FHV
Function
Provides ventilation and filtration for the fuel handling building during fuel movement and storage operations.
Key Components
- Exhaust Fans: 21 and 22 Fuel Handling Area Exhaust Fans (one normally in service, one in standby)
- Filter Units: 21 HEPA ONLY Filter Unit and 22 HEPA PLUS CHAR (charcoal) Filter Unit
Automatic Response to High Radiation
Exam — 2019 Q36
2R9 (Fuel Storage Area Monitor) alarm response: BOTH Fuel Handling Area Exhaust Fans receive an auto start signal (standby fan starts). 21 HEPA ONLY Filter Unit ISOLATES and 22 HEPA PLUS CHAR filter unit automatically aligns (charcoal filtration for iodine removal). After 2R9 alarm, both exhaust fans running, only the HEPA PLUS CHAR filter unit in service. Trap: believing both HEPA filter units remain in service — the HEPA ONLY unit isolates when the charcoal unit aligns. Also, 2R32A (Fuel Handling Crane area monitor) does NOT cause FHB ventilation to shift — only 2R5 and 2R9 cause the shift.
Connections
- Related systems: Spent Fuel Pool, Radiation Monitoring
- Related procedures: S2.OP-AR.ZZ-0001 — Overhead Annunciators Window A
- Related exam questions: 2019 Q33, 2019 Q36
- Related exam: 2019 NRC Written Exam