Q22 — IR Channel Bypass Alarm
APE33AA2.09 (3.4)
Given:
• Unit 2 is at 100% Power.
• The Intermediate Range (IR) Channel N35 has just failed high.
• The crew has entered S2.OP-AB.NIS-0001(Q), Nuclear Instrumentation System Malfunction.
• The PO is removing N35 from service in accordance with S2.OP-SO.RPS-0001(Q), Nuclear Instrumentation Channel Trip / Restoration and OHA E-29, SR & IR TRIP BYP, annunciates.
Which of the following identifies the cause of the alarm?
• Unit 2 is at 100% Power.
• The Intermediate Range (IR) Channel N35 has just failed high.
• The crew has entered S2.OP-AB.NIS-0001(Q), Nuclear Instrumentation System Malfunction.
• The PO is removing N35 from service in accordance with S2.OP-SO.RPS-0001(Q), Nuclear Instrumentation Channel Trip / Restoration and OHA E-29, SR & IR TRIP BYP, annunciates.
Which of the following identifies the cause of the alarm?
A. Control Power Fuses have been removed.
B. Instrument Power Fuses have been removed.
C. LEVEL TRIP switch has been placed in bypass.
D. POWER MISMATCH BYPASS switch has been placed in bypass.
▶ Show Answer & Explanation
✓ C. Correct. SO.RPS-0001 places the LEVEL TRIP switch in bypass and then verifies that OHA E-29 has illuminated/alarmed.
✗ A. Plausible because the candidate may believe that SO.RPS-0001 removes the IR channel from service by removing the control power fuses. The procedure removes the control power fuses when removing a PR channel from service, but not for an IR channel.
✗ B. Plausible because the candidate may believe that SO.RPS-0001 removes the IR channel from service by removing the instrument power fuses. Could remember that the procedure removes fuses for a power range channel and confuse power with instrument. Incorrect as the procedure does not remove instrument power fuses.
✗ D. Plausible because the candidate may confuse the procedural steps for removing an intermediate range channel with that of a power range channel. He may remember the power range having a POWER MISMATCH BYPASS switch and believe that a similar one exists for removing intermediate range channels from service. Incorrect as there is no POWER MISMATCH BYPASS switch for IR Channels.
Ref: S2.OP-AB.NIS-0001(Q), Nuclear Instrumentation System Malfunction and Bases. S2.OP-SO.RPS-0001(Q), Nuclear Instrumentation Channel Trip / Restoration. | LO: NOS05FISHERNI-00, ELO 9 | Source: Bank | Cognitive: Fundamental
Connections
- Related systems: Excore NIs, RPS/SSPS
- Related procedures: S2.OP-SO.RPS-0001 — Nuclear Instrumentation Channel Trip / Restoration, AB.NIS-0001 — Nuclear Instrumentation System Malfunction, S2.OP-AR.ZZ-0005 — Overhead Annunciators Window E
- Related exam: 2020 NRC Written Exam