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Exams > 2023 Q55 — Urgent Failure / Rod Control Gripper Coils

2023 Q55 — Urgent Failure / Rod Control Gripper Coils

⚠️ DRAFT
Q55 — Urgent Failure / Rod Control Gripper Coils T2G2 001 K1.03 (3.7)
Given:
• Salem Unit 2 is performing a load reduction from 100% power
• Rod Control is in AUTO

Then:
• Console Alarm, URGENT FAILURE, is Alarming
• Rod motion has stopped

Which of the following completes both statements concerning the effect on the rod control system?

1. Rods (1) be inserted in MANUAL.
2. The rods are currently held in position by energizing the (2) gripper coils.
A. (1) can (2) stationary
B. (1) can (2) moveable
C. (1) can NOT (2) moveable
D. (1) can NOT (2) stationary
▶ Show Answer & Explanation
✓ D. Correct. Per console ARP S2.OP-AR.ZZ-0012, Urgent Failure alarm will prevent all rod motion in Manual or Automatic. In this condition the rods are held in position by the stationary gripper coil being energized at a reduced current. The moveable gripper coil is de-energized at this time.
✗ A. Incorrect. Part 1 is incorrect. Plausible because the operator could believe that even with an Urgent Failure present, the operator will always be able to insert rods. Incorrect in that all rod motion is inhibited in Manual and Automatic. Part 2 is correct.
✗ B. Incorrect. Part 1 is incorrect. Plausible because the operator could believe that even with an Urgent Failure present, the operator will always be able to insert rods. Incorrect in that all rod motion is inhibited in Manual and Automatic. Part 2 is incorrect. Plausible because the moveable gripper coil is used to hold the rods in position until the lift coil is energized/de-energized to withdraw or insert rods. Incorrect in that the stationary coil is energized at a reduced current to hold rods in position.
✗ C. Incorrect. Part 1 is correct. Part 2 is incorrect. Plausible because the moveable gripper coil is used to hold the rods in position until the lift coil is energized/de-energized to withdraw or insert rods. Incorrect in that the stationary coil is energized at a reduced current to hold rods in position.
Ref: NOS05RODS00-14, S2.OP-AR.ZZ-0012 (R40) | Source: Modified Bank — Diablo Canyon 2019 NRC RO29 | Cognitive: Fundamental/Memory
K/A: 001 K1.03 — Knowledge of the physical connections and/or cause and effect relationships between the Control Rod Drive System and the following systems: CRDM

Connections