Term
| Describe the Core Spray Inboard/Outboard Isolation Valve Interlock |
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Definition
| Neither valve may be opened if the other is not fully closed; bypassed for inboard valve ONLY when reactor pressure is less than 420 psig. The interlock forces the operator to open the outboard isolation valve first when performing a manual initiation of the system. |
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Term
| How can core spray be isolated with an initiation signal present? |
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Definition
Keylocked bypass switch on Panel C-03 allows operation of the OUTBOARD isolation valve. Also, INBOARD isolation valve may be operated (throttle valve) NOTE: the pump switch should also be placed in "pull-to-lock. |
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Term
| Power supply to Div I motor operated valves |
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Definition
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Term
| Power supply to Div II motor operated valves |
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Definition
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Term
| Control Power to Core spray motor operated valves |
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Definition
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Term
| Describe the connection between Core spray and Auto Depressurization Logic |
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Definition
| Core spray provides relay contacts for Reactor Low Low Water Level in ADS logic. In addition, Core Spray provides one of the permissives for an initiation of ADS; by means of a 100 psig signal, indicating the core spray pump is running. |
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Term
| Describe the connection between Core Spray and EDG logic |
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Definition
| Core spray logic provides a start signal for the EDGs with a one of two taken twice logic on Reactor Low Low Water Level or High Drywell Pressure. |
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Term
| Describe the connection between Core Spray and High Pressure Coolant Injection logic |
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Definition
| Core Spray provides relay contacts in the HPCI start logic for High Drywell Pressure. |
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Term
| Describe the connection between Core Spray and Reactor Core Isolation Cooling logic |
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Definition
| Core spray provides relay contacts for Reactor Low Low Water Level in the RCIC initiation logic. |
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Term
| What does the condensate service system do for core spray? |
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Definition
| Keep fill of at least 30 psig (normally 40 psig) which minimizes the chance of water hammer. |
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Term
| Besides logic, what is another connection between core spray and HPCI? |
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Definition
| The HPCI min flow line ties into B loop Core Spray test return line. |
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Term
| Besides logic, what is another connection between core spray and RCIC? |
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Definition
| The RCIC minimum flow line ties into A loop core spray test return line. |
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Term
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Definition
| Restore and maintain reactor coolant during a loss of coolant accident in combination with other emergency cooling systems. |
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Term
| Core spray rated flow (and associated reactor pressure) |
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Definition
| 3020 gpm when reactor pressure has dropped to 145 psig. |
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Term
| Purpose of core spray orificed min flow line. |
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Definition
| Designed to allow a flow of 300 gpm at pump shutoff head to prevent pump damage after an automatic start until the isolation valves are opened and flow to the vessel is initiated. |
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Term
| Purpose of Core spray relief valve |
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Definition
| Set at 500 psig to protect the piping between the pump and testable check valve from over-pressurization when both isolation valves are open. |
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Term
| Discuss the sequence of events that occur upon receipt of an automatic initiation of Core spray. |
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Definition
| In each loop: Core spray pump starts after a 15 second time delay. Core Spray test return line valves isolate. When reactor pressure reaches 420 psig, inboard and outboard isolation valves automatically receive an open signal. Due to the discharge head of the pump (375 psig) and head losses, flow does not commence until reactor pressure reaches approximately 310 psig. |
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Term
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Definition
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Definition
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Definition
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Term
| Conditions required for auto initiation of core spray |
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Definition
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Term
| Explain core spray leak detection. |
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Definition
| Differential pressure sensed between above the core plate (HP) and the Core spray discharge line downstream of the testable check valve (LP). If discharge line is intact, pressure sensed will be inside core shroud. If there is a break in the piping between the vessel wall and shroud, the pressure sensed will be the downcomer region. NOTE: Due to relative densities, the differential pressure is negative. With a break in the discharge line, the differential pressure will be LESS NEGATIVE. |
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Term
| Discuss RHR room heatup analysis and consequences |
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Definition
| Analysis assumes coolers are started within 13 minutes of accident initiation when all three pumps are running. Therefore, if room coolers are unavailable, RHR and Core spray pumps in that room are INOP. |
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Term
| What is a consequence of not having ECCS sump pumps? |
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Definition
| Associated RHR and Core spray pumps are considered inoperable. |
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Term
| Core spray minimum indicated flow restrictions |
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Definition
Continuous operation: 2000 gpm Short-term operation (less than 2 hours in 24 hours): 1500 gpm. NOTE: minimize time spent operating with indicated flow less than 2000 gpm. |
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Term
| Non-emergency core spray motor start restrictions |
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Definition
| Two starts in succession from ambient temperature or one start from rated temperature. For subsequent starts, allow thirty minutes running time at full speed or sixty minutes idle time. |
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Term
| Discuss the dual safety function of the core spray valves |
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Definition
| Valves must operate in the OPEN direction for the Core Spray System to be operable. And must operate in the CLOSE direction for the Primary containment system to be operable. |
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Term
| Concerns with closing the Outboard Core spray isolation valve |
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Definition
| Pressure locking. Therefore ANY time the outboard isolation valve is closed, the "associated subsystem" is considered inoperable. |
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Term
| Concerns with opening test return valves |
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Definition
MO-1749 does not close on torque and therefore may not prevent diversion of flow upon receipt of an auto intiation signal. Although MO-1750 logic was recently changed to close on torque, it is still lumped into the above category. Hence, if either test return valve is open, the associated subsystem is considered inoperable. No longer the case as of Feb. 2008
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