LOT 201.43,44,45 Refueling Operations Flashcards
- LOT 201.43,44,45 Refueling Operations*
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What is the definition of core alterations?
- Movement of:*
- *Fuel**
- *Sources**
- *Reactivity Control Components**
- Excludes RCCAs attached to integrated head*
- Applicable:*
- *Head Removed**
- *Fuel in Core**
- LOT 201.43,44,45 Refueling Operations*
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Which hoist is used to snare the loop of the emergency transfer cart during a traverse drive failure of the fuel transfer system?
FHB Aux Hoist
- LOT 201.43,44,45 Refueling Operations*
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What is the minimum water level of the SFP?
- *23 ft**
- Above the top of fuel assemblies in racks*

Basis: Iodine removal of the assumed 99% of the iodine gap activity from a ruptured irradiated Fuel Assembly.
Must secure fuel movements at 62 ft (22.25 ft above fuel racks).
- Note:*
- Top of fuel racks is 39.75’. Fuel sits ≈ 12” farther down.*
- LOT 201.43,44,45 Refueling Operations*
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What is the the 2 ton hoist designed to lift?
- *Fuel Assembly and RCCA (1)**
- 1,900 lbs*
- *Failed Fuel Container (1)**
- 1,700 lbs*
- *The Tool (1)**
- 400 lbs*
- Note:*
- Overload protection provided at 125% (5000 lbs)
- Overload protection device that can withstand single failure.
- LOT 201.43,44,45 Refueling Operations*
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What are the design requirements for the Spent Fuel storage racks?
- *< 1.0 keff**
- Unborated water*
- *≤ 0.95 keff**
- 700 ppm boron*
- *Region 1: 10.95” center to center**
- Distance between fuel assemblies*
- *Region 2: 9.15” center to center**
- Distance between fuel assemblies*

- LOT 201.43,44,45 Refueling Operations*
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What is the capacity of the new fuel storage racks?
66 Fuel Assemblies
≈ 1/3 of core
- LOT 201.43,44,45 Refueling Operations*
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The weight indicator should be watched continuously while lowering or raising the refueling machine hoist. What weight change would cause the operator to stop hoist motion?
- *200 lbs**
- Applicable with or without a fuel assembly engaged.*
Underload safety circuit prevents hoist going down with fuel assembly if a 150 lbs weigh loss occurs except during last 1.5” of travel.
- Note:*
- Prevents damaging adjacent fuel assembly.*
- LOT 201.43,44,45 Refueling Operations*
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What is the storage capacity of the region 1 and region 2 areas of the SFP?
- Region 1:*
- *288**
- Spaced farther apart*
- Region 2:*
- *1681**
Total: 1969

- LOT 201.43,44,45 Refueling Operations*
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What must the boron concentration of the SFP be if fuel is stored in the SFP?
≥ 2500 ppm

