Equipment Failure Procedure

PP-21 SL-37 Primary Purification & Buffer Seal Systems 10/22/62

A. One Letdown Cooler Becomes Inoperative

• 1. Switch to alternate cooler, isolate defective cooler, and tak out manual cooling water valves and pushbuttons on main console for diaphragm stop valves.
• 2. Repair defective unit during hext shutdown.
• 3. Monitor the letdown outlet temperature of the operating unit.
• 4. Should the operating unit become inoperative, isolate the unit, shut the reactor down and cooldown with the secondary system and DK system.

B. One Normal Flow Ion Exchanger Becomes Inoperative When the Second Normal Flow Unit Is Already Inoperative

NOTE: The units may be inoperative due to either spend ion exchanger resins or mechanical failures.

• 1. Switch to the ion exchanger designated for flows less than 10 gpm, isolate the defective unit, and tag out the pushbuttons on the main console for the diaphragm valves.
• 2. Repare the defective units.
• 3. Monitor the water quality of the influent and effluent of the operating unit and limit the letdwn flow to 30 gpm.
• 4. Should the operating unit become inoperative because of mechanical failure such that a flow path is not available when two defective units are also out of service because of mechanical failures, open bypass valve PP-29V and isolate the unit. Shutdown the reactor and cooldown the primary system.
• 5. Should the operating unit become inoperative because of spent resin, or if one of the two defective units is out of service because of spent resin, continue to operat ethe unit, or switch to another spent resin unit.

C. One Effluent Filter Becomes Inoperative

• 1. Switch to the alternate filter, isolate the defective filter, and if the defective unit is permanently out of service, tag out pushbuttons on console for diaphragm stop valves and diaphragm backflush valve. Also, tag out manual back flush supply valve.
• 2. Backflush the inoperative filter if this is required. If the filter needs chemical fleaning, filter element replacement or other mechanical repairs, take corrective action during a reactor shutdown.
• 3. Monitor the pressure drop accross the operating filter and see that the letdown flow is limited to 30 gpm.
• 4. If the operating filter becomes inoperative, open bypass valve PS-34V and isolate the unit. Shut down the reactor and enter the secondary shield for repairs.

D. One Letdown Flow Control Valve Becomes Inoperable In the Open Position

• 1. If the valve remains open in a position which provides flow equal to or greater than the letdown requirements, continue to operate with letdown being controlled with the open valve. IF the valve remains open in a position which supplies flow less than the letdown requirements, use the other letdown valve to increase the letdown flow. Tag the inoperative valve.
• 2. Repair the defective valve.
• 3. Monitor the letdown flow to verify acceptable operation.
• 4. IF the second valve should fail while supplementing the stuck open valve and if the minimum letdown requirements cannot be met or the maximum letdown flow is exceeded, shutdown the reactor for repairs.

E. Flow Controller For Letdown Control Valves Becomes Inoperative

• 1. Switch the operating letdown control valve or valves from Auto to Manual and adjuect the letdown flow rate to the desired setting. Tag out the controller.
• 2. Repair the defective controller.
• 3. Monitor the letdown flow.

F. One Letdown Flow Control Valve Fails Closed

• 1. Switch to the alternate letdown valve, and tag the controls for the inoperative valve.
• 2. Repair the defective valve.
• 3. Monitor the operating valve closely.
• 4. If the operating letdown valve fails in such a manner that it cannot supply the minimum letdown requirements, shut the reactor down for repairs.

G. Loss of Diaphragm Operated Make-up Valve PP-43V

• 1. Isolate the make-up valve and use the manual bypass valve to add make-up Tag the valve.
• 2. Repair the diaphragm valve.
• 3. Monitor the level in the SL surge tank closely and carry the level somewhat above the normal level.
• 4. IF the normal make-up is lost completely, place the emergency make-up from the waste storage tanks into operation. Shutdown the reactor and make repairs if they cannot be accomplished prior to reaching the established minimum requirements for waste storage for shutdown.

H. One Charge Pump Becomes Inoperative When Another Pump is Already Inoperative

• 1. Observe that the charge pump on standby starts automatically and maintains the proper pressure differential betweenthe pump discharge header and the primary system. Isolate inoperative pump and tag out valves and controls.
• 2. Repair the defective units.
• 3. Monitor the operation of the operating pump.
• 4. IF the operating unit should fail, shut down the reactor and cool down the primary system with the emergency cooling system.

I. One Booster Pumpe Becomes Inoperative

• 1. Check that the other pump starts automatically and maintains the proper discharge pressure. Switch controls to use operable pump. Isolate inoperable unit. Maintain SL surge tank pressure.
• 2. Repair the inoperable pump during the next shutdown.
• 3. Monitor the operating pump operation.
• 4. Should the second unit fail, continue to operate as long as a minimum of 10 psig can be maintained in the surge tank and as long as a booster pump can be left open to provide a flow path from the surge tank to the charge pumps.

J. One Buffer Seal Cooler Becomes Inoperative

• 1. Switch to the standby cooler and tag out the isolation valves.
• 2. Repair the inoperative cooler.
• 3. Monitor the outlet temperature of the operating cooler.
• 4. Should the operating cooler fail, monitor the outlet temperature and when it exceeds 120F shut down the reactor and cool down the primary system.

K. Loss of Auto Operation of Bypass Valve SL-9V

• 1. Switch the valve from Auto to Manual control and maintain the buffer seal header - primary system pressure differential with the manual loader. Tag out the auto controls.
• 2. Repair the defective auto controls.
• 3. Monitor the buffer seal header - primary system pressure differential closely.
• 4. IF the manual controls for the valve fail, open the manual bypass valve SL-60V and close the manual isolation valves for SL-9V. Maintain the buffer seal header - primary system differential pressure 10 to 15 psi with SL-60V while shutting down the reactor and cooling the primary system.

L. Loss of auto OPeration of Primary Makeup Valve SL-6V

• 1. Switch the valve from Auto to Manual control and maintain the pressurizer level with the manual loader. Tag out the auto controls.
• 2. Repair the defective Auto controls.
• 3. Monitor the pressurizer level.
• 4. Should the manual controls for the valve fail, open the manual bypass valve SL-57V and close the manual isolation valves for SL-6V. Maintain the pressurizer level while shutting down the reactor and cooling the primary system.

M. One Buffer Seal Header Strainer Becomes Inoperative

• 1. Switch to the alternate strainer, isolate the defective unit and tag out the isolation valves.
• 2. Repair the defective unit.
• 3. Monitor the pressure drop accross the operating filter closely.
• 4. If the operating strainer becomes inoperative due to a plugged strainer, continue to operate as long as the buffer seal header - primary system pressure differentials can be maintained and until the other strainer is repaired.