Traversing Incore Probe System(TIPS) - 1.0

Question 1

What is the purpose of TIPS?

Answer 1

A subsystem of the Neutron Monitoring System used in the calibration of the LPRM

Question 2

Under which conditions will any inserted TIP retract?

(NSSS Containment Isolation Signals)

Answer 2

All TIP detectors will be automatically withdrawn to their “in-shield” position with their associated ball valve closing in response to:
1. High drywell pressure - 1.68#
2. Low reactor water level - -38”
3. Manual isolation signal of NSSSS
4. Both Channel A RWCU valve ISLN Logic test switches are in the Test position
5. Both Channel A trip valve ISLN logic test switches are in the TEST position.

Question 3

What is the purpose of the TIPS shear valves?

Answer 3

Provide a backup means of isolating their associated TIP guide tubes following the receipt of a Primary Containment Isolation signal

Question 4

When do the SQUIB MONITOR and SHEAR VALVE MONITOR lights come on? Is there a circumstance where only one will be lit?

Answer 4

Both lights illuminate when its respective shear valve has been fired.
Additionally the SQUIB MONITOR light will be the only light lit if power has been lost to the firing circuit(lost continuity from power supply 125VDC 1AD318)

Question 5

How are the shear valves operated?

Answer 5

Manually via a keylock switch at the control panel, there are no automatic actuations

Question 6

Describe the TIPS interlocks.

Answer 6

1. Prevents the actuation of the indexing mechanism when a TIP detector and/or its cabling is within the unit
2. Prevents the drive mechanisms from driving a detector into a drive tube which has a closed ball valve
3. Prevents more than one TIP detector from being inserted into the common TIP calibration tube at a time

Question 7

Is there a way to bypass any of the TIPS interlocks?

Answer 7

By repositioning the CHANNEL SELECT switch you can bypass the interlock preventing multiple TIP detectors from being inserted into the common TIP calibration tube at a time. This could cause damage to TIPS if the switch is repositioned when the associated TIP is in the common channel and another TIP is inserted into that common channel.

Question 8

What is the normal condition of the TIPS indicating lights?

Answer 8

TIPs never does anything so when it does it has to show the world its excitement(ie normally deenergized)

Question 9

What is(are) the speed(s) that TIPs travel?

Answer 9

Slow - In Vessel
Fast - Bottom of Vessel to Pos. 25
Slow - From Pos. 25 to In-shield

Slow = 1.5”/sec
Fast = 12”/sec

Question 10

What are the power supplies to TIPS?

Answer 10

120 VAC Instrument Power System panel 1AJ483 supplies power to the TIP System drive control units, the purge system control circuits, and the TIP System isolation circuit
125 VDC (Non-1E) Power System panel 1AD318 supplies power to panel 10C607 indicating lights, to the shear valve firing circuits and to the ball valve solenoids

Question 11

What occurs in TIPS upon receipt of a containment isolation signal?

Answer 11

Upon receipt of NSSSS signal, any TIP machine inserted past in-shield shifts to reverse.

TIP reverses:
- Slow in vessel.
- Fast from bottom of vessel to position 25.
- Slow from position 25 to in-shield.

Question 12

What causes 5161 TIP Purge to close?

Answer 12

• -38”
• 1.68 PSIG
• RB Rad levels 1X10^6
• Channel D PCIS

Question 13

How can you bypass an interlock with the Channel Select Switch?

Answer 13

By repositioning the switch when a TIP is inserted past position 1. This could bypass the interlock that prevents more than one TIP probe from going into a common tube.