Term
RHR
Describe the purpose and function of RHR. |
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Definition
-Restore and maintain Rx vessel coolant inventor to prevent fuel clad melt.
-Extend redundancy of ECCS by providing drywell and TORUS spray.
-Suppression pool cooling.
-Decay and sensible heat removal.
-Supplement spent fuel pool cooling.
-Means of draining TORUS to radwaste. |
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Term
RHR
Describe the basis of ECCS. |
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Definition
-Cooling performance following a LOCA meets the following criteria:
-Peak cladding temp <2200F.
-Cladding oxidation <.17 times total cladding thickness prior to oxidation.
-Max hydrogen generation.
-Coolable geometry.
-Long-term cooling. |
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Term
RHR
Describe the RHR keep fill. |
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Definition
-Discharge of heat exchanger maintained at 40# by condensate service system up to checkvalve at discharge of RHR pumps.
-Rest of system kept full by being below the TORUS which is the normal suction.
-Prevents water hammer.
-<40# must declare system inop. |
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Term
RHR
Describe the room cooler power supplies |
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Definition
-Room cooler V-AC-5 (A loop): MCC-133.
-Room cooler V-AC-4 (B loop): MCC-143. |
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Term
RHR
Describe the pump start initiation sequence. |
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Definition
-T=0: Initiation.
-T=5 sec: 11/12 RHR pumps start.
-T=10 sec: 13/14 RHR pumps start.
-T=15 sec: 11/12 Core spray pumps start.
-On loss of power the 1AR picks up 15/16 bus in 5 secs.
-If no 1AR the 11/12 EDGs pickup in 10 secs. |
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Term
RHR
Describe the LPCI initiation signals. |
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Definition
-Low-low water level -47" and Rx pressure < or equal to 420#.
-20 minutes at the low-low water level of -47".
-High drywell pressure of 1.84#.
-NOTE: These signals start the pumps (must be < or equal to 420# for injection valves to open). |
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Term
RHR
Discuss the open signals on LPCI initiation. |
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Definition
-The RHR HX bypass valves get a open signal for 60 seconds.
-The selected loop inboard injection valve gets an open signal until open.
-The selected loop outboard injection valve gets an open signal for 5 minutes. |
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Term
RHR
Describe the close signals upon LPCI initiation. |
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Definition
-(MO-2006/2007/2008/2009) the TORUS cooling valves.
-(MO-2010/2011/2020/2021/2022/2023) the TORUS and Drywell spray valves.
-(MO-4085A/4085B) the intertie valves.
-The non-LPCI loop select injection valves (MO-2012/2014 or MO-2013/2015).
-Also secures all 4 RHR SW pumps. |
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Term
RHR
Describe the AC interlock. |
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Definition
| -The AC interlock is satisfied when 100# is sensed on the discharge of a RHR pump and feeds into the ADS logic. |
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Term
RHR
Describe the relationship with ADS. |
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Definition
-If the AC interlock is met and a channel of ADS logic is satisfied by any of the LPCI low-low water level initiation signals then;
-107 second timer is started.
-If 107 second timer elapses the reactor will blowdown by opening ADS valves A,C, & D.
-ADS must have a low-low water signal.
-Can be bypassed by utilyzing the ADS inihibit switches. |
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Term
RHR
Describe minimum flow in RHR. |
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Definition
-4 total (2 per loop) AOVs with orifices downstream.
-Open when RHR flow < 646gpm for 10 seconds and allow flow back to TORUS.
-Air valves fail open on loss of air/power. |
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Term
RHR
Describe RHR operation from ASDS. |
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Definition
-Only can operate on the B RHR loop.
-Operates the #12 RHR pump.
-Operates 1 minimum flow valve (CV-1995).
-Operates B loop HX bypass valve (MO-2003) with no 60 sec seal in.
-Operates the B side TORUS ring header suction (MO-1987) and TORUS return (MO-2009) valves.
-Operates drywell spray supply line (MO-2007) up to the spray injectio valves).
