onofre Nuclear Generating Station Unit 1 On September 15, 1978, we met with members of the NRC staff in Bethesda, Maryland to discuss the final fire protection modifications in the 4160-volt Switchgear Room and the Lube Oil Reservoir and Conditioner Area. The methods which would be utilized to maintain San Onofre Unit 1 in a safe shutdown condition in the event of a fire in either area were also discussed at the meeting.
The purpose of this letter is to formally submit the information presented at the meeting and the additional information requested at the conclusion of the meeting.
Items 1, 2 and part of 3 below describe the information pre sented at the meeting and Items part of 3, 4, 5 and 6 below provide the additional information requested at the conclusion of the meeting.
- 1. The final modifications to the 4160-volt Switchgear Room are described in Enclosure 1 to this letter.
It was noted that an evaluation was being conducted to determine the appropriate "fire rating" to be assigned the penetration seals without experiencing a cable derating problem. The results of this evaluation will be reviewed for acceptability by the NRC staff.
-"1; o
2-3
/SNJ
-2
- 2. The final modifications to the Lu#Oil Reservoir and Conditioner Area are described in Enclosure 2 to this letter.
It was noted that the evaluation to determine the appropriate "fire rating" to be assigned the penetration seals in the 4160-volt Switchgear Room would also include consideration of the penetration seals in the north wall of the turbine building.
- 3. The interim modifications to be accomplished during the current refueling outage are described in Enclosure 3 to this letter.
The modifications would remain installed until the final modifications described in 1 and 2 above can be completed. Following completion of the interim modifications, San Onofre Unit 1 can be brought to and maintained in a safe shutdown condition in the unlikely event of the total loss of the 4160-volt Switchgear Room or the Lube Oil Reservoir and Conditioner Area. The "Casualty Procedure" which would be implemented to bring San Onofre Unit 1 to a safe shutdown was also reviewed by the NRC staff. As a result of their review, the NRC staff requested that flow diagrams be provided showing the safe shutdown systems which would be utilized to bring San Onofre Unit 1 to a safe shutdown condition and the instrumentation available to determine the operating status of the safe shutdown systems. Accordingly, flow diagrams are provided as Enclosure 4 to this letter and the available instrumentation (shown on the flow diagrams) is described in Enclosure 5 to this letter.
- 4. As requested by the NRC staff, an evaluation has been performed to determine the effect of spurious valve actuation on the capability to bring San Onofre Unit 1 to a safe shutdown condition following the immediate and complete loss of all power and control sources. The results of-the evaluation are described in Enclosure 6 to this letter, and indicate that a safe shutdown can be accomplished utilizing the "Casualty Procedure" provided as Enclosure 7 to this letter. However, credit has been taken for the early warning provided by the hourly fire watch patrol (refer to Item 5 below) in order to perform manual actions to secure the power supply to several valves (CV 722A, B, C and MOV 356, 357, 358).
The spurious actuation of these valves would result in heatup of the reactor coolant pump seal cooling water. This heatup may result in deterior ation of the reactor coolant pump seal integrity and increased leakage. The early warning provides adequate protection against the instantaneous and simultaneous loss of component cooling water, loss of reactor coolant pump seal water injection and the spurious actuation of one of these valves affecting safe shutdown of San Onofre Unit 1.
- 0.
-3
- 5. As requested by the NRC staff, an evaluation has been performed to determine the necessity to reroute cables in the Lube Oil Reservoir and Conditioner Area (Fire Zone 9A).
The results of the evaluation are described in Enclosure 8 to this letter, and indicate that San Onofre Unit 1 can be brought to and maintained in a safe shutdown condition.
as summarized below:
Hot Shutdown Condition The existing power cable which will be utilized to energize 480 volt Switchgear 2 from the alternate offsite power supply described in Enclosure 3 to this letter is routed along the boundary line between Fire Zones 9A and 9C (there is no fire rated barrier separating the zones).
The cable tray which carries the power cable is located a minimum of eight feet west of the edge of the curb being installed around the Lube Oil Reservoir and Conditioner in Fire Zone 9A. In addition, the power cable for Air Compressor KlB is also routed in a cable tray at this location (a minimum of ten feet west of the edge of the curb).
Neither of the power cables are routed directly over the curbed area around the Lube Oil Reservoir and Conditioner. Since we have agreed to maintain an hourly fire watch patrol in this area, the physical distances (eight feet and ten feet) provide adequate protection against loss of the power cables due to an oil spill and fire in the Lube Oil Reservoir and Con ditioner curbed area.
The Steam Dump Relief Valve Control at the Control Room and at the Auxiliary Control Panel has control circuitry routed directly above the curbed area around the Lube Oil Reservoir and Conditioner. However, the Steam Generator Self-Actuating Safety/Relief Valves can be used instead of the Steam Dump Relief Valves to maintain a hot shutdown condition.
The combination of the physical distances (eight feet and ten feet), the implementation of an hourly fire watch patrol and the use of the Steam Generator Self Actuating Safety/Relief Valves provides adequate pro tection such that San Onofre Unit 1 can be brought to and maintained in a hot shutdown condition with an oil spill and fire in the Lube Oil Reservoir and Conditioner curbed area.
Cold Shutdown Condition The existing cable trays which carry the power cables for both Residual Heat Removal Pumps Gl4A, B are routed from their respective switchgear located in the 4160 volt Switchgear Room and the 480 volt Switchgear Room
- e.
