Q45 — SG Program Level and BF19 Response
059 A3.02 (2.9)
Given:
• Unit 2 is at 30% Power and stable.
• ALL Steam Generator Narrow Range levels are 45%.
Based on the above condition, which ONE of the following completes both statements?
1. Steam Generator Narrow Range levels are __(1)__ program setpoint.
2. Assuming SGFP speed remains constant, to return Steam Generator levels to program setpoint, the demand on the BF19's will automatically __(2)__.
• Unit 2 is at 30% Power and stable.
• ALL Steam Generator Narrow Range levels are 45%.
Based on the above condition, which ONE of the following completes both statements?
1. Steam Generator Narrow Range levels are __(1)__ program setpoint.
2. Assuming SGFP speed remains constant, to return Steam Generator levels to program setpoint, the demand on the BF19's will automatically __(2)__.
A. 1) above
2) decrease
2) decrease
B. 1) above
2) increase
2) increase
C. 1) below
2) decrease
2) decrease
D. 1) below
2) increase
2) increase
▶ Show Answer & Explanation
✓ A. Correct. IAW S2.OP-AB.CN-0001, Attachment 2, SG program level with power above 20% is 44% NR level. With a SG NR level at 45%, the actual SG NR level is above the program setpoint of 44%. The digital feedwater system will lower the demands to the BF19s to throttle the valves closed to reduce feedwater flow with SGFP speed remaining constant.
✗ B. Incorrect. First part is correct. Second part is incorrect. The BF19 demand will lower to throttle the valves closed more to reduce feed flow to lower SG levels. Plausible in that the applicant may incorrectly believe that the operation of the BF19 works opposite to the demand signal.
✗ C. Incorrect. First part is incorrect. SG program level above 20% is 44%. Plausible because the operator may incorrectly recall the proper level setpoint for digital feedwater. Second part is correct.
✗ D. Incorrect. First part is incorrect. SG program level above 20% is 44%. Plausible because the operator may incorrectly recall the proper level setpoint for digital feedwater and how the BF19s should respond. Second part is incorrect. The BF19 demand will lower to throttle the valves closed more to reduce feed flow to lower SG levels.
Ref: S2.OP-AB.CN-0001 | LO: NOS05CNFDW-19, Obj 15 — Given plant conditions, relate the Condensate and Feedwater System with the following: Advance Digital Feedwater Control System | Source: Bank — Comanche Peak 2016 RO17 | Cognitive: Comprehension/Analysis
Connections
- Related systems: Feed & Condensate
- Related abnormals: AB.CN-0001 — Condensate System Abnormality
- Related exam: 2022 NRC Written Exam