Q46 — CSF Priority Implementation
G2.4.22 (3.6)
Given:
• The crew is monitoring the Critical Safety Functions
• The following parameters are observed:
o Containment Pressure is 5.8 psig
o Power Range NI is 2.1% with an IR SUR of (+) 0.1 DPM
o RCS Subcooling is (-) 15 °F
o ALL RCPs are stopped
o 8 CETs are reading 750 °F
o RVLIS Full Range is 41%
o 21 SG NR Level is 10%, 22 SG NR Level is 7%, 23 SG NR Level is 8% and 24 SG NR Level is 9%
o Total AFW flow to SGs is 0 LB/HR
o BOTH Containment Spray Pumps are stopped
o Containment Sump is 63%
o R-44 Radiation is reading 5 R/HR
Which ONE of the following completes the statements below?
Based on the Functional Restoration Implementation Priority, the crew is required to FIRST address the challenge to ___
• The crew is monitoring the Critical Safety Functions
• The following parameters are observed:
o Containment Pressure is 5.8 psig
o Power Range NI is 2.1% with an IR SUR of (+) 0.1 DPM
o RCS Subcooling is (-) 15 °F
o ALL RCPs are stopped
o 8 CETs are reading 750 °F
o RVLIS Full Range is 41%
o 21 SG NR Level is 10%, 22 SG NR Level is 7%, 23 SG NR Level is 8% and 24 SG NR Level is 9%
o Total AFW flow to SGs is 0 LB/HR
o BOTH Containment Spray Pumps are stopped
o Containment Sump is 63%
o R-44 Radiation is reading 5 R/HR
Which ONE of the following completes the statements below?
Based on the Functional Restoration Implementation Priority, the crew is required to FIRST address the challenge to ___
A. Containment Environment
B. Shutdown Margin
C. Core Cooling
D. Heat Sink
▶ Show Answer & Explanation
✓ D. Correct. IAW OP-AA-101-111-1003, CSF Hierarchy (high to low) is SHUTDOWN MARGIN, CORE COOLING, HEAT SINK, THERMAL SHOCK, CONTAINMENT ENVIRONMENT and COOLANT INVENTORY. Additionally, CFST Color Hierarchy (high to low) is Red, Purple, Yellow, and Green. Based on the plant conditions and IAW 2-EOP-CFST-1, the status trees are: Shutdown Margin (Purple), Core Cooling (Purple), Heat Sink (Red) and Containment Environment (Green). Consequently, the crew is required to FIRST address the challenge to Heat Sink.
✗ A. The candidate could incorrectly analyze plant conditions and incorrectly determine Containment Environment must first be addressed.
✗ B. The candidate could incorrectly analyze plant conditions and incorrectly determine Shutdown Margin must first be addressed.
✗ C. The candidate could incorrectly analyze plant conditions and incorrectly determine Core Cooling must first be addressed.
Ref: NOS05PROCED-08 (USE AND CONTROL OF PROCEDURES), 2-EOP-CFST-1 (CRITICAL SAFETY FUNCTION STATUS TREES) | LO: NOS05PROCED-08 | Source: New | Cognitive: Higher
Connections
- Related EOPs: EOP-CFST-1 — Critical Safety Function Status Trees, EOP-FRHS-1 — Response to Loss of Secondary Heat Sink
- Related procedures: OP-AA-101-111-1003 — Use of Procedures
- Related exam: 2019 NRC Written Exam