Q25 — High Containment Radiation / CFCU Low Speed HEPA
W E16 EA1.05 (3.2)
Given:
• Unit 2 reactor trip from 100%
• STA reports valid CFST YELLOW path for Containment Environment (high radiation)
• CRS enters EOP-FRCE-3
What speed and filter alignment is required for CFCUs?
• Unit 2 reactor trip from 100%
• STA reports valid CFST YELLOW path for Containment Environment (high radiation)
• CRS enters EOP-FRCE-3
What speed and filter alignment is required for CFCUs?
A. High speed, roughing filters
B. High speed, HEPA filters
C. Low speed, HEPA filters
D. Low speed, roughing filters
▶ Show Answer & Explanation
✓ C. Correct. Per EOP-FRCE-3 step 2, place all CFCUs in LOW speed. In LOW speed, dampers realign flow through HEPA filters (bypassing roughing filters) to reduce radioactivity inside containment.
✗ A. High speed is normal operation with roughing filters. LOW speed is required for HEPA filtration to reduce containment radioactivity.
✗ B. CFCUs can run high speed but dampers only realign to route flow through HEPA filters when in low speed.
✗ D. LOW speed is the correct speed, but flow goes through HEPA filters not roughing filters. The damper realignment in low speed bypasses roughing filters.
Ref: 2-EOP-FRCE-3 (R41) | LO: NOS05FRCE00-08, Obj 3 | Source: New | Cognitive: Comprehension/Analysis
Connections
- Related systems: CFCUs
- Related procedures: EOP-FRCE-3 — Response to High Containment Radiation Levels
- Related exam: 2023 NRC Written Exam