-4 into Fire Zone 9A then north through the north wall of the turbine building to the containment penetration area.
One cable tray is located a minimum of twenty five feet and the other one is located a minimum of two feet north of the edge of the curb being installed around the Lube Oil Reservoir and Conditioner in Fire Zone 9A and are not routed directly over the curbed area. Power can be supplied to the pumps from the alternate offsite power supply described in Enclosure 3 through 480 volt Switchgear 2 (pump Gl4B) or the 4160 volt Switchgear IC (energized by a diesel generator) through 480 volt Switchgear 1 (pump Gl4A).
Since we have agreed to maintain an hourly fire watch patrol in this area, the physical distance (twenty five feet) provides adequate protection against loss of the power cables to both pumps due to an oil spill and fire in the Lube Oil Reservoir and Conditioner curbed area.
As discussed above for the hot shutdown condition, the Steam Dump Relief Valve Control at the Control Room and at the Auxiliary Control Panel has control circuitry routed directly above the curbed area around the Lube Oil Reservoir and Conditioner.
Without the capability to use the Steam Dump Relief Valves, San Onofre Unit 1 can not be brought to a cold shutdown condition immediately following loss of the control circuity due to an oil spill and fire in the Lube Oil Reservoir and Conditioner curbed area.
However, if the Steam Dump Relief Valve Control is rendered inoperative, sufficient time would be available to provide alternate sources of control power for the Steam Dump Relief Valves from operable switchgear in order to initiate a cold shutdown.
Rerouting of power and control cables for the safe shutdown equipment described in Enclosure 7 which are routed in Fire Zone 9A will be considered in evaluating the alternate methods (not dependent on the test pump) to bring San Onofre Unit 1 to a safe shutdown condition.
The criteria to be considered in evaluating the alternate methods are discussed below.
- 6. As indicated in Enclosures 1 and 2, an evaluation is being performed to determine the appropriate "fire rating" to be assigned to the penetration seals planned for the 4160-volt Switchgear Room and the north wall of the turbine building without experiencing a cable derating problem. The evaluation is expected to be completed by.
November 15, 1978.
With the exception of the "fire rating" to be assigned to the penetration seals, the final modifications described in Enclosures 1 and 2 are acceptable to the NRC staff.
In addition, the interim modifications described in Enclosure 3 are acceptable to the NRC staff. The additional information described in
-5 in reviewing the safe shutdown capabilities at San Onofre Unit
- 1.
Subsequent to the September 15, 1978 meeting, the NRC indicated that we would have to propose some method to bring San Onofre Unit 1 to a safe shutdown condition which does not rely on the Chemical Volume and Control System Test Pump for reactor coolant system inventory makeup. Following an investi gation of the systems required for safe shutdown, alternate methods not dependent on the test pump can be evaluated and a conceptual proposal can be submitted to the NRC by January 15, 1979.
An implementation schedule for the conceptual proposal can also be submitted by January 15, 1979.
The criteria to be considered in evaluating the alternate methods are as follows:
- 1. San'Onofre Unit 1 can be safely shut down assuming a fire in any zone, including the 4160-volt Switchgear Room or the Lube Oil Reservoir and Conditioner Curbed Area.
- 2. Hot shutdown can be maintained for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
- 3. Cold shutdown can be achieved within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of reaching the hot shutdown condition,
- 4. Use of both offsite and onsite power sources to operate required safe shutdown equipment will be considered in the evaluation, and
- 5. Cable rerouting will be considered and appropriate instrumentation will be made available, as necessary, to allow safe shutdown from a minimum of remote locations.
San Onofre Unit 1 is currently scheduled to return critical by approximately November 1, 1978.
It is respectfully requested that you review the enclosed information and take appropriate action before that date.
If you have any questions concerning the enclosed information, or desire additional information, please contact me.
Very truly yours, Enclosures(8)
Final Modifications to 4160-volt Switchqear Room (Fire Zone 8)
.1. Automatic Halon System (Double Shot)
- 2.
Fire Detectors
- 3. Fire/Smoke Dampers
- 4.
Drainago Modifications
- 5. Hose Reel at Southeast Door
- 6. Penetration Seals for Leak Tightness*
- 7.
Spray Splash Shields for Switchgear
- Note:
An evaluation will be conducted to determine the appropriate "fire rating" to be assigned to the seals without experiencing a cable derating problem.
Final Modifications to Lube Oil Reservoir and Conditioner Area (Fire Zone 9A)
- 1. Foam System Over Lube Oil Reservoir and Conditioner Area
- 2. Relocate Detectors and Add New Detectors
- 3.
Directed Sectionalized ater Spray to Protect Cable Trays (Actuated by temperature detectors placed in cable trays)
- 4.
Backup Area Fusable Link Wet Pipe Sprinklers (Provides Protection for 480-volt Switchgear Room-Walls and Turbine Building Structural Steel)
- 5.
Upgrade North Wall of Turbine Building to 3-Hour Fire Rating
- 6. Penetration Seals in North Wall to Suitable Fire Rating*
- 7.
New East Door to 480-volt Switchgear Room (3-Hour Ratinq)
- 8. Modify Firewater-Crossover Piping in Fire Zone 9A
- Note:
An evaluation will be conducted to determine the appropriate "fire rating" to.be assigned to the seals without experiencing a cable derating problem.
