Q9 — Station Battery Capacity During SBO
EPE 55 K3.01 (4.1)
Which of the following describes the capacity of the station batteries during a station blackout?
Note: 2-EOP-LOPA-1, Loss of ALL AC Power
Note: 2-EOP-LOPA-1, Loss of ALL AC Power
A. 2 hours assuming 2-EOP-LOPA-1 load shedding.
B. 2 hours during worst case loading (no 2-EOP-LOPA-1 load shed)
C. 6 hours during worst case loading (no 2-EOP-LOPA-1 load shed)
D. 6 hours assuming 2-EOP-LOPA-1 load shedding.
▶ Show Answer & Explanation
✗ A. Incorrect. With load shedding per EOP-LOPA-1, battery life extends to 4 hours, not 2 hours. The 2-hour capacity is without load shedding.
✓ B. Correct. The 125 VDC vital batteries are designed to have adequate capacity to supply its Station Blackout (SBO) coping and restoration loads during the four (4) hour SBO coping duration with manual stripping of some non-essential loads (ref. section 7.2.2.3 in VTD 314204). The batteries are rated for two (2) hours of operation following a Loss of All AC Power without load shed. With load shedding per EOP-LOPA-1, battery life extends to 4 hours. Loss of All AC Power is not a Design Basis Accident (DBA).
✗ C. Incorrect. Battery capacity during worst case loading (no load shed) is 2 hours, not 6 hours.
✗ D. Incorrect. With load shedding, battery life extends to 4 hours, not 6 hours.
Ref: S2.OP-AB.LOOP-0001 (R32), PSBP 314204 (SBO calculation), FSAR Sect 8.1.4.1 | LO: NOS05DC ELEC-11, Obj 2 | Source: Bank - Beaver Valley 2017 NRC RO11 | Cognitive: Fundamental/Memory
Connections
- Related systems: DC Power
- Related procedures: AB.LOOP-0001 — Loss of All Offsite Power
- Related exam: 2023 NRC Written Exam