Q63 — LOCA-6 RHR Piping Concern and Leak Isolation
WE04 LOCA Outside Containment (3.6)
Given:
• The crew has just transitioned to 1-EOP-LOCA-6 (LOCA Outside Containment)
In accordance with 1-EOP-LOCA-6, which ONE of the following completes the statements below?
As part of the leak isolation strategy, the crew is MOST concerned with the piping connecting the _(1)_ System to the RCS.
The crew will monitor rising _(2)_ to determine when the leak has been successfully isolated.
• The crew has just transitioned to 1-EOP-LOCA-6 (LOCA Outside Containment)
In accordance with 1-EOP-LOCA-6, which ONE of the following completes the statements below?
As part of the leak isolation strategy, the crew is MOST concerned with the piping connecting the _(1)_ System to the RCS.
The crew will monitor rising _(2)_ to determine when the leak has been successfully isolated.
A. (1) RHR (2) RCS pressure
B. (1) RHR (2) Pressurizer level
C. (1) SI (2) RCS pressure
D. (1) SI (2) Pressurizer level
▶ Show Answer & Explanation
✓ A. Correct. For Part 1 and IAW 1-EOP-LOCA-6, as part of the leak isolation strategy, the crew is MOST concerned with the piping connecting the RHR System to the RCS, since this piping is only rated to 600 psig (compared to the RCS Piping being rated to 2500 psig). For Part 2 and IAW 1-EOP-LOCA-6, the crew will monitor rising RCS Pressure to determine when the leak has been successfully isolated.
✗ B. Incorrect but plausible. Part 1 is correct. For Part 2, since ECCS flow is injecting water into the core during performance of 1-EOP-LOCA-6, RCS inventory will increase once the leak has been isolated. An increase in RCS inventory can be measured by rising PZR level. Consequently, the candidate could incorrectly conclude that 1-EOP-LOCA-6 monitors rising PZR level as a determination that the leak has been successfully isolated.
✗ C. Incorrect but plausible. For Part 1, since the SI Piping / pumps are also outside of containment and connected to the RCS, the candidate could incorrectly conclude that LOCA-6 is most concerned with the piping connecting the SI system to the RCS. Part 2 is correct.
✗ D. Incorrect but plausible. For Part 1, since the SI Piping / pumps are also outside of containment and connected to the RCS, the candidate could incorrectly conclude that LOCA-6 is most concerned with the piping connecting the SI system to the RCS. For Part 2, since ECCS flow is injecting water into the core during performance of 1-EOP-LOCA-6, RCS inventory will increase once the leak has been isolated. An increase in RCS inventory can be measured by rising PZR level. Consequently, the candidate could incorrectly conclude that 1-EOP-LOCA-6 monitors rising PZR level as a determination that the leak has been successfully isolated.
Ref: 1-EOP-LOCA-6 (LOCA OUTSIDE CONTAINMENT) | LO: NOS05LOCA06-03 | Source: Modified Bank - ILOT 1601 NRC RO 63 | Cognitive: Lower
Connections
- Related systems: RHR, ECCS, RCS
- Related EOPs: EOP-LOCA-6 — LOCA Outside Containment
- Related exam: 2019 NRC Written Exam