Interim -Modifictost
-~dfca tions to be AccopihdDrn
'rent ueu1n ua Ce ULnt i F~inalModifi2cations Are Complete 2 kV Line Routing to Unit 1 nstallation of 12 kV/480V Transformer ansformer hook-up Low Side and High Side Thermal Barrier Emergency Cooling Pump Power Cable
-routing
'Thermal Barrier Emergency Cooling -Pump Control Cable routing
'PMCotoCal note Manual Operation at Control Room and Local at
!rter Motor to DC Thermal Barrier Emergency Cooling pump j
ves2Ap nand C Air Accumulator Modification to Maintain yes Open on! Loss Of Air*
tim Control Tank Level Indication at Test Pump Switchgear tall Curb Around Lube Oil Reservoir and Conditioner Area
-nage Modifications Under Turbine Deck all 3 -Hour Self ClosingnFire Door at Southwest Door of
-Volt SWitchgear Room and South Door of 4 8 0-volt chgear Room (Due to manufacturing and delivery problems, the doors ot be installed until after the refuelinZ. oi'tage.)
Ill Curb Around Southeast Door of 4 l60-volt Switchgear
- e DC Control Power to Operate 480-volt Breakers required to feed
)t Switchgear from l2kV/48OV Transforer and install local and Control nnunciation to indicate Operating Status of 12 kV line.*
Z Power cable to operate pressurizer heater Bank D.*
ests perfoo d during the current refueling outage has sho nves fail open on both loss ofpower and loss of air whichis initial information; therefore, air accumulator modifi Dt required.ha cr
, the door will be sealed rather than a curb being installed.
1 14 were not previously identified during September 15, 1978 meeting.
J.
S INSTRUMENTATION AVAILABLE TO DETERMINE SAFE SIUTDOWN SYSTEMS OPERABILITY Reactor Coolant System P&ID 568766 Instrumentation available at the Auxiliary Control Panel
- 1. Neutron Level N120X
- 2.
Primary Loop Temperature T1402B,TI4/32B,TI422B
- 3. Pressurizer Pressure PI434A
- 4.
Pressurizer Level L1430A
- 5. Steam Generator Secondary Side Water Level L1450C, LI4SIC, L1452C.
Local Instrumentation (Non-electrical)
- 1. Loop B Hot Leg Pressure P1410
- 2.
Loop C Line -to RHRSystem Pressure P1426 Radioactive Waste Disposal Systems P&ID 568772 Local Instrumentation (Non-electrical)
- 1. RCS Drain Tank Level LG44
- 2. RCS Drain Tank Pumps Discharge Pressure PI189,190.
Auxiliary Coolant System P&ID 568768 Local Instrumentation (Non-electrical)
- 1. Component Coolant Flow at Outlet of RCP's FI611A,B,C and F1612A,B,C.
- 2. Outlet Temperature from -
Reactor Shield Cooling Coils TI128.
- 3. Component Coolant Outlet Temperature from Sample Heat
,Exchangers TI608C
- 4. Component Coolant Outlet Flow F1608B and Temperature T1608B from Seal Water Heat Exchanger.
- 5. Component Coolant Return Header Temperature T1603
- 6. Component Cooling Pump Gl5B Discharge Pressure PIG05B
- 7. Component Coolant Outlet Temperature and Pressure from Component Cooling Heat Exchangers T1606A,B and P1606.
- 8. Component Cooling Surge Tank LG410
- 9. RHR Pump G14B Discharge Pressure PI600B.
- 10.
RHR Heat Exchanger Outlet Temperature T1602.
Circulatory Water P&ID 568775
- 1. Salt Water Cooling Pump G13B Discharge Pressure PI74.
- 2. Salt Water Coolant Outlet Temperature from Component Cooling Heat Exchanger T177 and T178.
- 3. Salt Water Coolant Inlet Temperature and Pressure to Component Cooling Heat Exchanger TIl5, TI118 and PI112, P1111.
Chemical and Volume Control System P&ID 568767 Local Instrumentation (Non-electrical)
- 1. CVCS Test Pump Discharge Pressure P11120
- 2. Seal Injection Bypass Flow F11116
- 3. Seal Water Filter Inlet and Outlet Pressure PIll8A and P1118B.
- 4. Seal Water Heat Exchanger Outlet Temperature TIllS.
- 5. Volume Control Tank Level. LIll00B (installed at location of CVCS Test Pump Control with independent power supply).
Compressed Air P&ID 568780 Local Instrumentation (Nonelectrical)
- 1. Air Receiver C4B Pressure P155
- 2. Instrument Air Dryer Temperature and Pressure TI17,18, and P175,76.
- 3.
Air Filter Outlet Pressure P160
- 4. Reactor Instrumentation Line Pressure P1230
- 5. PCV36,37 Outlet Pressure P1213.
Feedwater and Condensate P&TD568779 Local Instrumentation (Non-electrical)
- 1. Steam Driven Auxiliary Feedwater Pump G10 Discharge Pressure P1208 Steam P&ID568773
- 1. Steam Driven Auxiliary Feedwater Pump GlO.Steam Inlet Pressure P1212.
ENCLOSURE 6 THE EFFECT OF SPURIOUS VALVE ACTUATION ON SAFE SHUTDOWN CAPABILITIES A fire which results in complete loss of all the A.C. and D.C. power and control sources at San Onofre Unit 1 is a highly unlikely event. However, in accordance with an NRC request, an evaluation has been performed to determine the effect of spurious valve actuation on the capability to bring the station to a safe shutdown condition following
- the immediate and complete loss of all power and control sources.