-Operates RHR x-connect (MO-2033).
-Operates B side room coooler (V-AC-4).
-NOTE: no pump suction or valve interlocks on ASDS. |
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Term
RHR
Describe the effect on drywell and TORUS spray valves on LPCI initiation. |
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Definition
| -Valves (MO-2010/2011 TORUS, MO-2020/2021/2022/2023 drywell) shut and signal cannot be bypassed unless drywell pressure > 1#. |
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Term
RHR
Describe the TORUS and drywell spray flow rates. |
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Definition
-Drywell: 7200gpm per side.
-TORUS: 330gpm per side. |
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Term
RHR
Describe the TORUS strainers. |
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Definition
-4 sets of strainers.
-Openings of 1/8" so don't suck up anything that could clog the spray nozzles.
-Can deliver rated flow with 1 strainer clogged. |
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Term
RHR
Describe the LPCI injection flow path (B loop). |
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Definition
-Normal suction from TORUS ring header (alternate suctions from CST).
-Through RHR pumps.
-Bypasses RHR HX for at least 60 seconds.
-Through injection valves to B recirc line to jet pumps.
-The A side pumps also start and take same flow path on A side except after HX they go through the x-connect line and tap into the B side line just prior to injection valves. |
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Term
RHR
Describe the drywell and TORUS spray flow path (B side). |
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Definition
-Suction from TORUS ring header.
-Through pumps and HX and HX bypass.
-Up through to a T where branches off to either go to drywell or TORUS spray. |
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Term
RHR
Describe the TORUS cooling flow path. |
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Definition
-Suction on TORUS ring header.
-Through pumps and HX and HX bypass.
-Loops back around and injects through strainers in the TORUS. |
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Term
RHR
Describe the temperature TORUS cooling is used to maintain. |
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Definition
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Term
RHR
Describe actions that should be taken if a RHR pump trips while in TORUS cooling mode. |
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Definition
| Should shut first return valves back to torus (MO-2006/2007) to prevent draining system. |
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Term
RHR
Describe when the TORUS and drywell spray supply valves (MO-2010/2011 TORUS, MO-2020/2021/2022/2023) can be bypassed with a LPCI initiation signal present. |
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Definition
-If drywell pressure is > 1#.
-Switch to bypass if also > 2/3 core height.
-Keylock to bypass if also < 2/3 core height.
-Valves automatically reshut when < 0.75#. |
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Term
RHR
Describe the shutdown cooling mode flowpath. |
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Definition
-Takes suction from vessel on recirc suction line.
-Through RHR pumps to HX and HX bypass (cooled by RHR SW).
-Back through LPCI injection valves to discharge side of recirc line to jet pumps. |
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Term
RHR
Describe the diff pressure between RHR and RHR SW required. |
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Definition
-Maintain RHR SW at least 20# greater than RHR.
-Alarms at 15#. |
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Term
RHR
Describe the intertie valve (MO-4085A/4085B/4086) positions when shutdown and why. |
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Definition
-Open when out of run and all rods are in.
-Keeps legs of piping full to prevent water hammer. |
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Term
RHR
Describe valve interlocks for shutdown cooling. |
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Definition
-First valve returning back to TORUS for TORUS cooling (MO-2006/2007) can only be opened if the suction valve for shutdown cooling (MO-1988/1989) is shut.
-The TORUS ring header suction valve (MO-1986/1987) must be shut to open the shutdown cooling suction valve (MO-1988/1989).
-These are done to prevent draining the Rx. |
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Term
RHR
Discribe when shutdown cooling valves (MO-2029 and MO-2030) can be opened. |
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Definition
| -Interlock to prevent opening unless pressure is < 74#. |
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Term
RHR
Describe the Group II isolation in regaards to RHR. |
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Definition
-Waste surge tank supply valves (MO-2032/2407) shut.
