Q88 — Containment Sump Blockage and CS Pump D/P
026 Containment Spray System - A2.07 (3.9)
Given:
• The crew is performing 2-EOP-LOCA-3 (TRANSFER TO COLD LEG RECIRCULATION)
• Containment Pressure is 23 psig
• RCS Pressure is 50 psig
At time 19:10
• ALL ECCS Pumps are aligned to the Containment Sump
At time 19:15
• Erratic flow and pressure on 21 SI Pump, 21 Charging Pump and 21 RHR Pump is observed
At time 19:20
• Erratic flow and pressure on 22 SI Pump, 22 Charging Pump and 22 RHR Pump is observed
Which ONE of the following completes the statements below?
At 19:10, the discharge of the _(1)_ Pumps provides the D/P to drive Containment Spray.
At 19:20 and in accordance with 2-EOP-LOCA-3, the crew will IMMEDIATELY transition to _(2)_.
• The crew is performing 2-EOP-LOCA-3 (TRANSFER TO COLD LEG RECIRCULATION)
• Containment Pressure is 23 psig
• RCS Pressure is 50 psig
At time 19:10
• ALL ECCS Pumps are aligned to the Containment Sump
At time 19:15
• Erratic flow and pressure on 21 SI Pump, 21 Charging Pump and 21 RHR Pump is observed
At time 19:20
• Erratic flow and pressure on 22 SI Pump, 22 Charging Pump and 22 RHR Pump is observed
Which ONE of the following completes the statements below?
At 19:10, the discharge of the _(1)_ Pumps provides the D/P to drive Containment Spray.
At 19:20 and in accordance with 2-EOP-LOCA-3, the crew will IMMEDIATELY transition to _(2)_.
A. (1) RHR (2) 2-EOP-APPX-7 (CONTAINMENT SUMP BLOCKAGE GUIDELINE)
B. (1) RHR (2) 2-EOP-LOCA-5 (LOSS OF EMERGENCY RECIRCULATION)
C. (1) SI (2) 2-EOP-APPX-7 (CONTAINMENT SUMP BLOCKAGE GUIDELINE)
D. (1) SI (2) 2-EOP-LOCA-5 (LOSS OF EMERGENCY RECIRCULATION)
▶ Show Answer & Explanation
✓ A. Correct. For Part 1, at 19:10 the Containment Spray Pumps are taking suction from the outlet of the RHR HXs. For Part 2 and IAW 2-EOP-LOCA-3 (TRANSFER TO COLD LEG RECIRCULATION) CAS, transition to 2-EOP-APPX-7 (CONTAINMENT SUMP BLOCKAGE GUIDELINE) is required "ANYTIME ECCS PUMPS ARE ALIGNED TO THE CONTAINMENT SUMP AND AT LEAST ONE TRAIN OF EMERGENCY COOLANT RECIRCULATION CAN NOT BE MAINTAINED DUE TO INDICATIONS OF CONTAINMENT SUMP BLOCKAGE." Cavitation of ECCS Pumps is an indication of sump blockage per 2-EOP-LOCA-3 Background Document. Consequently, the crew will IMMEDIATELY transition to 2-EOP-APPX-7.
✗ B. Incorrect but plausible. Part 1 is correct. For Part 2, 2-EOP-LOCA-3 has a transition to 2-EOP-LOCA-5 when "EMERGENCY COOLANT RECIRCULATION CAN NOT BE ESTABLISHED OR MAINTAINED FOR REASONS NOT RELATED TO CONTAINMENT SUMP BLOCKAGE". Consequently, the candidate could incorrectly conclude that at 19:20, the crew will IMMEDIATELY transition to 2-EOP-LOCA-5.
✗ C. Incorrect but plausible. The candidate could incorrectly conclude that SI pumps provide the D/P to drive Containment Spray. Part 2 is correct.
✗ D. Incorrect but plausible. The candidate could incorrectly conclude that SI pumps provide the D/P to drive Containment Spray. For Part 2, 2-EOP-LOCA-3 has a transition to 2-EOP-LOCA-5 when "EMERGENCY COOLANT RECIRCULATION CAN NOT BE ESTABLISHED OR MAINTAINED FOR REASONS NOT RELATED TO CONTAINMENT SUMP BLOCKAGE". Consequently, the candidate could incorrectly conclude that at 19:20, the crew will IMMEDIATELY transition to 2-EOP-LOCA-5.
Ref: 2-EOP-LOCA-3, Training Drawing CS-1 | LO: NOS05LCA3U2-04 — Given 2-EOP-LOCA-3 and a set of plant conditions, determine a discrete path through the EOP and an appropriate transition | Source: New | Cognitive: Higher
Connections
- Related systems: Containment Spray, ECCS, RHR
- Related EOPs: EOP-LOCA-3 — Transfer to Cold Leg Recirculation, EOP-APPX-7 — Containment Sump Blockage, EOP-LOCA-5 — Loss of Emergency Coolant Recirculation
- Related exam: 2019 NRC Written Exam