The evaluation was.performed based on the following assumptions:
- 1.
Immediate and complete loss of all A.C. and D.C.
power and control sources
- 2. Power restored to equipment operated from 480-volt Switchgear No. 2
- 3.
A spurious signal effects only one valve at a time
- 4.
Safe Shutdown is accomplished as described in the Casualty Procedure
- 5. Valves outside safe shutdown system boundaries were not included.
Page 1 of 13 EVALUATION OF SPURIOUS VALVE ACTUATION WORMAL FAILURE MODE SPURIOUS MOVEMENT LOSS OF LOSS OF TO UNFAVORABLE MANUAL EFFECTS OF SPURIOUS VALVE P&ID SYSTEM POWER AIR POSITION OPERATION MOVEMENT ON SAFE SHUTDOWN REMARKS pNo None Pressurizer spray flow PCV 430 H,C 568766 RCS Closed Closed I open pat woldboioatd Flow path normally.
utilized to achieve cold shutdown; however, cooldown to cold shut down can be achieved via increased steam generator blowdown through steam dump valves, Reactor Coolant System makeup through reactor coolant pump seals and natural heat losses through Reactor Coolant System.
Additional time would be required to achieve cold shutdown.
CV544 568766 RCS Open Closed None No None Controls flow to Flange Leak Detection System which is inoperative.
Closed 1 open No None Reactor Coolant System CV545, 546 568766 RCS Closed Cwould be depressurized through Pressurizer Re lief Tank rupiure disk into containment.
Isolation of C's 545 or 546 is normally achieved by closing CV's 531 or 532.
How ever, normal failure mode of Cv's 531 and 532 is to the open position on loss of power and loss of air.
CV's 545 and 546 can be manually reclosed by securing the power supply to the valves at the con tainment penetration.
Securing of the power supply to the valves can be achieved within 15 minutes prior to empty ing the Pressurizer.
NORMAL FAILURE MODE SPURIOUS MOVEMENT LOSS OF LOSS OF TO UNFAVORABLE MANUAL EFFECTS OF SPURIOUS VALVE P&ID SYSTEM POWER AIR POSITION OPERATION MOVEMENT ON SAFE SHUTDOWN REMARKS The Chemical Volume Control System would be able to maintain Reactor Coolant System Inventory.
CV530, 531 568766 RCS Open open 1 Closed No None Safety valves (W532 or 533) are available to reduce Reactor Cool ant System pressure.
Reactor Coolant System pressure can be main tained by steam genera tor blowdown through steam dump valves and Reactor Coolant System makeup through reactor ooolant pump seals.
CV106 568772 Rad Waste Closed Closed Open No None Containment of Reactor Coolant System inventory in Reactor Coolant Sys tem Drain Tank would be achieved by redundant containment isolation valve CV107.
CV104 568772 Rad Waste Closed Closed Open No None Containment of Reactor in Reactor Coolant Sys tem Drain Tank would be achieved by redundant containment isolation valve CV105.
Under normal operating M0V720 A, B 568768.
Aux.
As is N/A 1 Closed Yes None Une nomloprtn Coolant conditions one valve is closed and one is open.
Worst case occurs when, initially the open valve spuriously closes, block ing the flow path through the Component Cooling Heat Exchanger.
Since TCV601 A and B fail open, an alternate flow path exists by backflow through the RHR Heat Exchanger.
This applies
Page 3 of 13 NORMAL FAILURE MODE SPURIOUS MOVEMENT LOSS OF LOSS OF TO UNFAVORABLE MANUAL EFFECTS OF SPURIOUS VALVE P&ID SYSTEM POWER AIR POSITION OPERATION MOVEMENT ON SAFE SHUTDOWN REMARKS only during the time when no component cooling or saltwater cooling exists (first 30 minutes of event) and when the circulation of Component Cooling Water is provided by the Thermal Barrier Emergency Cooling Pump.
At the time when the Component Cooling System is returned to normal operation, the operator will open both MDV720 A and B to prevent a spurious actuation from affecting safe shutdown (see Casualty Procedure).
CV722A, B, C 568768 Aux.
Open Open 1 Closed No None Closure of one of these Coolant valves would result in heatup.of the reactor oolant pump seal water bypass flow past the thermal barrier heat exchanger. This would re sult in heatup of reactor coolant pump seals and increased leakage.
How ever the hourly fire watch patrol which has been implemented provides early warning such that the power supply for these valves can be secured at the 6ontainment penetra tion prior to the instan taneous and simultaneous loss of component cooling water, loss of reactor coolant pump seal water injection and the spurious actuation of one of these valves.
Page 4 of 13 NORMAL FAILURE MODE SPURIOUS MOVEMENT LOSS OF LOSS OF TC UNFAVORABLE MANUAL EFFECTS OF SPURIOUS VALVE P&ID SYSTEM POKER AIR POSITION OPERATION MDVEMENT ON SAFE SHUTDONN REMAES TCV601A, B 568768 Aux.
Open Open Closed No None one valve is normally Coolant open and one valve is closed.
Worst case is open valve spuriously closing during Residual Heat Removal System operation.
However, both TCV's can be manually opened when the Residual Heat Removal System is put into service by securing and venting the air supply to the valves (see Casualty Procedure).