-If shutdown cooling valves (MO-2029/2030) are open they shut and will shut LPCI inboard injection valves (MO-2014/2015). |
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Term
RHR
Describe where shutdown cooling suction comes from. |
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Definition
| ONLY comes from the A side recirc line pump suction line. |
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Term
RHR
Describe where the RHR to waste surge tank line is and any precautions. |
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Definition
-Located on the A loop side of RHR.
-Cannot transfer TORUS water to waste surge tank if on A shutdown cooling, or will drain Rx to waste surge tank. |
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Term
RHR
Describe any LPCI injection valve (MO-2012/2013/2014/2015) interlocks. |
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Definition
| Cannot open both valves in the same loop if pressure greater than 420#. |
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Term
RHR
Describe the fuel pool cooling assist flowpath. |
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Definition
-From fuel pool skimmer tanks.
-Through suction valve to single RHR pump.
-Through HX & HX bypass.
-Returns to fuel pool. |
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Term
RHR
Describe the RHR pump start interlocks. |
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Definition
-Must have a suction path aligned to start a pump.
-Shutdown cooling from A recirc valves (MO-2029/2030 and MO-1988 if on A or MO-1989 if on B).
-Normal LPCI lineup from TORUS valves (MO-1986/1987).
-Alt LPCI suction valves (RHR18-1/18-2).
-If on fuel pool cooling assist must jumper out the interlock. |
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Term
RHR
Describe the TORUS to waste surge tank flowpath. |
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Definition
-NOTE: Cannot be done if on shutdown cooling from A loop.
-Suction from TORUS ring header.
-Through suction valve (MO-1986/1987).
-Through pump and HX and HX bypass.
-To waste surge tank.
-If coming from B loop must first go to system x-connect prior to waste surge tank. |
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Term
RHR
Describe LPCI loop select logic. |
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Definition
-See diagram.
-1 out of 2 logic twice for signals.
-Needs to see 3.14# pressure to see recirc pump running in a loop.
-Chooses loop with higher pressure when diff press > 2 psid.
-If in single loop waits to 900# prior to continuing in logic.
-Logic will trip recirc pump in good loop first and then will trip second when goes back through logic. |
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Term
RHR
Describe the A loop power supplies. |
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Definition
-Recirc pump suction and discharge and LPCI injection valves: 133B.
-All other MO valves (unless stated): MCC-133.
-Second waste surge tank supply and second shutdown cooling valve (MO-2030): D313.
-Min flow valves: Y-20.
-Flow indicators: Y-70.
-First waste surge tank supply: 142A.
-12 & 14 RHR pumps: Bus 16. |
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Term
RHR
Describe any fire protection for RHR. |
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Definition
-When > 212F:
-First shutdown cooling valve (MO-2029) and first waste surge tank supply valve (MO-2032) breakers are open. |
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Term
RHR
Describe the B loop power supplies. |
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Definition
-Recirc pump suction and discharge, LPCI injection valves, and B intertie: 143B.
-RHR pumps 11 & 13: Bus 15.
-Other MO valves: MCC-142A and MCC-143.
-Flow indicators: Y-80.
-Min flow valves: Y-20.
-Also ASDS supplies power to components on previous ASDS card. |
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Term
RHR
Describe other supply lines on RHR. |
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Definition
-Emergency river water supply on A side loop.
-To the PAS system on discharge of HX and return on RHR pump suctions on both loops. |
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Term
RHR
Describe the RHR test flow path. |
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Definition
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Term
RHR
Describe what cools the RHR rooms and RHR pump motor coolers. |
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Definition
-Service water.
-Emergency service water is the backup. |
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Term
RHR
Describe what cools the RHR heat exchangers. |
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Definition
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Term
RHR
Describe what cools the RHR pump shaft seal cooler. |
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Definition
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Term
RHR
Describe the power supplies to RHR logic. |
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Definition
-Channel A: D-11.
-Channel B: D-21.
-Control power: Bus 15 breakers is D-111 and bus 16 breakers is D-211. |
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Term
RHR
Describe what instrument air does for RHR. |
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Definition
-Maintains position of minimum flow valves.
-Loss of air causes them to fail open. |
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