CRDM Flashcards
LCO 3.1.4 “Control Rod Alignment” requirement
All control rods, including their position indication channels, shall be operable and aligned to within 8” of all other rods in their respective group, and the control rod position deviation alarm shall be operable.
LCO 3.1.4 “Control Rod Alignment” applicability
Modes 1-2
LCO 3.1.4 “Control Rod Alignment” required action if 1 channel of rod position indication is inoperable for 1 or more control rods.
ONCE WITHIN 15 MINUTES FOLLOWING ANY ROD MOTION IN THAT GROUP, perform rod position verification (verification that rods are within 8” of each other for their group).
LCO 3.1.4 “Control Rod Alignment” required action if rod position deviation alarm is inoperable.
ONCE WITHIN 15 MINUTES OF MOVEMENT OF ANY CONTROL ROD, perform rod position verification (verification that rods are within 8” of each other for their group).
LCO 3.1.5 “Shutdown and Part-Length Control Rod Group Insertion Limits” requirement
All shutdown and part-length rod groups shall be withdrawn to >= 128”
LCO 3.1.5 “Shutdown and Part-Length Control Rod Group Insertion Limits” applicability
Mode 1
Mode 2 with any regulating rod withdrawn above 5”
Not applicable while performing rod exercise test
LCO 3.1.5 “Shutdown and Part-Length Control Rod Group Insertion Limits” required action if 1 or more shutdown or part-length rods not within limit
IMMEDIATELY declare affected control rod(s) inoperable and enter the applicable conditions and required actions of LCO 3.1.4
LCO 3.1.6 “Regulating Rod Group Position Limits” requirement
The PDIL alarm circuit and the CROOS alarm circuit shall be operable, and the regulating rod groups shall be limited to the withdrawal sequence, overlap, and insertion limits specified in the COLR.
LCO 3.1.6 “Regulating Rod Group Position Limits” applicability
Modes 1-2
Not applicable while performing rod exercise test
LCO 3.1.6 “Regulating Rod Group Position Limits” required action if PDIL or CROOS alarm circuit inoperable
ONCE WITHIN 15 MINUTES FOLLOWING ANY ROD MOTION, perform group position verification (verify each reg rod group is within its withdrawal sequence, overlap, and insertion limits).
How many control rods do we have?
45
How many shutdown rods do we have?
20 rods in 2 groups
Rods 1-12 in Group A
Rods 13-20 in Group B
How many reg rods do we have?
21 rods in 4 groups Rods 21-28 in Group 1 Rods 29-32 in Group 2 Rods 33-37 in Group 3 Rods 38-41 in Group 4
How many part-length rods do we have?
4 rods in 1 group (rods 41-45)
What is the normal rod withdrawal sequence?
- All 4 groups start at 3”
- Group 1 rods start moving first.
- When Group 1 gets to 83”, Group 2 starts moving.
- Once Group 1 is full out, Group 2 is moving alone from 51” to 83”.
- When Group 2 gets to 83”, Group 3 starts moving.
- Once Group 2 is full out, Group 3 is moving alone from 51” to 83”.
- When Group 3 gets to 83”, Group 4 starts moving.
- Once Group 3 is full out, Group 4 is moving alone from 51” to full out.
What condition(s) must be met for Group 1 rods to be sequenced either in or out?
Group 2 must be < 52”
What condition(s) must be met for Group 2 rods to be sequenced either in or out?
- Group 1 must be > 80”
- Group 3 must be < 52”
What condition(s) must be met for Group 3 rods to be sequenced either in or out?
- Group 2 must be > 80”
- Group 4 must be < 52”
What condition(s) must be met for Group 4 rods to be sequenced either in or out?
Group 3 must be > 80”
What are the 4 positions of the Rod Mode Selector Switch?
Manual Individual
Manual Group
Emergency Off
Manual Sequential
What is the function of the Manual Individual mode of operation?
- Allows an individual rod to be selected for movement.
- If moving part-length rods in Manual Individual and the individual rod selector switch for the part-length rods is in the “GR” position, then all part-length rods will move.