HCV602 568768 Aux.
Open Open Closed No None Wps case s e ualte Cooan spuriously closing during Residual Heat Removal system operation. However, the valve can be manually opened when Residual Heat Removal System is put into service by securing and venting the air supply to the valve (see Casualty Procedure).
MV813, 814, 568768 Aux.
As is N/A Closed Yes None Worst case is open valve
~j 33,834Coolant spuriously closing during Residual Heat Removal System operation. However, all valves can be manually opened when Residual Heat Removal System is put into service and the power.supply secured (see Casualty Procedure).
MDV822A, B 568768 Aux.
As is N/A Closed Yes None One valve is normally open Coolant and one valve closed. Worst case is open valve spuriously closing during Residual Heat Removal System operation. However, both valves can be manually
Page 5 of 13 NORMAL FAILURE MODE SPURIOUS MDVEMENT LOSS OF LOSS OF TO UNFAVORABLE MANUAL EFFECTS OF SPURIOUS VALAZ P&ID SYSTEM POWER AIR POSITION OPERATION MOVEMENT ON SAFE SHUTDOWN REMARKS opened when the Residual Heat Removal System is put into service and the power supply secured.
Control of Residual Heat Removal System cooling capacity can be achieved by manually closing valves 777 A or B-8"-632, restricting component cooling water flow into the Residual Heat Removal System heat exchangers (see Casualty Procedure).
POV6 568775 Circ.
As is As is Closed Yes None The salt water cooling Water pump (G-13B) associated with POV 6 can be made operational within thirty minutes. Prior to return ing the salt water cooling pump to service, POV 6 can be manually Opened and the air supply to the valve secured and vented (see Casualty Procedure).
5 568775 Circ.
As is As is None Yes None.
The salt water cooling pump Water (G-13A) associated with POV 5 cannot be made operational. Backflow through POV 5 cannot occur.
MOV9 568775 Circ.
As is N/A Closed Yes None Valve can be manually Water opened and its power secured at the time when the Salt Water Cooling System is returned to service.
(see Casualty Procedure)
e,~
fo%
I m
Page 6 of 13 NORMAL FAILURE MODE SPURIOUS MOVEMENT LOSS OF LOSS OF TO UNFAVORABLE MANUAL EFFECTS OF SPURIOUS VALVE P&ID SYSTEM POWER AIR POSITION OPERATION MOVEMENT ON SAFE SHUTDOWN REMARKS take 568775 Circ.
As is N/A Closed No None Intake stop gate cannot topGate Water be manually opened; however,
- t.
reverse flow can be achieved in the intake structure by manual oper ation of MOV's 10, 11 and 12 and securing their power supply at the time when the Salt Water Cooling System is returned to service.
(see Casualty Procedure).
N0V10 568775 Circ.
As is N/A Closed Yes None Saltwater discharges Water beyond MOV 10 and the outfall stop gate.
Dutfall 568775 Circ.
As is N/A Closed No None Saltwater discharges Stop Gate Water beyond MOV 10 and the outfall stop gate.
MOV11, 12 568775 Circ.
As is N/A 1 Open Yes None Some outfall water would Water be recirculated back to intake pipe but this would not impact the cooling characteristics of the Saltwater Cooling System.
CV100A 568775 Circ.
Closed Closed Open No None Line is closed.
Water Closed.
Closed I Open No None Reactor coolant pump F 1 Dseal water injection would be increased through one reactor coolant pump.
Adequate reactor coolant pump seal cooling can be maintained by component cooling water to thermal barrier coil heat exchanger and reactor coolant pump seal water injection. Reactor Coolant System makeup would be unaffected.
Page 7 of 13
&NPORMAL FAILURE ODE SPURIOUS MOVEMENT 11)5 O 1155 F
~
'O NFAORALEMANUAL EFFECTS OF SPURIOUS
- VALVE,
~
P&ID SYSTEM POWdER AIR POSITION OPERATION MOVEMENT ON SAFESHINRERS Reactor coolant puP FCV115 A, 568767 CVCS Closed Open 1 Closed No None s
water injection B, C would be lost; however, sufficient time is avail able to manually open the valves prior to returning the reactor coolant pump seal water injection to service. The valves can be manually opened by securing and venting the air supply to the valves. (see Casualty Procedure)
Open Open 1 Closed No None Closure of one of these PCV115 5876 CVS Oen Oen ClsedNo onevalves would block reactor B, C coolant pump seal water injection return line for one reactor coolant pump.
The differential pressure across the seconday reactor coolant pump seal of this pump would increase as well as the leakage across this seal.
This would induce increaced reactor coolan leakage to HI the Vapor Seal Head Tank, RCS Drain Tank and into containment.
The leakage would be 2 gpm 'of reactor coolant into containment.
The valves can be manually opened by securing and venting the air supply to the valves when the reactor coolaft pump seal water injection is put into service (see Casualty Procedure).
Page 8 of 13 NDRMAL FAILURE MODE SPURIOUS MOVEMENT LOSS OF LOSS OF 10 UNFAVORABLE MANUAL EFFECTS OF SPURIOUS VALVE P&ID SYSTEM POWER AIR POSITION OPERATION MOVEMENT ON SAFE SHUTDOWN REMARKS CV276 568767 CVCS Closed Open Open No None The opening of this valve would increase the flow of primary coolant up through the thermal barrier of the rCP during intervals of time when the seal water injection was not being supplied. This flow may be in excess of the cooling capacity of the thermal barrier.
