Plant Operating Standard

PD-31 Equipment Drain and Waste Collection

Normal Operations

• 1. At any time the containment drain tank level reaches 27 in. it is to be drained down using the containment drain pump into the waste storage tank.
• 2. When the water level in containment reaches 1/2" it is drained manually and by gravity to an innerbottom tank.
• 3. Leakage which is slightly or potentially contaminated drains to the innerbottom tanks.
• 4. Water which can potentially be highly contaminated and chemical wastes are drained to the Lab Waste Tank.
• 5. The Buffer Seal Surge Tank, in the event of a high water level, is manually drained into the primary grade waste storage tank. In case this is full, the drainage waste storage tank may be used.
• 6. One waste storage tank contains primary grade water for makeup to the primary system during normal operation. The other is available for waste accumulation.
• 7. The waste storage tank containing primary grade water is valved open to the waste transfer pump suction and makeup valve PD-35 is open. This provides for immediate makeup from the control console by starting PD-P1 in case of a scram.
• 8. Once any water is drained into the innerbottoms it is not to be reused in any reactor system.
• 9. The waste collection tanks are not filled to their high level alarm points and are pressurized between vacuum breaker and relief valve settings.

Minimum Condition for Reactor Operation

• 1. Once the plant is in operation, the only continuous flow in the system will be from components draining into the containment drain tank. Means must be available to drain into a suitable storage tank.
• 2. One drain well sump pump in reactor compartment is operable.
• 3. Sufficient unfilled volume is always available in the various tanks to contain the waste water being generated. This volume requirement is to be based on losses existing at the time.
• 4. Sufficient primary grade water must be maintained in one of the waste storage tanks to provide enough makeup to the primary system to permit a cooldown to a point where primary system temperature can be maintained with the power available.