Term
SRM
Describe detector operation. |
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Definition
-Coated with 90% enriched U235.
-Pressurized to 14ATMs of Argon gas and center positively charged electrode to +350VDC.
-Ions caused by fission attracted to electrode.
-At high energy ions strips electrons off argon gas making an increase in output.
-Creating a pulse that is read proportional to neutron flux. |
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Term
SRM
Describe height in core when inserted. |
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Definition
| 2 feet above core centerline. |
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Term
SRM
Describe height in core when withdrawn. |
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Definition
| 2 feet below the core to prevent burnout. |
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Term
SRM
Describe total travel of SRM. |
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Definition
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Term
SRM
Describe the pressure boundary. |
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Definition
| Dry tube is RPV pressure boundary. |
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Term
SRM
Describe how many and location of SRMs. |
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Definition
-There are 4 SRMs.
-1 located in each quadrant of the core. (1 in each quadrant of X made by IRMs). |
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Term
SRM
Describe the range covered by SRMs. |
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Definition
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Term
SRM
Describe the design bases of SRMs. |
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Definition
-Provide minimum count rate of 3cps when s/d.
-Provide overlap w/IRMs.
-Show increase in at least 1 detector prior to reaching 20 second period in rod withdrawal casualty. |
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Term
SRM
Describe the speed of inserting/withdrawing a SRM. |
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Definition
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Term
SRM
Describe power supply for AC drive motor. |
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Definition
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Term
SRM
Describe how to insert/withdraw SRM. |
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Definition
-Press SRM channel select button to select/deselect (light on/off)
-Can select all four channels and IRMs.
-Press DRIVE IN to insert (sealed).
-Press and hold DRIVE OUT to withdraw (not-sealed). |
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Term
SRM
Describe relay power to SRM drive switches. |
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Definition
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Term
SRM
Describe the major components of instrument (block diagram). |
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Definition
-Pulse preamp: amplifies pulse.
-Pulse height discriminator: only pass pulse from neutron.
-Log integrator: analog current.
-Count rate amp: DC amp drive meters.
-Period meter: Count rate in CPS, period changes by factor of "e". |
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Term
SRM
Describe power supply to SRMs. |
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Definition
SRMs 21 and 22: D-15
SRMs 23 and 24: D-25 |
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Term
SRM
Describe the SRM SCRAM function. |
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Definition
-Normally do not have a SCRAM function.
-During refueling shorting links can be removed giving it a SCRAM function.
-Signal from any 1 SRM will cause a full SCRAM. |
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Term
SRM
Describe when the SRMs are bypassed. |
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Definition
-Mode switch in RUN.
-SRM channel bypassed.
-IRMs are > or equal to range 8.
-IRMs > or equal to range 3 = retract/downscale bypassed. |
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Term
SRM
Describe when SRMs cause a rod block. |
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Definition
5
-SRM > 10 cps, unless IRM > or equal to range 8 or SRM bypass.
-SRM is inoperative, unless IRM > or equal to range 8 or SRM bypass.
-SRM < 5 cps unless IRM > or equal to range 3.
-SRM > 100 cps, unless SRM is full in. |
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Term
SRM
Describe the Ramp switch. |
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Definition
-2 position switch on SRM drawer.
-Fixed position: equal to a 10 second period.
-Variable position: adjustable from infinity to 10 seconds. |
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Term
SRM
Describe the 6 position switch. |
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Definition
-6 position switch on SRM drawer.
-Operate: Normal all trips operable.
-Standby: Same as operater exept inop alarm.
-Zero: Check zero adjustments.
Period: Reads period.
5 5
-10 : 10 signal into pulse height discriminator.
-10: 10 signal into pulse height discriminator. |
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Term
SRM
Describe SRM bypass switch. |
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Definition
-4 position switch on C05.
-Can only bypass one SRM channel at a time. |
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Term
SRM
Describe when the SRM HI/INOP anunciator actuates. |
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Definition
-Bypassed when RX MODE switch is in RUN.
-HI: 90,700 CPS or greater when in START or HOT STBY position.
-HI: 150 CPS or greater when in REFUEL position.
-INOP: SRM channel function switch not in OPERATE position
-INOP: High voltage power supply failure
-INOP: Any circuit module removed from an SRM channel. |
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Term
SRM
Describe when SRM DOWNSCALE anunciator actuates. |
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Definition
-Bypassed for all channels when in RUN.
-Downscale: 5cps or less indicated on SRM.
-INOP: SRM panel drawer function switch not in OPERATE.
-INOP: SRM high voltage power supply failure.
-INOP: Any circuit module removed from SRM panel. |
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Term
SRM
Describe when the SRM RETRACT NOT PERMITTED anunciator actuates. |
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Definition
-Bypassed when in RUN.
-Less than 100 cps on SRM when any SRM is not fuly inserted into the core. |
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Term
SRM
Describe when the SRM PERIOD anunciator actuates. |
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Definition
-Bypassed when in the RUN position.
-12 seconds or less on any SRM period monitor. |
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Term
SRM
Describe what happens if power is lost to any SRM. |
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Definition
| -INOP rod block if below IRM range 8. |
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Term
SRM
Describe what will happen on a loss of Y-20. |
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Definition
-Y-20 supplies power to detector drive control relays.
-SRM detectors will be prevented form being driven in or out.
-SRM Full-in/Full-out indication lost.
-SRM count rate recorder fails "as is". |
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Term
SRM
Describe what happens on a loss of L-38. |
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Definition
-L-38 supplies power to detector drive motors.
-Drive system operation will be prevented.
-Damage can occur to the detectors due to high flux as power increases during startup. |
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Term
SRM
Describe SRM relationship with IRM. |
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Definition
-Above range 3 on the IRM channels, the detector retract permit and downscale rod blocks are bypassed.
-Above range 8 on the IRM channels, all rod blocks initiated by SRM channels are bypassed.
-IRM channels 11,13,15,17 are required for bypassing SRM channels 21 and 22 rod blocks. |
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