Q86 — Loss of RHR EAL CA4.1
005 RHR System - G2.4.41 (4.6)
REFERENCES PROVIDED
Given:
• Unit 2 has entered MODE 3 for a planned refueling outage on October 15 at 0700
On October 17 at 0700
• Containment is OPEN
• TAVG is 150 °F
• PZR Level is 10%
• BOTH RHR Pumps have tripped
• The crew has just entered S2.OP-AB.RHR-0001 (Loss Of RHR)
Which ONE of the following completes the statements below?
If the RHR Pumps remain tripped, ___ is the EARLIEST time that the criteria for declaring an Alert per EAL# CA4.1 will be met.
Given:
• Unit 2 has entered MODE 3 for a planned refueling outage on October 15 at 0700
On October 17 at 0700
• Containment is OPEN
• TAVG is 150 °F
• PZR Level is 10%
• BOTH RHR Pumps have tripped
• The crew has just entered S2.OP-AB.RHR-0001 (Loss Of RHR)
Which ONE of the following completes the statements below?
If the RHR Pumps remain tripped, ___ is the EARLIEST time that the criteria for declaring an Alert per EAL# CA4.1 will be met.
A. 0710
B. 0715
C. 0810
D. 0815
▶ Show Answer & Explanation
✓ C. Correct. Using the provided references, the operator should determine a heat up of 5 °F per minute (2 days after shutdown per before offload curve). Unit 2 will be in MODE 4 (>200 °F) in 10 minutes ((200 - 150) / 5). The RCS is intact. IAW EAL#CA4.1, to meet the criteria of CA4.1 with the RCS intact, RCS must be > 200 °F for 60 minutes. This will occur at 0810.
✗ A. Incorrect but plausible. 0710 would be the time if the candidate correctly calculated the heatup to 200 °F with a 5 °F / minute heatup rate and incorrectly used a 0 minute duration to meet EAL# CA4.1 criteria (by misinterpreting CA4.1 EAL Table).
✗ B. Incorrect but plausible. 0715 would be the time if the candidate incorrectly calculated the heatup to 200 °F with a 3.4 °F / minute heatup rate and incorrectly used a 0 minute duration to meet EAL# CA4.1 criteria (by misinterpreting CA4.1 EAL Table).
✗ D. Incorrect but plausible. If the candidate used the wrong heatup curve (after offload curve), then the heatup rate would be 3.4 °F / hr. Therefore, it would then take 15 minutes ((200-150) / 3.4) for the RCS to reach 200 °F. If the candidate then correctly applied 60 minute criteria for meeting CA4.1, this would equate to 0815.
Ref: S2.OP-AB.RHR-0001 (Loss Of RHR), EP-SA-111-27, AB.RHR-0001 Attachment 5 (HEATUP RATE FOR LOSS OF RHR COOLING), EA-SA-111-127 EAL# CA4.1 | LO: EMERGENCY COORDINATOR AND DIRECT SUPPORT PERSONNEL DUTIES — Given plant conditions for an emergency, CLASSIFY the event in accordance with the ECG | Source: New | Cognitive: Higher
Connections
- Related systems: RHR
- Related abnormals: AB.RHR-0001 — Loss of RHR
- Related admin: EP-SA-325 — Emergency Plan Implementing Procedures
- Related exam: 2019 NRC Written Exam