In order to prevent this event, the operator can secure the power supply to this valve upon entering the contain ment (see Casualty Procedure).
This event is a problem only when the isolation valves CV 527 and 528 are open.
MOV/LCVll00C 568767 CVCS As is N/A Closed Yes None Closure of this valve would block flow of makeup water from Volume Control Tank.
When CVCS is put into operation, power supply for this valve can be secured to prevent spurious actuation (see Casualty Procedure).
CV527, 528 568767 CVCS Closed N/A/ER 1 Closed Yes None The failure of one of these valves would re sult in the closure of the seal water return line for all three RCP's.
The differential pres sure across the secon dary seals of the RCP'S woub I
IJ X!inII -I% ;I: tI, lo Is w t
as the leakage. This would induce increased leakage to the Vapor Seal Head Tank, RCS Drain Tank and into containment.
The end result would be an
Page 9 of 13 NDRMAL FAILURE MODE SPURIOUS MOVEMENT LOSS OF LOSS OF TO UNFAVORABLE MANUAL EFFECTS OF SPURIOUS VALVE P&ID SYSTEM POWER AIR POSITION OPERATION MOVEMENT ON SAFE SHUTDOWN REMARKS uncontrolled leakage of 6gpm of primary coolant into containment. In order to prevent any problem associated with the spurious closure of these valves, the opera tor can mechanically block the valves in the open position before initiation of CVCS test pump seal water injection.
At the leakage rate of 6gpm, the Pressurizer would not be emptied for 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />.
CV291 568767 CVCS Open Open Closed No None The closure of this valve would divert return seal water from the Seal Water Heat Exchanger. During periods of time when the CVCS test pump is in operation injecting seal water into the RCP, the seal water would begin to heatup and increase the temperature of the water in the Volume Control Tank. In order to prevent any problem associated with the spurious closure of this valve, prior to initiation of CVCS seal water injection, the operator can manually secure and vent the air supply to the~valve.
Page 10 of 13 NORMAL FAILURE MODE SPURIOUS MOVEMENT LOSS OF LOSS OF TO UNFAVORABLE MANUAL EFFECTS OF SPURIOUS VALVE P&ID SYSTEM POWER AIR POSITION OPERATION MOVEMENT ON SAFE SHUTWN REMARKS CV410, 411 568767 CVCS Closed Closed None No None Since both of these valve fail closed, the spurious opening of one would not impact safe shutdown since they are in series on the line between the Volume Control Tank and the CVCS Test Pump.
CV406A 568767 CVCS Open Closed Open No None If this valve were to open when the CVCS test pump is in operation the possibility exists for gas from the hydrogen blanket of the Volume Control Tank to be admitted to the suction of the pump.
In order to prevent this event prior to initiation of CVCS teot pump operation, the air supply can be secured and vented (see Casualty Procedure).
CV406B 568767 CVCS Open Open None No None Prior to initiation of CVCS test pump operation, the lines to this valve can be isolated by securing and venting the air supply to CV 406A (as described above) and by closing manual valve 235-2"-T42 (prevents boron dilution from the primdry plant makeup tank).
MOV 18, 19 568767 CVCS As is 1 Open Yes None Some seal water flow would bypass Seal Water Filters but would have no impact on safe shutdown since the RCP's are inoperative.
AA Page 11 of 13 NORMAL FAILURE MODE SPURIOUS MOVEMENT LOSS OF LOSS OF TO UNFAVORABLE MANUAL EFFECTS OF SPURIOUSREAK VAJyE P&ID SYSTEM POWqER AIR POSITION OPERATION MOVEMENT ON SAFE SHUTDWNRMAK FCV112 5876 CVC Cloed pen oneNo None This valve affects safe FCV112 6877 VCS Cloed Oen oneshutdown only when CVCS test pump is in operation.
Prior to initiation of C.VC8 test pump operation, the operator can isolate
'J3 the lines associated with thip valve by closing
- '4 manual valves 253-3/4"-T58, 251-3"1-TS8, 252-3", and 252-3"1-T58.
None This valve affects safe CV304 568767 CVCS Closed Closed None.
No Noeshutdown only when CVCS test pump is in operation.
Prior to initiation of CVCS test pump operation, the operator can isolate the lines associated with this valve by closing manual valves 253-3/4"-T58, 251-3"--T58, 252-3", and 252-3"-TS8..
.CV305 568767 CVCS Closed Coe None No None Thi vave nafec safe test pump is in operation.
Prior to initiation of CVCS test pump operation, the operator can isolate the lines associated with this valve by closing manual valves 253-3/4"-T58, 251-3-T58, 252-3", and 252-3-T58.
No None The spurious actuation to FCVll02 A, B 568767 CVCS
- Closed, Open, None Noan unfavorable position open Closed uld only impact safe shutdown when the CVCS Test Pump is operating. In order to prevent this event, the oerator can isolate the CVCS Test Pamp from these valves by closing manual valve 235-2"-T42 before the CVCS Test Pump is operated (see Casualty Procedue).