LCO 3.9.13 SFP Minimum Boron Concentration
Applicability: ≥ 1 fuel assembly stored in the SFP racks.
- LOT 201.43,44,45 Refueling Operations*
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What is the capacity of the in-containment fuel storage racks?
64 Fuel Assemblies
≈ 1/3 of the core
- LOT 201.43,44,45 Refueling Operations*
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When must the fuel handling machine be operated in slow hoist speed?
Seating/Removing tool on fuel assembly
Assembly being lowered and within 10” of racks
Assembly being lowered and within 10” of bottom
Hoist Speed:
- Normal: 20 fpm
- Slow: 3 fpm (Machine set for 7 fpm but operator must jog to get 3 fpm)
Bridge:
- Normal: 30 fpm
- Slow: 10 fpm
- LOT 201.43,44,45 Refueling Operations*
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When is a spent fuel assembly transferred from region 1 to region 2 in the SFP?
All spent fuel initially sent to Region 1
- *Begin moving 50% of fuel to region 2 after 20-30 days**
- B5B Security*
- *Must be completed moving fuel within 60 days**
- B5B Security*
- *Rest moved at ≈ 1 year**
- Before next outage*
- LOT 201.43,44,45 Refueling Operations*
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What are the requirements to disengage a fuel assembly from the refueling machine?
“Gripper Mast Down” Light on
“Slack Cable” Light on
Load cell indicates < 480 lbs
- *SR Counts are stable**
- Must call MCR*
Z-Axis tape shows fuel assembly fully inserted
Permission from Core Loading Supervisor
- LOT 201.43,44,45 Refueling Operations*
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What powers the major equipment for the fuel transfer system?
- Fuel Handling Machine
- FHB Console for fuel transfer machine
- RCB Console for fuel transfer machine
- Fuel Handling Machine / FHB Console:*
- *MCC 1J4**
- 41’ MAB*
- RCB Console:*
- *MCC 1K1**
- 35’ EAB Pen Space*
- LOT 201.43,44,45 Refueling Operations*
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What fills the FHB and RCB fuel transfer system hydraulic reservoirs?
Demin Water
RCB Side: DWS-1613 (64’9” near RCP “D” Standpipe)
FHB Side: DWS-1612 (68’ near PASS Lab)
- LOT 201.43,44,45 Refueling Operations*
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What are the refueling machine hoist’s automatic slow zones?
- Top of the Core:*
- *20” Above - 10” Below**
- Can be bypassed with open water permissive*
- Bottom of the Core:*
- *20” Above**
- Top of Upender:*
- *10” Above - 10” Below**
- Bottom of Upender:*
- *12” Above**
Slow Zones occur entering or exiting core.
- LOT 201.43,44,45 Refueling Operations*
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What are the different overloads in the fuel transfer system?
- 250 lbs overload (1 sec TC):*
- *Active in-between slow speed regions**
- *Can be bypassed in opposite direction of travel**
- If load does not diminish (5 sec TC) after bypassing and reversing travel, system will lockup in both direction and a Traverse Motion Fault will occur*
- 600 lbs overload:*
- *Active in-between slow speed regions**
- Cannot be bypassed*
- 150 lbs overload:*
- *Active in slow speed regions**
- (Last few inches of travel)*
Tells system carriage in position
Max expected drag for new fuel is 150 lbs and spent fuel is 250 lbs. Notify Rx Engineering if exceeded.
- Note:*
- Can always defeat interlocks with interlock override or manual handwheel. (Core Load Supervisor permission req.)*
- LOT 201.43,44,45 Refueling Operations*
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What is the function of the upper limit switch on the fuel handling machine?
When fuel assembly fully raised, bottom nozzle will clear highest obstruction in SFP by ≥ 6 inches
- LOT 201.43,44,45 Refueling Operations*
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What interlocks are associated with the new fuel elevator?
- *Will not raise elevator with load sensed**
- Detected by motor current*
Taking bypass key switch to bypass and pressing the bypass pushbutton OR up pushbutton will raise new fuel elevator with load to ≈ 10 ft below waterline for fuel repairs.
- LOT 201.43,44,45 Refueling Operations*
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What conditions will make the operator secure a core alteration?
Loss of communications with the MCR
Loss of audible count rate in the MCR or RCB
SR NI counts double on both
SR NI Counts ↑ 5x on 1 SR Detector
RHR changes by 10 ˚F or 25 ppm boron
- *RCS < 2800 ppm boron**
- Systems that are connected to RCS (Cavity/SFP/RHR)*
Water not clear enough
- *High SFP Temperature**
- Plant Curve Book (118 ˚F)*
Load Limits on Refueling Machine/Aux Hoist exceeded
Communications between FHB/RCB control consoles, Refueling Machine, Fuel Handling Machine, and Rx Engineer in MCR required.
- LOT 201.43,44,45 Refueling Operations*
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How long must the reactor be shutdown prior to removing fuel?
100 hrs

TRM 3.9.3 Decay Time
Applicable: During movement of irradiated fuel in the Rx Vessel
- LOT 201.43,44,45 Refueling Operations*
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What are the design requirements for the new fuel storage racks?
- *≤ 0.98 keff**
- Optimum Moderation*
- *≤ 0.95 keff**
- Flooded with unborated water*
U-235 enrichment ≤ 5%
- *21” center - center**
- Distance between fuel assemblies*

- LOT 201.43,44,45 Refueling Operations*
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How many SR detectors must be operable while in MODE 6?
2 SR Detectors
Both with visual indication
One with audio for MCR and Containment
1 Extended Range may be substituted for 1 SR if remaining SR provides audible count rate.
