ML13322A855

Unit 1 Shutdown to Hot Standby Condition,Revision 9

ML13322A855
Person / Time
Site:	San Onofre
Issue date:	07/26/1979
From:	Brunet R, Curran J Southern California Edison Co
To:
Shared Package
ML13322A854	List: ML13322A853 ML13322A855 ML13322A857 ML13322A858 ML13322A860 ML13322A863 ML13322A873 ML13322A892
References
S-3-1.4, NUDOCS 8008060304
Download: ML13322A855 (5)

Text

.SAN ONOFRE NUCLEAR GENERATING STATION OPERATI INSTRUCTION S-3-1.4 evision 9 - July 26, 1*

UNIT I SHUTDOWN TO HOT STANDBY CONDITION I. OBJECTIVE To shut down Unit 1 from full load or any intermediate load to a hot standby condition of the primary plant and secondary plant to a generator off-the-line, full vacuum, steam dump control of main steam at 930 psig condition.

RECEIVED II.

CONDITIONS A.

Unit I is on the line at any electrical load.

AUG 0 3 1979 EDM-SITE B. The nuclear instrumentation: startup, intermediate, and power channels shall be operating normally or in a ready-to-operate condition.

C. Auxiliary systems are in service as required for hot standby conditions.

III. PRECAUTIONS A. Any plant changes which produce a sudden change in reactor coolant temperature of the order of 100F or in reactor coolant boron con centration of the order of 10 ppm must be avoided.

B. Xenon level variations must be anticipated following a load decrease and boron concentration changes made as required to maintain the control group in the normal operating band.

C. Whenever reactor power is greater than or equal to 10% full power, three (3) reactor coolant pumps shall be in operation. Whenever reactor power is less than 10% of full power, operation with less than three (3) reactor coolant pumps operating shall be limited to less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />; except during low power physics testing.

(Con ducted below 5% of full power.)

D. The steam generator water levels should be manually controlled when in the hot standby condition and maintained at 50% level as indicated on the narrow range recorders to prevent the feedrings from being uncovered.

E. Failure to place the feedwater controls on manual prior to tripping the turbine stop valves may result in a large volume of feedwater being added to the steam generators. This could result in cooldown of the reactor coolant.

F. Isotopic analysis for iodine in the reactor coolant must be made.

between 2 and 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> following a thermal power change exceeding 15%

within a one hour period.

IV. CHECK-OFF LIST (Not Applicable)

V.

INSTRUCTIONS IMPORTANT STEPS KEY POINTS

1.

Inform System Dispatcher and Switching

1. The Dispatcher and Switching Center the unit is ready to reduce load, Center should be informed as estimated time of going off the line, far in advance as practicable and the rate of load reduction.

when preparing to take the unit off the line.

8008060 304

SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S-3-1.4 REVISION 9 -

July 26, 1979 Page 2 IMPORTANT STEPS KEY POINTS

2. Reduce load on the unit.

2.

a. Mark charts as per 0.1.

S-12-11.

3. On load reduction, observe

3.

alarms and recorder indica tions.

a. Alarm "Alert-Switch NIS Mode of Operation to Mid-Range".

b. Change mode of operation switch from High to Mid.

4. At less than 70% load, re-

4. See Operation Instruction move reheater steam dump S-9-2.

system from service.

5. Remove flash evaporators

5. Refer to 0.1. S-2-5.

from service.

6. Borate as necessary to keep control rods above shutdown marg in.

7. Unit at 33% of full load.

7.

a. Observe operation of reheater controls.

b. 125*F/hr. maximum rate of temperature change on cross over

8. Unit at 20% of full load.

8.

a.

a. (1) Transfer reactor over power mode of operation from Mid to low position.

(2) Transfer rod control from automatic to manual.

(3) Transfer feedwater to manual control and slowly increase level to 50% as indicated on the narrow range recorders.

(4) Transfer steam dump mode switch from automatic to pressure control at 930 psig set point.

SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S-3-1.4 Revision 9 -July 26, 1979 Page 3 IMPORTANT STEPS KEY POINTS

8. (continued)

8. (continued)

a. (5) Open turbine drain valves and extraction trap bypasses.

b. Transfer 4160 volt bus

b. (1) If the 220 kv and 138kv 1A and IB from the unit switchyards are con auxiliary transformers nected, transfer by to station auxiliary buses IC and 2C (refer to 0.1. S-6-5).

(2) If the 220kv and 138kv switchyards are not interconnected, transfer by drop and pickup operation.

C. Stop heater drain pumps

9. Reduce unit load to minimum on

9.

load limit.

a. Under manual control, insert control rods to maintain avg Tavg between 5350 and 5400F.

b. Verify that steam dump or pressure control is regu lating for a stable reactor power level.

10. Below 10% of full load, reduce 10. Stop a feedwater pump and a con feedwater pump and condensate densate pump.

pump requirements

11.

Start turbine auxiliary oil PUMP.

12. Notify Dispatcher and Switching 12.

Center that unit is ready to

a. The Dispatcher and Switching take off the line.

Center should be informed of status of unit. The Dis patcher gives permission to take unit off the system.

b. Take the power system stabilizer and voltage regulator out of service.

SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S-3-1.4 Revision 9 - July 26, 1979 Fage 4 IMPORTANT STEPS KEY POINTS

12.

(continued)

12.

(continued)

c. If turbine tests are plan ned, remove unit from line by opening unit PCB's.

d. If no tests are planned, reduce steam flow to zero and allow unit to be removed from service by no-load and anti-motoring circuits.

13. Turbine-generator on turning

13.

gear.

a. Verify unit automatically on turning gear, and field breaker open.

b. Lube oil cooling set points changed from 115 0F to 850F.

c. Turbine hood sprays on tempera ture control.

14. Complete switching to provide

14.

an alternate source of auxiliary

a. Notify Switching Center of electrical power.

switching procedure.

5. Check open Unit 1 PCB's and 4160V ACB's 11A04 and 11B04.

C. Open the generator motor operated disconnect.

d. Close unit PCB's

15. Maintain reactor nuclear power 15. a. Adjust reactor makeup con level <10% of full load power.

trol to automatic at reactor coolant boron concentration for leakage requirements.

b. Periodically initiate pres surizer spray flow to adjust boron concentration.

16. Reduce primary and secondary

a. Mark charts as per 0.I.S-12-11.

plant auxiliary requirements.

SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S-3-1.4 Revision 9 July 26, 1979 Page 5 VI.

FINAL CONDITIONS The final conditions of hot standby are:

A. The reactor power level is being maintained by manual control of the controlling group of rods at <10% of full power by observ ing the nuclear intermediate channels and maintaining Tavg between 525* -

540*F. The pressure control of the main coolant will be automatically controlled and maintained at 2085 psig.

B. Secondary plant (turbine-generator and auxiliaries) is in a hot standby condition with the unit on turning gear, steam seals on, normal vacuum, steam generator levels manually controlled at 50%,

and a minimum number of auxiliaries in operation. An alternate source of auxiliary electrical power is available.

R. R.

BRUNET SUPERINTENDENT UNIT 1 APPROVED:

J. M. CURRAN PLANT MANAGER JER:sel

• Indicates revision