Page 12 of 13 NORMAL FAILURE MODE SPURIOUS MOVEMENT LOSS OF LOSS OF TO UNFAVORABLE MANUAL EFFECTS OF SPURIOUS VALVE P&ID SYSTEM POWER AIR POSITION OPERATION MDVEMENT ON SAFE SHUTDOWN REMARKS CV333,,334 568767 CVCS
- Closed, Closed, None No None The spurious actuation to Open Open an unfavorable position would only impact safe shutdown when the CVCS Test Pump is operating. In order to prevent this event, the operator can isolate the CVCS Test Pump from the Boric Acid Tank by closing manual valve 329-2"-X42D and by securing and venting the air supply to CV333, before.
the CVCS Test Pump is operated (see Casualty Procedure).
MDV883 568769 SIS As is N/A Closed Yes None Interruption of supply of RwST borated water for cool down to cold shutdown.
In order to prevent spurious closing of this o
valve, the operator can secure the power supply to the valve at the time when RWST water is put to use for cool down (see Casualty Procedure).
MOV/LCVll00B, D 568769 SIS As is N/A Closed Yes None The operator can open both valves at the time when RWST
,water is supplied for cool down so that the spurious closing of one valve would not interrupt flow.
MOV 356, 357, 568769 SIS As is N/A 1 Open Yes None The opening of one of these 358 valves would result in heatup of the seal water injection line.' This heatup may result in deterioration of reactor coolant pump seal integrity and increased leak age.
However, the hourly fire watch patrol which has been implemented provides early warning such that the power supply for these valves can be secured at the con tainment penetration prior to the instantaneous and simultaneous loss oE
Page 13 of 13 NDRMAL FAILURE MODE SPURIOUS MOVEMENT LOSS OF LOSS OF TO UNFAVORABLE MANUAL EFFECTS OF SPURIOUS VALVE P&ID SYSTEM POWER AIR POSITION OPERATION MOVEMENT ON SAFE SHUTDOWN REMARKS component cooling water, loss of reactor coolant pUMp seal water injection and the spurious actuation of one of these valves.
HV853 A, B 568769 SIS Closed N/A 1 Open Yes None Some borated water will be diverted into the Feedwater and Condensate System. In order to isolate the RWST, the operator will close manual valves 861A-16" G42 and 861B-16"-G42 (see Casualty Procedure).
CV125 568780 Copressed Closed Closed None No None Loss of service air inside Air containment.
Not required for safe shutdown.
Solenoid Valves 568780 Compressed N/A N/A None Yes None These valves are mechani for Instrument Air cally interconnected so Air Dryer that there is always one dryer available.
CV76, 77, 568773 Steam Closed Closed 1 Open No None The steam pump.valves are 78, 79 used for control 'of secondary side system pres sure. The spurious open ing of one of these valves will induce aiq uncontrolled cooldown of tle primary coolant. In order to pre vent this event, the operator can secure the power supply to these valves at 4
the time when-feedwater flow to the Steam Generator is reestablished.(see Casualty Procedure).
- Evaluation underway to verify system operation as described.
CASUALTY PROCEDURE TO BE IMPLEMENTED FOLLOWING TOTAL LOSS OF 4160V SWITCHGEAR Hot Shutdown Sequence of Events t=0
- 1)
Loss of All A. C. Power and D. C. Control Reactor Scram No Saltwater or Component Cooling No FW to Steam Generators No Chargine or Seal Water Injection Seal Water Return to Volume Control Tafnk block by Isolation Valves CV527 and CV528 Seal Water Leakage to Containment at 6 gpm max.
- 2)
Before evacuating control room, manually start D. C.
powered Thermal Barrier Emergency Pump providing cooling water to RCP leakoff to seals (CV722 A, B, C-fail open)
.2A)
Manually secure power supply to CV545, 546, CV722A,B,C and MOV356,_ 357, 358 at Containment Penetration.
- 3)
Manually Restore Power to 480V Switchgear No. 2.
- 4)
Manually Start Air Compressor KlB.
- 5)
Manually open Saltwater Cooling Pump discharge valve POV6 and close POV5 (if necessary).
Secure and vent air supply to valves to avoid spurious actuation.
Inspect Intake Stop Gate and MOV9 to assure that they are in the open position and secure the power supply to avoid spurious actuation.
6A)
Manually Restore Normal RCP Seal Cooling by the following method:
Open Manual Valve 780-3"-T32 MOV720A and MOV720B fail as is (1 open), operator insures that both are open.
Start Saltwater Cooling Pump Gl3B Start Component Cooling Pump Gl5B t=20 minutes 6B)
Manually Restore Power to Auxiliary Control Panel C38.
- 7)
Initiate Feedwater Flow to Steam Generators by Startup of Steam Driven Auxiliary Feedwater Pump Gl0.
Secure power supply to SV 85, 86, 87, 88 to prevent spurious actuation.
Close two manual (air wrench) valves 24"-600-27BG for Steamline Isolation.
For steam supply to FW pump open manual valve 3"-600-19, CVll3 will auto matically regulate steam flow.
For water supply to steam generators open manual valve 4"-600-140.
Close manual valves 861A-16"-G42 and 861B-16"-G42 to isolate RWST.
t=40 minutes
- 8)
Initiate flow of water from Reservoir to Condensate Storage Tank by gravity feed through Fire Water System. Manually attach fire hose to fire hydrant No. 10 and open valve.
t=60 minutes
- 9)
Manually startup Pressurizer Heaters if needed.
- 10)
Containment Entry for Manual Operations.
Manually open CV527, 528 and block in open position Secure and vent air supply to FCV1115 A, B, C, PCVlll5 A, B, C.
