Q23 — Area Rad Monitor Crane Interlock
APE61AK3.02 (3.4)
Which of the following interlocks are activated when Area Radiation Monitor 2R32A, Fuel Handling Crane fails to its' alarm setpoint?
A. ALL crane hoist operation is prevented, but the hoist may be lowered after pressing the BYP INT pushbutton.
B. FHB exhaust shifts to 22 HEPA plus Charcoal.
C. ALL Crane trolley operation is prevented.
D. ONLY Crane hoist-up operation is prevented
▶ Show Answer & Explanation
✓ D. Correct. Only crane hoist-up operation is prevented. Conservative operation would allow the assembly to be lowered back into the spent fuel location (increased water shielding).
✗ A. Plausible because the candidate may believe that all crane hoist operation is prevented and that a BYP INT pushbutton exists to defeat the interlock. Incorrect as there is no bypass interlock pushbutton and the alarm only prevents upward motion of the hoist.
✗ B. Plausible because the candidate may remember that two other area radiation monitors in the FHB (R5 & R9) do cause the FHB exhaust filter to swap to 22 HEPA plus Charcoal. Incorrect as the R32A only affects the crane. Plausible that the candidate could feel the cause of an actual high alarm condition would cause R5 & R9 to alarm as well. Incorrect, the stem states the monitor has failed to its alarm setpoint.
✗ C. Plausible because the candidate may believe that all crane trolley operation is prevented. Incorrect as only the crane hoist-up operation is affected.
Ref: S2.OP-AB.RAD-0001(Q), Abnormal Radiation and Bases. OHA Alarm Response A-6. | LO: N/A | Source: New | Cognitive: Fundamental
Connections
- Related systems: Radiation Monitoring, Refueling
- Related procedures: AB.RAD-0001 — Radiation Monitor Abnormality, S2.OP-AR.ZZ-0001 — Overhead Annunciators Window A
- Related exam: 2020 NRC Written Exam