2018 Q52 — CVCS Charging Line Leak

✓ C. Correct. For Part 1, based on the question stem conditions, there is a leak on the CVCS charging line (seal injection lowering, PZR level lowering, Plant Radiation Monitor rising, and flashing in the letdown line). For Part 2, a leak in the charging supply line is an entry condition for S2.OP-AB.CVC-0001.

✗ A. Incorrect but plausible. For Part 1, many of the indications given are also indicative of a letdown line leak (PZR level lowering and Plant Radiation Monitor rising). Consequently, the candidate could incorrectly conclude that a leak on the CVCS letdown line exists. For Part 2, the candidate could incorrectly conclude that a leak on the letdown would ultimately affect charging flow rate. A reduction in charging flow is an entry condition to S2.OP-AB.CVC-0001.

✗ B. Incorrect but plausible. For Part 1, many of the indications given are also indicative of a letdown line leak (PZR level lowering and Plant Radiation Monitor rising). Consequently, the candidate could incorrectly conclude that a leak on the CVCS letdown line exists. For Part 2, a leak on the letdown line is not an entry condition to S2.OP-AB.CVC-0001.

✗ D. Incorrect but plausible. Part 1 is correct. For Part 2, since RCS inventory is being lost, the candidate could incorrectly conclude that only entry conditions to S2.OP-AB.RC-0001 (Reactor Coolant System Leak) are met. Additionally, since the charging pump is providing flow to seal injection and the regenerative heat exchanger, the candidate could also incorrectly conclude S2.OP-AB.CVC-0001 entry conditions are not met.

Ref: S2.OP-AB.CVC-0001 (Loss Of Charging) | LO: NOS05ABRCP0-06 | Source: New | Cognitive: Higher