Secure the power supply to CV276.
- 11)
Initiate Primary Coolant Makeup from Volume Control Tank.
Manually open MOV/LCV1l00C (if necessary) and secure power supply.
Secure and vent air supply to CV291, CV406A, CV333.
Close manual valves 235-2"-T42, 253-3/4"-T58, 251-3"-T58, 252-3"-T58, 329-2"-X42D.
CV410 and 411 fail closed.
Startup CVCS test pump G42.
Control level in Volume Control Tank by operation of test pump using local level indication. When test pump is not in operation, seal return flow goes to Volume Control Tank through RV283.
t=5 hours
- 12)
Pressurizer Level and Pressure, Primary Loop Temperature, Steam Generator Level and Neutron Level are monitored and Steam Dump is controlled from Auxiliary Control Panel.
- 13)
Unit is in the Hot Shutdown Condition.
HOT SHUTDOWN TO COLD SHUTDOWN SEQUENCE OF EVENTS
- 1) The unit is in the Hot Shutdown Condition.
- 2) Initiate Cooldown by increased blowdown to atmosphere.
- 3) Supply Borated Water from RWST.
MOV 883 is locked open, secure power supply.
Manually open MOV/LCV1100 C.
Startup Test Pump (if necessary).
Makeup water is supplied through RCP seal injection flow.
Seal water return flow is to suction of test pump.
- 4) Initiate RHR System When Primary Coolant characteristics reach RHR system design limits, the RHR cooling mode can be initiated as follows:
MOV882A or MOV882B fail as is (1 open) open both and secure power supply.
TCV601A and TCV601B fail open, secure and vent air supply.
HCV602 failsopen, secure and vent air supply.
MOV814 and NOV834 open and secure power supply.
MOV813 and MOV833 open and secure power supply.
Manually start RHR Pump Gl4B.
- 5) Continued cooldown can be accomplished by appropriate control of Component Cooling,Water flow through RHR Heat Exchangers by.using manual valves 777A-8"-G32 and 777B-8"-G32.
CASUALTY PROCEDURE TO BE IMPLENTED FOLLOWING TOTAL LOSS OF LUBE OIL RESERVOIR AND CONDITIONERF CUD AR'EA (FIRE ZONE 9A)
The Steam Dump Relief Valve Control at the Control Room and at the Auxiliary Control Panel has control circuitry routed above the Lube Oil Reservoir and Conditioner curbed area in Fire Zone 9A.
In the event of an oil spill and fire in the Lube Oil Reservoir and Conditioner curbed area, San Onofre Unit 1 can be brought to a Hot Shutdown Condition using the Casualty Procedure. to be implemented following total loss of 4160 volt Switchgear with a revised procedural step as follows:
The Steau Generator Self-Actuating Safety/Relief Valves can be used instead of the Steam Dump Relief Valves.
Since the Steam Damp -Relief-Valve Control at the Control Room and at the Auxiliary Control Panel has control circuitry routed as described above, San Onofre Unit 1 cannot be brought to a cold-shutdown condition.
immediately following an oil spill and fire in the Lube Oil Reservoir and Conditioner curbed area. However, sufficient time would be available to provide alternate sources of control for the Steam Dump Relief Valves to initiate a cold shutdown.
While the power and control cables for the Alternate Power Supply, the Air Compressor KlB and both Residual Beat Removal Pumps are also routed in Fire Zone 9A, the physical distances from-the fire hazard and the imple mentation of an hourly fire watch patrol provide adequate protection against the loss of the power afd control cables due to an oil spill and fire in the Lube Oil Reservoir and Conditioner curbed area.:
Power and control cable routing for safe shutdown equipment is listed on the attached sheet.
EQUIPMENT FIRE ZONES
- Air Ccmi-;ressor KiB
- P(7,9A,9c), C(7,8,9A,9C)
Saltwater Cooling-Pu-iip G13B P(3B,3E,4,7),C(3B,3C,3E,4,7,8,9A,9B,9C 9D,9E)
ComnponenI-t Cooling Put-int G15B P(3A,3B,3C,7),C(2E,3B,7,8,9A,9B,19)
Aux.
Control Paiiel.
1ressurizer-Level P(2A,2E,3B,9C',9D,9E),C(3B,9C,9D,9E,19)
Pressurizer Pressure P(2A,2E,3B,9C,9D,9E ),C(3"B,9C,9D,9E,l9)
Primary Loop Teumperature P(2A,2E,3B,9C,9D,9E),C(3B,9C,9D,9E,19)
Steam Generator Level P(2A,2E,3B,9C,9D,9E),C(3B,9G,9D,9E,l9)
- Steamn, Relief Valve Control P(2A,2E,3B,9C,9D,9E),C(3B,9A,9C,9D,9E,19)
NedLron Level P(2A,2E,3B,9C,9D,9E),G(3B,9C,9D,9E,19)
Pressurizer Heaters B&D P(8,l9),C(...,9A,...)
GVCS Test Pump G42 P(2A)
- RHR Pump G14B P(7,9A,l9),c(l,7*8,9A,19)
- PJIR Pump G14A P-(8,9A,19),C(8,9A,19)
- Alternat.e Power Supply Gables P(lO,9E,9D,9C,9A,7), C(9E,9D,9C,9A,7)
- P=Power Gables, G=Control Gables "Rfequired equipment routed through Fire Zone 9A