Term
TIP
Describe the function of TIPs. |
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Definition
| -Provide the operator and Gardel with neutron flux measurements from all requested LPRM/TIP locations. |
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Term
TIP
Describe the normal operation of TIP. |
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Definition
-TIP is normally operated by the ATCUs on C-13.
-Manual Drive: Used for positioning the TIP between chamber shield and the indexer for auto scans.
-Host-initiated AUTO-TIP: Normal method for gathering flux data. All 3 TIPs traverse simultaneously, after being moved to the park position via manual drive.
-Local AUTO-TIP: Only to collect and display data at ATCUs. |
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Term
TIP
Describe the detector path from housed to core. |
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Definition
-From drive mechanism to the detector shield.
-From detector shield to the shear and ball valves.
-From the valves to the drywell penetration.
-From drywell penetration to the indexing mechanism.
-From indexing mechanism to the individual LPRM assemblies. |
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Term
TIP
Describe the TIP detector. |
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Definition
-Similar to LPRM fission chamber.
-Titanium, U235 coated and filled with argon gas, polarizing voltage of 100Vdc. |
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Term
TIP
Describe the drive cable/signal lead. |
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Definition
-Signal current from detector and polarizing voltage is transmitted by means of triaxial cable.
-Carbon steel in helix wrap.
-Driven by gear wheel in the drive mechanism. |
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Term
TIP
Describe the drive mechanism. |
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Definition
-Dry instrument with air purging for low moisture.
-Motor moves at 60'/min in fast and 7.5'/min in slow.
-Reels store cable (2 reels, 1 for keeping it untwisted).
-No slip rings and noise free design.
-Has manual hand crank.
-Absolute encoder has chain/sprocket gives electronic signal of position. |
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Term
TIP
Describe the shield chamber. |
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Definition
-Stores detector when not in use.
-When absolute encoder output matches programmed shield position it stops probe x2.
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Term
TIP
Describe the ball valve. |
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Definition
-Containment isolation from drywell.
-Normally closed, opens when detector is moved from shield.
-5 seconds for ball valve to open, if not drive mechanism is de-energized. |
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Term
TIP
Describe the shear valve. |
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Definition
-Emergency means of sealing guide tube if:
-Containment isolation needed and;
-TIP cannot be retracted or;
-Ball valve fails open.
-Squib type valve, manual firing, 125Vdc. |
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Term
TIP
Describe the indexing mechanism. |
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Definition
-Allows one detector to acces up to 10 LPRM assemblies.
-All 3 can access the one core location for cross calibration (interlock for 1 at a time).
-Interlock prevents driving of detector if indexer is rotating.
-Powered from drive mechanisms. |
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Term
TIP
Describe the purge systems. |
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Definition
-Dry tubes to maintain low moisture content or could damage detector wiring.
-Nitrogen supplies drywell side up to ball valve.
-Air supplies TIP room side up to ball valve.
-Nitrogen kept at higher pressure than air.
-Can supply air to whole assembly if lose nitrogen. |
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Term
TIP
Describe radiation levels pertaining to TIP. |
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Definition
-Following a scan, radiation levels in TIP room can reach 1000 mrem/hr for 24 hours.
-Normal radiation levels are 100m mrem/hr. |
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Term
TIP
Describe the required calibration of LPRMs. |
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Definition
-Full LPRM calibration required every 2000 EFPH.
-Calibration required after reaching full power after new LPRM installation.
-At Gardel requests.
-At Nuclear Engineer request. |
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Term
TIP
Describe the relationship with primary containment. |
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Definition
-Group II isolation will result in:
-Nitrogen purge system isolation.
-Detectors retracted in fast to in-shield position and ball valve closes. |
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Term
TIP
Describe what Y-20 powers in relation to TIP. |
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Definition
-ATCUs.
-Flux probe monitor.
-Panel C-13.
-X-Y recorder. |
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Term
TIP
Describe what MCC-133 powers in relation to TIP. |
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Definition
-Drive units.
-Ball valves.
-Indexers. |
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Term
TIP
Describe what Div I 125Vdc powers in relation to TIP. |
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Definition
-Valve control monitor.
-Shear valve.
-Indexer purge solenoid valves. |
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Term
TIP
Describe the TIP interlocks. |
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Definition
-Tip cannot be moved from shield to PARK by computer.
-If ball valve not open 5 seconds after TIP starts to move then detector stops.
-Ball valve cannot be closed w/detector inserted.
-TIP must be in PARK to move indexer.
-TIP cannot be moved if indexer is rotating.
-Only one detector can access 28-29 at a time.
-TIP retract (fast) and ball valve isolation at +9" water level or 1.84 psig drywell pressure.
-If TIP at core top for > 10 minutes automatically retracts to PARK. |
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Term
TIP
Describe the PARK position in relation to TIP. |
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Definition
| -24" before the indexer in the drywell. |
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Term
TIP
Describe when slow speed is enforced. |
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Definition
-The first 3' of travel out of the detector shield.
-3' either side of PARK position.
-Last 1' before core top.
-Throughout the in-core region when scanning. |
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